OTC 4913

Hutton TLP Installation

by H. Bradshaw and E.G. Stokes, Conoca (U.K.) Ltd., and M.J. Leece, Brown & Root (U.K.) Ltd.

Copyright 1985 Offshore Technology Conference

This paper was presented at the 17th Annual OTe in Houston, Texas, May 6-9, 1985. The material Is subject to correction by the author. Permission to
copy is restricted to an abstract of not more than 300 words.

ABSTRACT

PRINCIPLES OF INSTALLATION

Installation of the Hutton TLP required

precise simultaneous control of several complex
systems. This paper describes the eqUipment
and operations involved in the deployment and
connection of the sixteen tension legs, and the
documentation used for control. The eqUipment
trials and personnel training programmes
undertaken to ensure the first-time success of
this unique operation are presented. The paper
concludes with an appraisal of the installation
process and the significance of the principles
employed to the development of deep water TLPs.

The TLP is a compliant structure where the

vertical motions of heave, pitch and roll are
suppressed by leg tension. The tension is
induced by an excess of buoyancy over platform
weight. This concept can be represented by
the equation of static equilibrium:
Displacement =
Weight + Leg Tension + Riser Tension
The static 'pre-tension' must be sufficient
to maintain the legs in tension for all
operating conditions and extreme environmental
events. Approximate values are:

INTRODUCTION
Installation of the Hutton Tension Leg
Platform,
a
new
concept
in
oilfield
development(l), was carried out in under four
days. The process of installation involved
translation of the free floating vessel into a
vertically restrained platform. This operation
was unprecedented in its reliance on mUltiple
systems, novel equipment and specially trained
personnel.
It entailed the assembly and
deployment of sixteen tension legs, their
connection to four pre-installed foundations,
and the application of 13,000 tonnes of
tension.

61,650 tonnes

= 47,300t

+ 13,OOOt + l,350t

This condition is achieved by restraining

the platform approximately 10 metres deeper in
the water than its free floating draft.
Significant changes in operating loads, riser
tensions and platform centre of gravity can be
accommodated by the transfer of ballast.
Installation requirements were a major
factor influencing the design of the mooring
system, thus engineering for installation
proceeded in parallel with mooring system
design. An early decision in the design
process was the method of 'stabbing' the legs
into the foundation mooring sleeves. Unaided
stabbing was considered the most reliable,
efficient and easily engineered method,
provided the platform position could be
maintained within acceptable tolerances. The
desi gn
envi ronmenta1
conditi ons
were
established as a wind speed of 10 mls and a
sea state typically of 2m significant wave
height and 7s period. Analyses and model
tests demonstrated acceptable leg motions and
established a vessel positioning tolerance
requirement of 1.5m during stabbing.

These unique operations required the

deve1opment of detail ed procedures to control
the installation systems and activities. The
use of eqUipment unproven in service and
personnel
inexperienced
in
the
special
operations necessitated intensive trials and
training programmes to ensure a safe and
efficient installation.
The installation of the TLP, 90 miles
north-east of the Shetl and Is1 ands and ina
wa ter depth of 148 metres, was compl eted on
15th July and first oil produced on 6th August,
1984.

Installation of the TLP was designed as a

diver1ess operation although saturation and
surface divers were ava'ilable on site as a

References and ill ustrati ons at end of paper

159

HUTTON TLP INSTALLATION

OTe 4913

INSTALLATION SYSTEMS

contingency measure. The operation is capable

of bei ng reversed wi thout diver i nterventi on
for partial or complete change out of a tension
leg and removal of the platform at the end of
the field life.

The four mooring compartments 18m in height

and diameter were the focus of activities
during installation. Each compartment contained
si xty-ei ght tensi on 1eg components and thei r
dedicated handl ing equipment, and were manned
by a crew of nine. Supporting systems consisted
of temporary moorings, acoustic positioning,
remote
operated
vehicles,
ballasting,
communications, and platform utilities (5).

