westhaven marina proposed pile berth redevelopment ... · may use the area. harbour bridge traffic...
TRANSCRIPT
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Westhaven Marina Proposed Pile Berth
Redevelopment Navigation Safety Report
Capt. Jim Dilley, Master Mariner
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Contents INTRODUCTION ....................................................................................................................................... 3
EXECUTIVE SUMMARY ............................................................................................................................ 5
EXISTING SITUATION ............................................................................................................................... 5
Western Entrance/Exit ........................................................................................................................ 5
Navigation at the entrance ............................................................................................................. 6
Area outside the entrance .............................................................................................................. 7
Other traffic .................................................................................................................................... 8
Harbour bridge traffic ..................................................................................................................... 8
Race starts ....................................................................................................................................... 9
Risk assessment .............................................................................................................................. 9
Berthing ......................................................................................................................................... 10
Eastern Entrance/Exit ....................................................................................................................... 10
Navigation at the entrance ........................................................................................................... 11
Pile Moorings .................................................................................................................................... 12
Marina Fairways and Traffic Hubs .................................................................................................... 12
PROPOSED SITUATION .......................................................................................................................... 14
Construction ...................................................................................................................................... 14
Marina Berths ................................................................................................................................... 15
Closure of Western Entrance ............................................................................................................ 15
Vessels affected ............................................................................................................................ 15
Berthing ......................................................................................................................................... 16
Marina fairways and traffic hubs .................................................................................................. 16
Oil spills ......................................................................................................................................... 17
Start box ........................................................................................................................................ 17
CONCLUSION ......................................................................................................................................... 18
Recommendations ............................................................................................................................ 18
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INTRODUCTION
This report discusses potential navigation safety implications that could arise from the
construction and subsequent operation of the redevelopment of Westhaven
Marina, hereafter referred to as the Application. The Application includes an
extension for the western breakwater to connect to the eastern breakwater to
provide public open space and parking. The public open space has been
designed in conjunction with local iwi. The proposal also includes the conversion of
existing pile moorings to pontoon berthage. (see Fig. 1 and the Westhaven Marina
Proposed Occupation Area Fig. 2).
Figure 1. Proposed re-development: Breakwater extension Pontoon berths
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Figure 2. Westhaven Marina Occupation Area
The term navigation safety refers to the safety of a vessel or vessels interacting with:
another vessel or vessels; the seabed; a structure; a natural object, such as rock or
the foreshore; or any combination of the above. As such, as soon as one vessel is
operating in an area, there will be navigation safety issues. Navigation safety issues
may be minimized or reduced to an acceptable level, but cannot be completely
resolved if vessels are operating in an area. Navigational Safety Management is the
system of criteria, standards and competence that maintain the ability of a vessel or
craft to navigate safely in confined waters such as are found in harbour areas. The
most recent occupation permit has addressed this matter to an extent by
delineation a vessel transit area (refer Fig. 2)
The New Zealand Port and Harbour Safety Code (the Code) was introduced in 2004.
The Code brings together a succinct digest of the formal duties and responsibilities
of participants in port and harbour safety and a corresponding statement of the
specific measures appropriate to their fulfilment. A critical component of the Code is
safety management systems based on risk assessment. The Code has been adopted
by the Auckland Council and a Code Application Assessment, Risk Assessment and
Safety Management System has been developed. The assessments and Safety
Management System have been approved by Maritime New Zealand and are
under continual review and audit. The Safety Management System sets out how the
Auckland Council, through the Harbourmaster, manages the safety of navigation.
The risk assessments assist in identifying where possible risk may exist and how control
measures may help in the mitigation of a risk. The Auckland Region Risk Assessment
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and its annual review (the Risk Assessment) (excluding the operation of shipping to
POAL wharves and the operation of RNZN vessels and berths) is undertaken by the
Harbourmaster. Navigation safety issues in the Waitemata Harbour are part of this
Risk Assessment.
EXECUTIVE SUMMARY
The proposed re-development has built on existing good practice and international
standards to provide a practical and effective use of existing space. The increase in
the safety of navigation both within the marina, and in the area immediately to the
north of the marina, is evident.
The only possible adverse effects are a small time inconvenience to some of the
vessels that use the western entrance, and a small percentage increase in traffic
volume at the eastern entrance.
