Anchor Running Procedures for Stanislav Udin

Anchor Running Procedure
for
Stanislav Yudin
Project Name : Loggs Platform Installation
Project No.: 17.012
Prepared by
SHL.17.012/PC/001
Rev. 0
:
R. van Kranen
Page 1 of 22
Preface
Since this procedure will be Chapter 4 of the Offshore Installation Manual Volume 2, the
different paragraphs of this procedure are numbered with number four (4).
This preface and the Table of Contents will not be part of the procedure included in the
Offshore Installation Manual - Volume 2 but will only be part of this document if the
procedure is submitted for approval / information as a stand-alone document.
SHL.17.012/PC/001
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Table of Contents
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
Marine Procedures
Introduction
Compliance
Equipment
Personnel
Responsibilities
4.2.1
4.2.2
Anchor Plans and Catenaries
Anchor Plans
Catenary Curves
4.3.1
4.3.2
Clearances and Restrictions
Clearances
Restrictions
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7
4.4.8
Anchor Handling Procedures
General
Approach
Anchor Running
Mid-line buoy installation
Anchor Positioning
Test moorings
Anchor retrieval
Proposed Anchor Positions
4.2
4.3
4.4
4.5
Anchor Handling Records
4.6
Environmental Conditions
4.7
Contingencies
General
Anchor drag
Mooring line failure
Deteriorating weather
Anchor recovery
Missing buoy
HLV Loss of Motive Power
AHT Loss of Motive Power
4.7.1
4.7.2
4.7.3
4.7.4
4.7.5
4.7.6
4.7.7
4.7.8
4.8
SHL.17.012/PC/001
Drawings / Charts / Reports
Rev. 0
Page 3 of 22
4.1
MARINE PROCEDURES
4.1.1
Introduction
This procedure describes equipment, line of command and details of the method
of deploying anchors of the HLV "Stanislav Yudin" at Loggs Riser Platform
location.
4.1.2
Compliance
The following procedures are in compliance with the Offshore Marine and
Anchoring Procedures as laid down in Client's document No. CUK-L-IY-80XC00-002. Where required, changes may be implemented in mutual agreement
between SHL and Client.
They will apply to all vessels required, to approach or operate near installations
during anchoring preparations of the HLV "Stanislav Yudin".
4.1.3
Equipment
The standard vessel spread will consist of the HLV "Stanislav Yudin" and two (2)
Anchor Handling Vessels.
Both Anchor Handling Vessels will be of the open-sterned type, capable of
decking the anchors. Only the lead AHV will lay anchors that cross or are placed
adjacent to existing pipelines.
The Anchor Handling Vessel(s) will be typical North Sea Class AHT. Since final
commitments concerning hiring AHT are not yet in place, the particulars of the
Anchor Handling Vessel(s) will be included in due course.
Mobilization of the vessel spread will be described in section 3 of this document
(Offshore Installation Manual - Volume 2).
Prior to mobilization, the vessel(s) will undergo a suitability survey. This survey
will be witnessed by the Client's Warranty Surveyor and will include a visual
inspection of the vessel and examination of the validity of the certificates as laid
down in Contract document LRP-C-02 / Exhibit "B" / part I / 6.8.
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The HLV will be equipped with the appropriate surface positioning system for
precise positioning of the anchors. This positioning system will comprise of:
-
One (1) DGPS receiver onboard the HLV and the lead AHV
One (1) Laser positioning system onboard the HLV
One (1) Laser positioning system spare
One (1) Gyro Compass
Information about the anchor spread is summarized in section 4.8 of this
document.
4.1.4
Personnel
The following critical personnel / parties will be involved during the anchoring
operations:
Seaway Heavy Lifting
HLV Captain
HLV 1st Officer
HLV Captain's Advisor
AHT Captain
(Ass.) Superintendent
Rigger Foreman with riggers
Crane Operator
Positioning Subcontractor
Conoco
Client's Marine Representative
Loggs O.I.M.
