1 General
1.1 Purpose
The purpose of these Guidelines is to provide recommendations and
guidance for maintenance and in-service inspections of mooring equipment including
lines and tails, criteria for identifying worn-out lines and tails for removal from
service before failure, and criteria for selection of replacement mooring lines and
tails.
1.2 Application
These Guidelines apply to all ships. Certain provisions are intended for
reference by shipboard personnel, and other provisions are intended for Company
personnel responsible for selecting and procuring replacement mooring lines.
2 Definitions
For the purpose of these Guidelines:
2.1 Bend radius (D/d ratio) means the diameter, D, of a mooring
fitting divided by the diameter, d, of a mooring line that is led around or through
the fitting. The D/d ratio is used by mooring line manufacturers to specify the
minimum radius of a fitting around or through which a mooring line of diameter "d"
should be led, in order to reduce or mitigate bend loss of strength of the mooring
line.
2.2 Company means company, as defined in SOLAS
regulation IX/1.2.
2.3 Line Design Break Force (LDBF) means the minimum force that a
new, dry, spliced, mooring line will break at. This is for all synthetic cordage
materials.
2.4 Mooring arrangement means the configuration of the mooring
equipment and fittings and other design features of the ship related to the mooring
operation, i.e. lighting and communication equipment.
2.5 Mooring boat means the boat handling mooring lines between the
ship and ashore mooring facilities during mooring and unmooring operations and does
not include harbour ship assist tugs (see the Guidelines on minimum training and
education of mooring personnel (FAL.6/Circ.11/Rev.1)).
2.6 Mooring equipment and fittings means items such as winches,
capstans, bollards, bitts, fairleads, rollers, chocks, etc. and also includes
mooring lines.
2.7 Mooring line configuration means all components of an
individual mooring line, including tails, eye splices, etc. Any change or
replacement of a component is a change to the line's configuration, unless a
component is replaced by a part having the same specification as in the original
configuration.
2.8 Mooring operations means normal mooring and unmooring of the ship,
including associated in-harbour towing movements.
2.9 Mooring personnel means personnel tasked to assist in the activity of
mooring and unmooring ships, either ashore or from mooring boats, carried out within
the framework of port marine services.
2.10 Rotation of mooring lines means periodical change of mooring lines for
respective mooring drums to equalize the wear of mooring lines.
2.11 Ship Design Minimum Breaking Load (MBLSD) means the minimum
breaking load of new, dry, mooring lines for which shipboard fittings and supporting
hull structures are designed in order to meet mooring restraint requirements.
2.12 Towing and mooring arrangements plan means the plan as described in
section 5 of the annex to the Revised guidance on shipboard towing and mooring
equipment (MSC.1/Circ.1175/Rev.1). This plan presents specific information
regarding the towing and mooring fittings aboard the vessel, the mooring lines, as
well as the arrangement of mooring lines and the acceptable environmental conditions
for mooring.
3 Safe use of mooring equipment
3.1 Safe use of mooring equipment and fittings
Throughout its operational life, mooring equipment should be maintained and operated
in accordance with the original design concept, if available, including when
replacing parts and lines. In order to ensure all mooring equipment functions as
designed, the Company should establish procedures for mooring operations, inspection
and maintenance of mooring equipment, including mooring lines, taking into account
appropriate references listed in paragraph 7 of these Guidelines.
3.2 Protection and storage of mooring lines
To preserve the design life of mooring lines, the following practices should be
followed during mooring operations:
3.3 Control of mooring lines
3.3.1 The Company should establish procedures to allow the identification and control
of mooring lines, tails and associated attachments when on board and to facilitate
inspection and maintenance of mooring lines. Such procedures should include:
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.1 providing a means of recording the number, type and
location of mooring lines, tails and associated attachments. Such
records may be included in either the towing and mooring arrangements
plan or with records of inspection and maintenance or an alternative
established by the requirements of the Company; and
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.2 providing a means of linking specific mooring lines,
tails and associated attachments to the relevant records and a
manufacturer's certificate, if available.
3.3.2 Any defect discovered to the mooring lines during mooring operations should be
immediately reported to the Master by all parties concerned including shore-based
mooring personnel. If no actions are taken as appropriate the competent authorities
should be informed, as necessary.
4 Inspection and maintenance of mooring lines
4.1 Inspection of mooring lines
4.1.1 To prevent the deterioration of mooring lines to a condition which may result
in the failure of the line during mooring operations, the periodic inspection of
mooring lines, mooring line tails and associated attachments should be included in
the onboard maintenance plan or equivalent maintenance management system. The
maintenance plan may be computer based.
4.1.2 The requirements for inspection of individual mooring lines will be specific to
the type of mooring line used on board. In general, onboard inspection of mooring
lines will be based on manufacturer recommendations and by visual inspection of the
outside of the mooring line to identify excessive wear or damage, e.g. external
abrasion, external cut, kink, heat damage such as fusion and slackening or fraying
of eye splices. Such visual inspections should be based on:
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.1 the recommendations of the mooring line and/or tail manufacturer,
particularly the criteria provided for the assessment of mooring line
condition;
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.2 operational experience regarding the performance of the mooring line
and/or mooring line tail during previous mooring operations; and
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.3 the environmental conditions to which the mooring lines and/or mooring
line tails are routinely exposed.
