advance trend in boat design

IBEX 2013 SESSION 102 Advanced Trends in Powerboat Hull Design

Page 1

Robert Kaidy - Naval Architect

OCEAN5 NAVAL ARCHITECTS

Robert S. Kaidy Naval Architect & CEO

360 NW ALICE AVE., STUART, FL 34994

O: 772-692-8551 E: [email protected]

www.ocean5inc.com


Page 2



Presentation Goals

Introduce New & Innovative Hull Forms

Identify Strengths and Weaknesses of Each Type

Define Major Design and Build Issues for Each Type


Page 3



TABLE OF CONTENTS

1) Introduction

2) Special Bow Types

a) Axe Bow

b) X Bow

c) Very Slender Vessel

3) Trimarans / Wave Piercing Cats

4) Conclusions

A-1 References

Note that Axe Bow, X-Bow, Very Slender Vessel

and other terms used in this paper, are and may

be trademarked and owned by others. This is an

academic paper, and not meant to advertise,

usurpe or otherwise infringe on the intellectual

property rights of the respective owners. Refer to

the owners of such rights for more information

regarding licensing or other usage.


Page 4



1.0 INTRODUCTION

Whats Old is New Again

Solving Old Problems.Seakeeping


Page 5



1.0 INTRODUCTION

With Old and New Solutions &

Applications

New Ways of Looking at Old

Problems


Page 6



1.0 INTRODUCTION

Concepts

Fundamental Concept :

Reduce Seakeeping Accelerations


Page 7



1.0 INTRODUCTION

Concepts

Fundamental Concept :

Added Power in Waves


Page 8



2.0 Special Bow Types

ULSTEIN

DAMEN

2.1 General Description

2.2 Example Vessels

2.3 Pro/Con

2.4 Limits

2.5 Design & Build Issues

Overview.


Page 9



2.1 Special Bow Types - General

Type: Fast Displacement Monohull & Planing Hull Forms

Speed: 25 50 knots Typical

Description: Small Waterplane Area Bow Sections achieved using:

Extremely Narrow Beam, Extremely High Deadrise Forward Sections

Above and Below Waterline. May also include Patented Hogged Keel Shape.

May include plumb stem, or aft raking stem May include unique topsides/deck shapes

Trade Names / Alias: Axe Bow (Damen) X-Bow (Ulstein) Wave Piercing Hull Slender Vessel

ULSTEIN

DAMEN


Page 10




Description Three Main Varieties : Patented Axe Bow Damen

Extended Bow Portion Extreme Narrow Beam Extreme Deadrise Plumb Bow Stem Hogged Keel

X-Bow Type Ulstein Extreme Narrow Bow Below Waterline Narrow Waterplane Reverse Stem Minimal Flare at Bow Sagged Keel Rounded Topsides

Slender Vessel USMI & Others Extreme Narrow Beam Bow Long/Extended Bow Portion No Flare / Round Topsides Conventional Prismatic Stern for Planing

ULSTEIN

DAMEN


Page 11




Description Three Main Varieties : Patented Axe Bow Damen

Extended Bow Portion Extreme Narrow Beam Extreme Deadrise Plumb Bow Stem Hogged Keel

DAMEN


Page 12




Axe Bow


Page 13



2.2 Special Bow Types Example Vessels

Sea Axe Type Feadship SY M/Y PREDATOR

DAMEN Fn = 2.3

Fn = 1.8


Page 14




Description Three Main Varieties : X-Bow Type Ulstein

Extreme Narrow Bow Below Waterline Narrow Waterplane Reverse Stem Minimal Flare at Bow Sagged Keel Rounded Topsides Conventional Hull Bottom

Fn = 0.82


Page 15




X-Bow


Page 16




X-Bow


Page 17




X-Bow


Page 18




Blohm & Voss 118M M/Y SIGMA, Philip Starck Design

Fn = 1.16


Page 19




Description Three Main Varieties : Slender Vessel US Marine

Extreme Narrow Beam Bow Long/Extended Bow Portion No Flare / Rounded Topsides Conventional Prismatic Stern for Planing

Fn = 7.2


Page 20




Very Slender Vessel:


Page 21




Fn = 5.00


Page 22



2.3 Special Bow Types Pros and Cons

Advantages Challenges

Improved Seakeeping Reduced Interior Volume (or 20% more length

for equiv. volume)

