Southampton Solent University

SCHOOL OF MARITIME SCIENCE AND ENGINEERING

This project is submitted in part fulfilment of the Degree of

Bachelor of Engineering with Honours in Yacht and Powercraft Design

Southampton Solent University

April 2016

BEng (Hons) Yacht and Powercraft Design

Alexander MacLean

DESIGN OF A 17 METRE FAST PATROL BOAT WITH

AN INSIGHT INTO AN INNOVATIVE BOW TYPE

April 2016

i

Project Abstract

This project is to design of a 17 metre fast patrol boat. The ergonomics and comfort of the crew were to be a prominent consideration throughout the design process. The design process considers: hull shape and form; general layout above and below deck to include both the structure and fitting out of the crew space; and, propulsion systems. In addition, there is an examination, under tank test conditions, between a conventional hull and a hull with the addition of a deflector. This is done by creating a 1:15 scale model of the design and then using a tank, with various simulated sea conditions, to examine and then compare the performance (resistance and accelerations) of the two hulls.

ii

Contents

Page

Project Brief ............................................................................ Aims and Objectives ................................................................... Research Undertaken and Design of the Vessel ................................... Area of Operation ...................................................................... Structural Theory Introduction to the Structures and the Rule Followed .................. Structural Layout .............................................................. Material Considerations ...................................................... Structural Calculations ....................................................... Appraisal ........................................................................ Tank Testing Reasoning for Testing ......................................................... Building of the Model ......................................................... Test Matrix Followed .......................................................... Preperation for Tests ......................................................... Analysis of Tests ............................................................... Results of Tests ................................................................ Powering Calculations ......................................................... Validation of Deflector ....................................................... Appraisal ........................................................................ Machinery and Systems Installed Onboard Introduction .................................................................... Reasoning of Choices ......................................................... Detail of the Scania DI-16076M Engine ..................................... Detail of the ZF 825A Gearbox .............................................. Detail of the Rolls Royce Kamewa A3-36 Jets ............................ Ventilation System Design ................................................... Cooling System Design ........................................................ Exhaust System Design ....................................................... Fuel and Tankage Layout and System Design ............................. Layout of the Machinery with an Insight into Access and Egress ...... Environmental Compliance ................................................... Alternative Propulsion Options .............................................. Appraisal ........................................................................ General Arrangement Below Deck Layout Forward Stowage ..................................................... Galley and Saloon .................................................... Main Cabin ............................................................. Machinery Spaces ..................................................... Above Deck Layout Wheelhouse ........................................................... Deck and Special Features .......................................... Stability Introduction .................................................................... Weights and Centres .......................................................... Calculations .................................................................... Rule Compliance ............................................................... Damage Stability ............................................................... Appraisal ........................................................................ Critical Analysis of the Project ...................................................... Conclusion ............................................................................... References .............................................................................. Appendices Section .................................................................... Visual Representations ................................................................

1 1 2 4 5 8 8 9 14 15 16 16 18 19 20 23 25 26 27 27 27 30 31 33 35 35 36 37 38 38 40 41 41 42 42 43 44 45 45 46 46 50 50 51 52 53 56 68

iii

Technical Drawings Drawing 001 – Lines Plan ...................................................... Drawing 002 – Structural Layout, Plan view ............................... Drawing 003 – Structural Layout, Profile View ........................... Drawing 004 – Structural Layout, Midship Section ....................... Drawing 005 – Deflector Design and Structural Arrangement .......... Drawing 006 – Wheelhouse Structural Design ............................. Drawing 007 – Installment of the Drivetrain .............................. Drawing 008 – Representation of the Ventilation Design ................ Drawing 009 – Representation Cooling and Exhaust Design ............. Drawing 010 – Representation Fuel and Tankage Arrangement ........ Drawing 011 – Access and Egress from the Machinery Spaces .......... Drawing 012 – Interior General Arrangement ............................. Drawing 013 – General Arrangement, Section View ...................... Drawing 014 - Exterior General Arrangement ............................

72 73 74 75 76 77 78 79 80 81 82 83 84 85

Page | 1

Project Brief

The initial brief was set by the Scottish Government Coastal Agency, who were

looking to replace their current fleet of patrol boats with a new vessel with a more

human focused design. There were some limitations that had to be taken into

account and also several requirements that the Client detailed. These were as

follows:

• A commercial boat to carry out littoral patrol, pilot, search and rescue and

light military activities

• Must have a minimum speed of 30 knots

• Compliment of 6 permanent crew and 4 survivors

• Hotel facilities for 2 persons

• Human focused design philosophy to be adopted

Aims and Objectives

The aim of this project design was to adhere to the Client’s requirements, whilst

maintaining a modern and up to date design. The aesthetics of a commercial boat

can sometimes be overtaken by the practicality of the craft. However, for this

design, the aesthetics of the vessel and comfort of the crew were to be of high

importance throughout the design process, whilst maintaining a practical and

functional design. The vessel itself will be designed to meet with the requirements of

the Lloyds Register Special Service Craft Guidelines (LR SSC) [01] and the stability

requirements of the MGN280 code [02].

With the stress on a human design philosophy, it was key to ensure that the comfort

of the crew and the ergonomics of the vessel were to a high quality design. The

addition of a wave deflector was to try and reduce the vertical motions of the craft,

and thus reduce the pitching motions that will be felt in the wheelhouse by the crew.

The vertical motions are those most linked to sea sickness, and therefore crew

fatigue. It is hoped that the deflector will reduce these vertical motions and,

therefore, reduce crew fatigue. This concept will be tested in tank conditions and

the results will be appraised in the Tank Testing Section (Page 15).

Page | 2

Research Undertaken and the Design of the Vessel – Drawing 001

There was an initial research carried out into several different types of commercial

craft [03, 04, 05, 06, 07] that met with the length requirements of the proposed

design. The data analysed here included: design ratios such as the slenderness ratio,

length/beam ratio, volumetric Froude number; and, the measure of the installed

power to weight. This gave a good insight as to what the vessel should incorporate

into its design. As well as each vessel’s parameters being studied, the vessel itself

was studied in order to ascertain as much information as possible from the research.

With the initial outline of the Client’s requirements, and the base parametric study

carried out, the design of the first of 26 hulls began. The hull was designed in the

Maxsurf Modeller design program, where the shape and hydrostatics of the hull can

be altered easily. The final hull sits above the parametric studied for all values,

mainly due to the speed that the proposed vessel will be achieving. The final design

parameters are shown in Table 1 below along with the comparison between the

parametric study design ratios and that of the actual design in Table 2 shown

overleaf.

Measurement Abbreviation Value Units

Length Overall Loa 17.60 Metres

Length Waterline Lwl 16.85 Metres

Beam Overall Boa 4.85 Metres

Beam Waterline Bwl 4.24 Metres

Draft Tc 0.96 Metres

Freeboard Fb 1.61 Metres

Volumetric Displacement ∇ 25.23 Metres 3

Displacement ∆ 25.87 Tonnes

Table 1: Technical particulars of the vessel

Page | 3

Value for Comparison Parametric Study Value Designed Vessel Value

Slenderness Ratio 5.06 5.75

Volumetric Froude Number 3.36 3.07

Length/Beam Ratio 3.42 3.97

Power/Displacement Ratio 48.80 62.54

Beam/Draft Ratio 4.10 4.48

Table 2: Comparison of ratios between the parametric study and the designed vessel

As can be seen, the vessel is a very slender design with a low draft and a high length

in relation to the beam of the boat and this lends itself to a fast vessel. However, the

vessel does operate at a lower volumetric Froude number than those of the

parametric study. (This is due mainly to the fact that several Interceptor craft were

studied as part of the research, and these types of craft have a very slender, low

volume design capable of travelling at speeds in excess of 40 knots.) As a result of

this, the power/displacement ratio for the proposed vessel is somewhat higher than

that of the parametric study. This is mainly due to the vessel travelling at a top

speed of 32 knots. The power output requirements of the proposed engines will be

discussed at length in the Tank Testing Section (Page 15).

The hull shape is set to be of deep V-style, with a relatively high deadrise angle. The

deadrise angle has been set at 22.50 following the results from the parametric studies

and the characteristics that are associated with a vessel with this hull form. The bow

of the vessel has a very sharp forefoot, but this quickly transforms into a constant

deadrise angle of Station 6 (6.74 m forward of the stern) in order to try and create

the biggest planing surface possible.

The final design of the hull can be seen in Drawing 001 of the Technical Drawing

Section (Page 72). This drawing is the 2D lines plan of the hull, portraying the

curvature of the hull.

Page | 4

The reasoning behind installing a deflector was via research undertaken into the

different bow types that can be used in order to reduce vertical accelerations [08,

09]. This bow type is used and installed in two of Naviform’s [10] supply vessels.

Area of Operation

The detailed area of operation for this craft

will be the Firth of Clyde and out into the Irish

Sea towards the Northern Channel [11]. This is

shown in Figure 1.

The weather in the channel has been analysed

using shipping forecasts and a weather buoy

which is located just south of the lower

extents of the chart in Figure 1. This will be

important when the waves in the tank testing

are to be sized, as the data could be scaled

and used to replicate real-life and operational

sea conditions to test the design in more

common sea states.

The Firth of Clyde has commercial, pleasure and

military traffic passing through it every day, with

the Port of Glasgow and the Faslane Naval Base

being the major shipping ports. There are also

several small ferries than run from mainland ports located on the Firth of Clyde (such

as Ardrossan) to ports across the firth (such as Dunoon) and to off-shore islands (such

as the Isle of Bute). Therefore, it is important that the channel is monitored and any

incident responded to quickly. This is why the vessel is constantly manned and

equipped with hotel facilities for two crew members.

Figure 1: Admiralty chart 2724 of

the North Channel and the Firth of

Lorn

Page | 5

Structural Theory

Nomenclature

Hull Form Pressure

Factor Stiffener Spacing

Vessel Displacement Convex Curvature Factor

Panel Location Factor Panel Aspect Ratio Factor

Waterline Length Limiting Bending Stress

Coefficient

G0 Support Girth 0.2% Proof Stress of the

Material

Section Modulus

Coefficient p Design Pressure

Moment of Inertia

Coefficient Effective Span Length

Web Area Coefficient Modulus of Elasicity

Limiting Stress

Coefficient

Shear Strength of Material

(

)

Limiting Deflection

Coefficient

Introduction to the Structures and the Rule Followed

It was decided to construct the vessel out of aluminium of differing tempers. The

structure system chosen was predominately transverse frames with longitudinal

stiffeners. The calculations and reasoning behind the structural component design

and choices will be discussed throughout this section of the report.

The structure will be built in accordance to the Lloyds SSC guidelines [12]. These

rules detail what the structural requirements of the plating in various locations

throughout the vessel need to be, as well as specifying the stiffener members

required section modulus, section area and moment of inertia depending on what

role they play in the supporting structure.

Page | 6

There were several structural considerations that had to be made in the design

process which were detailed in the Lloyds SSC rule. Most notably, these included

considerations to be made around the chine [13]. It was a detail in the rule that the

plating had to be increased by 6mm (or 10%, whichever is greater) or to place a

reinforced chine rod of a wall thickness of a minimum of 10% of the surrounding

plate. It was decided to increase the thickness by 6mm, as it was thought this would

be the simplest and easiest change to make to the design. Elsewhere the rule would

help calculate the minimum plate thickness, the required plate thickness, the

subsequent section modulus, area and inertial moment requirements of the

surrounding supports. The calculations will be discussed throughout this section.

Throughout the rule, several factors of safety were included in the design pressures

and subsequent calculations with respect to thickness equations. The design factors

[14] in use throughout this document will reference to this table shown below (Table

3) and the corresponding values.

Lloyds Factor of Safety Factors

Implied Abbreviation Notation Value

Service Type Notation Factor Sf Pilot 1.25

Service Area Notation Factor Gf G5 1.2

Craft Type Notation Factor Cf Mono 1.0

Hull Notation Factor Hf Light Displacement Craft 0.95

Table 3: Notation Factors (Safety Factors) used throughout the design process

The design pressures associated with the design of the structure are based around

the greater of: the impact pressure, wave distribution pressure and the forebody

impact pressure. These were calculated separately, and the maximum calculated

values taken for the use in the design pressure of the plating. In terms of high speed

planing vessel, the dominant factor of the three was to be the impact pressure. This

is due to the fact that there was an ‘acceleration due to slamming’ factor (av) in the

equation to calculate the design pressure. This factor is as defined in Appendix 1.

Page | 7

The equation [15] for calculating the impact pressure was as follows:

This equation was then multiplied by the factors of safety which Lloyds employ and

which denote the vessel and service type notation factors (as previously defined in

Table 3) in order to gain the value that will be used to calculate the plate thickness

in the bottom of the boat, PBP . This value of PBP would then be used in the following

equation, which calculates the minimum thickness that the plating needs to be. The

equation [16] used to calculate the bottom slamming region plating thickness was:

The strength requirements of the stiffeners could now be calculated. This was done

via the use of the formulae [16] shown below in the order of Section Modulus (Z),

Inertia (I) and Area of the Web (AW). It should be noted that the coefficients used

below for all the calculations were assumed to be the highest they could be to

ensure the structure would be strong enough. If weight of the structure was a

concern, then this should adjusted so as to meet with the requirements shown in

Appendix 2.

With the use of these equations, the vessel’s structures were designed and

calculated. The limitations of the rule will be discussed in the Appraisal (Page 14).

Page | 8

Structural Layout - Drawings 002-006

The layout of the vessel was to be a transverse framing system supported by

longitudinal stiffeners. This was the chosen method of construction as it was decided

that this would lead to the fastest construction time, and also be the lightest

method. The supporting frames were calculated to be at a spacing of 1230mm,

however, in the bow and around the machinery sections of the vessel, the frames

were to be condensed so as to deal with the adverse loads and additional structural

loads in each of these areas respectively. The associated loads in these areas were

the engine girders and the waterjet frame which each required additional support

around the structure. The additional structure was required in the bow to ensure

that the curvature in the base of the boat was maintained as per the design and also

to support the additional loads that the deflector associated loads would create.

There are 6 main floor levels on the vessel. These include the wheelhouse floor, main

deck, waterjet maintenance, engine maintenance, main subdeck floor and the floor

in the forward stowage compartment.

Material Considerations

The structure of the vessel will be made up of 5083-H111 Marine Grade Aluminium

for all the plating, floors and bulkheads and 6082-T6 Marine Grade Aluminium for all

the extrusions. These materials show excellent resistance to corrosion and have good

welding properties as compared to other marine grade aluminiums.

There was the option to build this craft in GRP, however this was discounted as it

was thought that an aluminium structure would be more durable and the facilities to

construct the vessel do not need to be as advanced as that of a high technology GRP

boat. Therefore the skill level of the workers, although still high to achieve a good

quality weld, is not as high as the engineers required to calculate the skin

thicknesses and lay up of the GRP vessel.

There were two tempers of aluminium used throughout the vessel as previously

mentioned, with 5083-H111 being used for all the plating and decks present

throughout the vessel. All the extrusions such as the frames and stringers would all

be constructed out of 6082-T6 grade aluminium. The reasoning for the change

Page | 9

between the two tempers of aluminium is that the 6082 grade lends itself to being

used for extrusions. The material properties [17] are shown below in Table 4.