Overall, the proposal provides an appreciable increase in the safety of navigation in
the area and provides for manageable and accessible berthing of vessels. The
possible effects of any construction and ongoing maintenance and dredging work
are easily managed in line with current good practice.
I recommend the movement of the Start Box to the east as suggested in the
proposal.
EXISTING SITUATION
At present, vessels may enter or leave Westhaven Marina through one of two
entrances, the western and eastern entrances (Figs. 3 and 5).
Western Entrance/Exit
The western entrance/exit (hereafter western entrance) is approximately 60 m wide1
(see Fig. 3). On either side of the gap are rock breakwaters, which extend at an
angle underwater thus, reducing the effective width of the channel. The wider
western breakwater has a gangway for access to marina berths on pier A extending
at an angle2 (see Fig. 3). The fairway in the marina adjacent to this entrance is
approximately 60 m wide. The entrance is marked by aids to navigation on both
sides (lights: Oc.G.5m5M and Oc.R.5m5M). There is a tidal flow during the flood tide
through the entrance of approximately 0.2 m/s (0.4 knots).2 Outside the entrance the
flood tide flows west and the ebb tide flows east, at approximately 2 knots.3 There is
1 Proposed Westhaven Pile Berth Redevelopment (Stage 1) Design Report. Beca Ltd 5 August 2015, Fig 1. 2 Ibid., p.10. 3 Chart NZ5323
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an extreme significant wave height through the western entrance of 0.95 m.4 to the
west of the entrance is an area of shallow water (<5 m) marked by a red buoy (see
Fig. 4).
The western entrance provides a route for vessels in the marina navigating to, and
from, destinations to the west in the upper harbour and the start line for yacht races,
which is shorter than using the eastern entrance. Vessels may also use this entrance
to navigate to, and from, areas to the east (the Hauraki Gulf). This is likely to be the
vessels berthed immediately adjacent to the entrance i.e. only the vessels in the
berths of row A and the western pile moorings in the 100 series berths have a shorter
distance to travel using this route rather than the eastern entrance. Once outside
the western entrance, vessels are restricted to a speed of 5 knots within 200 m of the
shore and to 12 knots in the harbour. This speed restriction means that vessels
traveling outside the marina are unlikely to reach a point opposite the eastern
entrance any faster than vessels travelling in fairways within the marina.
Navigation at the entrance
Vessels departing the marina through the western entrance must alter course in the
entrance to avoid the gangway to pier A (see Fig. 3). This line of approach means
that departing vessels may not see vessels entering the marina until level with the
start of pier A (see Fig. 3). Vessels entering the marina through the western entrance
must also alter course in the entrance to avoid the gangway to pier A. Once inside
the marina, vessels navigate between pier A on the right and a line of vessels in pile
moorings to the left. This line of approach means that vessels entering the marina
here may not see vessels departing the marina until level with the start of pier A. In
general, the best practice for passing through a narrow channel is to navigate in a
straight line. This allows vessels to line up an approach to the entrance with a clear
line of sight. Vessels are then able to see other traffic that may be using the
entrance and also are able to judge the effect of tide on the vessel before passing
through the narrow gap. Being forced to make a course adjustment in a narrow
channel introduces more potential for mistakes to be made. In addition, the tidal
flow (0.4 knots) and wave heights (0.95 m)1 will at times cause vessels to have
difficulty in negotiating this entrance.
4 Ibid.
7
Figure 3. Western entrance showing passage route in and out on same scale as
figure 5.
Area outside the entrance
Vessels departing the marina through the western entrance emerge into an area of
the Waitemata Harbour approximately 600 m from the Harbour Bridge and 150 m
from the start box for yacht races. The start box is currently situated on the
breakwater between rows C and D (see Fig. 4). This area is subject to strong tides
flowing perpendicular to vessels departing the entrance (the flood tide flows west
and the ebb tide flows east, at approximately 2 knots4).
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Figure 4. Race start box area Start box Harbour Bridge precautionary area
Other traffic
Other vessels in this area include vessels transiting under the Auckland Harbour
Bridge (Harbour Bridge), including bulk carrier ships navigating to and from Chelsea
Wharf, naval vessels navigating to and from Kauri Point Wharf, scheduled ferries
navigating to and from West Harbour, Northcote Point, Birkenhead, Hobsonville and
Beach Haven, superyachts, charter vessels and various recreational craft; yachts
heading toward or positioning at the start line for yacht races (opposite the start
box); seaplanes; and various other small commercial and recreational craft that
may use the area.