TENSION LEGS AND HANDLING EQUIPMENT

Each of the 16 tension legs consists of
seventeen components connected together by
screwed couplings
(Fig.1)
(2,3,4).
The
lowermost component is the anchor connector
which incorporates a mechanism for latching
into the foundation mooring sleeve. Next there
are ten standard tension leg elements (TLEs)
each 9.5m long, nominally 260mm in diameter and
weighing 4.5t.
The make-up TLE sets the
separation between the hull and each foundation
and its length is different for each corner of
the platform. The cross load bearing is at the
bottom of the tension leg shroud in the hUll,
and is the heavi est component at 22t. Above
the cross load bearing is a pup length TLE and
two standard length TLEs. These extend the leg
up to the mooring compartment where the tension
adj usti ng el ement transmi ts the tensi on loads
through an adjustable locking collar into the
load block assembly. The load block assembly
consists of two latchplates that Open to allow
the passage of components. The latchplates are
supported on load cells to provide measurements
of leg tension. The leg is coated with flamesprayed aluminium for corrosion protection, and
the 75mm bore is filled with a water glycol
solution for hydraulic unlatching of the anchor
connector. Two centralisers on each TLE below
the cross load bearing prevent contact of the
leg with the shroud during deployment.

The world's largest semi-submersible crane

vessels (SSCVs), Hermod and Balder, were used
to manoeuvre and hold the platform in position.
The platform was moored on either side by two
350m lines to each SSCV. The tugs remained
attached to provide additional restraint and to
enable rapid revertion to tow. Manoeuvring was
performed by adjusting the platform moorings or
the SSCV anchor lines.
Precise multi-functional acoustic positioning systems (APS) were developed to perform
three roles during installation: to monitor the
position of the platform relative to the
foundati ons, to track the remote operated
vehicles, and to monitor the movements of the
anchor connectors during stabbing of the first
four tension legs. Distance, position and
movements were presented in various formats on
visual display units. An accuracy of 200mm was
achieved for tracking the anchor connectors.
Four remote operated vehicles (ROVs) were
deployed simultaneously and used continuously
throughout installation to provide video
pictures of activities at each foundation.
Tension legs were stabbed into their foundation
mooring sleeves with the aid of this visual
information, and anchor connector latching was
confirmed by ROV inspection. On completion of
installation a full visual inspection of the
1egs from the foundations to the hull was
carried out.

Assembly, deployment, connection and initial

tensioning of the legs was carried out entirely
within the four mooring compartments using
purpose built equipment (Fig.2). In each
compartment there is a 125t polar crane capable
of lifting a fully assembled tension leg and
1ifting and manoeuvring all equipment in the
mooring compartment. Supplemetary lifting is
provided by a 3t davit. Components are screwed
together using an hydraulic, self-reacting
torque tool. The tool is capable of applying
torques up to 820kNm (600,000 ft.lbs). Torque
and rotation are controll ed and recorded by a
mini-computer.

TLP ballast was adjusted throughout installation to maintain the correct separations
between the hull and foundations as tide
varied, and to increase tension in the legs
after connection. Transfer of ballast was
manually controlled and monitored from a load
and ballast computer.
The control centre for installation was the
barge master's control room (BMCR).All installation systems were controlled or monitored from
this location by. voice communication between
key personnel. The BMCR contained the installation console, the load and ballast computer,
APS control modules and other information
systems. Communication between the BMCR, the
four mooring compartments and the four ROV
stations was by dedicated, hardwired intercom.
This crucial link was backed up by platform
telephone and local UHF radio. Commumication
with marine vessels was by VHF radio.

Installation of the first leg in each

corner, while the platform was still heaving,
required the use of motion compensators during
anchor connector latching and tensioners to
These
suppress heave and apply tension.
functi ons
were
combi ned
in
the
four
hydro-pneumatic tensioner/motion compensators
(TMCs). Each TMC elevated to a height of 17m
and was capable of supporting a tension of
850t. For safety reasons they operated on high
pressure nitrogen and a phosphate ester fluid.
Tensi on was appl i ed to subsequent 1egs usi ng
tension adjusting jacks acting on collars
screwed onto the tension adjusting elements.

Installation was supported by the normal

utilities
and
accommodation
platform
facilities. Special arrangements were made to
160

BRADSHAW, STOKES & LEECE

OTC 4913
back up critical operations such as the
installation procedures. Although all equipment
provision of dedicated stand-by power for the
had, where practicable, been fully tested and
TMCs during heave suppression.
An on-board
commissioned, its dimensional interfacing and
meteorologist provided constantly updated
operation with other equipment and components
forecasts. Additional data was obtained from
in the confined space of the mooring compartthe
pl atform
motion
and
envi ronmental
ment had only been demonstrated on the drawing
monitoring systems.
board.
INSTALLATION MANUAL

An oscill ating pl atform was buil t to test

the heave compensation and suppression performance of the TMCs. The extreme oscillations and
loads that might be imposed on the TMCs during
installation could not be duplicated. However
the test programme was invaluable for debugging
and fine-tunning the equipment, and to give
confidence in this most critical phase of
installation.