4.1.5
Responsibilities
The chain of Command and Communications for this operation will be as shown
on the organization and communication chart included in section 4.8
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Responsibilities of the key personnel are as follows :
Conoco
Loggs O.I.M.
Is responsible for all marine activities within the Loggs
500 metre zone. Anchor running and retrieval will not
commence without prior approval of the O.I.M.
Client's Marine Rep.
Will witness the anchor handling operations and give
approval where necessary. He will liaise with the HLV
Captain and will keep the Loggs O.I.M. informed of all
anchor handling operations. Will obtain approval to
commence the anchoring operations from the Loggs
O.I.M.
Seaway Heavy Lifting
HLV Captain
Is responsible for all marine activities associated with
tug movements and anchor laying within a one mile
radius of the HLV. Will liaise directly with the Client
Marine Representative.
HLV 1st Officer
Will assist the HLV Captain in anchor laying
operations. Reports to the HLV Captain.
HLV Captain Advisor Will assist/advise the HLV Captain during vessel
operations in general and during anchor-handling
operations in specific.
(Ass.) Superintendent
Responsible for all deck activities on board the HLV.
Reports to the HLV Captain.
Crane Operator
Will transfer the pennants from the HLV to the anchor
handling tug. Reports to the (Ass.) Superintendent.
AHT Captain
Responsible for running of anchors under the direction
of the HLV Captain.
Positioning Supervisor Responsible for setting up and operating all positioning
equipment including DGPS and the HLV Laser
Positioning System. Will report to the HLV Captain.
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SHL.17.012/PC/001
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4.2
ANCHOR PLANS AND CATENARIES
4.2.1
Anchor Plans (Patterns)
Anchor Plans for the installation of the Loggs Riser Platform Jacket / Topside and
Bridge are included in section 4.8 of this document.
Since there will be a different set-up for both the Jacket / Topside installation and
Bridge installation, there will be two separate anchor plans.
4.2.2
Catenary Curves
Catenary curves for the appropriate water depth (20.5 M.) and covering the full
range of working tensions ( 0-120 tonnes) are included in section 4.8 of this
document.
Normal operating tension range
Maximum tension for pre-tension
- 20/40 tonnes
- 80 tonnes
For mid-line buoy installation, "Segment 1" represents the distance from the
anchor to the buoy and "Segment 2" represents the distance from the buoy to the
HLV.
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4.3
CLEARANCES AND RESTRICTIONS
4.3.1
Clearances
This paragraph describes the clearances which will be observed by the HLV
"Stanislav Yudin" at Loggs Riser Platform location.
The following clearances apply :
4.3.2
(a)
The initial setting up and tensioning of anchors will take place not less
then 200 meters from any structure. Similarly the vesselwill be hauled off
the same position for anchor recovery.
(b)
Mooring wires will at no time be run in such a way that they will ever
come within 10 meters of the structure, unless it is deemed absolutely
necessary and prior agreement is given by the Client's Marine
Representative and the Loggs O.I.M.
(c)
No anchor will be placed closer than 200 m. from an installation.
(d)
Where a pipeline lies between the HLV and its anchor, the drag distance
to the pipeline will not be less than 400 m. with a minimum direct
distance between the pipeline and anchor of 200 m.
(e)
When mooring wires are crossing over a pipeline, the anchor pattern will
be such that a minimum vertical clearance of the mooring above the
pipeline of 10 m. can be maintained at lowest working tension (20
tonnes). If required this minimum vertical clearance will be maintained
using chaser vessels and/or midline buoys.
Restrictions
This section describes the restrictions which will be observed by the HLV
"Stanislav Yudin" at Loggs Riser Platform location.
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4.3.2.1 Anchor running
(a)
No anchor will be passed from one vessel to another over or within the
direct vicinity of any subsea installation or pipeline.
(b)
When an anchor is run over a pipeline, the anchor will be decked on an
open-sterned anchor handling vessel, and secured with a second
(preventer) wire of the same diameter as the main pennant.