Aluminium Type 0.2% Proof Stress [Nmm-2] Ultimate Tensile Strength [Nmm-2]

Welded Unwelded Welded Unwelded

5083-H111 125 125 275 275

6082-T6 240 125 280 190

Table 4: Properties of the materials used in the design

There is only one difference in the composition of these materials, and that is that in

the 6082 grade series, there is a silicon element in the alloy. Both share a magnesium

percentage in the composition of the alloy. There are some evident differences that

are subsequently found between the two different series of the aluminium. The most

notable is how the 6082 grade changes when it is in the welded state, whilst the 5083

grade does not. The way in which they are treated also differs as the 5083 series is

not heat treated (but strain treated) whilst the 6082 series is heat treated and

artificially aged. Heat treating the material is why the unwelded proof stress is

almost twice as strong. Despite these changes, it should be noted that the same

modulus of elastic and density will be used throughout the calculations of weight and

strength.

Structural Calculations

The structure was assessed initially using Dave Gerr’s book The Elements of Boat

Strength [18], and this gave a good base outline of what the structure would

comprise of and what size the plate and stiffeners needed to be. This was only a base

estimate, and carried out solely to gain a base weights and centres estimate for the

vessel and also that of the volume that the structure would take up within the hull,

so an initial general arrangement could be drafted up. These structures were then

optimised so as to meet with the requirements of the Lloyds SSC guidelines.

It was calculated that the following plate thicknesses were required as shown in

Table 5 overleaf. The reason for the increase in plate thickness around the chine is

as previously discussed and the transom plate thickness has been increased so as to

support the waterjet attachment [19].

Page | 10

Plate Location Thickness [mm]

Bottom Plate 10

Chine Plate 16

Topsides Plate 10

Transom Plate 18

Table 5: Definition of calculated plate size

The subsequent stiffener size and spacing could then be designed and calculated. It

was found that a stiffener spacing of 305mm and frame spacing of predominantly

1050mm was the best for the design of the structure. With this frame and stiffener

spacing, the longitudinals were sized as 80x8mm flat bar in the hull bottom and

topsides. In the deck, the stiffener spacing drops to 250mm, and therefore the

longitudinals were sized as 60x8mm flat bar.

In order to support the engines and waterjets installed, there is a main girder that

the engine will sit on, and the waterjet structure will be welded to. This girder is

sized as a plate of 14mm with a flange of 70x12mm. There is also a central girder

that runs all the way from the forefoot of the vessel to the stern. This provides a

huge amount of strength to each frame and the vessel as a whole.

It is detailed in the rule [20] that the minimum number of bulkheads be 2, although

in the case of this design there are 3, due to the fact that the machinery

compartments are independent of each other. This is to maintain watertight integrity

between each room and compartment of the vessel. The main room definitions, in

the way of watertight bulkheads, are defined in Drawing 012 (Page 83).

The calculated bulkhead thickness was 10mm and the ring frame thickness 8mm,

with a web height of 180mm and a flange of 90x11mm. This allowed for an adequate

space for the longitudinal cutouts in the frame to be supported by the surrounding,

solid, plate.

It is important to consider the longitudinal strength of the vessel with regard to how

the structure will behave when it is supported on a sinusoidal wave. The tested wave

was to be a 6.67m high, 16.84m long wave, as this is the worst wave height that is

detailed for the craft in the Lloyds SSC Guidelines [21], which states the vessel

Page | 11

should survive a significant wave height of 4m and a maximum wave height of 6.67m.

The length of the wave was chosen as the worst wavelength for a vessel of that hull

length. There were three tested cases, and the two wave bending moment set ups

can be seen below in Figure 2.

Figure 2: Schematic of the wave bending moments measured

The maximum section modulus of the craft mid section was compared with the

section modulus requirements of the three bending moments. This was calculated by

the use of the formula:

.

This formula had two knowns, as the maximum bending moment was calculated and

the material stress was detailed in Lloyds SSC as 125Mpa.

The section modulus of the midship section was calculated using tabular methods and

the results of the tests are shown below in Table 6. The calculated section modulus

of the midship section was 40682412.76mm3.

Tested Condition Bending Moment

Calculated [kgm]

Section Modulus

Requirement

[mm3]

Pass

Factor

Still Water Moment 3231.69 253623.27 160.40

Wave (Hull Length) 2 Supports 41071.99 3223329.46 12.62

Wave (Hull Length) 1 Support 25508.63 2001917.16 20.32

Table 6: Calculated wave bending moment and section modulus requirements

From the calculations shown above, it can be seen that the vessel is strong enough to

survive the worst possible wave bending moment measured.

Page | 12

It is also important to consider the forces that the vessel will experience when a

point load of a pair of lifting straps is applied. This is important, as a mark can then

be made on the vessel in order to indicate where the lifting points should lie. It was

found that the lifting points will lie at 3m and 10.5m from the aft end of the boat, as

this is where the lowest bending moment was found over each frame tested. This

calculated value was 3814kgm and gave a corresponding section modulus

requirement of 299322.72mm3 for the section. The section modulus of the midship

section was 40682412.76mm3.

Therefore, there is a factor of 135 before the structure is going to fail under this

load. The position of the lifting straps and the vessel’s CoG is shown below in Figure

3.

Figure 3: Position of the vessel’s CoG and the lifting straps

In respect of the deflector, there is a support network of framing and longitudinal

supports. These correspond to the frames in the hull. Up to the deflector these are

built as solid plate, and then become ring frames in the upper half of the hull. This is

to provide strength to the deflector and keep space free in the forward storage

compartment. The deflector is made from 12mm plated aluminium and the grillage

network underneath is constructed out of 8mm plate of varying depths depending on

the curvature of the deflector. These are spaced at 350mm and provide adequate

support for the forces that the deflector will experience.

With respect to the design of the wheelhouse structures, these were designed to

cope with a base hydrostatic load. It was found that the structural requirements are

for 6mm plate and 17mm glass as according to Lloyds SSC [22]. There was to be a

transverse framing system of 4 frames which are all sized at a web depth of 120mm

Page | 13

and thickness of 8mm. These ring frames would have a corresponding flange of

40x10mm. There was to be 4 supporting longitudinal per side of the wheelhouse,

with 30x6 flat bar stringers providing the strength at a spacing of 400mm. In the roof,

there are two main girders that are made of 50x6/50x6mm Tee section. These run

fore to aft and act as pillars in the foremost section of the wheelhouse, where the

front windows are located. There are also 3 supporting 30x6 flat bar supports in the

roof of the wheelhouse.

The frames in the wheelhouse line up and correspond with those in the hull in order

to maintain structural continuity between the hull and the wheelhouse. If these were

not lined up, then there would be a shear concentration at the join, and the

structural joint may become compromised when the boat is in use.

The wheelhouse will be welded and bolted onto a lip built into the deck and framing

system of the hull. This will comprehensively attach the wheelhouse to the hull and

also allows for the two structural entities to be built in separate modules.

The floors on the vessel, including the main deck, cabin floor, engine floor and

wheelhouse floor, will all be constructed out of 6mm aluminium plate. The floors in

the wheelhouse and cabin will be covered in carpet to make them more visually

aesthetic.

The aft platform of the vessel used for access and egress will be constructed out of

aluminium grille plate. This is to allow the water to drain from the platform, so as to

lower the design requirements and the weight of the component if it were to be

made from solid plate. This platform is supported by two 450 angle 120x120mm box

section with a wall thickness of 10mm. This is then bolted and welded to the shelf on

the inside of the waterjet compartment. The platform is also bolted onto the

transom. However, this is only strong enough to support the platform weight, hence

the need for the additional support.

The bulwark of the vessel will involve the frames running up to the underneath of the

bulwark and the 6mm plating being welded onto these. The fender of the vessel will

be mechanically attached to a central box section that is to be bolted and welded to

the hull. The rubber fender provides a rub rail for the docking of the vessel and

should it need to approach any vessels in open water.

Page | 14

Appraisal

Overall, it is felt that the decision to choose aluminium for the application was

correct. Aluminium is the most widely used material in small, fast commercial craft.

The durability of the material when it is compromised and the weight of the material

are relatively good as compared to other materials.

The structural layout of the vessel has been laid out and optimised to meet with the

Lloyds SSC guidelines, after an initial estimation. This optimisation was done in order

to ensure that the designed components met with the requirements of the

classification society. It was found that the stringers in the deck needed to be

increased with respect to the section modulus of the components.

Elsewhere, all the loads to calculate the strength requirements of the platform,

handrail and bulwark were based upon sense loads such as a person’s weight acting

on the component.

The interior volume displaced by structure was not a major concern in the design of

the structures onboard. Therefore, there is no requirement to go down to Tee

sections anywhere in the hull bottom.

The rule itself was chosen as the majority of the commercial craft studied were built

in accordance to the rule. There are some limitations however, such as the minimum

requirements for the increase in plate thicknesses around the chine and waterjet

instalment area. The fact that the waterjet has increased by 8mm to an 18mm

thickness of plate (almost double the 10mm plate used everywhere else) suggests

that perhaps this is an over estimation on Lloyds behalf. However, in the case of the

craft, there is also the opportunity to over design the craft, because weight saving

was not an issue.

Page | 15

Tank Testing

Nomenclature

Total Resistance due to

Drag V Velocity

Viscous Drag Component Rn Reynolds Number

Wave Drag Component Fn Froude Number

Friction Drag Component Cf Coefficient of Friction

Form Factor Ct Coefficient of Total Drag

Epower Effective Power LCF Longitudinal Centre of

Floatation

Indices

M Model FS Full Scale

Reasoning for Testing

The vessel required tank testing to fully assess the effect, if any, the deflector would

have. Therefore, there were two sets of tests done: one without the deflector, and

one with the deflector added. It was be important to maintain a constant

environment and test conditions between the tests so as to give a good reflection of

how the vessel performs without and then with the deflector.

The deflector is expected to decrease the pitching motion of the craft by damping

the bow’s motions as it moves through waves. The hydrostatic force from the water

on both the topside and underside of the bow is the reasoning as to why this moment

or damping motion is created. There were some concerns over how the deflector

would behave in the waves and whether or not it would actually amplify the pitching

motion of the vessel. Also, there were concerns raised over whether the vessel will in

fact dive when a wave flows over the deflector, as the force of the water may be too

large for the vessel to correct its trim, and thus push the boat deeper into the wave.

Page | 16

Building of the Model

The model was sent to Monstercam [23] for milling and some 3 months later, the 5-

star CNC cut 1:15 scale model arrived. There was some work to be done on the

model, which included laminating [24] over the polystyrene surface and then

finishing the model in a high-finish paint filler [25] to give the model’s hull a smooth

finish. Detailed in Appendix 3 is the method used on each day and then the steps

taken to resolve any issues.

The model was tested between Hits 4 and 5 and also after Hit 6, as these times

corresponded with the model being ready for testing, before and after the deflector

was added. The high-finish paint filler was used to give a smooth surface finish to the

model thus preventing any roughness presenting extra drag on the day(s) of testing.

In summary, the construction of the model passed with ease, and the model was

finished to the highest standard in order to ensure the tests were uniform over the

course.

Test Matrix Followed

The testing matrix to be followed was to vary between the two days of testing. On

the first day of testing (4th February 2016) the flat calm conditions and initial

powering calculations test runs were carried out. The model was tested from full

scale speeds of 5.64 knots up to a maximum speed of 32 knots over 18 test runs. It

was found that more runs were required at interim speeds to both confirm the results

of the afternoon’s session in the tank, and also ascertain more data points on the

resistance graph. These runs were carried out on the second day of testing (5th

February 2016), when the model was to be tested in waves.

The deflector was then tested in exactly the same test matrix in order to assess the

effect that the deflector had on the design. The dates set for the second set of tests

were 18th and 19th February 2016 respectively.

The tested sea states were set according to the Beaufort Scale at a Force 4

(Condition 1) and 5 (Condition 2 and 3) sea state respectively. The data used in

calibrating the wave machine to the height and associated time period was real life

Page | 17

data taken from a weather buoy in the Irish Sea [26] and the marine forecast in Malin

[27]. The wave period was then transposed to length by use of the formula:

Where:

g = Gravitational constant (9.81ms-2)

Tp = Time period of the wave [seconds]

λ = Wavelength [metres]

This is the format the data was required to be in by the wave machine. The wave

data set used was as displayed in Table 7.

Wave

Condition

Wave Height Model

(Full size)

Wave Length Model

(Full size)

Wave Time Period Model

(Full size)

1 0.067 (1.00) m 2.63 (39.50) m 1.30 (5.03) secs

2 0.167 (2.50) m 1.63 (39.50) m 1.30 (5.03) secs

3 0.204 (3.06) m - 1.81 (7.00) secs

Table 7: Data used for calibration of the wave machine

The waves analysed in the test were set to be the same wave set and speeds for both

test dates, so as to confirm and compare the data set for the vessel both with and

without the deflector. The waves in Conditions 1 and 2 were based upon a constant

sea state, so as to guarantee that the vessel would encounter the same wave set for

both tests, whereas the waves created in Condition 3 were a long crested random sea

state. This random sea state is programmed according to Pierson and Moskowitz [28]

and will create a random sea state which produces waves all across the spectra of

heights and lengths. The H1-3, time period and scale factor of the waves were

needed in order to calibrate the machine correctly and for the machine to produce

the desired waves. The random sea states were used solely when the vessel was

without its deflector as a measure of how the vessel would perform in a real life sea

state.

The accelerations of the vessel were measured in the forward compartment which

lay 30-40% aft of the forward perpendicular along the DWL. In theory, this should be

where the maximum slamming impact the boat would be felt according to Heller and

Page | 18

Jasper [29]. It should be noted that the accelerations were used using a Smartphone

app [30], and although this has its limitations, the data provided gave a good

interpretation of what accelerations the boat was experiencing at this position. The

sample rate was set at 100Hz, so there was a broad set of data obtained at a high

sample rate. It should be noted that the Smartphone app was used solely as a

comparison in order to qualify the success of the deflector, and the accelerations

measured by the app may in fact not be accurate.

It is possible to calculate these accelerations at any point along the vessel. This

would be of use if the accelerations had to be analysed for crew sleeping quarters or

passenger seating. However, because there is no passenger or crew to be located

anywhere other than in the wheelhouse during the voyage, then the accelerations

throughout the craft do not need to be fully analysed other than for structural needs.

Preparation for tests

In order to ensure that there was a consistent and accurate set of data recorded, the

model and the tank measuring equipment required calibration.

The way the tank measuring equipment measures the data is by measuring a change

in voltage across a terminal, which is then translated into a change in resistance,

side force, heel or trim. It is therefore important to set the calibration of these so as

to ascertain a definite change in drag, etc for a corresponding change in voltage.

This was carried out by using a set of calibration weights equalling 20N of force. The

computer was calibrated by use of these artificially creating 20N of force for drag

and side force respectively. The trim was measured by using a small 50mm block and

placing this under the gauge cylinder. This created a 50mm change in trim to

calibrate to. The heel was done in much the same way, although a 150 block was

placed between the post fitting in the model and an artificial angle of heel was

created. Again, this created a voltage difference that could be used for calibration.