Direction of the installation systems

through a preci se sequence of operati ons
demanded stri ngent documentary control.
The
five volumes of the TLP Installation Manual
defined all installation requirements from the
organisation of personnel to the operation of
equipment, with the installation procedures as
the key volume.

The one week trials programme conducted in

each mooring compartment simulated installation
activi ti es, and for the fi rst time producti on
ten si on 1eg components were assembl ed.
The
programme was based on the SOPs and EOPs, and
the experience gained was utilized in modifying
these procedures for optimum performance. Minor
equipment foul s and faults were rectified and
improvements made in component handling
techniques. Some equipment did not perform as
expected and changes to procedures were
necessary.

The organisation
and
its means
of
communication, defined in Volume I, was
structured to allow a maximum of independent
pre-pl anned acti ons by the system operators,
while
maintaining
central
control
and
co-ordination of the overall activities.
Pre-requisites to installation were specified
in master check-lists contained in Volume II,
which were completed at a series of readiness
review meetings leading up to installation.
Volume III, the installation procedures
(IPs), dictated the sequence of events in the
form of
i nstructi ons
issued
from
the
installation console to the system controllers.
Each phase of operations required an authority
to proceed based on a status review of the
systems and weather forecast. Volume III also
contained procedures for the management of
contingencies. The IP instructions initiated a
series of activities prescribed in the system
operating procedures (SOPs) of Volume IV.
Issue of i nstructi ons and compl eti on of each
activity were recorded in the IPs and in the
SOPs in each mooring compartment. Data such as
TLE identifications and coupling torque values
were also recorded.
Volume V contained the
mooring
operating
procedures
for
the
compartment handling equipment.
These EOPs
were used mainly during training.

Trials were also performed on other installation systems. A real time computer simulation
of pl atform response to tug and SSCV moori ng
line loads resulted in a change to the arrangement of mooring lines and much improved
manoeuvring and holding capability.
The
extensive use of acoustics for positioning and
other data retrieval gave rise to concerns
about si gna1 interference and accuracy of
measurements. Deep water tri al s were carri ed
out simulating the operational requirements of
the APS in the presence of other acoustic noise
and in combination with ROV activities. APS and
ROV trial s were repeated with the equipment
installed on the TLP at the mating site.
Improvements in equi pment and procedures and
confirmation of correct hook-up resulted in a
faul tl ess performance of both systems duri ng
installation.

The installation procedures were developed

from a series of logic diagrams which defined
the sequence of
events and i denti fi ed
constrai nts.
Install ati on of the fi rst four
legs
involved
activities
performed
simultaneously
in
all
four
mooring
compartments, while installation of subsequent
legs could proceed independently in each
The installation schedule was
compartment.
generated from the logic diagrams and the
installation
procedures,
and
estimated
durations for activities were confirmed during
the
trials
and
training
programmes.
Ins tall ati on was estimated to take 87 hours
excluding any allowance for contingencies.

Ballast transfer- capabilities were demonstrated at the mating site. All communication
systems were checked under worki ng noi se
environments and adjustments made where
necessary.
E1 ectrical power fail ures were
s imul ated,
the
effects
determi ned
and
conti ngency procedures practi sed for cri ti cal
phases of the installation.
As well as
demonstrating operability of equipment and
procedures, the trials also confirmed time
estimates used in prepari ng the install ati on
schedule, and provided valuable operating
experience for the installation personnel.
TRAINING

TRIALS

A total of 298 personnel were on board the

TLP during installation.
135 were directly
involved in installation and required special
training.
The remainder provided support
through their normal job functions.
All

System tri al s were performed to prove the

operation of equipment in its working
environment and in the manner prescribed by the
161

UllTTf3N

TI D TNKTAI I ATT(lN

personnel received offshore safety and survival

training. The extent of special training varied
from familiarization with the installation
process to thorough knowledge of procedures and
experience with equipment operation.