(c)
The project specific catenaries will be used to determine minimum
allowable wire tensions.
(d)
Anchor running at the working location will not start until the following
conditions have been met :
-
-
The Client representative is on board the vessel to monitor the
anchoring.
All surveyors and their equipment are ready.
Weather forecasts for the next 72 hours have been seen by all
concerned and a favorable weather window for the next 12 hours is
forecasted (Beaufort 6 and decreasing).
Permission to start has been agreed with by the Client.
4.3.2.2 Anchor Positioning
(a)
No anchor will be lowered unless the positioning surveyor confirms that
its position will be within the intended target area.
(b)
If any undue delay occurs after confirmation that the position is
acceptable, then the anchor will not be lowered, and the operation
suspended until further instructions are received.
(c)
Once the anchor has been lowered the moment that it reaches the seabed
will be reported to the positioning surveyor so that a check fix can be
taken. During tensioning of the wires, lengths and tensions will constantly
be monitored, until the vessel confirms that the anchor is set. The
surveyor will then confirm and log the anchor position, and this record
will be made available to the Client immediately on request and for a
period of up to one year after completion of work.
(d)
No anchor will be moved or raised without prior agreement of the Client's
Marine Representative, except in case of an emergency, but still to the
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agreed Conoco procedures.
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4.3.2.3 Anchor Line Tension
Under normal operating conditions, the tension on any anchor line shall not exceed
33% of the minimum breaking load of the anchor line (MBL of the anchor wire
is 238 mT).
4.3.2.4 Marker Buoys
(a)
Any buoy which can present a hazard to small vessels will, as far as
possible, be designed and constructed of material which will minimize
damage in the event of collisions.
(b)
Buoys will have the name or signal letters of the vessel to which they are
attached at least 0.5 mtr. high painted in a color contrasting to the body
of the buoy.
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4.4
ANCHOR HANDLING PROCEDURES
4.4.1
General
The Scope of Work in relation to anchoring procedures for the HLV "Stanislav
Yudin" at Loggs Riser Platform location can be divided into two (2) phases :
1.
2.
Installation of Jacket / Topside
Installation of Bridge
This section describes details of the method of deploying anchors.
It should be emphasized that the anchor running sequence will be dependent upon
tide, current, wave and wind direction and shall be decided by the HLV Captain
at the time of anchor running.
In case of pipelines, anchors will be run as much as possible with the HLV
positioned between final anchor position and pipeline. This may involve repositioning of the vessel during the anchoring operation.
4.4.2
Approach
When the HLV and attending tug(s) are approaching the installation site the Client
Marine Control shall be informed and all vessel movements shall be notified to the
Client Marine Representative.
When on location the HLV shall manoeuvre into the required anchor running
position using its own propulsion system, however in the event that prevailing
weather and loss of power on the HLV could drift the vessel onto the Loggs
Structures, a tug will be connected to the bow of the HLV.
Recommended anchor running position is the "stand-off" position as indicated on
the project specific anchor plans.
The location of the HLV during the approach to the installation site shall be
monitored using the on board DGPS navigation system.
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The required platform centre line co-ordinates are :
Latitude
Longitude
UTM-Zone
Central Meridian
Eastings
Northings
4.4.3
53o-23'-27.1" N
002o-00'-15.4" E
31
3o East
433737.30 E
5916329.97 N
Anchor Running
The following sequence can be considered as normal running practice :
(1)
The pennant wire will be handed over to the anchor handling tug.
(2)
While paying out anchor wire from the HLV, spool the pennant wire onto
the anchor handling winch, until the anchor reaches the AHT stern roller.
(3)
Run the anchor into position
(4)
Lower the anchor to the seabed by paying out the pennant wire
(5)
Attach the pennant buoy to the pennant wire and deploy the buoy.
In case an anchor is run over a pipeline the anchor will be secured on the anchor
handling tug as follows:
(1)
The pennant wire will be handed over to the anchor handling tug and
spooled onto the anchor handling winch.