The model (once completed) needed to be ballasted in order to be scaled down

correctly. The required weight was 7.65kg according to the 1:15 scale. The model

itself only weighed 1.82kg, and therefore required 5.83kg of ballasting weight. 2.5 kg

of this was accounted for by the tom post and heel fitting, which is located at the

LCF of the vessel, therefore does not affect the trim of the vessel. This left 3.33kg of

ballast to be located. 2.5kg of this ballast was located in the main compartment of

Page | 19

the model, whilst 0.5kg was located in the aft compartment. The remaining 0.33kg

was located in the compartment where the accelerometer was to be placed. The

location of these weights resulted in a level trim of the vessel.

Analysis of Tests

With these results, several calculations were then carried out which would allow the

results to be scaled from those obtained at model scale up to what they would be for

the full size boat. All of these calculations are based upon the ITTC1978 Formula [31]

which states that:

Where:

Shown below in Table 8 are the calculated results for a chosen test run. These

involve the use of the numbered equations also shown overleaf in Figure 4. The full

results from all the test runs from both cases can be seen in Appendices 4 and 5.

Test Speed [m/s] Fn Fn4 Rn Cf

12 3.000 0.9039 0.6674 2.96 E6 0.0038

Equation N/A 1 14 2 3

Test Rf

[N]

Rv

[N]

Rw

[N]

Rt

[N] Ct

12 4.7958 5.5151 8.7465 14.262 0.0119

Equation 4 5 6 N/A 7

Table 8: Example of how the results were analysed

Page | 20

Where the above Equations reference to:

1-

2-

3-

4-

5-

6-

7-

Figure 4: Formulae used in the calculations shown above in Table 8

In order to calculate the value for the wave drag, the value for the viscous drag

component was required. This in turn required the calculation of , involving the

ITTC1957 Formula [32] (shown in Figure 4 in Equations 3 and 4 ) and then multiplying

this value by the form factor (1+k).

There were also more lower speed runs done to try and gain a better interpretation

of the value of (1+k) for the model, however due to the low speeds and low forces

associated with these speeds at a 1:15 scale, the values were too varied to gain any

useable data from this. Therefore a (1+k) of 1.15 was assumed in the analysis of the

tests as will be discussed.

Results of Tests

The full data set recorded from the tank test including the model scale and full size

results can be seen in Appendices 4 to 7. The data set was scaled according to the

ITTC1975 method. The value for (1+k) was assumed to be 1.15. This was due to the

lack of useable data that was ascertained from the tests at low speeds. It would be

recommended that a larger scale model be made in order to test the resistance at

these low speed runs if that was an option, in order to gain a good interpretation of

the (1+k) factor. A larger scale would result in higher forces being tested than those

at a lower scale, and thus more accurate data should follow.

Page | 21

The graphs of the three resistance components and the measured data can be seen in

Figure 5 below.

Without Deflector With Deflector

Figure 5: Resistance curves for both test sets, without the deflector (left) and with (right)

The accelerations, with respect to gravity, that begin to result in human blackout are

+8g and -3g over a prolonged amount of time [33]. This means at -3g, your body will

weigh 3 times as much as it would on a day to day basis. The accelerations measured

by the Smartphone application were almost double this for one tested situation,

however the test was done from a purely experimental point of view, to see if the

deflector would have a damping effect on the pitching motions of the craft, and the

values should not be taken as an accurate set of results. The accelerations measured

can be seen in Appendices 8 to 28 of the Appendix section. The corresponding run

and wave conditions are in Table 7.

The results of the test show that with the added deflector, the model’s accelerations

in waves do in fact drop by some 23% for the best scenario. It was found that if the

boat could plane (and plane well) in a sea state, then the deflector would not be of

use in the design, as it is nowhere near breaking the surface water. The vessel

however displayed good sea keeping in a force 4 of speeds of 21 knots without the

deflector.

Despite this apparent success of the design, it should be noted that at some speeds,

the deflector actually amplifies the accelerations of the bow of the vessel. This was

one of the concerns before testing began, and will be a key factor in the decision

quantifying the success of the deflector. A summary of the results found is shown in

Table 9 overleaf. A full set of results can be seen in Appendix 27.

Page | 22

Run Numbers Speed

[ms-1]

Wave

Condition

Resistance

Increase in

Waves

Positive

Acceleration

Increase

Negative

Acceleration

Increase

Without

Deflector

With

Deflector

1 8 2.00 1 12% 0% 18%

2 9 2.71 1 14% -6% 5%

3 11 1.00 2 34% 10% 71%

4 12 1.00 2 44% 25% -9%

5 14 0.50 2 108% 43% -18%

7 15 1.62 1 11% -9% -23%

Table 9: Comparison of the effect of the deflector expressed as percentage increases

The deflector also added resistance to the design, and again this varied with the

speed of the vessel. It was found that an average of 13% of the total resistance of the

vessel was added when the deflector was installed in calm water tests. This increase

in resistance required the powering to be reassessed, and a drivetrain with a higher

total power to be installed. This is portrayed graphically in Figure 6.

Figure 6: Resistance comparison of the model with and without the deflector in calm water

Page | 23

The trim of the vessel was affected, as at lower speeds with the deflector attached,

the trim was relatively much higher. This can be put down to the fact that the

deflector blade will create some lift due to the air passing over it and the water

pushing up from underneath the vessel. This lift produced by the blade will be

minimal, but enough to increase the relative trim of the vessel by some 25% in the

worst case. This could be linked to the increase in drag, as the running angle of the

boat is greater for the speed of the vessel in the non-deflector test series. This may

mean that there is a higher wetted surface area at the transom and therefore more

frictional resistance as the boat travels through the water.

Despite this, as the boat speed increases, the deflector actually helps to level out

the running trim of the vessel. This is due to the airflow of the blades increasing and

thus creating more surface velocity on either side of the deflector. The force

associated with this was lift, but this lift is now beginning to act as downforce.

Powering Calculations

The results of the tank test allowed for the calculation as to how much effective

power the vessel would require at full scale. This was first of all achieved by finding

the speed at which the power required calculation and using the following formula:

It was important that this value was not taken for the power that the vessel actually

required to operate at the desired speed, as there are several efficiencies to take

into account. These can be summarised as the open water, machinery and appendage

efficiencies and reduce the effective power from 100% down to 55%. The result of

this is the effective power needs to be divided by 0.55 in order to calculate the

actual power required for the boat to achieve the desired speed.

In the case of the tested boat, the results from the service speed to the maximum

speed are detailed overleaf in Table 10. The results used are already at full scale and

are from tests when the deflector was added.

Page | 24

Test Speed

[knots]

Froude

Number

Total Resistance

[Newtons]

Effective

Power [kW]

Required

Power [kW]

13 24.45 0.98 42158.99 530.66 964.84

14 26.35 1.05 45462.01 616.26 1120.47

15 28.23 1.13 48930.56 710.07 1292.10

16 30.11 1.21 49362.20 764.72 1390.41

17 32.00 1.28 47762.13 786.17 1429.40

Table 10: Powering Calculations carried out to assess the power requirements

As can be seen, the power requirements actually drop off as the model speeds up.

This is due to a drop in the total resistance of the craft at this speed. Despite this,

the power still increases by some 40kW. The reason behind this drop in resistance is

because of scaling issues between model and full size regarding the resistance due to

waves. The resistance due to waves is the key factor as the vessel’s speed increases

and, at these high speeds and small scale, a small change can have a huge effect on

the results. It is at the speed of 32knots full scale that the resistance factors due to

waves and friction uncharacteristically cross over. This crossing over at model scale

means when the full scale results are analysed, there will be a drop in the total

resistance after this speed of 32 knots.

Therefore, it was decided that the machinery capacity should have a minimum power

of the required power + 10% of the total power. The engines that would be searched

for and will be discussed in the Machinery and Systems Installed Onboard Section

(Page 27) must have a minimum combined power of 1572.34 kW.

Page | 25

Validation of Deflector

Therefore, it was decided that the model testing was inconclusive. However the

results found were of interest. Further study and analysis into the tank testing

showed why it was that the deflector behaved in the way it did. The reasons were as

follows:

The added resistance was because of more aerodynamic and hydrodynamic

drag factors increasing due to more surface area present in the design.

The accelerations increased because of the added buoyancy the deflector

created, thus making the bow ‘jump’ up out of the water.

The trim of the craft decreased as speeds got higher because the flow over

the deflector blade started to level out and create a down force moment.

In terms of qualifying the success of the deflector, the results were so varied that

there is no definite answer. This is because of the additional accelerations that were

experienced at some speeds and the added drag. If there was a constant drop in

accelerations across the spread of the results, then the deflector would have been a

definite success. However, because the results were inconclusive it would require a

much more in depth test matrix than that carried out, including several more sea

conditions and changes to deflector shape and gyradius of the model in order to find

the ideal combination where the deflector is a constant aid throughout the data set.

Appraisal

It was found from the first set of tests carried out, that there was a set of speeds

around 1.75ms-1 at model scale that resulted in an air bubble being formed on the

starboard chine. This may be a result of the low pressure created by the chine

around the pressure difference boundary, thus pulling the air down under the vessel

and having an adverse effect. This effect causes the water to slap of the hull side

and causes a huge resonance effect throughout the model and tow post, which

results in the model jolting and vibrating wildly. These movements affect the results

taken from the dynamometers, as they are measuring a much broader range of data.

For the worst measured case (1.75ms-1 itself), the variation in maximum and

minimum drag measured was some 64 Newtons. However, out with this speed set,

the data measured was not of as high a variation as this, and could be used

efficiently.

Page | 26

It was concluded that this was a model scale problem and could be discounted from

occurring at full scale. The reason for this assumption was that the pressure due to

atmosphere and water cannot be scaled and therefore it is much easier for smaller

objects to create abstract vortices that on a full size vessel, would simply not occur.

Another example of this was when the deflector was being tested, some of the water

would not separate from the blade, and thus add more residual resistance to the

total drag. Again, this would not affect for the full scale model of the craft, as the

water would separate much more efficiently off a larger surface.

The problems which were encountered with the resistance curves for all three

components (especially the resistance due to waves at model and full scale, and the

total resistance at model scale) were down to the results at model scale

uncharacteristically crossing over. The viscous drag (associated with friction) should

not be the predominant factor in the resistance at model scale at the higher tested

speeds. In the case of the results explained previously, this does become happen.

The reasoning for this is that the resistance measured by the dynamometer actually

begins to plateau at certain points, and at this point, the plateau has allowed the

wave resistance component to decrease below that of the ever increasing frictional

component. The frictional component will keep on rising, as it is based on speed

being the major variable, and is no way related to the total resistance as can be seen

in Figures 5 and 6. The fact that this is not related and that wave resistance is

directly related to the total resistance measured at model scale and the total

resistance found at full scale, means any anomalies may be carried through to the

graphs, and be amplified at full scale. This is why the graphs are as scattered as they

are, especially at full scale.

It should be noted that for when a vessel to be built in accordance to LR SSC

Guidelines that requires tank testing, must meet with guidelines set out by the rule

[34]. However, although these are the requirements, it would not have been possible

to carry out the tests that are required. This is because of both facility and time

constraints.

In summary, the effects of the deflector, in the tests carried out and after the

results were analysed, were deemed to be negative. However, the deflector will

remain in the design process, as after refining has taken place, it is believed that the

deflector will aid in damping the accelerations of the vessel.

Page | 27

Machinery and Systems Installed Onboard

Introduction

The machinery installed on board the vessel will be a drivetrain of twin engines

driving two waterjets. The engine choice is a Scania DI-16076M [35], which has a

power of 809kW per engine at 2300RPM, whilst the waterjet choice is a Rolls Royce

Kamewa A-33 A3 Waterjet [36].

This engine was chosen primarily because its design can be optimized for waterjet

applications and also because the power produced by these engines closely reflects

the power required by the vessel discovered during the tank test process.

Reasoning behind Choices

The reasoning behind choosing to utilise a waterjet based propulsion unit ahead of a

more conventional propeller arrangement was that the waterjets would give the best

efficiency for the craft when it is operating at higher speeds and the best

manoeuvrability for the craft when it is operating at lower speeds. It was thought

that a hybrid propulsive unit could be used in place of the diesels, however this was

discarded due to the already limited amount of machinery space that there is on

board the vessel.

Detail of the Scania DI-16076M Engine - Drawing 007

The engines are V8 style, with 4 cylinders on either side of the longitudinal

centreline of the engine at a 450 offset, thus representing a V-shape as would be

viewed in the body plan view of the engine.

The engine’s operating profile states that the engine is rated for 1/6 hours maximum

power use and a recommended usage of 2000 hours per annum. When the engine has

been put to the maximum power output, it is recommended that the revs of the

engine must be lowered by 10% between maximum power usages. In theory this

suggests that when the engine has been running at 2300 RPM, then the revolutions

must be reduced by at least 10% (<2070RPM). This is in order to comply with and

meet the Scania warranty requirements [37].

Page | 28

The load factor of the Patrol craft requires 960kW of combined power in order to

maintain its 24knot service speed. This equates to around 60% of the total power of

the engines. This would suggest that the load factor of the vessel will fit in with that

of the engine operating profile.

Scania also provide an unlimited operational use engine, with the same power output

as the one selected, and although this engine has a more compensating load factor

where 1/3 hours can be maximum power and 80% total load factor is allowed, the

lower rated engine was chosen as the boat will not be in use for more than 5.5 hours

per day (on average). This intermittent usage rating is the middle rating that Scania

carry, with the lowest rating having an annual recommended usage of only 1200

hours, which is too low for this vessel’s intended usage.

These engines are also fitted with a crankcase ventilation valve, which allows the

engine to be rolled over, without damaging the engine. Without this valve, the

engine’s cylinders would fill with oil and this would lead to either irreparable

damage or the engine combusting uncontrollably. When the engines pass an angle of

300 of heel, the valves begin to close and the engine will power down as a safety

precaution. There are engines, such as the MTU 8v2000M84L [38], which are fully

roll-over proof and will keep running for a period of 30 seconds, whilst upside down.

However, the engines chosen can be started again after the boat has self-righted.

Scania have produced a recommended time schedule for the maintenance of varying

components of the engine. These range from daily checks to once every 4800 hours

of use. It should be noted that although Scania do not explicitly state a Time

Between Overhaul (TBO) period when the engines should have a full service and be

rebuilt, one has been estimated as every 9600 hours of use. This operational window

relates to around 5 years of service for the vessel and ties in with when the valves

and injectors will be requiring service for the fourth time according to the schedule

set by Scania. The maintenance schedule [37] is as follows:

Daily checks

o Oil level

o Coolant level

o Fuel level

o Obvious leaks

Page | 29

Every 400 hours of use

o Oil and corresponding filters changed

o Oil centrifugal pump cleaned

o Heat exchanger anodes and sea water impeller checked and

changed if necessary

Every 1200 hours of use

o Air and fuel filter cleaned

o Batteries changed

o Drivebelt checked

o Coolant checked and replaced if necessary

Every 2400 hours of use

o Coolant replaced

o Rocker cover removed, and injectors, gasket, valves and piston

cylinder cleaned and replaced where appropriate

Every 4800 hours of use

o Cooling system flushed and cleaned

o Air and fuel filters replaced

It is essential that this maintenance is followed by the engineer maintaining the craft

as this will result in the engines operating to their full potential for the maximum

amount of time, and preserve the TBO time period.