Harbour bridge traffic
In particular, vessels exiting the marina at the western entrance come into conflict
with vessels navigating in the vicinity of the Harbour Bridge that may be constrained
because of their draft or air draft. Large vessels, such as ships, superyachts and
ferries can only pass under the bridge between the two northern-most supports (this
corresponds to the highest point of the bridge). This means that large vessels are
navigating to approach a gap of approximately 300 m wide (compared with the
total bridge span that is approximately 980 m wide).
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The centre span of the bridge is 45 m above chart datum. This reduces to 43 m at 76
m either side of centre. Vessels transiting the bridge must have a minimum
clearance of 1 m at the 76 m off centre point. If the clearance is less than 3 m Transit
NZ must be contacted to ensure there is no staging, hosing, or scaffolding under the
centre span. Transits can only be conducted in daylight and all vessels over 80 m in
length must have one tug made fast. A precautionary area surrounds the Harbour
Bridge in which no vessel may impede the passage of a vessel under pilotage, a
warship, a passenger ferry or a vessel over 500 gross tonnes. Shown in magenta on
charts NZ5323 (see Fig. 4) and NZ5322. The western entrance is approximately 150 m
from the start of the precautionary area (see Fig. 4). Thus, vessels using the western
entrance heading west are almost immediately in the precautionary area and in
potential conflict with large vessels restricted in their approach to the Harbour
Bridge.
Race starts
The site of the start box determines the start line, which is approximately 150 m from
the western entrance. Thus, vessels using the western entrance emerge into an area
in which yachts are positioning at the start line during yacht races. Racing yachts
prior to the race start are usually performing many short manoeuvres in a confined
space in an attempt to get to a desired position for the start. This results in many
yachts on different, unpredictable courses, which can cause confusion, especially
for non-racing vessels, resulting in the potential for collisions.
The start line is approximately 200–300 m from the Harbour Bridge. This results in
potential conflict between racing yachts and other vessels navigating in the vicinity
of the Harbour Bridge, particularly commercial ships and ferries. In addition, the
close proximity of the bridge has resulted in racing yachts colliding with the bridge
structure.
Risk assessment
The Auckland Council has a risk assessment matrix for the Auckland region, including
the Waitemata Harbour. This matrix assesses the frequency of an incident occurring
and the consequence if it were to occur. The Auckland Regional Council’s Annual
Risk Assessment Review 20145 for Waitemata ferry operations (Birkenhead to
Westhaven Marina) identifies risks, including risks associated with a commercial ferry
colliding with a recreational vessel, a recreational vessel colliding with another
recreational vessel, a recreational vessel contacting the Harbour Bridge and a
collision as the result of a vessel encountering a yacht race.
5 Auckland Regional Council’s Annual Risk Assessment Review 2014.
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Berthing
The narrow western entrance creates an increased tidal flow [at flood tide of
approximately 0.2 m/s (0.4 knots)].6 This tidal flow can create problems for vessels
mooring or berthing in the area. Tidal flows can cause vessels to speed up, slow
down or push vessels sideways depending on the speed and direction of the flow.
For vessels manoeuvring in a confined space when berthing, external influences
such as tide, and also wind, make it difficult to accurately judge the vessel’s relative
position and speed, which is needed to be able to place the vessel in the berth
without hitting adjacent objects (e.g. other vessels, piles, marina structure).
Eastern Entrance/Exit
The eastern entrance/exit (hereafter eastern entrance) is approximately 270 m wide
(see Fig. 5). On the western side is a rock breakwater and to the east is Wynyard
Quarter and various berthing structures on the western edge of Wynyard Quarter.
The fairway on the marina side of this entrance varies from approximately 130–270 m
wide. The entrance has aids to navigation on both sides (lights: Fl.G.5s5m5M and
Oc.R.6s5m5M). In addition, there is a light on the southern end of the breakwater
around the marina (Oc.G.6s3m). The entrance has a tidal flow during the flood tide
of approximately 0.15 m/s (0.3 knots).6
The eastern entrance is used by most vessels in the marina navigating to, and
from, areas to the east (the Hauraki Gulf), including commercial vessels at Z pier, as
well as vessels from the Silo Park, Orams and Pier 21 marinas and haul out facilities,
the Orams dry stack facility (small boats under 12 m), the dry dock and the refuelling
facility. These vessels include superyachts and other larger vessels using the slipway
and superyacht berths. In addition, there is a proposal to bring the Kiapara Carrier II,
an aggregate carrier of 563 gross tonnes, to a berth within the eastern entrance,
with up to four movements per week. Larger vessels, including the Kaipara Carrier II
and superyachts, will either have a licensed pilot or licenced pilot-exempt master on
board who and will be operating in accordance with the Auckland Council
Harbourmaster guidelines.