The platform arrived at the Hutton Field

shortly after midnight on 12th July, and was
connected to the waiting SSCVS.
As the
platform was positioned 40m north of its final
location over the foundations, assembly and
deployment of the first leg in each corner
commenced. The leg running sequence began with
the polar crane lifting an anchor connector
from its storage rack and, with the latchplates
open, lowering it into the shroud.
The
latchplates
were
closed
and
the
anchor
connector hung off the load block assembly.
The first TLE was taken from the storage rack
and the pin end aligned with the box of the
anchor connector. The torque tool was engaged
with the pin and the box and the coupling
screwed together to the correct torque and
angle. Any couplings not meeting the specified
torque and angle were broken out and remade.
Throughout installation none of the TLEs had to
be rejected due to faulty couplings.

Training sessions were organised at three

operations control in the BMCR,
levels:
mooring compartment crews, marine and platform
support groups.
Control personnel required a
complete understanding of the installation
principles, organisation and procedures as
described in the Installation Manual.
A
two-day
course
included
lectures
on
the
installation systems, dry run exercises of the
IPs and assessment of contingencies.

The anchor connector and TLE were lowered

and hung off at the TLE coupling box ready to
receive the next component. This procedure was
repeated fifteen times
until the tension
adjusting element was attached (Fig.3).
The
load block assembly was then converted from a
leg running tool to its load support function.
At
this point the anchor connectors were
approximately 5m above the sea bed (Fig.4).
The platform draught was continuously adjusted
by transferring ballast to maintain a constant
separation between the platform and the sea bed
as the tide varied. Water depth was measured
by monitors
on each corner
by APS and draught
column.

Greatest effort was concentrated on training

the
members
of
the
mooring
seventy-two
compartment crews. Six days were spent in the
classroom learning the system and equipment
operating procedures. Models, visual displays
and training videos were used for equipment
familiarization. Discussion was encouraged and
proved useful in improving the procedures.
After classroom training the crews assisted in
compartment

commissioning

and

before installation commenced.

Key
positions
in
the
installation
by
organisation
were
filled
engineers
responsible for the design of the systems and
equipment and development of the procedures.
These engineers were also responsible for
preparing and presenting the training courses.
Detailed attendance schedules were developed to
arrange the large number of training courses in
the limited time available, and to minimize
conflicts with ongoing work.

mooring

13TC 4913
.-

carried

out
the trials
programme, which
provided
practice
in
operation
of
the
equipment.
Hands-on training commenced as trials were
completed in each compartment. Sections of the
SOPS were carried out in order to practise each
activity at least once, with each crew member
performing
his
designated
task.
Many
activities were repeated during the seven days
to gain confidence and increase efficiency.
Hands-on training was utilized to make final
revisions to the procedures and schedule, and
to ensure the proper balance of experience and
ability in each crew.

The TMCS were assembled, connected to the

deployed legs and elevated to raise the legs 7m
giving a nominal clearance of 2m above the
foundations. The platform was then manoeuvred
and positioned
within
a
over the foundations
tolerance of 3m, which was to be maintained for
the remainder of TLP installation. Positioning
of the platform by the SSCVS guided by APS took
two hours.
With the platform in position, the ROVS were
flown to the foundations up to 60m away using
APS for guidance.
The movements of the leg
tips were monitored by APS to ensure that
positions and heights were correct for stabbing
the anchor connectors into the extended guide
cone on each foundation.
This information
together with video pictures from the ROVS was
displayed at the installation console for
~{~ol
of stabbing. The video pictures were
displayed
in
respective
mooring
compartments.

Key marine and platform support personnel

attended a one-day course to gain knowledge of
the operations and understanding of their role.
More detailed or specialised training was
provided where necessary. Final briefings were
held during platform tow.
INSTALLATION
Tow
from the Moray Firth in Scotland
commenced at 10 a.m. on 8th July, 1984, with a
forecast of perfect weather. All personnel and
equipment required for the installation were
carried on board the platform, and preparations
for installation continued during the tow. The
only notable event was the seizing of a polar
crane hydraulic pump.
A replacement was not
available amongst the installation spares on
board. One was assembled in Germany, flown to
the platform, and installed just three hours

Once satisfied with leg position and movement,

staying most of the time within the perimeter
of the guide cone, each anchor connector was
stabbed, one at a time, into its extended guide
cone.
This first critical operation proceeded
smoothly,
the
anchor
connector
buffer
occasionally contacting the edge of the cone.
On the fourth leg a fault occurred in the
intercom system and the instruction to stab had

1 u-=

t-r
1(,

II(II9
+>IJ

BRADSHAW. STOKES & LEECE

to be communicated by telephone. When all four

anchor connectors were captured, the platform
was ballasted down one metre and the TMCS
prepared for leg lowering, motion compensation
and heave suppression. The weather forecast
remained excellent predicting seas of lm and
winds of less than 10 knots for the next few
days.