4.1.3 In the case of jacketed synthetic fibre mooring lines, detailed visual
inspection of the condition of the synthetic fibre line may not be possible. The
condition of the external jacket is not an accurate indicator of the condition of
the load-bearing synthetic fibre material within the mooring line.
4.2 Maintenance of mooring lines
The Company should establish the maintenance procedures as required in paragraph 3.1
of these Guidelines. The maintenance procedures should specify replacement of
in-service mooring lines and may include the rotation of mooring lines.
4.3 Criteria for condemning worn-out mooring lines
4.3.1 The replacement of in-service mooring lines which have been assessed as no
longer suitable for use should be based on the removal prior to failure and in
accordance with criteria provided by the manufacturer.
4.3.2 For visual inspection and replacement of mooring lines, additional advice is
provided in industry guidance on mooring line and mooring line tail inspections.
4.4 Inspection and maintenance of equipment and fittings
4.4.1 Equipment and fittings should be properly inspected and maintained, based on
the manufacturer's recommendations. Mooring equipment and fittings should be
included in the onboard maintenance plan or equivalent maintenance management
system. The maintenance plan may be computer based.
4.4.2 Maintenance should include the preservation, by appropriate means, of the clear
marking of information on equipment and fittings, including Safe Working Load (SWL)
and winch control instructions.
4.4.3 Records of inspection and maintenance of equipment and fittings should be
available on board.
4.4.4 Records of the original design concept, equipment, arrangement and
specifications should be retained on board through the life cycle of the ship.
4.4.5 To preserve the design life of mooring lines and reduce the potential for
failure during mooring operations any storage provided for additional (loose)
mooring lines should minimize the exposure to harmful environments (e.g. UV light,
water, chemicals, cargo, extreme temperature).
5 Selection of replacement mooring lines
5.1 When replacing mooring lines, compatibility with the mooring equipment and
fittings on board, as specified in the mooring arrangement plan, should be taken
into account. This should be achieved by selecting a replacement mooring line which
meets the designed specifications. In cases where this is not possible, the
following properties should be taken into consideration and the towing and mooring
arrangement plan updated accordingly:
5.2 Any increase in LDBF for the mooring lines above the limits specified, i.e. 100%
to 105% of the MBLSD, may require a review of the operating parameters
and load limits of mooring equipment and fitting as well as of their hull supporting
structures.
5.3 It should be noted that, when selecting replacement mooring lines, over time in
service their strength will decay due to varying environmental conditions and thus
the original service life expectations may not be achieved. Therefore, the Company
should ensure that the condition of mooring lines is tracked throughout their
service with the objective to replace the line before failure.
5.4 For wire ropes, corrosion protection should be considered.
5.5 For both wire and fibre mooring lines, the acceptable minimum bend radius (D/d
ratio) recommended by the manufacturer should be taken into consideration as
strength and life expectancy of these lines are directly related to the bend radius
they are exposed to in service.
5.6 Where the acceptable minimum bend radius recommendations for a particular mooring
line are not achievable, the service life of the line may be less than that stated
by the manufacturer and therefore the line may need to be replaced before the end of
the service life recommended by the manufacturer. The condition of lines regularly
exposed to below the acceptable minimum bend radius should be subject to particular
attention during inspections.
5.7 When selecting replacement mooring lines with high stiffness, including wire and
high modulus synthetic lines, consideration should be given to the use of synthetic
tails in order to reduce peak loading when the ship is secured alongside.
5.8 Consideration of the use of synthetic tails on high stiffness mooring lines
should take into account industry and manufacturer guidance and the potential
effects of synthetic tails on the stored energy of mooring lines under tension. The
use of tails can change the characteristics of a mooring line and its behaviour in
the event of failure. High stiffness mooring lines may exert significant dynamic
force and have significant snap-back zones when used with synthetic tails that have
a low stiffness.
6 Updating of ship documents and record-keeping
6.1 Records of inspection and maintenance of mooring equipment and inspection and
replacement of mooring lines should be retained on board. Such records should be
kept for a period determined by the Company, but in any event the records should be
kept until completion of the next annual survey.
6.2 Consideration should be given to control and certification of mooring lines,
wires, tails and associated attachments. Manufacturers' test certificates for
mooring lines, joining shackles and synthetic tails should be kept on board and
properly linked back to the equipment.
6.3 The items to be recorded during inspection and maintenance should be determined,
taking into account the recommendations of the manufacturers of the mooring lines.
6.4 Any change of mooring line configuration requires updating of the towing and
mooring arrangements plan.
7 References
(1) Oil Companies International Marine Forum (OCIMF), Mooring Equipment
Guidelines, 4th Edition 2018, ISBN: 978-1-85609-771-0.
(2) Ian. C. Clark BSc, MSc, Master Mariner, MNI, The Nautical Institute, Mooring
and Anchoring Ships Vol.1, Principle and Practice, ISBN: 9781906915934,
2009.
(3) Walter Vervloesem AMNI, The Nautical Institute, Mooring and Anchoring Ships
Vol.2, Inspection and Maintenance, ISBN: 9781870077941, 2009.