(2)
The anchor will be decked and secured with a second (preventer) wire of
the same diameter as the main pennant.
(3)
After the anchor is run into position, release the preventer wire, gently
lower the anchor over the stern roller by paying out the pennant wire and
deploy anchor and buoy.
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4.4.4
Mid-line Buoy Installation
In the event that specified vertical clearance above a pipeline cannot be obtained
by tensioning, anchor wire lifting buoys, i.e. midline buoys, will be attached to the
anchor wire.
Outlined below are two (2) methods of running anchors using mid-line buoys.
These procedures may be altered due to weather conditions and shall be decided
on board by the HLV Captain.
Prior to commencement of work, the final mid-line buoy installation procedure
will be agreed between all parties concerned.
Option A
(1)
The anchor will be decked on board the AHT and disconnected from its
anchor wire.
(2)
The anchor wire will be spooled on a AHT winch for a distance equal to
the distance between the anchor (in position) and the position of the midline buoy.
Mid-line buoy is now attached to the anchor wire on board the AHT.
(3)
(4)
AHT proceeds to mid-line buoy position while anchor wire is paid out
from the HLV.
(5)
Deploy mid-line buoy and proceed to anchor location point by paying out
anchor wire from the AHT.
(6)
Attach anchor to anchor wire and deploy anchor and pennant buoy.
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Option B
4.4.5
(1)
Anchor will be decked and secured with a second (preventer) wire of the
same diameter as the main pennant.
(2)
When the tug has steamed a distance equal to the distance between the
anchor (in position) and the cross point anchor line / pipeline she will stop
and maintain her position.
(3)
The anchor line will then be pulled onto the deck of the HLV and the
mid-line buoy shall be connected to the anchor line.
(4)
After this the anchor line and buoy will be lowered into the water.
(5)
The tug will then pick-up tension to clear the anchor wire from the seabed.
(6)
When the tug is in final position, deploy anchor and pennant buoy.
Anchor Positioning
The anchors will be positioned at the location indicated on the relevant anchor
plan.
The anchor handling tug positioning will be monitored using DGPS and a Laser
system. The ships radar system will function as back-up.
Before permission is given to lower an anchor, the position of the anchor handling
tug relative to the HLV will be checked and marked on the anchor plan. The
tension will be released in the anchor line and the anchor lowered to the seabed.
The "as installed" position of each anchor will be shown by a large surface
pennant buoy.
Anchor handling tug(s) will remain on station until successful pre-tension has
taken place.
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4.4.6
Test Moorings
When all anchors have been laid, the anchor will be proof loaded (test load) at 80
tonnes for a 15 minute period to ensure the anchors have adequate holding
capacity.
If an anchor does not hold it will be recovered by the AHT and redeployed.
4.4.7
Anchor Retrieval
The anchor retrieval sequence will be dependent on wave and wind directions and
will be decided by the HLV Captain at the time of demobilization.
Retrieval of anchors will be monitored by the survey / positioning system and/or
vessel radar system.
Anchors will only be recovered to the HLV when they are secured close against
the stern of the anchor handling tug. When recovering an anchor, the anchor
handling tug shall not move from its position above the anchor, until the anchor
has been lifted to the surface.
The anchors will be retrieved to the same method as detailed in the anchor running
methods in 4.4.3 and 4.4.5
During anchor retrieving anchor line tensions will be checked and verified with
the limitations stated in section 4.3.2.1 and 4.3.2.2
Prior to departing from location, the Captain of the installation vessel shall obtain
clearance from the Client Marine Control and state departure time and destination.
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4.4.8
Proposed Anchor Positions
Information about the proposed anchor positions is summarized in Table 4.2
below. For the anchor patterns, reference is made to section 4.8 of this document.