At this point the anchor

adjusting element.
connector was suspended below the top of the
foundation pile sleeves, and care had to be
taken to ensure that the TLP was accurately held
In the event, no positioning
in position.
adjustments
had to be made any time during
installation.
The fully assembled leg was lowered by the
polar crane into its mooring sleeve, aided by
video pictures displayed at the crane console.
As the anchor connector contacted the bottom and
load
was shed from the crane the anchor
The leg was raised by the
connector latched.
crane to bring the load faces into contact and
to allow the locking collar to be screwed down
until it supported the leg on the load block
Tensioning of the leg was performed
assembly.
As the
using the tension adjusting jack.
tension in the second leg increased, the tension
decreased
in the first leg until they were
When installation of two legs in all
equal .
four corners had been completed, the TLP was
deballasted to increase the corner tensions to
2,600t (l,300t per leg). The third and fourth
leg in each corner were installed in the same
manner. Failure of another crane pump caused a
Final
six
hours
delay
in one
corner.
deballasting was carried out to achieve a
nominal tension of 840t in each of the sixteen
legs.

The
instruction was given to all fOUr
This allowed
compartments to lower the leg.
the anchor connectors to bottom out in the
mooring sleeves while the TMCS compensated for
heave and each maintained a downward force of
10t (Fig 5). This was immediately followed by
the second critical operation of latching the
anchor connectors by releasing the bore fluid
pressure and increasing the downward forces to
2ot. Inspection by ROV showed that none of the
anchor connectors had latched. The calm seas
and lack of platform heave had not provided
enough impetus to overcome friction in the
Repeated pressuring and
latching mechanisms.
release of bore fluid caused one anchor
connector to latch. For the remaining three the
downward force had to be increased by bleeding
nitrogen from the TMC systems.
Anchor connector latching was confirmed and
a nominal 10t tension applied to each leg to
bring the connector and foundation load faces
into contact. With satisfactory seating of the
load faces the tensions were increased to 40t
before proceeding with the third critical
Heave
suppression.
heave
operation
the
achieved by allowing
suppression was
platform to descend in wave troughs while TMC
non-return
valves
prevented
it
rising again.
the
increased
Successively
deeper
troughs
platform draught and nominal leg tension until
The
no
further heave motions occurred.
platform became a TLP at 0757 hours on Friday,
This highlight of the
1984.
13th JuIY,
operation was somewhat an anticlimax as heave
The only sign that
was less than 0.2m.
suppression had been achieved was the steadying
TMC
stroke
oscillating
slightly
the
of
indicators.

At this point installation acceptance checks

were carried out on leg lengths, leg tensions,
ballast distribution and draught.
All were
were
adjustments
and
no
within
tolerance
necessary. Cross load bearing lower seals were
inflated
Installation

to

allow
was

dewatering
completed

of

the

shrouds.

1800 hours on
Sunday, 15th July, 90 hours after arrival at
Hutton and three hours later than scheduled.
at

APPRAISAL
Success of the TLP installation is attributed
to the in-depth engineering and the time and
effort expended in preparing detailed documentand
exhaustive
tests
out
ation,
carrying
The tension leg
ensuring thorough training.
components and handling equipment performed well
no major repairs or replacements were
and
The
necessary, other than the crane pumps.
tight, overlapping schedules for mooring system
design and manufacture undoubtedly resulted in
equipment and procedures more cumbersome than
necessary. Future designs can be improved based
on the knowledge and experience gained.

After heave suppression the TLP was pulled

down 1.5m to its operating draught of 32.5m by
increasing the tension in each leg to 500t
using, the TMCS. The locking collars were set
at their predetermined positions and the leg
loads transferred from the TMCS to the load
Checks were made on leg
block assemblies.
tensions and platform trim and draft but no
adjustments to leg length were necessary. The
first four legs had been installed in a period
of 28 hours, two hours faster than predicted.
Deballasting was carried out to increase the
leg tensions to l,300t and establish the TLP in
a condition capable of withstanding a 10-year
seasonal storm.