Figure 7 is the ratings curve for the Scania DI-16. This displays the Torque, Power,

Fuel Consumption and Specific Fuel Consumption for the engine with respect to

whatever speed the engine may be doing at that specific time of operation [35]. This

gives a good overview as to what the engine is capable of at a given RPM.

Figure 7: Ratings curve for the Scania DI16-076M

Page | 30

Another measurement that can be used as a base for comparison is the Brake Mean

Effective Power (BMEP). This is a measure of the average pressure that is exerted on

the engine’s pistons by the gas in the cylinders throughout one whole cycle of the 4-

stroke. The values for the BMEP are measured in Pascals (Newtons per square metre).

The formula used to work out the BMEP of the engine is as follows:

Where:

T = Torque of the engine at a given RPM [Nm]

Nc = Number of Revolutions per Power Stroke (2 for a 4 stroke engine)

Vd = Volume Displaced by the Engine Cylinders [m3]

The graph showing the BMEP of the engine is shown in Figure 8. It can be seen that

the BMEP of the engine drops sharply as the RPM of the engine increases. This is due

to the decrease in torque that the engine experiences at this specific RPM.

Figure 8: BMEP curve for the Scania DI16-076M

Detail of the ZF 2050 Gearbox - Drawing 007

The chosen gearbox for use in the installation will be a ZF 2050 (medium duty

gearbox) [39]. This is rated by ZF as a gearbox which can absorb 0.3771kW of power

per revolution of the engine. This gearbox is rated for use with engines up to a power

of 980kW at 2600 RPM and 867.6kW at 2300 RPM, so the power factor of the gearbox

Page | 31

matches the chosen engine. Scania engines also have a close partnership with ZF, so

there should be no issues arising when it comes to the installation of the gearbox and

engine components.

The gearbox chosen has a relatively low reduction factor of only 1.5 which means the

majority of the engine’s RPM is transferred to the waterjets. This gearbox has a

vertical offset of 220mm from the engine flywheel to the coupling on the driveshaft,

which is also an aid in the installation of the machinery aboard, as there is an overall

drop of 420mm to be accounted for.

The gearbox itself is a non-reversing type, as there is no need for a reversing style

gearbox to be installed when the propulsion unit is a waterjet. The rating of the

gearbox is medium, as this is similar to the rating that Scania have detailed for its

own engine. The gearbox is manufactured to ISO9001 standards.

Detail of the Rolls Royce Kamewa A3-36 Jets – Drawing 007

The chosen jets were to be the Rolls Royce Kamewa A3-36 jets. These jets were

primarily chosen again due to the size restrictions that the craft presented in terms

of the power required and the space available for the length of installation. These

jets are rated to absorb 950kW of power and therefore are suited for the installation

in this vessel’s drivetrain. The weight of these jets is 575kg when dry and when there

is water passing through the ducts, the weight increases to 170kg. Having this data

allowed for a more comprehensive analysis of the weights and centres of the craft.

When the craft needs to come to an abrupt halt and when the craft is reversing, the

buckets are lowered to reverse the direction of the flow. It is reported by Rolls Royce

that the overall efficiency of this is 70% of when the bucket is not lowered.

These waterjets are hydraulically operated and controlled by a series of levers. The

rods are located on the exterior of the jet, pulling and pushing the bucket, nozzle

and interceptor trim tab as the coxswain sees fit. The cylinders driving these rods

however are located on the inside of the hull, creating an efficient and compact

design.

The design of the A3 Kamewa waterjets [40] has been enhanced from the previous

generation of waterjets (Kamewa A series), with a weight saving of 35% from the

previous design. The efficiency of the bucket and steering nozzle has also been

Page | 32

increased by some 16%. The majority of this weight saving has come about from the

time invested into designing a new and more efficient waterjet pump. The new pump

is a mix flow design instead of an axial flow design. The nature of this design and the

controlling nature of the mixed flow velocities allows for a more efficient use of the

water passing through the pump. The controlling of these velocities minimises the

effects of cavitation within the duct and impeller tube. By the use of a mix flow

pump, bollard pull of the jet is increased by 40% over its predecessors.

The jets themselves are constructed out of aluminium, however they have stainless

steel nozzles and pump sections. There are two bulkhead location welding points on

the waterjet that will be used to tie in with the structure of the craft. Because of

the nature of the instalment of the engines, there is a 200mm drop that needs to be

overcome between the gearbox coupling and the waterjet coupling. There is also a

125mm offset inboard between the two components. The way that this is overcome

is by utilising a twin, double universal slip jointed driveshaft. This has a permissible

safe working angle of 11.50 and will allow the offset and down angle of the

instalment to be resolved.

The efficiency lost in this nature of installation is a key factor to consider, however

the effects of such an installation are said to be negligible when the angle is less

than 11.50 [41]. The angled instalment of the shaft does raise the problem of

maintaining the watertight integrity of the bulkhead. However, this will be achieved

by welding the shaft from the bulkhead located on the waterjet to the engine room

bulkhead, and down to the supporting stringers of the base plate. There will be

access hatches for inspection of the universal joints for maintenance purposes. The

shaft, when it is parallel to the waterline again, will then pass through a watertight

bearing and subsequent stepped bulkhead to the gearbox coupling. This box

arrangement will maintain the integrity of the bulkhead both in terms of water

tightness and fire proofing.

The calculated shaft diameter of the driveshaft linking the engine to the waterjet

was carried out according to Gerr [42]. The equation used for the calculation is

shown below and as it can be seen, the calculated size was 70mm diameter Aqualoy

17 shaft.

Page | 33

Where:

kW Shaft = Shaft Power in Kilowatts

SF = Factor of Safety (8)

St = Strength of Material (Aqualoy 17, 482 MPa)

RPM = Revolutions per Minute after Gearbox Reduction Ratio

The way in which these jets will be mounted will be a straight weld between the

fabricated aluminium plate on the jets and a supporting structure on the hull shell,

which coincides with the same supporting structure that the engine will use. This

leads to a fast and easy installation, which provides adequate strength to the

structure for the support of the jet. The underlying supporting structure network will

be analysed fully in the structures section of the report.

Ventilation System Design – Drawing 008

It was stated by Scania that the required air to each engine is 63kg/min for each

engine at the top RPM of each engine [43]. The full range can be seen below in Table

11.

Air Consumption [kg/min] for a given engine speed [RPM]

RPM 1200 1500 1800 2100 2300

Air

Consumption 20 33 47 60 63

Table 11: Air consumption of the engine at each respective RPM

The ventilation was to be powered by 3 axial fans on each side of the engine room,

namely two 11-inch diameter fans and a 9-inch booster fan [44, 45]. These were

supplied by Delta T marine. The two 11-inch diameter fans had the capacity to pass

40m3 of air per minute whilst the 9-inch was half of this at 20m3 of air per minute.

The air in fans are located at the forward end of the engine room space to prevent

the air from heating up too rapidly by passing over the dry exhaust run immediately.

Page | 34

The air is drawn from the ambient via a Munters DF2500 mist eliminator [46] which

will remove the majority of the spray and salt from the air. There is also a fire

damper located between the fans and the mist eliminator. In the case where there is

a fire, the air into the engine room can be stopped, and thus suffocate the fire of

oxygen. These dampers would also be closed in the case that the boat rolls over, as it

is then that any water ingress into the engine room would be extremely damaging, if

not fatal, for the engines.

To prevent the air that has been pumped into the engine room from charging and

compressing, it is important to also have an air outlet point. Because of the nature of

the instalment, with the Engine Room being a completely watertight space, the

ventilation is forced out by a pair of Delta T premium line 15-inch axial fans, each

capable of moving 115m3 of air a minute [47]. These are located at the aft end of the

engine room, above the exhaust run. There is also a series of circular dampers to

prevent air and water ingress, and at the aft, the air is also passed through a mist

eliminator. This prevents any rain or spray from entering in through the vents.

Both of these fire dampers are built in accordance to the A60 standard of fireproof

bulkheads, which states a minimum of 60 minutes without the transfer of latent heat

from one side of the damper to the other. Paroc supply a suitable product for to

serve the purpose of the bulkhead requirements [48].

The location of these fans should also create an ambient circulation of the air in the

engine room, which again is important in the design of the craft. It would be

recommended that the fans are switched on before, and left on for a minimum of 30

mins after, each use of the engines in order to flush any fumes and reduce the

ambient temperature of the engine room after it has been used to a minimum value

as compared to that when it was running.

The air is passed through a filter before entering the cylinder of the engine. There

are 4 valves per cylinder which increases the volumetric efficiency of the cylinder to

the most that it can be, as more ‘clean air’ will be pushing the heated air out.

The waterjet compartment will be naturally ventilated as there is a large enough

volume in the compartment for the air not to become compressed and the ambient

of the waterjets will be relatively low as compared to that of the engine room.

Page | 35

Ventilation of the cabin spaces is separate to that of the machinery spaces apart

from the wheelhouse, which draws from the same intake of air as the engine room.

This air is then circulated around the wheelhouse. There is the option to heat this air

as there is a heating element built into the blower. Below deck, there is the same

principal of heating the air. The vents are located on the side of the wheelhouse,

underneath and forward of the windows of the wheelhouse.

Cooling System Design – Drawing 009

The engines themselves are cooled by a sea water heat exchanger arrangement, one

for each block of cylinders on opposing sides of the engine. The sea water will be

taken in by a sea cock located in the forward frame compartment of the engine

room. This location of the sea cock will ensure that the water will always be

available to the engine, even when the boat is running at a 60 angle of trim.

This can, and should be, turned off whilst the boat is not in operation from a

stopcock located under the floor in the engine room. The sea water then passes

through the engine’s heat exchanger which cools the closed cooling system that the

engine incorporates. From this point, it is raised and injected into the hot exhaust

gases thus mixing and cooling these down, before it is ejected out of the transom of

the vessel back into the sea.

It should be noted that Scania have the option to fit an immersion heater into the

engine’s cooling circuit [37]. The immersion heater will be installed into the engine,

thus providing hot water from the heat of the engines.

Exhaust System Design – Drawing 009

The exhaust system of the vessel is a standard dry to wet arrangement, where the

exhaust gases from the engine are raised up before being injected with sea water

and passed out through the transom of the vessel. It should be noted that Scania

have detailed the minimum size of the exhaust pipe to be 220 mm in diameter [43].

This arrangement is suited to the duty of the vessel, as there is no need for the

exhaust to be solely dry. The sea water comes from the cooling system and will mix

with the hot exhaust gases and thus lower the temperature and noise of the exhaust

system.

Page | 36

The run of the pipe from the Engine Room to the Transom of the vessel passes

through its own segregated compartment in the Waterjet compartment so as to not

transmit the ambient heat to the Waterjet compartment from the exhaust. The

exhaust pipe has a constant decreasing gradient from the point of water injection to

the transom. At the bulkheads, the exhaust pipe passes through horizontally level

with the DWL so as to avoid creating concentrations of shear force.

Fuel and Tankage Layout and System Design – Drawing 010

The fuel system aboard the vessel utilises a direct feed from the fuel tanks to the

engines, via a set of fuel polishers and filters. There was the option to utilise the

facility of a day tank, where there would be a central draw of fuel to this one tank,

which in turn the engines would both feed from. However, it was decided to discard

this option and continue with a direct feed. The fuel tanks are located in the

compartment forward of the Engine Room, in the Main Cabin. These tanks take the

form of wing tanks and each hold 2.11m3 of diesel. This leads to a combined capacity

of 3500 litres of diesel carried by the vessel at full capacity. This capacity of fuel

gives the vessel a range of around 930 Nm at a service speed of 24 knots.

With respect to the system that Scania use to inject the fuel to the cylinders, it is a

common rail system that has been enhanced by the engineers at Scania, thus

creating their own brand of injection, Scania XPI [49]. This is an extra high pressure

system that has been designed to give low exhaust emissions and a good fuel

economy at a high torque level. Before the fuel can reach these injectors however, it

is passed through 2 separate fuel filters on the engine, namely a particle separator

and then a water separator.

The Scania XPI system was designed in conjunction with Cummins and uses a three-

phase injection process, which maintains a high burn temperature within the

cylinder, thus keeping the Nitrous Oxide and Sulphur Oxide levels down to a

minimum. This system is set up independently to the engine speed, but constantly

changes to ensure that the correct amount of fuel is going in at the correct time. The

three phase injection process is highly popular throughout the majority of engine

manufacturers.

Page | 37

Below in Figure 9 is a schematic of the fuel system that will be used on the Scania DI-

16076M [49]. As can be seen, there is only one injector shown, but on the engine

there will be 4 injectors per rail, and subsequently 2 rails per engine.

Figure 9: Schematic of the fuel injection system used in the Scania DI-16 engine range

As can be seen in the above schematic, there is a return rail (8) that is installed in

the fuel system. This is installed as any excess fuel that the system may draw, can be

returned to the tank. This pipe will run under the floor and be injected into the

lower reaches of the tank to prevent the fuel from dropping in whilst it is hot and

foaming the tank up.

The fuel will be cleaned by a pair of Wasp-HPS-WP-10 fuel polishers [50]. This is a

step taken to further purify the fuel and ensure that the cleanest fuel is being used

in the engine. This system can operate at 10 litres per minute, which is almost 3

times as much the rate that the engine will use fuel (3.5 litres per minute). The

system operates by processing the fuel before returning it to the tank for the main

fuel system to draw upon. This process should aid in the longevity of the engine.

Layout of the Machinery with an Insight into Access To and Egress From – Drawing

011

The permeability of the machinery spaces is an important factor to consider. This is

to do with how much of a percentage the machinery displaces in each respective

room. There was a 5% allowance built in for miscellaneous items. This resulted in an

81% permeability in the Engine Room, and an 83% in the Jet compartment. It should

be noted that the recommended permeability of machinery spaces is 85%.

Page | 38

Access and egress from the machinery spaces comes via 2 separate routes in both

cases. This is because if one route should become compromised for any reason, it is

important to have an alternative route. In the Engine Room, there are doors fore and

aft leading to the Jet Compartment and the Main cabin. As another means of access,

there is also a hatch to the Wheelhouse. For the Waterjet Compartment, there is the

aforementioned door to the Engine Room, and also a hatch towards the aft end of

the compartment. It is also important to place these access points as far away from

each other as physically possible. Access to the Waterjet hatch is via a ladder

mounted on the inside plate of the transom, whilst the Engine Room hatch is for

emergency use only, and the engine itself should be used for leverage.