With strict guidelines around the operation of large vessels, and a licensed pilot or
pilot exempt master onboard, the movement of these vessel is extremely well
conducted and managed in line with best practice through Auckland Councils
Safety Management System.
Vessel masters may also choose to use this entrance to navigate from the marina to
the west: the upper harbour and the race start line, as this entrance is easier to
negotiate than the western entrance.
6 Proposed Westhaven Pile Berth Redevelopment (Stage 1) Design Report. Beca Ltd 5 August 2015, p.10 and Fig. 2.
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Vessels departing the marina through the eastern entrance emerge into an area of
the Waitemata Harbour approximately 1.2 km (0.6 nm) from the Harbour Bridge.
Other vessels in this area include vessels navigating in the vicinity of the Auckland
Harbour Bridge (Harbour Bridge), including bulk carrier ships navigating to and from
the Chelsea Wharf, naval vessels navigating to and from the Kauri Point Wharf,
scheduled ferries navigating to and from West Harbour, Northcote Point, Birkenhead,
Hobsonville and Beach Haven, superyachts, charter vessels and various recreational
craft; seaplanes; various other small commercial and recreational craft; vessels
approaching the marina, including commercial vessels heading to Z pier, vessels
going to the Silo Park, Orams and Pier 21 marinas and haul out facilities, the Orams
dry stack facility (small boats under 12 m), the dry dock and the refuelling facility.
The greater distance from the Harbour Bridge means vessels departing via this
entrance are less likely to come into conflict with vessels navigating in the vicinity of
the Harbour Bridge than vessels departing from the western entrance.
Navigation at the entrance
Vessels using the eastern entrance pass thorough a wide area with good visibility
(Fig. 5). The width enables a good separation of vessels, even with more than two
vessels in the entrance. A straight line approach to the entrance is possible (in both
directions) ensuring good visibility and with no risks associated with manoeuvring in a
narrow channel.
While the entrance is undoubtly busy at times the width of navigable water,
together with the recently granted Westhaven Marina occupation permit which
identifies a delineated vessel transiting area (see Fig. 2), help manage potential
conflicts between commercial and recreational vessels.
Figure 5. Eastern entrance showing passage route in and out on same scale as figure
3.
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Pile Moorings
There is space for approximately 100 vessels to berth in pile moorings in two rows
inside the marina to the east of the western entrance. The narrow western entrance
creates an increased tidal flow [at flood tide of approximately 0.2 m/s (0.4 knots)].6
This tidal flow can create problems for vessels berthing in the area. Mooring to pile
moorings is particularly difficult as pile moorings do not have pontoons so can be
more difficult to tie up to compared with berths alongside pontoons.
Mooring to a pile mooring requires placing the vessel in a position to pick up four
lines attached to four piles. The vessel is not held in a stable position until all four of
these lines are attached. Any cross tidal flow will make approaching the piles, and
holding the vessel in position while the lines are attached, more difficult.
Marina Fairways and Traffic Hubs
Maritime rule No. 22.9 applies to vessels in a narrow channel and states that ‘A vessel
proceeding along the course of a narrow channel or fairway must keep as near to
the outer limit of the channel or fairway which lies on its starboard side as is safe and
practicable’. Vessels leaving the marina depart from a berth or mooring, move to
the starboard of the channel and then must join the starboard side of the main
fairway, which has a width that varies from approximately 20–80 m. Vessels then turn
at points A (to exit via the western entrance) or B (to exit via the eastern entrance or
access areas to the south e.g. the fuel berth). The areas where any pier or row of
moorings joins the main fairway will have converging and diverging traffic, but the
two main areas where traffic converges and diverges from multiple directions are at
hubs A and B as shown in Fig. 5 These two areas have navigation safety implications
arising from the flow of traffic and the need for collision avoidance.
