MARICO Marine NZ Limited WELLINGTON HARBOUR PORT AND ...

Report No: 05NZ104 WELLINGTON HARBOUR
Issue: Issue 1.1 Operational Risk Assessment
Rank No.
Hazard Reference
18 47
Affected
Areas
Main Harbour,
Lambton
Harbour
Accident
Category
Contact
Berthing
Hazard
Title
Vessel in
Contact
Berthing
Hazard
Detail
Large vessel
such cruise
vessel, car
carrier,
container or
general cargo
ship in contact
berthing with
wharf or
container
cranes in
restricted
visibility,
strong
onshore
winds,
berthing in
very strong
wind
conditions.
Affected Vessel
Types
Vessel
>500GT, All
Vessels
Affected
Stakeholders
Seafarers,
Vessel
Interests,
Wellington
Regional
Council,
CentrePort
Possible
Causes
(1) Misjudged speed or angle in cross
wind approach. Misjudged approach plan
and ship does not turn down wind due to
wind pressure and tugs or thruster unable
to control vessel. Low power -
displacement to windage ratio, downwind
approach too fast. Blackout on ship at
critical time, wind loading on ships hull
too high for bollard pull of available tugs
to check momentum. Tugs incapable of
regaining control. Tug operational failure
or towline breakage. Not using anchor/s.
(2) In a stern board, pilot misjudges due
to steep angle of approach, with stern tug
unable to lift off, engine fails to fire ahead
and lack of clear visibility aft, and no
closing information from lines crews,
vessel makes heavy contact with the
vessel's quarter. (3) Disregards SOPs for
berthing in restricted visibility. (4)
misjudges roundup point or vessel
refuses to put bow into the wind when
berthing head to wind. (5)Container
cranes not clear of berth. (6) Thruster
failure when berthing with one tug. (7)
Attempting to berth with only one tug (8)
Pilot inexperience for ship type. (9)
attempting to berth in adverse weather
with minimum berthing clearances.
Consequence Descriptions
Most Likely
(ML)
Minor damage to
plating of hull and
wharf fendering
system.
Worst Credible
(WC)
Risk By
Consequence
Category
M L W C
Greater Wellington Regional Council /
CentrePort Ltd Page E12 of E41
People
Property
Environment
Stakeholders
People
Property
Environment
Stakeholders
Risk Overall
Serious damage to hull
plating and wharf.
Wharf piles damaged
and container cranes
unable to be traversed
past damage, berth out 0 6 0 0 4 6 4 6 4.63
of action for
considerable time with
associated loss of port
trade. Potential for
breach of fuel line.
Remarks
This applies to other vessels required to
berth downwind or in adverse
conditions. NZ car trade attracts lower
quality PCC displaced from main world
routes, thus they may be not so well
equipped. Due to low BP of tugs there is
no reserve capacity to provide for ship
failures. Ships own bow thrust (where
this unit is fitted) is not usually sufficient.
An average sized PCC of 175m with a
draft of 7m has a beam windage area of
approx 4000m2. With a 28 knot beam
wind the pressure due to a beam wind is
60 tonnes, at 40 knots it is 122 tonnes.
PCCs are getting bigger with vessels
now up to 200m loa, greatly increasing
windage and wind forces over quoted
examples. Most PCCs must berth
starboard side to due to hull/ramp
configuration with the result that
downwind berthing for these vessel
types becomes common. Downwind
berthing may also be necessary for
other ship types to fit with stevedores
requirements (i.e. for container crane to
fit over high box stack at HW) or siting of
operational gangway on one side only.
Ships are required to berth at least 30m
from a tanker but berth clearances
between other vessels may be 20m or
less. If fuel pipeline (presently protected
under the quay) along Aotea Quay is
damaged, there is potential for a
significant spill.