Environmental Compliance

These engines are said to fully comply with IMO MARPOL AnnexVI (Tier II), EU Stage

IIIA and EPA Tier II emission standards [51, 52, 53]. These are some of the most up to

date engine emission standards set by the authority bodies. These standards are

widely recognized throughout the world’s. There are higher standards set by the EPA

governing body, which reach up to Tier IV, however the majority of marine diesel

engines all comply with the EPA Tier II standard. In 2021, IMO will set a standard

where engines must comply with the new Tier III standards. However, although some

ship engines are now beginning to be designed to meet with this standard, the desire

to comply with the regulation of smaller commercial and yacht engines has not yet

become of as much importance

Alternative Propulsion Options

As with any craft, it is important to note any other engines and or jets that were

discarded in the selection process, and why the Scania DI-16076M and Rolls Royce A3-

36 Jets were chosen. The primary factor behind choosing these machinery options

was that they both displaced the least amount of volume in the respective machinery

spaces. Because it is quite a tight fit between the engine room for fitting in regards

to width and height, the Scania proved to be the smallest option. However, there

were still two other competing engines that were compared. A full comparison table

is shown overleaf in Table 12. These included the MAN D2842 LE410 [54] and the MTU

12v2000 M70 [55].

Page | 39

Comparative Component Scania DI-16076M MTU 12v2000-

M70

MAN D2842

LE410

Rated Power [kW] 809 788 749

Rated RPM 2300 2100 2100

Fuel Usage @ Rated

Power [l/hr] 210 198.4 198

Compression Ratio 15.70 - -

Displacement [l] 16.40 23.90 21.93

Dry Mass [kg] 1660 2795 1860

Maximum Torque [Nm] 4000 - 3700

Rated Usage [hrs/annum] 2000 UNLIMITED 4000

Emission Standard

IMO Tier II, EPA

Tier II, EU Stage

IIIA

IMO Tier I EPA Tier II, IMO

Tier II

Dimensions (LxBxD) [mm] 1551x1270x1131 1890x1400x1290 1795x1227x1216

Table 12: Comparison of similar engines that may have been installed

If the Client disagrees with the use of Scania engines for any reason, the secondary

choice would be the MAN D2842 LE410. This is because the properties of this engine

closely match that of the Scania DI-16076M.

There were two other waterjet manufacturers studied for the use in this project.

These included models from Ultrajet [56] and Hamilton Jet [57]. Again, the main

reason for the use of Rolls Royce waterjets was the fact that they weighed the least

and displaced the least length. Rolls Royce waterjets also carry the highest efficiency

rating. Overleaf in Table 13 is a base comparison table between the three waterjets.

Page | 40

Comaritive

Component Rolls Royce A3-36 HamJet HM461 Ultrajet 525

Interior Length

[mm] 2134 2048 2234

Exterior length

[mm] 1166 1440 1287

Total Breadth [mm] 796 1040 1000

Total Depth [mm] 836 900 1050

Displacement Dry

[kg] 575 640 1150

Displacement Wet

[kg] 745 750 1328

Max Power Absorb

[kW] 950 900 1100

Table 13: Comparison of similar waterjets that may have been installed

Appraisal

This section aimed to cover the systems installed in the vessel and all the

considerations taken in the design of the respective arrangements. It is felt that the

systems have been designed to a high standard and if the Client has any issues, then

these can be discussed. With respect to sourcing the product installed in the vessel,

the components that were fitted were the most suited to the vessel in terms of the

available space and duty requirements of the vessel.

Page | 41

General Arrangement

Below Main Deck

This section will describe and detail the fitting out and design considerations taken

when the interior of the vessel was being designed. The drawings of the general

arrangement in plan and profile view can be seen in Drawing – 012 and in section

view in Drawing – 013 (beginning Page 83). All throughout the main compartments

(Galley, Saloon and Main Cabin) there is a minimum of 1.9 m headroom. This was a

key part in the design to ensure that the crew could operate and use the facilities

below deck with ease.

Forward Stowage

In the very forepeak of the vessel, there is a stowage and anchor locker. This

contains a windlass as well as two 80kg anchors. These have been sized according to

LR SSC [58] which also dictates the size and length of the chain required. Because of

the overhang of the deflector, it was required to extend the pivot point for the

anchor chain. However, this was incorporated into the fender of the vessel.

Elsewhere, in this locker, the vessel carries all its ropes, tow lines and emergency

equipment as well as a spare set of life rafts. This compartment can be accessed via

a hatch on the forward deck.

Galley and Saloon

As part of the Client’s requirements, there was the request for hotel facilities on

board for two members of crew. This was the reasoning behind installing a gas cooker

[59] in the Galley area. There is a fridge [60] as well as a sink elsewhere in the

Galley. There are adequate food and utensil storage areas located above the sink and

the cooker and also behind the deck access ladder. Completing this area, there is a

table with seating for 4 people located in the foremost half of this compartment.

The Saloon and Galley have been designed to make use of the limited space

available, due to the high deadrise angle that is associated with the hull in this

location.

Page | 42

Main Cabin

The main cabin has been designed to provide sleeping accommodation for two

members of crew, as well as storage facilities for all their personal effects. In

addition there is a head arrangement, with toilet [61] and shower [62] facilities. The

beds are located around midships of the vessel in order to keep the effects of trim

and heave to a minimum whilst the crew are in the bunk beds. There is a small

storage area in each of the bunk bed areas for personal use. The toilet is located

directly opposite the bunk beds and is split into two compartments, namely the toilet

and sink and the shower compartment. The floor level in the two compartments is

different, with the shower compartment having a lower floor level in order to

prevent the toilet floor flooding. There is a curtain that separates these two areas.

In this compartment, there are the 4 tanks that the vessel requires; with a pair of

2.11m3 diesel wing tanks located at the aft end of the compartment, and two

subsequent bunker tanks underneath the floor level for the fresh (0.4m3) and grey

(0.45m3) water that the vessel will use and create. Although this is not ideal to have

the fuel tanks where they are, it is the most efficient way to use the space.

The access to and from this area is via watertight doors fore and aft to the Galley

and Saloon and Engine Room respectively. There is also a set of stairs that is used to

access the wheelhouse. The stairs run from starboard to port, and are off-centre to

the centreline of the floor. Underneath the stairs is a small locker for the stowage of

tools and materials.

Machinery Spaces

Aft of the Main Cabin there are the Machinery Spaces. The first of these is the Engine

Room. Because of the high deadrise angle associated with the design of the hull,

installing the engines with a sensible clearance height and width was an issue.

However, there is adequate space between the engines to carry out any maintenance

required, with 970 mm between the outermost edges of the two engines. In terms of

height, the roof of the engine room had to be raised, thus impeding the space in the

wheelhouse. However this was a vital requirement in order to raise the exhaust high

enough and allow maintenance of the engines.

Page | 43

Access from the Engine Room has already been covered in depth in the Layout of the

Machinery with an Insight into Access To and Egress From Section of the Machinery

and Systems Installed Onboard Section of the report on Page 37. The access is two

weather tight doors, one at the fore and one at the aft of the compartment, leading

to the Main Cabin and the Jet Compartment respectively. There is also an emergency

hatch that opens up to the wheelhouse, should the other access doors become

compromised.

The Jet Compartment is the aftmost compartment in the vessel, and is solely home

to the twin Rolls Royce jet drives. In this room, there is no floor due to the nature of

the jet instalment, but the roof is a lower height in this room, in order to help create

a deeper deck space at the aft end of the vessel without raising the bulwark to an

unnatural looking height.

Above Main Deck

This section will describe and detail the fitting out and design considerations taken

when the wheelhouse was being designed and also the exterior features that are

present on the vessel. The drawings of the exterior and wheelhouse general

arrangements in plan and profile view can be seen in Drawing – 013 and in section

view in Drawing – 014 (beginning Page 84). In the wheelhouse alone, there is over 2

metres of headroom to ensure an airy design and that the crew can operate

comfortably within this area.

Wheelhouse

In accordance to the Client’s requirements, the wheelhouse has been designed to

house 6 permanent members of crew as well as 4 survivors. Therefore, there are 6

Ullyman Jockey [63] style seats for the crew and 4 bench seats for the survivors. The

6 Jockey seats are spread around the wheelhouse, and are non-symmetrical due to

the access hatch for below deck. There are 3 seats for the Coxswain and the 2

navigators in the forward end of the wheelhouse, as these seats have the best access

to the computers and controls of the vessel. There is then a row of 3 seats behind

the starboard navigator’s chair, which is space for the remaining 3 crew. The

coxswain has an excellent view in all directions thanks to the 3 rooflights in the

wheelhouse and the large surrounding windows in the front and side of the

wheelhouse.

Page | 44

The bench seats on the port side also coincide with the navigation table of the

vessel. Located behind these seats is a dry locker that can be used for hanging up any

oilskins or waterproofs. This avoids dragging them through the wheelhouse. This

locker is ventilated to avoid condensation, dampness and also aid in the drying

process of the clothing.

Because of the manner in which the Engine Rooms roof had to be raised to maintain

sufficient free volume, there is a step in the wheelhouse. A small compromise has

arisen because of this. As can be seen in the drawings, the aftmost Jockey seat is

raised up on this level. Should the Client be unhappy with this arrangement, the

issue will be addressed.

The wheelhouse is ventilated as part of the Engine Room’s circuit, where the vents

are drawing a proportion of the air from the Engine Room inlet. This is then

circulated around the wheelhouse, and is drawn out through the locker at the aft end

of the wheelhouse.

Deck and Special Features

The most prominent feature of the vessel from some angles is the clearly visible

rescue zone of the vessel. This is located in such a place that the coxswain and

navigator will have an excellent view of the rescue operation. This is located as far

forward as possible in order to prevent the survivor from being sucked into the Jet

intake. It is a requirement of the LR SSC rules that a ladder be available that reaches

600mm below the DWL. This is achieved in the form of a rope ladder attached to a

frame and stored in a locker (visible in the drawings). This can be deployed when

needed.

At the aftmost end of the vessel, there is a small platform with ladders on either

side. The sole function of this platform is for boarding and disembarking from the

craft. The material for the plating is an aluminium grille, this reduces weight yet

provides strength for the platform.

Page | 45

Stability

Introduction

The stability of the vessel is designed to comply with the MGN280 guidelines [02], as

Lloyds Register does not have their own set of compliance rules. The software used

to analyse the stability of the vessel was Maxsurf Stability and a weights and centres

analysis had to be carried out in order to complete this as accurately as possible.

Weights and Centres

The weights and centres of the craft were analysed from the initial design of the

vessel, as it was necessary to depict a weight and initial displacement of the craft.

Throughout the design spiral this was constantly updated as more tasks were

completed and further developments were made into the design of the structures

and arrangement of the vessel to name but two examples. Shown below in Table 14

and Figure 10 is a summary of the weights and centres analysis carried out and the

distribution of the weight around the craft in terms of overall allocations (machinery,

structure etc) via a pie chart respectively. The full weights and centres analysis of

the vessel can be seen in Appendix 30.

Table 14: Summary of the weights and

centres analysis

Figure 10: Graphical representation of the

weight distribution around the vessel in 4

main categories

With regard to the weights and centres of the vessel, it should be noted that the fuel

tanks were located as close to the LCF of the vessel as possible. This was in order to

reduce the effect of the most variable load on the vessel in terms of how the vessel

would trim. The difference between 100% and 10% loadcases is only 0.0360. This

Page | 46

relates to the bow lifting another 5mm out of the water, with the stern sinking by

5mm. This is a minimal change in the trim of the vessel, with the considerable loss of

3100 litres of diesel as well as a several hundred kilograms of stores.

Calculations

An intact and damaged stability study was to be carried out at three load conditions

as defined below in Table 15. Consumables include the fuel, food and crew stores,

water and people on board.

Vessel Particulars Load Conditions

100% Consumables 50% Consumables 10% Consumables

Displacement [tonnes] 25.870 23.515 22.036

Draft at stern [metres] 1.024 1.015 0.991

Trim [degrees, +ve by

stern] 0.746 0.762 0.782

MCTC [tonne.metres] 0.463 0.452 0.442

LCF [metres, fwd of

transom] 6.626 6.610 6.617

Table 15: Definition of the three tested loadcases

Rule Compliance

The vessel will be operating in Operation Group G5 as set by LR SSC [64], which

translates to Category 1 by MGN280 thereby meeting with the initial criteria set by

the rule. Working through the weights and centres of the vessel, the weight was

distributed as it would be in the vessel structure and therefore the stability provides

an excellent analysis of how the vessel should perform in given loadcases.

The definition of a Category 1 vessel is that which will travel up to 350 nautical miles

from a safe haven port. The rule’s stability guidelines are mostly involved with

utilising the GZ.Area curve and the corresponding area underneath said curve for a

given angle of heel.

Page | 47

Shown in Table 16 below are the rule expectations for intact stability and the

vessel’s actual stability values for three loadcase conditions (10%, 50% and 100%

consumables) in accordance with the requirements of the rule.

MGN 280 Requirements 100%

Consumables

50%

Consumables

10%

Consumables

Area under curve up to

300 angle of heel

[metre.radians]

>0.055 0.135 0.132 0.134

Area under curve up to

400 angle of heel

[metre.radians]

>0.090 0.210 0.205 0.208

Area under curve

between 300 and 400

angle of heel

[metre.radians]

>0.030 0.075 0.072 0.074

Minimum GM value after

free surface corrections

[metres]

>0.350 1.600 1.621 1.654

Minimum GZ value

[metres] >0.200 0.781 0.786 0.813

Maximum GZ occurrence

angle [degrees] >250 45 45 45

Table 16: Table showing the compliance of the vessel with the MGN280 rules

As can be seen in Table 16, the vessel reaches and passes all of the appropriate

criteria for stability. It should be noted that the maximum GZ occurrence angle as

stated in the final row was capped at a 450 angle of heel as it is at this point that

deck edge immersion will occur. The vessel’s wheelhouse actually produces a higher

GZ value when the vessel is inverted, however this should be discounted due to the

fact that the vessel will never operate at this angle of heel (some 1300). Therefore it

was decided that the deck edge immersion would be an appropriate upper limit for a

region of upright stability.

Page | 48

Shown in Figure 11 (overleaf) is the corresponding GZ curve for the three defined

loadcases. The curve ranges from 00 through to 1800 angle of heel to starboard. As

can be seen, for all three curves, the vessel remains at a positive value of GZ.

This suggests that the vessel will be self righting and therefore have excellent

stability. The corresponding section view of the vessel heeled over with relation to

the waterline is shown at various angles of heel along the graph in Figure 12.

The reasoning for the vessel remaining at positive stability throughout the inversion

process is because of the large volume that the wheelhouse carries. The large volume

creates a huge amount of buoyancy that will cause the craft to become unstable

when inverted and thus self right. Although this is not a requirement of the Client, it

was felt that a vessel of this design duty should have the facility for self righting

should it be needed.

Page | 49

Figure 11: GZ curve of stability of the vessel Figure 12: Image representation

of the vessel at angles of heel

*Nota Bene: The Centre of Bouyancy (CB) and gravity (CF) of the vessel is shown in

the schematics in Figure 12 along with the fluid Centre of Gravity (CF Fluid)

Page | 50

Damage Stability

In terms of damage stability, there were again minimum and maximum values that

the vessel had to adhere to in order to meet with the classification of the rule. This

meant that the vessel was to be split into its respective compartments via the use of

bulkheads already applied to the design of the vessel. These compartments were

then individually damaged in the software package and the stability of the vessel was

analysed again with the compartments and subsequent tanks damaged.