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Figure 6. Existing areas of traffic convergence/divergence
Hub A is approximately 2800 m2. At hub A, any vessels using the western entrance
and vessels in berths rows A to U using either entrance will converge (see Fig. 7). As
can be seen in Fig. 7, there are multiple points where vessels may cross the line of
another vessel due to the constrained size of the area and obstructions to clear
views caused by the moored vessels. Thus, there is an increased risk of collision at this
point.
Figure 7. Traffic convergence/divergence at hub A for western entrance
Hub B is approximately 7800 m2. At hub B, vessels using the eastern entrance will
converge (see Fig. 8). There are likely to be more vessels navigating at hub B than
hub A. However, it can be seen in Fig. 8 that traffic flow is clearer here, compared
with hub A. and there are less points where the paths of vessels may cross. In
addition hub B is substantially larger than hub A, allowing for more room and better
visibility for navigating vessels. The recently granted occupation permit (see Fig. 2)
manages potential conflicts between commercial and recreational vessels),
providing a delineated vessel transiting area.
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Figure 8. Traffic convergence/divergence at hub B for eastern entrance
PROPOSED SITUATION
The Application includes an extension for the western breakwater to connect to the
eastern breakwater to provide public open space and parking. The public open
space has been designed in conjunction with local iwi. The proposal also includes
the conversion of existing pile moorings to pontoon berthage (see Fig. 1). The new
berths will be built according to Australian Standard AS3962-2001. This in compliance
with best practice in relation to the layout of the piers, marina berths and the access
channels and is used throughout NZ marinas. The access channel between pier A
and the new marina berths will be approximately 40 m, in line with other access
channels in the marina.
Navigation safety implications may arise from the bridging (closing) of the western
entrance, the presence of marina berths where pile moorings are currently located
and the construction of the marina.
Construction
The proposed marina breakwater extension will be formed using dredged material
from the marina using a dredge mounted on a barge. Dredging will be carried out
under an existing maintenance dredging consent held by Westhaven Marina.
Any additional navigation safety issues arising during the construction of the
breakwater and the new marina berths should be similar to the existing issues that
arise during current dredging. In these cases a dredger and associated traffic are
operating within the marina, effectively blocking access ways and restricting access
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to some parts of the marina. There are no reported incidents involving navigational
safety issues with the current dredging or maintenance operations undertaken at
the marina over many years.
These issues should be easily addressed with a Notice to Mariners and, if necessary,
suitable signage to make marina users aware of the issue e.g. dredging and
construction operations.
Marina Berths
The new facilities will cater for approximately 117 new marina berths replacing
space for approximately 125 pile moorings, a slight decrease in vessels using the
space. Some pile moorings will still be available in the marina. Marina berths, with a
pontoon facility, are more user friendly compared with pile moorings, offering with
walk-on, walk-off access and easier berthing. In general, marina berths are more
likely to be used than pile moorings and are a more efficient use of space.
With a pontoon berth, a vessel master has several options for holding the vessel
stable while berthing. The vessel can be brought alongside the berth and a crew
member step off onto the pontoon to hold the vessel or once one spring line has
been picked up, the vessel can steam ahead on the spring to hold position while
the rest of the lines are secured. Alongside the pontoon the vessel can be secured
with only two lines. A cross tide or wind may be helpful in some cases if berthing can
be timed so that the tide is pushing the vessel onto the pontoon when arriving and
off the pontoon when departing.
When entering or departing from a pile mooring a vessel is not held in a secure
position until at least both head line and both stern lines are secure. Further to this
there is no pontoon or similar structure to assist the master in remaining in the correct
position. Pile moorings require a higher level of competence from the vessel master
and are more susceptible to issues with cross tide or wind.
Closure of Western Entrance
Vessels affected
Closing the western entrance will mainly affect vessels in the marina navigating to,
and from, destinations in the upper harbour and the start line for yacht races. These
vessels will have to navigate approximately an extra 0.6 nm to reach a position
opposite the start box going through the eastern entrance. This distance would be
slightly less for vessels that may ‘cut the corner’ of the eastern entrance. This
translates to approximately an extra 7 min travel time (for a vessel traveling at 5
knots). If the start box were to be moved to a position located on the new extension
(shown as X in Fig. 9) as has been proposed, this time reduces to an extra 5 min of
travel.