Anchor Positions
Jacket/Topside
Installation
Anchor Positions
Bridge
Installation
Anchor
number
Eastings
Northing
s
Eastings
Northings
1 (S1)
2 (S2)
3 (S3)
4 (S4)
5 (P4)
6 (P3)
7 (P2)
8 (P1)
433140
433643
434644
434536
434016
433285
432635
432698
5917366
5917413
5916753
5916056
5915475
5915548
5916427
5916931
433440
433643
434644
434016
433285
432635
432698
5917437
5917413
5916753
5915475
5915548
5916427
5916931
Table 4.2 - Proposed Anchor Positions
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4.5
ANCHOR HANDLING RECORDS
The positioning of the anchors will be monitored as follows:
a)
A positioning Subcontractor will be used to operate the DGPS system.
The anchor positions will be recorded of co-ordinated positions and a plot
plan, or calculated co-ordinates from bearings and distances from either
the HLV or an adjacent platform using the DGPS system.
b)
The positioning may be monitored from the HLV radar and subsequently
plotted on the anchor pattern drawing.
The final position of the anchors will be recorded on the anchor running report
(see section 4.8)
This report, when signed by the Captain, together with any printouts or plans
necessary, shall be submitted to the Client Marine Representative.
The Client Marine Representative shall return the reports to the Field Engineer for
enclosure within the "As-Built" documentation package.
In addition, all anchor line tensions during anchor running and when in position,
together with the anchor positions shall be recorded in the vessels log. All
information shall be kept on file for further reference.
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4.6
ENVIRONMENTAL CONDITIONS
Based on the available information, the following environmental conditions can
be expected during the anchor operations of the HLV "Stanislav Yudin" at the
Loggs Riser Platform location:
Maximum current
Speed / Direction
3 knots (1.6 M/S)/ NW-SE
Average wind
Speed / Direction
14 knots (7.2 M/S)/013E
Average waves
Height / Direction
1.28 M / 195E
Significant Waves
Height / Period
2.10 M / 5 sec.
Water depth
20.5 M from LAT
Table 4.3 - Environmental summary
During anchor running the only weather restriction that applies is the motion of the
anchor handling tug(s) and their ability to maintain position during the handling
and placing of anchors. A 12 hour fair weather forecast (Beaufort 6 and
decreasing) is recommended before anchor running commences and visibility
should be maintained between the HLV and anchor handling tug(s).
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4.7
CONTINGENCIES
4.7.1
General
The contingency procedures as described in this section, should be read in
conjunction with the relevant sections of these anchor handling procedures.
All decisions and activities will be agreed with the Loggs O.I.M. prior to any
action taking place, unless remedial action is required to safeguard the platform
complex and/or vessel spread. If remedial action is required, the Loggs O.I.M. will
be notified as soon as possible.
4.7.2
Anchor Drag
Whenever an anchor drags or is dropped accidentally in a prohibited zone, the
anchor cable will be slackened and no further remedial action taken without the
prior consultation with the Client Marine Representative except that at the same
time preparation should be made to lift the anchor.
If slackening does not eliminate risk of the anchor dragging then the cable should
be slipped or cut and the position of the bitter end accurately recorded. If
practicable the end should be buoyed for recovery.
4.7.3
Mooring Line Failure
In the event of a mooring line failure, the HLV Captain shall adjust the tension on
remaining anchors to maintain the vessel safely in position, until remedial action
to retrieve and re-attach the anchor can be taken.
The Client Marine Representative will be advised accordingly. The anchor shall
be re-deployed in accordance with section 4.4
4.7.4
Deteriorating Weather
In the event of deteriorating weather conditions the HLV Captain and
Superintendent shall agree their intended course of action and advise the Client
Marine Representative. He will in turn inform and discuss the course of action
with the Loggs O.I.M.
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4.7.5.
Anchor Recovery
If for any reason anchors are not recovered before the onset of severe weather the
attendant or available vessel or vessels should be made fast to windward and
utilized to ease the strain on the weather moorings.