It was detailed in the rule that the vessel should not trim or heel by more than 70

when a compartment is damaged. It was found that the compartment most

vulnerable to damage was the waterjet compartment at the aft of the vessel. This

resulted in a trim of 3.50 stern down which, as previously detailed, passes the rule

limitations. Another requirement was that the deck edge immersion occur at least

150 after the vessel has taken up an angle of trim or loll after being damaged. Again,

there is a minimum GM value that needs to be exceeded, and in the damaged case,

this is set at 0.1m. In the case where the vessel is damaged in the waterjet

compartment, this value is 0.15m, which again passes the rule guidelines.

The compartment permeability was set according to the code, where all

compartments and tanks were set at 95% permeability, whereas the machinery space

was set at 85%. It should be noted that these are only a guideline and that in reality,

the permeability of the rooms should be calculated by use of lost volume and further

analysed.

Appraisal

In summary, the vessel has been designed to meet and comply with the stability rules

and requirements of the MGN280, and has excelled at doing so, without any changes

needing to be made to the design throughout. It should be noted, however, because

of the vast amount of weight located aft of the vessel, then the vessel does actually

trim aft by around 0.750. However, this can easily be solved by placing some ballast

under the floor in the forward compartment in the form of lead ingots. This would

not be an issue, as currently the boat is under weight as can be seen in the weights

and centres spreadsheet in Appendix 30.

Page | 51

Critical Analysis of the Project

In this section, the project will be critically analysed and any thoughts as to what

may have been done differently and why will be discussed.

With respect to the overall design of the vessel, it is felt that a different hull shape

will benefit more from the use of a deflector than the current one. Although the

vessel is already very slender as compared to other similar craft, a more slender

design still would increase the effectiveness of the deflector. As well as a slender

hull shape, that of a longer hull would also be of much greater benefit than one of

only 17 metres.

The machinery installed onboard the ship is chosen because of its size, although the

Scania engine can be customised for waterjet applications, which suggests that it

should in fact be one of the most efficient. The waterjets installed on the vessel are

suited to the design, with the correct absorption power and size length. It could be

the case that the power requirement of the waterjet could drop closer to the 809kW

that the engine produces, however this may lead to maintenance issues for the

owner if the waterjets are on at close to threshold constantly. In the way of engine

room space, there could be more space built into the design by raising the deck of

the vessel up. This would mean that the deadrise angle would have to be much less

than the current 22.50.

The tank testing of the vessel could have produced more consistent results, as the

results were, on the whole, very scattered. Most likely this problem will have

stemmed from the fact that the model is of such a small size, doing relatively high

speeds. Therefore, if the model were of a larger scale, then higher forces would have

been measured, and thus more accurate results produced.

Page | 52

Conclusion

On the whole, the project was an insight into all the considerations that have to be

made when designing a vessel, whether it be commercial, pleasure, motor or sailing.

This provided the platform for the exploration of new technology and ideas that

could revolutionise the way in which vessels are designed.

Where the deflector was installed and designed, although the initial set up did not

provide the desired results, it is thought that with refining and changes made to the

design, the deflector can be a useful tool to be installed on a vessel in order to

reduce the vertical motions that affect the crew. However, this would not have been

achievable in the time frame set out, but work that could improve on the design can

continue to be done.

It should be noted that in order for the vessel to comply with the Lloyds SSC rules,

there needed to be much more testing completed. This included the testing of the

vessel in beam, stern and quartering seas. This would not have been achievable with

the facilities available.

The aim of the project was to comprehensively design the systems onboard, and it is

felt that all the considerations into the design of the systems have been fully taken

into account and detailed suitably throughout the report. Any choices that had to be

made have been justified.

Where the human design philosophy was a key part of the Client’s requirements, the

fact that there is a minimum height of over 1.9 metres in the open space of the

vessel is a huge bonus, as the crew should not have to worry about hitting their heads

on the ceiling when passing through the cabin or wheelhouse. This also helps to

create a large interior volume. The working of the vessel is also very ergonomic, with

large windows giving excellent all-round visibility in the wheelhouse and a well laid

out console for both the navigators and coxswain respectively. The location of the

berths is around amidships so as to keep the motion effects of the sea down to a

minimum.

In summary, it is believed that the vessel has been designed, tested and fitted out to

meet with all of the Client’s initial requirements and thus an efficient, well laid out

and aesthetic commercial vessel has been created.

Page | 53

References Aims and Objectives

[01] - Lloyds Register, Rules and Regulations for the Classification of Special Service Craft, Volume 3, July 2014 - Abbreviation Henceforth: LR SSC

[02] - MGN280 (M), Small Vessels in Commercial Use for Sport, Pleasure, Workboats and Pilot Boats, Part 11, Intact Stability, 2005

Research Undertaken and Design of the Vessel

[03] - Camarc Design - http://www.camarc.com/

[04] - MacDuff Ship Design, Naval Architects and Marine Consultants - http://www.macduffshipdesign.com/

[05] - Alusafe Workboats - http://maritime-partner.com/

[06] - Baltic Workboats Shipyard - http://www.balticworkboats.ee/

[07] - Marine Alutech - http://www.marinealutech.com/

[08] - Design and Development of the NH1816, J.E. Nieboer, RINA SURV 8 International Conference March 2013

[09] - Advanced Hull forms, Warship Technology, October 2014 [10] - Naviform Consulting and Research LTD

- http://www.naviform.com/ Area of Operation

[11] - Admiralty Chart 2724, North Channel and Firth of Lorn - http://www.gpsnauticalcharts.com/main/2724_0-north-channel-to-

the-firth-of-lorn-nautical-chart.html Structural Theory

[12] - LR SSC, Parts 5, Design and Load Criteria and Part 7, Hull construction in Aluminium

[13] - LR SSC, Part 7, Chapter 3, Section 3 [14] - LR SSC, Part 5, Chapter 3, Section 2 [15] - LR SSC, Part 5, Chapter 2, Section 5 [16] - LR SSC, Part 7, Chapter 3, Section 1 [17] - LR SSC, Part 2, Chapter 8, Section 1 [18] - The Elements of Boat Strength, Dave Gerr, 2000 [19] - LR SSC, Part 7, Chapter 5, Section 2 [20] - LR SSC, Part 3, Chapter 2, Section 4 [21] - LR SSC, Part 5, Chapter 2, Section 2 [22] - LR SSC, Part 3, Chapter 4, Section 7

Tank Testing

[23] - MonsterCAM Modelling - http://monstercam.co.uk/

[24] - SP Gurit, Ampreg 22, Epoxy Resin Laminte Matrix - http://www.gurit.com/ampreg-22-1.aspx

Page | 54

[25] - Kapci 2k High Finish Primer (625) - http://www.kapci.com/Products/CarRefinish/KAPCI/FillersSealers/tab

id/663/language/en-US/Default.aspx [26] - Weather Buoy Report (M2)

- http://www.met.ie/latest/buoy.asp [27] - Malin Marine Weather Forecast

- http://www.metoffice.gov.uk/public/weather/marine-shipping-forecast#malin

[28] - CODECOGS, Pierson and Moskowitz Wave Spectra, July 2014 - http://www.codecogs.com/library/engineering/fluid_mechanics/wave

s/spectra/pierson_moskowitz.php [29] - On The Structural Design of Planing Craft, S.R. Heller and N.H. Jasper,

1961 [30] - SensorKineticsPro iPhone Application [31] - ITTC – Recommended Procedures, Performance Prediction Method, 1999

- http://ittc.info/downloads/Archive%20of%20recommended%20procedures/2002%20Recommended%20Procedures/7.5-02-03-01.4.pdf

[32] - ITTC – Recommended Procedures, Testing and Extrapolation Methods, 2002 - http://ittc.info/downloads/Archive%20of%20recommended%20procedu

res/2002%20Recommended%20Procedures/7.5-02-03-01.1.pdf [33] - Acceleration of Blackout Point, Hyper Textbook, Glenn Elert, 2001

- http://hypertextbook.com/facts/1998/PhillipAndriyevsky.shtml [34] - LR SSC, Part 5, Chapter 1, Section 3

Machinery and Systems Installed Onboard

[35] - Scania DI-16076M - http://scania.com/_system/img/doc/engines/m/DI16076M_809kW.pdf

[36] - Rolls Royce Kamewa A3-36 - http://www.rolls-royce.com/~/media/Files/R/Rolls-

Royce/documents/customers/marine/waterjets.pdf [37] - Scania DI-16 manual, Scania Corportaion

- https://til.scania.com/idcplg?IdcService=GET_FILE&RevisionSelectionMethod=LatestReleased&Rendition=web&noSaveAs=1&dDocName=OPM_0000460_01

[38] - MTU M84L 8V2000 Data Sheet - https://mtu.cwshops.com/media/files_public/86e36f70ac0624c42131d

7257ba94613/3234091_MTU_Marine_spec_8V2000M84_L_1D.pdf [39] - ZF Marine 2050 Medium Duty Gearbox Datasheet

- http://marine.zf.com/matran/#/dataSheet/196 [40] - Benfiting from the New Kamewa Waterjet Designs, J. Adamsson and R.

Aartojärvi, Rolls Royce Marine, High Speed marine Vessels, 3rd March 2011 [41] - Spicer Compound Angle Vibration and Size Technical Article, Dana

Corporation, 2005 [42] - Boat Mechanical Systems Handbook, Dave Gerr, 2009 [43] - Scania Technical Data Issue, Marine Engines, DI-16

- http://www.scania.com.au/Images/Technical_Data_Issue_12_tcm51-411869.pdf

[44] - Delta “T” Systems 11inch Marine Axial Fan - http://www.deltatsystems.com/specs/Ignition_Protected_DC_Axial_F

ans.html [45] - Delta “T” Systems 9 inch Marine Axial Fan

- http://www.deltatsystems.com/specs/Ignition_Protected_DC_Axial_Fans.html

Page | 55

[46] - Munters DF2500 Mist Eliminator Datasheet - https://www.munters.com/globalassets/inriver/resources/products/

mist-eliminators/me_prodsheet_df2500.pdf [47] - Delta “T” Systems 15inch A/C Premium Axial Fans

- http://www.deltatsystems.com/specs/AC_Axial_Fans.html [48] - Paroc A60 Fireproof Aluminium Bulkhead Datasheet

- http://www.paroc.com/solutions-and-products/solutions/marine-and-offshore/a60-aluminium-bulkhead

[49] - Scania Technical Innovations, XPI Fuel injection, October 2007 - https://www.sae.org/ohmag/techinnovations/10-2007/11-15-7-6.pdf

[50] - Wasp-HPS-WP-10 Fuel Polisher Datasheet - http://www.wasp-pfs.com/products/w-pfs/w-pfs-010

[51] - IMO MARPOL Annex VI Tier I, II and III Regulation Datasheet - http://www.imo.org/en/OurWork/Environment/PollutionPrevention/A

irPollution/Pages/Nitrogen-oxides-(NOx)-%E2%80%93-Regulation-13.aspx

[52] - EU Stage IIIA Emission StandardDataSheet - https://www.dieselnet.com/standards/eu/nonroad.php

[53] - EPA Tier II Emission Standard Datasheet - https://www.epa.gov/sites/production/files/2016-

03/documents/420b16022.pdf [54] - MAN D2842 LE410 Datasheet

- http://www.manrollo.com/wp-content/uploads/D2842-medium-duty.pdf

[55] - MTU 12v2000 M70 Datasheet - http://www.transdiesel.com/app_docs/MTU%2012V&16V2000M70.pdf

[56] - UltraJet 525 Datasheet - http://www.marinejetpower.com/assets/upload/files/1508%20MJP%2

0Ultrajet%20525_web.pdf [57] - HamJet HM461 Datasheet

- http://www.hamjet.co.nz/global/hm-series General Arrangement

[58] - LR SSC, Part 3, Chapter 5, Sections 2-6 [59] - Eno Marine Open Sea Cooker

- http://service.eno-marine.fr/categorie.php?id=MjQ= [60] - Penguin Frigo, Vitrifrigo C40L

- http://www.penguinfrigo.co.uk/shop/product/405/ [61] - Lee Sanitation, LeeSan LS40 Stainless Steel Toilet

- http://www.leesan.com/index.asp?m=3&cat1=4&cat2=168&p=329&t=LeeSan+LS40%2C+12v+DC

[62] - Penguin Engineering LTD, D180 Shower - http://www.penguineng.com/TapsShowers/Showers-

StraightShowerHandles/D180PenguinTap.php [63] - Ullyman Dynamics Webpage, Biscaya Jockey Seats

- http://ullmandynamics.com/suspension-seats/jockey-seats/jockey-seat-biscaya

Stability

[64] - LR SSC, Part 1, Chapter 2, Section 3

Page | 56

Appendices Section

Appendix 1: Acceleration formula used in the calculation of the impact pressure

Appendix 2: Limiting coefficients in accordance to the panel/stiffener fixity type

Page | 57

Appendix 3 - Laminate Log for the building of the model

Hit Number Work Completed Problems Discovered Resolutions Image Representation of

Work

Prep

Model brushed to remove any excess glass bubbles from the surface. Model laminated with 120gm-2 satin weave woven roving Fibre cut to shape of the bottom, top sides and transom with a 10mm overlap allowance Ampreg 22 [24] resin matrix mixed with a 25:7 ratio

There was some damage to the model, with knicks on the transom and aft part of the keel The bow section was damaged where the polystyrene foam bubble size was too large to fit with the curvature The topsides bow section had not been cut, where the curvature was too complex for the machine.

Knicks presented no significant problem as the area would be glassed over Bow section would be artificially shaped using foam moulded blocs to shape the laminate The topside bow’s lack of shape was manually shaped using a pen knife

1

Bottom sides laminated with two layers of the fibre cloth Layer of Resin laid down first to ensure good bond between the fibre and the model Fibre overlapped at the keel join where the underbody shape was consistent Forward of this, fibre clamped together at the centreline join Fibre allowed to drape over chine in order to create a join with the topsides in ‘Hit 2’

Where the keel was clamped together, the fibre hadn’t bonded closely enough to the model shape. This left areas of open laminate that would need to be resolved There was a large bubble in the laminate in the forward section of the bow

Epoxy would be ran over the laminate join edge and then sanded down to rejoin to the edge and match the curvature shape The bubble in the laminate was to be cut out, and the area left would be filled with filler and then correspondingly shaped to match the curvature of the hull.

2

Previous day’s laminate overlap trimmed to match the extremities of the model Topsides laminated with two layers of fibre cloth Layer of resin laid down to ensure good bond between the model and fibre Fibre draped over chine edge to create join Bow section clamped Bow ledge cut and overlapped for the bow section Tow post attachment plate (12mm wood board) glued into the recessed hull with epoxy mixed with glass bubbles to thicken the mixture

Bubble formed in topside laminate No action taken

3

Previous Hit’s laminate trimmed to model Transom to be laminated Layer of resin laid down to ensure good bond 2 layers of cloth laminated Keel at the bow also glued at this stage as previously discussed (Hit 1)

No significant problems No action required

Page | 58

Hit Number Work Completed Problems Discovered Resolutions Image Representation of

Work

4 6 coats of Kapci 2k high finish primer [25] added, thus creating a smooth surface after a mixture of wet and dry sanding

No significant problems No action required

5

Model’s deflector glued onto the model using epoxy resin matrix and filleted to the model to ensure there would be a smooth runoff of water both on top, and underneath the deflector Deflector covered with epoxy to ensure no damage and because the primer is corrosive to the polystyrene and the foam deflector

The deflector was damaged in the application of the glue

Damages filled and faired using epoxy resin with glass bubbles

6

6 coats of Kapci 2k high finish primer added, thus creating a smooth surface after a mixture of wet and dry sanding

Some of the bottom Kapci Primer had been damaged in the gluing of the deflector.