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Figure 9. Current start box location proposed location
Berthing
Closure of the western entrance will result in a decrease in tidal flow at the entrance
from approximately 0.2 to 0.03 m/s (0.4 to 0.06 knots)6. This will result in a decrease in
cross tide at the berths (whether pile or marina berths) situated where the pile
moorings are currently. The extreme significant wave height will be 0.3 m in the
marina down from 0.95 m previously at the eastern entrance7. Thus, closing this
entrance will make berthing or mooring in the vicinity easier.
Marina fairways and traffic hubs
Traffic at hub A will now only be navigating in two clear directions (see Fig. 10). Like
all pontoon fairways there will be vessels navigating to their berths in each pontoon,
but the volume of traffic will be small and will exclude all vessels that previously
navigated to or from the western entrance. Closing the western entrance will result
in a reduction of risk of collision at point A as traffic will now only be going in two
clear directions on either side of the channel as shown in Fig. 10. This will result in less
confusion at this fairly narrow point and provide a positive effect on the safety of
navigation.
7 Ibid.
17
Figure 10.Main traffic flow at hub A with western entrance closed.
With the closure of the western entrance the traffic volume at the eastern entrance
will increase. There will be an increase in traffic at hub B as all vessels will now transit
this area. However, this area is large, already has traffic coming from the direction of
the marina and the traffic flow is relatively clear — the only crossing situation is with
vessels returning to berths to the south of the entrance to the rows of marina berths
e.g. vessels at Z pier or vessels heading to the refuelling facility (see Fig. 8). Any
increase in traffic at the entrance or hub B caused by the closure of the western
entrance is likely to be small in comparison to the normal traffic volume using the
area. Thus, an Increase in traffic at these points is not expected to present any
appreciable navigation safety issues.
Existing issues with potential conflicts between commercial and recreational vessels
at this entrance have been already identified and the risks mitigated, and clear
access further enhanced with the recently granted occupation permit (see Fig. 2),
which provides a delineated vessel transiting area. Vessels entering or departing
Westhaven Marina are required to use the area to the western side of the entrance
as shown in Fig. 2. This provides a clear channel for the use of commercial traffic and
other recreational traffic not berthed in Westhaven Marina.
Oil spills
In an oil spill, one entrance will be easier to manage than two. This means that it will
be easier to protect the marina from an external spill and easier to contain an
internal spill from within the marina.
Start box
Closing the western entrance will allow the start box for yacht races to be moved to
a position on the eastern breakwater as the breakwater will then accessible (see Fig.
18
9). This relocation will result in a reduced distance for yachts in the marina to travel
to the start line. Therefore yachts will only have to travel approximately an extra five
minutes to reach the start line exiting through the eastern entrance compared with
exiting through the western entrance. The start line will be moved further away from
the Harbour Bridge. Moving the start line will reduce potential conflict between
racing yachts and vessels transiting under the Harbour Bridge, including bulk carrier
ships navigating to and from the Chelsea Wharf, naval vessels navigating to and
from the Kauri Point Wharf, scheduled ferries navigating to and from West Harbour,
Northcote Point, Birkenhead, Hobsonville and Beach Haven, superyachts, charter
vessels and various recreational craft. Moving the start line away from the bridge will
also reduce the risk of racing yachts colliding with the bridge structure.
CONCLUSION
The proposal to close the western entrance to Westhaven Marina and to redevelop
existing pile mooring areas to pontoon berths appears to increase the level of
navigational safety in most aspects, and provide safer and more easily accessed
and convenient berthing for vessels. The proposal also removes a traffic hub from
the inner part of the marina where vessels may not be expecting large numbers of
vessels crossing a narrow fairway in an area with restricted sight lines.
Furthermore, the proposal also improves the level of navigation safety to the harbour
area north of the western entrance by allowing the repositioning of the yacht race
start box, and removing the flow of vessels entering into the harbour area by the
Harbour Bridge. Both of these will reduce congestion and vessel numbers in the
confined and restricted area of the Harbour Bridge.
There will be an increase in traffic volume at the eastern entrance and the traffic
hub at that area. This will have a slightly negative effect on navigational safety, but
the size of the area, low percentage increase in the traffic volume, clear sight lines,
well-defined fairway areas and the delineated vessel transiting area means we are
unlikely to see any negative impact.
Overall, the proposal provides an appreciable increase in the safety of navigation in
the area and provides for manageable and accessible berthing of vessels. The
possible effects of any construction and ongoing maintenance and dredging work
are easily managed in line with current good practice.
Recommendations
I recommend the Start Box is moved towards the east as indicated in figure 9.