When any vessel requires to recover the anchors in bad weather her own ability
or that of the designated towing vessel or vessels to hold the moored vessel to
windward or uptide should be tested prior to commencing recovery. In the event
that there is insufficient power or time available, then depending on circumstances,
slipping of moorings may be the most appropriate action to safeguard existing
structures or pipelines.
4.7.6
Missing Buoy
In the event of a buoy being lost, the Client Marine Representative will be advised
immediately.
In case of a missing buoy, other than small plastic buoys, the relevant Coast Guard
authority will be informed immediately, giving the following details:
(a)
(b)
(c)
(d)
Size, color and marking of the buoy
Time buoy was last sighted
Probable speed and direction in which buoy is drifting
Action being taken to locate and recover
In view of the potential hazard to shipping, a seabed search to ascertain whether
the buoy has sunk and a vessel search of the area shall be performed.
The results shall be communicated to the relevant Coast Guard authority.
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4.7.7
HLV Loss of Motive Power
Reference is made to the "Marine Risk Assessment Report" prepared by Offshore
Marine Contractors b.v.
In the event of a black-out during anchoring operations, the course of action will
depend on the stage in which the anchoring operation has progressed.
* In case failure occurs when entering the 500 m Safety Zone, tow HLV to a safe
area outside the 500 m Zone.
* If, due to prevailing weather and a insufficient number of anchors positioned,
the HLV could drift onto the Loggs Structures, the HLV willbe moved to a safe
area outside the 500 m. zone. If there is no danger of drifting towards the Loggs
Structures, anchoring operations will be continued.
* when HLV is completely anchored, connect tug if required.
4.7.8
AHT Loss of Motive Power
Reference is made to the "Marine Risk Assessment Report" prepared by Offshore
Marine Contractors b.v.
In the event of a black-out during anchoring operations, the course of action will
depend on the stage in which the anchoring operation has progressed.
* In case failure occurs when entering the 500 m Safety Zone, maintain position
with other tug and suspend anchoring operations.
* In case failure occurs when running anchors, use HLV propulsion system and
lower anchor in a safe area. If there is a change that the AHT will drift onto the
Loggs Structures, connect the second tug and tow to a safe area.
4.8
DRAWINGS / CHARTS / REPORTS
-
Organization and communication chart
Summary of Mooring Equipment
Anchor plans
Catenary curves
Anchor running report
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Qty
Qty
Spare
Description
8
1
Mooring Anchor - 10 tonnes Delta Flipper
8
Mooring winch - Electrical Variable Speed
- Max. pull = 1800 kN (= 180 tonnes)
- Max breaking load = 2590 kN (= 259 tonnes)
8
Mooring wires
- Length
- Diameter
- Construction
- MBL
- Weight
= 2100 m
= 61 mm.
= 6 * 36 WS + IWRC
= 238 tonnes
= 15.5 Kg/m (10.4 lb/ft)
8
Pennant wires
- Length
- Diameter
- Construction
- MBL
- Weight
= variable to depth
= 61 mm.
= 6 * 36 WS + IWRC
= 238 tonnes
= 15.5 Kg/m (10.4 lb/ft)
Pennant buoys
- Brand
- Type
- Material
= "Dynoplast A.S - Scanmarin"
= Modular - 3 module floats
= Polyethylene skin and
polyurethane core
= 6 tonnes
4
min. 2
or
equiv.
- Buoyancy
- Brand
- Type
- Material
4
- Buoyancy
4
Mid-line buoys
- Brand
- Type
- Material
- Buoyancy
8
Fairleads - Height
= "Floatex"
= Modular - 3 module floats 18/60
= External rationally moulded
crosslinked polyethylene and
filled with ridged expanded
polyurethane. Central structure
of the buoy is hot galvanised
= 6 tonnes
= "Floatex"
= Modular - 6 module floats 18/120
= External rationally moulded
crosslinked polyethylene and
filled with ridged expanded
polyurethane. Central structure
of the buoy is hot galvanised
= 12 tonnes
= 6.1 m above water level at
mean operating draft
Summary of Mooring Equipment
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