Kapci was reapplied to these problem areas and subsequently sanded down to match in with the surrounding finish

Page | 59

Appendices 4-7 – Screenshots of Excel tables and results calculated for the testing without and with the deflector respectively

Appendix 4: Model scale results without the deflector

Appendix 5: Model scale results with the deflector

Appendix 6: Full scale results without the deflector Appendix 7: Full scale results with the deflector

Page | 60

Appendix 8:

Accelerations measured

for Run 1

Wave Condition 1 at

2.00ms-1 without the

deflector

Appendix 9:

Accelerations measured

for Run 2

Wave Condition 1 at

2.71ms-1 without the

deflector

Appendix 10:

Accelerations measured

for Run 3

Wave Condition 2 at

1.00ms-1 without the

deflector

Page | 61

Appendix 11:

Accelerations measured

for Run 4

Wave Condition 2 at

1.00ms-1 without the

deflector

Appendix 12:

Accelerations measured

for Run 5

Wave Condition 2 at

0.50ms-1 without the

deflector

Appendix 13:

Accelerations measured

for Run 6

Wave Condition 1 at

3.20ms-1 without the

deflector

Appendix 14:

Accelerations measured

for Run 7

Wave Condition 1 at

1.62ms-1 without the

deflector

Page | 62

Appendix 15:

Accelerations measured

for Run 8

Wave Condition 1 at

2.00ms-1 with the

deflector

Appendix 16:

Accelerations measured

for Run 9

Wave Condition 1 at

2.71ms-1 with the

deflector

Appendix 17:

Accelerations measured

for Run 10

Wave Condition 1 at

1.81ms-1 with the

deflector

Appendix 18:

Accelerations measured

for Run 11

Wave Condition 2 at

1.00ms-1 with the

deflector

Page | 63

Appendix 19:

Accelerations measured

for Run 12

Wave Condition 2 at

1.00ms-1 with the

deflector

Appendix 20:

Accelerations measured

for Run 14

Wave Condition 2 at

0.50ms-1 with the

deflector

Appendix 21:

Accelerations measured

for Run 15

Wave Condition 1 at

1.62ms-1 with the

deflector

Appendix 22:

Accelerations measured

for Run 16

Wave Condition 1 at

2.23ms-1 with the

deflector

Page | 64

Appendix 23:

Accelerations measured

for Run 17

Wave Condition 1 at

1.42ms-1 with the

deflector

Appendix 24:

Accelerations measured

for Run 18

Wave Condition 2 at

1.00ms-1 with the

deflector

Appendix 25:

Accelerations measured

for Run 19

Wave Condition 3 at

0.50ms-1 with the

deflector

Appendix 26:

Accelerations measured

for Run 20

Wave Condition 3 at

1.00ms-1 with the

deflector

Page | 65

Appendix 27: Full measurement of all acceleration data

Page | 66

Appendix 28 – Weights and Centres Analysis Spreadsheet

LCG +ve from stern fwd [mm]

VCG +ve from DWL up [mm]

Displacement [kg]

6660.8 478.8 25870.0

Part Abbreviation UnitsAluminium Temper

and GradeExtrusion Type

Plate Thickness and Extrusion Dimensions

[mm]

Individual Unit Weight [kg]

LCG +ve from stern fwd [mm]

VCG +ve from DWL up [mm]

Total Line Weight [kg]

Longitudinal Moment [kg.mm]

Vertical Moment [kg.mm]

Bottom Shell HB-P 2 5083 - H111 Plate 10 825.5 7711.3 -473.7 1651 12731356.3 -782078.7Topsides Shell HTS-P 2 5083 - H111 Plate 10 684.5 8226 734.4 1369 11261394 1005393.6

Chine HC-P 2 5083 - H111 Plate 16 25.3 6293.3 -40.4 50.6 318440.98 -2044.24Deflector DEF-P 2 5083 - H111 Plate 12 150.0 14813 220.4 300 4443900 66120

Wheelhouse WH-P 2 5083 - H111 Plate 6 554.4 5426.3 2822.12 1108.8 6016681.44 3129166.656

Transom HT-P 1 5083 - H111 Plate 18 300.0 16558.9 417.6 300 4967670 125280Line Totals 8314.7 741.1 4779.4 39739442.7 3541837.3

Weather Deck and Wheelhouse WD-P 1 5083 - H111 Plate 6 518.5 7206 1468.4 518.5 3736311 761365.4Main Cabin and Saloon CBN-FLR 1 5083 - H111 Plate 6 168.9 9532.4 -520 168.9 1610022.36 -87828

Machinery Floor ER-FLR 1 5083 - H111 Plate 6 85.0 4760 -312.3 85 404600 -26545.5Line Totals 7445.5 837.6 772.4 5750933.4 646991.9

Ring Frame 790 RF-00790 1 6082 - T6 Ring frame (with flange) 180X8/90X11 61.8 790.0 209.9 61.8 48822 12971.82Rng Frame 1745 RF-01745 1 6082 - T6 Ring frame (with flange) 180X8/90X11 62.0 1745.0 204.8 62 108190 12697.6Ring Frame 2455 RF-02455 1 6082 - T6 Ring frame (with flange) 180X8/90X11 62.1 2455.0 204.5 62.1 152455.5 12699.45Ring Frame 4205 RF-04205 1 6082 - T6 Ring frame (with flange) 180X8/90X11 48.3 4205.0 229 48.3 203101.5 11060.7Ring Frame 5255 RF-05255 1 6082 - T6 Ring frame (with flange) 180X8/90X11 48.2 5255.0 231 48.2 253291 11134.2Ring Frame 7355 RF-07355 1 6082 - T6 Ring frame (with flange) 180X8/90X11 51.4 7355.0 463.4 51.4 378047 23818.76Ring Frame 8405 RF-08405 1 6082 - T6 Ring frame (with flange) 180X8/90X11 37.9 8405.0 400.1 37.9 318549.5 15163.79Ring Frame 9455 RF-09455 1 6082 - T6 Ring frame (with flange) 180X8/90X11 36.7 9455.0 420.6 36.7 346998.5 15436.02

Ring Frame 11555 RF-11555 1 6082 - T6 Ring frame (with flange) 180X8/90X11 31.7 11555.0 483.8 31.7 366293.5 15336.46Ring Frame 12605 RF-12605 1 6082 - T6 Ring frame (with flange) 180X8/90X11 28.0 12605.0 515.6 28 352940 14436.8Ring Frame 14705 RF-14705 1 6082 - T6 Ring frame (with flange) 180X8/90X11 19.5 14705.0 604.7 19.5 286747.5 11791.65Ring Frame 15755 RF-15755 1 6082 - T6 Ring frame (with flange) 180X8/90X11 15.8 15755.0 593 15.8 248929 9369.4

Wheelhouse Ring Frame 5255 RF-05255 1 6082 - T6 Ring frame (with flange) 120x8/40x10 38.3 5255.0 1831.2 38.3 201266.5 70134.96Wheelhouse Ring Frame 7355 RF-07355 1 6082 - T6 Ring frame (with flange) 120x8/40x10 38.3 7355.0 1831.2 38.3 281696.5 70134.96Wheelhouse Ring Frame 8405 RF-08405 1 6082 - T6 Ring frame (with flange) 120x8/40x10 37.4 8405.0 1832.1 37.4 314347 68520.54

Wheelhouse Ring Frame 9455 RF-09455 1 6082 - T6 Ring frame (with flange) 120x8/40x10 34.8 9455.0 1793.3 34.8 329034 62406.84Line Totals 6425.5 670.2 652.2 4190709.0 437114.0

Bulkhead 3155 BH-03155 1 5083 - H111 Plate 10 208.4 5000.0 480 208.4 1042000 100032Bulkhead 6305 BH-06305 1 5083 - H111 Plate 10 206.8 12000.0 483.1 206.8 2481600 99905.08

Bulkhead 10505 BH-10505 1 5083 - H111 Plate 10 175.9 25625.0 518.2 175.9 4507437.5 91151.38

Bulkhead 13655 BH-13655 1 5083 - H111 Plate 10 107.7 34000.0 570.4 107.7 3661800 61432.08Line Totals 16732.7 504.5 698.8 11692837.5 352520.5

Central Keel Girder HB-CKG-0000 1 6082 - T6 Plate 15 277.3 8687.5 -760.8 277.3 2409043.75 -210969.84Engine Girder 550 HB-EG-0550 2 6082 - T6 Plate (with flange) 14/70x12 209.4 4086.6 -244.5 418.8 1711468.08 -102396.6

Engine Girder 1450 HB-EG-1450 2 6082 - T6 Plate (with flange) 14/70x12 126.5 4086.6 -59.8 253 1033909.8 -15129.4Wheelhouse Roof Main Girder 450 WHR-MG-0450 2 6082 - T6 Tee 50x6/50x6 18.6 7125.5 3397.4 37.2 265068.6 126383.28

Wheelhouse Roof Main Girder 1015 WHR-MG-1015 2 6082 - T6 Tee 50x6/50x6 13.5 7082.3 3489.4 27 191222.1 94213.8Line Totals 5537.1 -106.5 1013.3 5610712.3 -107898.8

Summary of Weights and Centres Analysis

Plat

ing

Bulk

head

sFr

ames

Prim

ary

Stiff

ener

sFl

oors

Machinery and Tankage

Consumables

Fixtures and Allowances

Structure

Weight Distribution

Page | 67

Part Abbreviation UnitsAluminium Temper

and GradeExtrusion Type

Plate Thickness and Extrusion Dimensions

[mm]

Individual Unit Weight [kg]

LCG +ve from stern fwd [mm]

VCG +ve from DWL up [mm]

Total Line Weight [kg]

Longitudinal Moment [kg.mm]

Vertical Moment [kg.mm]

Hull Bottom Flat Bar 400 HB-FB-0400 2 6082 - T6 Flat bar 80x8 26.1 8270.3 -716 52.2 431709.66 -37375.2Hull Bottom Flat Bar 705 HB-FB-0705 2 6082 - T6 Flat bar 80x8 26.1 8274 -518 52.2 431902.8 -27039.6

Hull Bottom Flat Bar 1010 HB-FB-1010 2 6082 - T6 Flat bar 80x8 26.1 8280.9 -446.4 52.2 432262.98 -23302.08Hull Bottom Flat Bar 1315 HB-FB-1315 2 6082 - T6 Flat bar 80x8 26.2 8290.7 -310.4 52.4 434432.68 -16264.96Hull Bottom Flat Bar 1620 HB-FB-1620 2 6082 - T6 Flat bar 80x8 27.5 7949.7 -176.8 55 437233.5 -9724Hull Bottom Flat Bar 1925 HB-FB-1925 2 6082 - T6 Flat bar 80x8 27.6 7964.9 -39.5 55.2 439662.48 -2180.4

Deflector Girder 0000 DEF-LG-0000 1 6082 - T6 Plate 8 15.0 15200 225.1 15 228000 3376.5Deflector Girder 0350 DEF-LG-0350 2 6082 - T6 Plate 8 10.0 14856 219.7 20 297120 4394Deflector Girder 0700 DEF-LG-0700 2 6082 - T6 Plate 8 7.5 14705 216.8 15 220575 3252Deflector Girder 1050 DEF-LG-1050 2 6082 - T6 Plate 8 2.5 14223 210.4 5 71115 1052

Hull Topsides Flat Bar 295 HTS-FB-0295 2 6082 - T6 Flat bar 80x8 27.7 7981.2 293.7 55.4 442158.48 16270.98Hull Topsides Flat Bar 565 HTS-FB-0565 2 6082 - T6 Flat bar 80x8 27.7 7948.5 564.5 55.4 440346.9 31273.3Hull Topsides Flat Bar 835 HTS-FB-0835 2 6082 - T6 Flat bar 80x8 27.7 7988.3 834.8 55.4 442551.82 46247.92

Hull Topsides Flat Bar 1100 HTS-FB-1100 2 6082 - T6 Flat bar 80x8 27.7 7992.4 1104.6 55.4 442778.96 61194.84Weather Deck Flat Bar 0000 WD-FB-0000 1 6082 - T6 Flat bar 80x8 27.3 7910.3 1428.7 27.3 215951.19 39003.51Weather Deck Flat Bar 0250 WD-FB-0250 2 6082 - T6 Flat bar 60x8 27.3 7910.3 1428.7 54.6 431902.38 78007.02Weather Deck Flat Bar 0500 WD-FB-0500 2 6082 - T6 Flat bar 60x8 27.3 7910.3 1428.7 54.6 431902.38 78007.02Weather Deck Flat Bar 0750 WD-FB-0750 2 6082 - T6 Flat bar 60x8 25.4 7384.2 1428.7 50.8 375117.36 72577.96Weather Deck Flat Bar 1000 WD-FB-1000 2 6082 - T6 Flat bar 60x8 25.4 7384.2 1428.7 50.8 375117.36 72577.96Weather Deck Flat Bar 1250 WD-FB-1250 2 6082 - T6 Flat bar 60x8 23.6 7258.1 1428.7 47.2 342582.32 67434.64Weather Deck Flat Bar 1500 WD-FB-1500 2 6082 - T6 Flat bar 60x8 21.8 6332 1428.7 43.6 276075.2 62291.32Weather Deck Flat Bar 1750 WD-FB-1750 2 6082 - T6 Flat bar 60x8 20.0 5806 1428.7 40 232240 57148Weather Deck Flat Bar 2000 WD-FB-2000 2 6082 - T6 Flat bar 60x8 18.2 5280 1428.7 36.4 192192 52004.68

Wheelhouse Side Flat Bar 1880 WHS-FB-1880 2 6082 - T6 Flat bar 30x6 2.9 5901 1880 5.8 34225.8 10904Wheelhouse Side Flat Bar 2280 WHS-FB-2280 2 6082 - T6 Flat bar 30x6 2.9 5901 2280 5.8 34225.8 13224Wheelhouse Side Flat Bar 2680 WHS-FB-2680 2 6082 - T6 Flat bar 30x6 2.9 5901 2680 5.8 34225.8 15544Wheelhouse Side Flat Bar 3710 WHS-FB-3710 2 6082 - T6 Flat bar 30x6 2.9 5901 3710 5.8 34225.8 21518Wheelhouse Roof Flat Bar 450 WHR-FB-0450 2 6082 - T6 Flat bar 30x6 2.9 5482.6 3990.8 5.8 31799.08 23146.64

Wheelhouse Roof Flat Bar 1315 WHR-FB-1315 2 6082 - T6 Flat bar 30x6 2.9 5482.4 3990.8 5.8 31797.92 23146.64Line Totals 7979.0 712.1 1035.9 8265430.7 737710.7

Part Line Weight [kg]Weld Allowance

Weight [kg]LCG +ve from stern

fwd [mm]VCG +ve from DWL up [mm]

Longitudinal Moment [kg.mm]

Vertical Moment [kg.mm]

