MSC.1/Circ.1619*
11 December 2020
______________
* Re-issued to refer to
the correct resolution MSC.474(102)
in paragraph 1 of the cover sheet.
GUIDELINES ON THE DESIGN OF MOORING ARRANGEMENTS AND THE SELECTION
OF APPROPRIATE MOORING EQUIPMENT AND FITTINGS FOR SAFE MOORING
1 The Maritime
Safety Committee, at its 102nd session (4 to 11 November 2020), having
considered a proposal by the Sub-Committee on Ship Design and Construction, at
its sixth session (4 to 8 February 2019), and recognizing the importance of
design of mooring arrangements and the selection of appropriate mooring
equipment and fittings for safe mooring operations, with a view to ensuring a
uniform approach towards the application of the provisions of SOLAS regulation
II-1/3-8, as amended by resolution MSC.474(102), which is expected to become
effective on 1 January 2024, approved the Guidelines on the design of
mooring arrangements and the selection of appropriate mooring equipment and
fittings for safe mooring, as set out in the annex.
2 Member States are
invited to bring the annexed Guidelines to the attention of ship designers,
shipyards, shipowners, ship managers, bareboat charterers and other
organizations or persons responsible for design of mooring arrangements and the
selection of appropriate mooring equipment and fittings.
3 Member States are
also invited to bring the annexed Guidelines to the attention of shipmasters,
ships' officers and crew, and all other parties concerned.
ANNEX
GUIDELINES ON THE DESIGN OF MOORING ARRANGEMENTS AND THE SELECTION
OF APPROPRIATE MOORING EQUIPMENT AND FITTINGS FOR SAFE MOORING
1 Introduction
1.1 Historical
evolution in ship designs, especially the design of large ships, has resulted
in optimized performance and a greater degree of complexity; this has not been
extended to the design of ships' mooring arrangements. These Guidelines support
the application of the provisions of SOLAS for mooring arrangements and
encourage greater consideration of the occupational safety and safe mooring of
the ship when designing new ships. Improving the design of mooring arrangements
should enhance usability and safety during towing and mooring operations.
1.2 Regulations
II-1/3-8.7 and II-1/3-8.8 of the International Convention for the Safety of
Life at Sea (SOLAS), as amended, require that for ships of 3,000 gross tonnage
and above constructed on or after 1 January 2024, the mooring arrangement shall
be designed, and the mooring equipment including lines shall be selected, in
order to ensure occupational safety and safe mooring of the ship; and ships of
less than 3,000 gross tonnage constructed on or after 1 January 2024 should
comply with these requirements as far as reasonably practicable, or with
applicable national standards of the Administration.
1.3 These Guidelines
provide an approach to the design of mooring arrangements, and the selection of
mooring equipment and fittings, which should be applied in conjunction with
principles of ergonomics and usability.
2 Definitions
For the purposes of these Guidelines:
2.1 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.
2.2 Mooring area
refers to the dedicated area on a ship where mooring equipment is installed and
line-handling takes place. It also includes areas where there is a risk of
personnel injury in event of snap-back or other failure of mooring equipment.
There may be multiple mooring areas on a ship.
2.3 Mooring
arrangements means the configuration of the mooring equipment and fittings
and other design features of the ships related to the mooring operation, i.e.
lighting and communication equipment.
2.4 Mooring
equipment and fittings means items such as mooring winches, capstans,
bollards, bitts, fairleads, rollers, chocks, etc. and also includes mooring
lines.
2.5 Mooring lines
means ropes, wires and combinations used for mooring operations other than
messenger lines but including tails.
2.6 Mooring
operations means normal mooring and unmooring of the ship, including
associated in-harbour towing movements.
2.7 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.
2.8 Shipboard
personnel means personnel assigned duties for supervising or working in
mooring areas during mooring operations.
2.9 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.
2.10 Supervising
personnel means shipboard personnel assigned duties for supervising mooring
areas during mooring operations.
2.11 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.
2.12 Working Load
Limit (WLL) means the maximum load that a mooring line should be subjected
to in operational service, calculated from the relevant environmental mooring
restraint requirement.
3 Goals
The equipment selection and mooring arrangement design safety
objectives should be to facilitate safe mooring operations and reduce the risk
to shipboard personnel and mooring personnel caused by inappropriate selection
and arrangement of equipment and fittings.