Reduced Vertical Accelerations in

Seaway (Aft Accommodations) Bow Anchor Handling Difficult or Impossible

Reduced Slamming Bow Line Handling Difficult or Impossible

Reduced Resistance in Seaway Potential Directionally Unstable without Control

Systems / Broaching

Proprietary (some) / Licensed Proprietary (some) / Patented

Weather Deck Wetting

Impaired Helm Visibility

Displacement Sensitive


Page 23





Page 24





Page 25



2.4 Special Bow Types - Limits

Special Bow Types Requires Substantial Additional Length for Same Hull Volume to

Achieve Advantage

High Speeds exacerbate Control Issues

Bow Operations Difficult


Page 26



2.5 Special Bow Types Design and Build Issues

Design Issues: Extended Length

Reduced Beam

Roll Stability / Period

Arrangements

Aesthetics

Proprietary/Patents

Directional Control

Helm Visibility

Build Issues: Extremely Narrow Bow Sections

Access for Welding

Access for Inspection

Rigging Routing

Special Bow Types Simplified Shapes

X Bow Much more complex Shapes


Page 27



3.0 Trimarans

3.1 General Description

3.2 Example Vessels

3.3 Pro/Con

3.4 Limits

3.5 Design & Build Issues


Page 28



3.1 Trimarans - General

Type: High Length to Beam Ratio

Main Hull

Small Outrigger Hulls

Speed: 5 40 knots Typical, 1-4 Fn

Description: Small Waterplane

Area Center

Hull

Outrigger Hulls Provide

Roll Stiffness

May include plumb stem, or

aft raking stem


Page 29



3.2 Trimarans Example Vessels

Fn = 2.0+


Page 30




Fn = 3.38


Page 31




Fn = 1.96


Page 32




Fn

2.68

2.44

1.96

1.92

1.74

1.37


Page 33



3.3 Trimarans Pros and Cons

Advantages Challenges

Improved Seakeeping Reduced Interior Volume

Reduced Vertical Accelerations in Seaway (Aft

Accommodations) Bow Anchor Handling Difficult or Impossible

Reduced Slamming Bow Line Handling Difficult or Impossible

Reduced Resistance in Seaway Directionally Unstable without Control Systems

Proprietary (some) / Licensed Proprietary (some) / Patented

Weather Deck Wetting

Impaired Helm Visibility

Displacement Sensitive

Cross Beam Slamming / Tunnel Top Slamming

Weight / LCG Sensitive


Page 34



3.4 Trimarans Design and Build Issues

Design Issues Build Issues

Weight Sensitive Extremely Narrow

Forebody

Structure Critical Weight Critical

Sponsons Highly Loaded

/ Cross Beams

Cross Beam

Fabrication/Structural

Continuity

Narrow Hulls in Way of

Arrangements

Deck Operations

Visibility and Height


Page 35



4.0 CONCLUSIONS

New Hull Forms Focused on Improved Seakeeping.

Three General Types of Bow Form Innovations.

Several Bow Forms proprietary.

Bow Forms appear to reduce accelerations in some seastates

Bow Forms appear to reduce resistance in some seastates

Trimarans reduce accelerations in seaway and reduce resistance in seaway

Interior volume of new hull forms significantly reduced

Construction Complexity and cost increased

Visibility can be significantly reduced in seaway

Bow Main Deck Operations limited


Page 36



Appendix A-1 REFERENCE

1. SNAME, TR No. R-42, SEAKEEPING OF HARD CHINE PLANING HULLS, SAVITSKY &

KOELBEL, JUNE 1993

2. MARINE TECHNOLOGY, VOL. 13 NO. 4, PROCEDURES FOR HYDRODYNAMIC

EVALUATION OF PLANING HULLS IN SMOOTH AND ROUGH WATER, SAVITSKY &

BROWN, OCT 1976, PP. 381-400

3. 19TH INTERNATIONAL HISWA SYMPOSIUM ON YACHT DESIGN AND YACHT

CONSTRUCTION, THE AXE BOW: THE SHAPE OF SHIPS TO COME, GELLING, 13 & 14

NOVEMBER 2006, AMSTERDAM

4.

5.

6.

7.

advance trend in boat design

Documents

powerboat hull design

kaidy naval architect

advanced trends

type ibex

major design

axe bow b x

seakeeping ibex

waves ibex