Plating 4779.4 802.9 8314.7 741.1 6676226.4 595028.7Floors 772.4 129.8 7445.5 837.6 966156.8 108694.6

Frames 652.2 109.6 6425.5 670.2 704039.1 73435.1Bulkheads 698.8 117.4 16732.7 504.5 1964396.7 59223.5

Primary Stiffeners 1013.3 170.2 5537.1 -106.5 942599.7 -18127.0Secondary Stiffeners 1035.9 174.0 7979.0 712.1 1388592.3 123935.4

Line Totals 1503.9 8406.0 626.5 12642011.0 942190.3

Part Line Weight [kg] Units Total Weight [kg]LCG +ve from stern fwd

[mm]VCG +ve from DWL up

[mm]Longitudinal

Moment [kg.mm]Vertical Moment

[kg.mm]

Engine 1660 2 3320 4990.0 53.0 16566800.0 175960.0Gearbox 342 2 684 4150.0 20.0 2838600.0 13680.0Waterjet 770 2 1540 1230.0 -240.0 1894200.0 -369600.0

Fuel Tanks 1770 2 3540 6948.0 435.0 24595920.0 1539900.0Fresh Water Tank 400 1 400 9600.0 -600.0 3840000.0 -240000.0Grey Water Tank 450 1 450 7800.0 -600.0 3510000.0 -270000.0

Allowance for Fixtures and Piping 600 1 600 4500.0 100.0 2700000.0 60000.0Line Totals 10534 5310.9 86.4 55945520.0 909940.0

Food Stores 100 1 100 0.0 0.0 0.0 0.0Crew Stores 200 1 200 0.0 0.0 0.0 0.0Bed Stores 20 1 20 0.0 0.0 0.0 0.0

Above Deck Stowage 800 1 800 0.0 0.0 0.0 0.0Crew 85 6 510 7031.2 2910.9 3585912.0 1484559.0

Survivors 85 4 340 4297.8 3000.0 1461252.0 1020000.0Line Totals 1970 2562.0 1271.3 5047164.0 2504559.0

Jockey Seats 21 6 126 7031.2 2010.0 885931.2 253260.0Bench Seating 30 2 60 4297.3 2180.0 257838.0 130800.0

Radar 50 1 50 3927.5 4330.2 196375.0 216510.0Galley 300 1 300 10816.0 250.0 3244800.0 75000.0

Furniture Outfit Below Deck 400 1 400 11492.0 50.0 4596800.0 20000.0Head and WC 200 1 200 8619.0 -23.0 1723800.0 -4600.0

Glass Windows 550 1 550 7255.9 3146.8 3990745.0 1730740.0Additional Allowance for Overbuild

and miscellaneous weight1224.1 1 1224.1 6971.9 0.0 8534302.8 0.0

Line Totals 2910.1 8051.5 832.2 23430592.0 2421710.0

Mac

hine

ry a

nd

Tank

age

Cons

umab

les

Fixt

ures

and

Allo

wan

ceW

eld

Allo

wan

ceSe

cond

ary

Stiff

ener

s

Page | 68

Visual Representations

This section aims to give the reader a better interpretation of what the design of the

project looks like and portrays the boat in the form of renders from the Rhinoceros

3D modelling programme.

Plate 1: Exterior view of the vessel, looking from the bow aft

Plate 2: Exterior view of the vessel, in profile view

Page | 69

Plate 3: Exterior view of the vessel, looking down on the rook in profile/plan

Plate 4: Exterior view of the vessel, looking from the stern forward

Page | 70

Plate 5: Interior view of the wheelhouse layout

Plate 6: How the boat sat in the water, viewed from the bow aft

Page | 71

Plate 7: How the boat sat in the water, viewed from the stern forward

Plate 8: Representation of how the ballast weights were distributed around the hull

DWL

BL-3BL-4BL-5BL-6BL-7BL-8BL-9BL-10

WL-1WL-2WL-3WL-4

WL-5

WL-6

BL-1BL-2

BL-3

BL-4

BL-5

BL-6

BL-7

BL-8

BL-9

BL-1

0

BL-1

BL-2

012345679AP FP8

Technical Particulars

Measurement Value Units

Length Waterline 16.90 metres

Length Overall 17.60 metres

Beam Waterline 4.25 metres

Beam Overall 5.66 metres

Draft 0.96 metres

Displacement 25870 kilograms

Volumetric Displacement 25.24 metres³

Longitudinal Centre of Floatation 41.38 % forward of stern

Longitudinal Centre of Gravity 41.00 % forward of stern

Length Beam Ratio 3.97 n/a

Slenderness Ratio 5.75 n/a

Righting Moment @ 1° 1021.98 kilogram.metre

Grid Particulars

Station (Number) Offset from AP [m] Buttock Line (BL) Offset from CL [m] Waterline (WL) Offset from DWL [m]

FP 16.850 BL-1 0.207 WL-1 -0.800

0 16.400 BL-2 0.414 WL-2 -0.600

1 15.165 BL-3 0.621 WL-3 -0.400

2 13.480 BL-4 0.828 WL-4 -0.200

3 11.795 BL-5 1.035 DWL 0.000

4 10.110 BL-6 1.242 WL-5 0.600

5 8.425 BL-7 1.449 WL-6 1.200

6 6.740 BL-8 1.656

7 5.055 BL-9 1.863

8 3.370 BL-10 2.070

9 1.685

AP 0.000

REVISION TABLE

Editon Revision Date Subject Revised

22 01/10/2015 Chine Edited23 04/10/2015 Chine Edited24 08/10/2015 Forefoot Lowered25 15/10/2015 Hull lines changed

26 28/10/2015 Drawing Finalised

Drawing title: Lines Plan

Drawing number: 001Edition: 26

Issue date: 28/10/2015

Drawn by: ADPM

Scale: 1:70

Units: mm

Page Number: 72

250

250

250

250

250

250

250

250

250

250

250

250

250

250

3160 3160 4210 3160WATERJET COMPARTMENT ENGINE ROOM COMPARTMENT MAIN CABIN GALLEY / SALOON FORWARD STOWAGE / ANCHOR LOCKER

400

305

305

305

305

305

400

305

305

305

900

900

AP 1 2 3 4 5 6 7 10 11 12 13 14 15 16

790 825 840 700 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050

FP

1160

RF-0

0790

RF-0

1615

RF-0

2455

BH

-03155

RF-0

4205

RF-0

5255

BH

-06305

RF-0

7355

RF-0

8405

RF-0

9455

BH

-10505

RF-1

1555

RF-1

2605

BH

-13655

RF-1

4705

RF-1

5755

3250

HB-FB-1925

WD-FB-2000

WD-FB-1750

WD-FB-1500

WD-FB-1250

WD-FB-1000

WD-FB-0750

WD-FB-0500

WD-FB-0250250

250

550

550

HB-FB-0705

HB-FB-1010

HB-FB-1315

HB-FB-1620

HB-FB-1925

HB-FB-0400

WD-FB-2000

WD-FB-1750

WD-FB-1500

WD-FB-1250

WD-FB-1000

WD-FB-0750

WD-FB-0500

WD-FB-0250WD-FB-0000

HB-CKG-0000

HB-EG-0550

HB-EG-1450

CL

CL

CL

CL

* DEFLECTOR STRUCTURAL DETAIL NOT INCLUDED FOR CLARITY.SEE DRAWING 005

Structural General Arrangement, Plan View

305

305

HB-FB-0705

HB-FB-1010

HB-FB-1315

HB-FB-1620

HB-FB-0400

MS8

1050

REVISION TABLE

Editon Revision Date Subject Revised

2 26/11/2015 General Update

3 20/01/2016 General Update

4 19/03/2016 Drawing Finalised

DRAWING KEYDenotes stringers start and end

DRAWING LEGEND

Reference Code Reference Component Description

HB-FB-XXXX 80x8 Flat Bar in the Hull Bottom with offset from CLHB-CKG-XXXX Central Keel Girder in the Hull Bottom with offset from CLHB-EG-XXXX 80x8 Engine Bed Girder in the Hull Bottom with offset from CL

WD-FB-XXXX 60x8 Flat Bar in the Weather Deck with offset from CLRF/BH-XXXXX Denotes Ring Frame (RF) or Bulkhead (BH) with offset from AP

Drawing title: Structural Layout, Plan View

Drawing number: 002Edition: 4

Issue date: 19/03/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 73

285

285

285

HTS-FB-0835

HTS-FB-1100

HTS-FB-0565

HTS-FB-0295

HTS-EG-0095

HTS-CKG- -585

3160 3160 4210 3160WATERJET COMPARTMENT ENGINE ROOM COMPARTMENT MAIN CABIN GALLEY / SALOON FORWARD STOWAGE / ANCHOR LOCKER

3250

* WHEELHOUSE STRUCTURAL DETAIL NOT INCLUDED FOR CLARITY.SEE DRAWING 006

DWL

DWL

RF-0

0790

RF-0

1615

RF-0

2455

BH

-03155

RF-0

4205

RF-0

5255

BH

-06305

RF-0

7355

RF-0

8405

RF-0

9455

BH

-10505

RF-1

1555

RF-1

2605

BH

-13655

RF-1

4705

RF-1

5755

DWL

DWL

Structural General Arrangement, Profile View

AP 1 2 3 4 5 6 7 MS8 10 11 12 13 14 15 16

790 825 840 700 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050 1050

FP

1160

REVISION TABLE

Editon Revision Date Subject Revised

1 28/10/2015 Initial Outlay

2 20/01/2016 General Update

3 19/03/2016 Drawing Finalised

DRAWING KEYDenotes stringers start and end

DRAWING LEGEND

Reference Code Reference Component Description

HTS-FB-XXXX 80x8 Flat Bar in the Hull Topsides with offset from DWL

HTS-CKG-XXXX Central Keel Girder in the Hull Topsides with offset from DWL

HTS-EG-XXXX Engine Bed Girder in the Hull Topsides with offset from DWLRF/BH-XXXXX Denotes Ring Frame (RF) or Bulkhead (BH) with offset from AP

Drawing title: Structural Layout, ProfileView

Drawing number: 003Edition: 3

Issue date: 19/03/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 74

WHS-FB-3710

WHS-FB-1880

WHS-FB-2280

WHS-FB-2680

WHR-FB-1315

WHR-MG-1015

WHR-MG-0450

WHR-FB-0000

WHR-FB-1315

WHR-MG-1015

WHR-MG-0450

AP 1 2 3 4 5 6 7 10 11 12

790 955 710 700 1050 1050 1050 1050 1050 1050 1050 1050

Wheelhouse Structural General Arrangement, Plan and Profile View

MS8

1050

REVISION TABLE

Editon Revision Date Subject Revised

2 08/01/2016 Change of Layout

3 25/02/2016 General Update

4 19/03/2016 Drawing Finalised

DRAWING KEYDenotes stringers start and end

DRAWING LEGEND

Reference Code Reference Component Description

WHS-FB-XXXX 30x6 Flat Bar in the Wheelhouse Sides with offset from DWLWHR-FB-XXXX 30x6 Flat Bar in the Wheelhouse Roof with offset from CLWHR-MG-XXXX Main Girders in the Wheelhouse Roof with offset from CLRF/BH-XXXXX Denotes Ring Frame (RF) or Bulkhead (BH) with offset from AP

Wheelhouse Structural General Arrangement RF-05255 Detail, Body Plan View

WHS-FB-1880

WH

R-F

B-1

315

WH

R-M

G-1

015

WH

R-M

G-0

450

WH

R-F

B-0

000

WHS-FB-2280

WHS-FB-2680

WHS-FB-3710

WH

R-F

B-1

315

WH

R-M

G-1

015

WH

R-M

G-0

450

Scale 1:35

Wheelhouse Stiffener and Cutout Detail Scale 1:3

Plate RepresentationLine

WHR/WHS-FB-XXXX WHR-MG-XXXX

Drawing title: Wheelhouse StructuralDesign

Drawing number: 006Edition: 4

Issue date: 19/03/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 77

008-C

DRAWING LEGEND

Code Definition008-A Inlet Louvre Grill008-B Delta-T LIL' Champ 11" Fan (Inlet)

008-C Delta-T LIL' Champ 9" Fan (Inlet)

008-D Outlet Louvre Grill008-E Delta-T A/C Axial 15" Fan (Outlet)

REVISION TABLE

Editon Revision Date Subject Revised

1 05/01/2016 Drawing Outlay

2 22/01/2016 Ventilation Requirement up

3 30/03/2016 Drawing Finalised

Drawing title: Representation of theVentilation Design

Drawing number: 008Edition: 3

Issue date: 02/04/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 79

DRAWING LEGEND

Code Definition009-A Dry Riser

009-B Wet Exhaust009-C Water Injection Point

009-D Sea Cock009-E Mechanical Sea Water Pump

REVISION TABLE

Editon Revision Date Subject Revised

1 05/01/2016 Drawing Outlay

2 22/01/2016 Headroom Increased3 04/04/2016 Drawing Finalised

DRAWING LEGEND CONT.009-F Heat Exchanger

Drawing title: Representation Cooling andExhaust Design

Drawing number: 009Edition: 3

Issue date: 04/04/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 80

011-A

011-A

011-E

011-B

011-B 011-C011-C

011-C

011-D

011-D

011-D

DRAWING LEGEND

Code Definition008-A Engine Room Door

008-B Engine Room Hatch

008-C Jet Compartment Door

008-D Jet Compartment Hatch

008-E Wheelhouse Main Door

REVISION TABLE

Editon Revision Date Subject Revised

1 05/01/2016 Drawing Outlay

2 22/01/2016 General Update

3 30/03/2016 Drawing Finalised

Drawing title: Access To and Egress Fromthe Machinery Spaces

Drawing number: 011Edition: 3

Issue date: 02/04/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 82

4240

EXTERIOR GENERAL ARRANGEMENT, BODY PLAN VIEW

956

INTERIOR GENERAL ARRANGEMENT, BODY PLAN VIEW

956

4100

REVISION TABLE

Editon Revision Date Subject Revised

1 21/02/2016 Drawing Outlay

2 02/03/2016 General Update

3 20/03/2016 General Update

4 26/03/2016 Drawing Finalised

Drawing number: 013

Issue date: 26/03/2016

Drawn by: ADPM

Edition: 4

Units: mm

Scale: 1:50 Drawing title: GeneralArrangement, Section View

Page Number: 84

EXTERIOR GENERAL ARRANGEMENT PROFILE VIEW AND WHEELHOUSE GENERAL ARRANGEMENT PLAN VIEW

RESCUEZONE

CL CL

VESSEL PARTICULARS

Length Overall 17.60 metresLength Waterline 16.90 metres

Beam Overall 5.66 metresBeam Waterline 4.24 metres

Draft 0.96 metresDisplacement 25870 kilograms

REVISION TABLE

Editon Revision Date Subject Revised

1 05/01/2016 Drawing Outlay

2 20/01/2016 General Update

3 02/02/2016 Stairs to Below Deck Move4 21/02/2016 Rescue Zone Move

5 02/04/2016 Drawing Finalised

Drawing title: Exterior GeneralArrangement

Drawing number: 014Edition: 5

Issue date: 02/04/2016

Drawn by: ADPM

Scale: 1:50

Units: mm

Page Number: 85