4 Functional
objectives
4.1 A ship should be
provided with mooring equipment and fittings appropriate for its type and size.
In addition, a ship should be provided with mooring lines appropriate for the
equipment and fittings installed on board. In order to achieve the goals for
the correct equipment selection and mooring arrangement design safety
objectives set out in section 3, the following functional objectives should be
applied.
4.2 Mooring equipment
and fittings should be:
.1 arranged to minimize
obstructed access to and operation of the mooring equipment;
.2 arranged to minimize
obstructed access to working space and minimize obstructed view of the mooring
area;
.3 arranged to minimize
the need for complex mooring line configurations during the normal operation of
the ship;
.4 selected and
arranged to minimize the need for manual handling of mooring lines under load;
and
.5 selected and
arranged to minimize the exposure of personnel involved in mooring operations
to the dynamic loads of mooring lines.
5 Achievement of the
functional objectives
To meet the functional objectives, the following design and
equipment features should be considered from the earliest stage in the design
process.
Selection of equipment, fittings and mooring lines should not be
undertaken independently. To facilitate safe mooring operations, it is
necessary for mooring equipment, fittings and mooring lines to be considered as
a complete system within which all components are compatible.
The guidance on the design of mooring arrangements and the
selection of equipment and fittings should be read in conjunction with MSC.1/Circ.1175/Rev.1.
This section should be implemented to the extent permitted by the
size and purpose of the ship.
5.1 Design of mooring
arrangements
5.1.1 To minimize the need
for complex mooring line configurations during the normal operation of the
ship, mooring winches and fairleads should be positioned to allow the use of
direct, unobstructed leads from the mooring winch to the fairlead for each of
the mooring lines described in the towing and mooring arrangements plan. It is
preferable to provide a dedicated fairlead for each mooring line.
5.1.2 Where a straight
lead is not possible:
.1 the deviation from a
straight lead should be by means of pedestal fairleads, rolling fairleads or
similar means that will reduce friction between line/fitting and reduce bend
losses. Steel fittings such as horns or bollards without chafe protection
should be avoided;
.2 the line should
traverse the mooring area from winch to the fairlead by the shortest route; and
.3 changes of direction
of mooring line should be minimized to prevent reductions in mooring line
strength due to bend loss and introduction of complex snap-back areas.
5.1.3 To provide for the
oversight and supervision of the mooring operations, the mooring area should be
designed to give supervising personnel an unobstructed view of the installed
mooring equipment and fittings. This should include the provision for a
platform, or other appropriate means, by which supervising personnel can obtain
an unobstructed view of the mooring area and berth arrangements planned to be
used from a position clear of hazards.
5.1.4 The mooring
arrangements should be designed to provide unobstructed views between shipboard
personnel, and of lines being worked, within the mooring area.
5.1.5 The winch operator
should be provided with mooring winch controls that are positioned so that the
winch operator has a direct view of the line in the mooring area being worked
without stepping away from the winch controls. Winch controls should be
positioned clear of hazards.
5.1.6 Deck illumination
should provide a clear view of the mooring area and the equipment and lines
being worked during hours of darkness or in conditions of limited visibility.
5.1.7 The design of
mooring arrangements and mooring areas should take into account the following
constraints:
.1 anticipated
variations in shore-based mooring arrangements and the need to preserve
flexibility in mooring line configurations to achieve an appropriate
restraining capacity;
.2 ships' structural
elements, including accommodation, ventilation exhausts, cargo equipment or
similar obstacles, on access; and
.3 special requirements
for the location and selection of mooring equipment and fittings, for example
special requirements for canal transits.
5.1.8 Unless the size and
special features of the ship do not permit it, equipment and fittings in
mooring areas should be positioned to provide shipboard personnel with
unobstructed access to the following during mooring operations:
.1 mooring winches and
winch controls;
.2 mooring fittings;
.3 mooring lines and
mooring line stowage; and
.4 the space between
shipside fairleads and winches to permit mooring personnel to safely apply
stoppers to mooring lines when necessary.