Many thousands of manhours were spent in

Strict
preparing the installation manuals.
control of activities at all levels by adherence
to pre-planned procedures avoided errors, and a
smooth operation was accomplished. The extensive
trials of systems and equipments were instruin achieving an almost trouble-free
mental
installation. Many minor problems, which would
have caused difficulties and delays during
installation, were resolved during trials in the
were
systems
Marine
compartments.
mooring
perfected and procedures refined to permit
without
conflicts.
operations
simultaneous

As deballasting proceeded, assembly of the

The four
second leg in each corner began.
compartments could now progress at their own
speed until all legs were installed. The leg
running sequence was similar to that for the
first leg, until the attachment of the tension
4RQ
,

Safety and efficiency warranted the effort

applied to providing effective training for a
large number of personnel. Despite the limited
access to personnel and equipment and the
pressure to complete,
training was
given
prominence in the hectic period leading up to
installation.
Good weather was a significant factor in
achieving
the
installation
schedule
and
avoiding the use of contingency procedures.
The ease with which the tension legs were
connected to the foundations fully justified
the free stabbing approach and the commitment
to the SSCVS. The performances of the APS and
ROV systems were impressive, and demonstrated
the accuracy and reliability that can be
achieved with careful preparation.
Passing
through the barrier of heave suppression was
less momentous than anticipated due to the
prevailing sea conditions, but must remain the
most critical phase of installing a TLP.
CONCLUSION
The ability to install a tension leg
platform has been effectively demonstrated at
Hutton.
The methods adopted, avoiding subsea
intervention other than visual and acoustic
aids, are applicable to deep water locations
for which the TLP concept is particularly
suited.
The success of these methods was
dependant upon accurately maintaining platform
position to minimize leg movements during
stabbing. The observed hydrodynamic damping of
increase
with
depth
and thus
leg motions will
help

compensate

for

greater

due
to
less
constraint
environmental conditions.

platform

or

movements

more

Major participants in the installation were:Brown & Root (U.K.) Limited

Comex Houlder Diving Limited
Dan-Smedvig Limited
Heerema Marine Contractors SA
Sonardyne Limited
VO Offshore Limited
The
authors
are
grateful
to
the
participating companies in the Hutton Field
Development for permission to publish this
paper.
Participating Companies are:Conoco (U.K.) Limited (Operator)
Britoil plc
Gulf Oil Corporation
Amoco (U.K.) Exploration Company
Enterprise Oil plc
Mobil North Sea Limited
Amerada Hess (U.K.) Limited
Texas Eastern North Sea Inc.
REFERENCES

1. Tetlow,J.H.,

Ellis,N. and Mitra,J.K. :

The
Hutton Tension Leg Platform, Conference on
Developments in the Design and Construction
of Offshore Structures,
Paper
No.14,
Institution of Civil Engineers, London (March
1983) .

2. Tetlow,J.H.
and
Leece,M.J. : Hutton TLP
Mooring
System,
Offshore
Technology
Conference, Paper OTC 4428 (1982).

severe

Rapid installation of a fully operational

platform is a major advantage of the TLP
concept.
This feature is of prime importance
for severe deep water environments where
weather windows suitable for installation are
limited.

3. Skilbeck,F., Leece,M.J. and Dearden,G.C.

:
Design and Manufacture of Couplings for The
Hutton
TLP
Mooring
System,
Offshore
Technology Conference, Paper OTC 4946 (1985).

ACKNOWLEDGEMENTS

4. Wilton,G.H., Hargroves,D.W. and

Whitehouse,P.J. :The Design Substantiation
of the Anchor Connectors and
Cross
Load
Bearings for the Hutton TLP,
Offshore
Technology Conference, Paper OTC 4947 (1985).

Success of the Hutton TLP is due to the

contribution of many organisations and the
skill and dedication of numerous individuals.

5. Hart,H.J., White,G.J. andVon Fischer,E.L. :

Hutton TLP Marine Operations, Offshore
Technology Conference, Paper OTC 4910 (1985).

2i

~ TEMPLATE

MOORING SLEEVE

INSERT

P-1

LOWERING OF
ANCHOR CONNECTOR
INTO
MOORING SLEEVE

BUFFER
COMPRESSED
ANCHOR CONNECTOR
LATCHECI
Fig.

5Anchor

connector

ANCHOR CONNECTOR
RAISED & MAKING
CONTACT WITH
TEMPLATE !NSERT
latching

sequence.

TEMPLATE INSERT
IN CONTACT WITH
ABUTMENT RING
OPERATING CONDITION