5.1.9 The mooring
arrangements should be designed to avoid the exposure of the shipboard
personnel to lines under tension through snap-back or sudden movements of
mooring lines. In this respect the following measures should be considered:
.1 locate winches close
to shipside fairleads. The position of winches should not result in
inappropriate mooring line orientations, or block or otherwise interfere with
the use of shipside fairleads for additional mooring lines, connecting up of
tugs for towage during mooring operations or the ability to safely moor the
ship;
.2 enclosing the
mooring line(s) behind barrier(s) provided that such enclosures do not
adversely affect the performance of the mooring system and do not prevent
effective inspection and maintenance of equipment, fittings and mooring lines;
.3 alternative
design(s) where crew members do not need to work close to or have to pass
mooring lines under tension or potentially under tension;
.4 use of appropriate,
alternative means to moor the ship, including but not limited to automated
mooring systems; or
.5 permanently fix
mooring lines to a mooring winch.
5.1.10 Mooring areas should
be considered as potential snap-back zones and signage should be provided to
indicate that this is the case.
5.1.11 To minimize the need
for manual handling of towing and mooring lines, the following measures should
be considered:
.1 equipment and
fitting arrangements should minimize the distance over which any mooring line
may need to be handled;
.2 the use of fixed or
dedicated mooring lines, taking into account the need to avoid inappropriate
mooring line orientations, or block or otherwise interfere with the use of
shipside fairleads for additional mooring lines, connecting up of tugs for
towage during mooring operations or the ability to safely moor the ship;
.3 the layout to be
designed to prevent manual intervention in transfer of the mooring line from
storage drum to mooring winch drum and vice versa;
.4 use of spooling
equipment;
.5 additional mooring
lines should be available for immediate use, provided that their stowage does
not interfere with the safe operation of the mooring equipment; and
.6 a sufficient number
of mooring winches so that, during mooring operations, manual use of warping
ends, stoppers, capstans and bitts is minimized, as far as possible.
5.1.12 The mooring
arrangement design should take into account the principles for effective
mooring arrangements included in appropriate industry guidance on mooring
equipment and fittings.
5.2 Selection of
equipment, fittings and mooring lines
5.2.1 The selection of
winches should take into account:
.1 the availability of
winches with alternative drum arrangements, including split drum arrangements,
which can reduce the need for manual handling of mooring lines during mooring
operations;
.2 the positioning of
winch controls, including the availability of remote controls for winches to
improve the line of sight and reduce operator exposure to snap-back;
.3 the availability of
constant tension winches and their appropriateness for the normal operation of
the ship; and
.4 limiting noise
levels to ensure proper communication during mooring operations.
5.2.2 The selection of
fittings should take into account:
.1 the type of mooring
line with which the fitting is designed to be used. The design or selection of
the fitting and the design of its hull supporting structure should be done in
accordance with MSC.1/Circ.1175/Rev.1;
.2 the diameter D of
surfaces of mooring fittings that are in contact with the mooring line in
relation to the mooring line diameter d (D/d ratio) to reduce or mitigate bend
loss of strength; and
.3 the need for the
load-bearing surfaces of fittings to minimize damage from chafing and abrasion.
5.2.3 The selection of
mooring lines should take into account:
.1 the guidance on
mooring restraint as per appendix A of MSC.1/Circ.1175/Rev.1;
.2 the diameter D of
surfaces of mooring fittings that are in contact with the mooring line in
relation to the mooring line diameter d (D/d ratio) to reduce or mitigate bend
loss of strength;
.3 the compatibility of
the MBLSD of mooring lines and the brake capacity of the mooring
winches installed on board;
.4 the Line Design
Break Force (LDBF) to be 100% to 105% of the MBLSD;
.5 the characteristics
and limitations of mooring lines including material properties and
environmental operating conditions anticipated during normal operation of the
ship;
.6 the anticipated
behaviour of the mooring line in the event of failure;
.7 the influence on
stored energy and the potential for snap-back of high stiffness mooring lines
caused by the use of tails; and
.8 as far as possible,
but at least for lines in the same service (e.g. headlines, breast lines or
springs), mooring lines of the same diameter and type (i.e. material) should be
used.
5.2.4 To avoid overload on
mooring winches, fittings and mooring lines, consideration should be given to
select mooring winches with brake capacity of less than the ship design minimum
breaking load of the mooring line or with adjustable brake capacity.
5.2.5 Fittings, particularly
shipside fairleads, should be positioned to minimize the potential for chafing
of mooring lines during the normal operation of the ship.