ISO 16548:2012

INTERNATIONAL ISO
STANDARD 16548
First edition
2012-10-15
Ships and marine technology —
Ship design — General guidance on
emergency towing procedures
Navires et technologie maritime — Conception du navire —
Directives générales sur les procédures de remorquage d’urgence
Reference number
©
ISO 2012
© ISO 2012
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ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General description . 2
4.1 General . 2
4.2 Limitation during towing operation . 2
4.3 Master’s response . 3
4.4 Safety considerations . 3
4.5 Towing preparations . 3
5 Decision matrix for determining towing pattern . 4
Annex A (informative) Towing patterns and decision matrix . 5
Annex B (informative) Procedures for connecting towing lines .12
Annex C (informative) Ship specific data .22
Annex D (informative) Organization of tasks .27
Annex E (informative) Current status .29
Bibliography .32
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16548 was prepared by Technical Committee ISO/TC8, Ships and marine technology, Subcommittee
SC8, Ship design.
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 16548:2012(E)
Ships and marine technology — Ship design — General
guidance on emergency towing procedures
1 Scope
This International Standard gives guidance on towing procedures for cargo ships and passenger ships in
emergency situations subject to SOLAS Regulation II-1/3-4.
Cargo ships which are constructed on or after 1 January 2010 shall be provided with a ship-specific
emergency towing procedure and all passenger ships shall be provided with a ship-specific emergency
towing procedure by 1 January 2010. For cargo ships constructed before 1 January 2010, they shall be
provided with ship-specific emergency towing procedure by 1 January 2012 in accordance with SOLAS
(Chapter II-1 Reg. 3-4).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
SOLAS Regulation II-1/3-4, Emergency towing arrangements and procedures
IMO MSC.1/Circ.1255:2008, Guidelines for Owners/Operators on Preparing Emergency Towing Procedures
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
towing ship
vessel or boat that manoeuvres vessels by pushing or towing them
3.2
towed ship
vessel that is towed or pushed by a towing ship
3.3
emergency towing system
ETS
system (equipment and fittings) for emergency towing for liquid cargo vessels based on SOLAS
Regulation II-1/3-4
EXAMPLE Chafing chain, towing wire, chain stopper, strong fairlead and pick-up gear etc.
3.4
towing line
strong rope that is used by a towing ship for pulling a vessel
3.5
messenger rope
rope that is located between the heaving rope and the towing line
3.6
heaving rope
rope connected to a messenger rope that is thrown to another vessel in order to prepare for towing
3.7
chafing chain
chafing gear
stud link chain that is long enough to ensure that the towing line remains outside the fairlead during the
towing operation
4 General description
4.1 General
This International Standard is prepared for use in emergency towing situations in accordance with
SOLAS Regulation II-1/3-4 and related IMO MSC.1/Circ.1255.
4.1.1 The following information is included in this International Standard:
a) Drawings of fore and aft deck showing emergency towing arrangements;
b) Inventory of equipment on board that can be used for emergency towing;
c) Means and methods of communication;
d) Sample procedures to facilitate the preparation for and the conducting of emergency towing;
e) Organization of tasks; and
f) Communication plan listing all information that is required to be communicated to the towing ship.
4.1.2 A minimum of three copies should be kept on board and located in the following locations:
a) The bridge;
b) A forecastle space; and
c) The ship’s office or cargo control room.
4.1.3 Owners, operators and crew should take into consideration that the nature of an emergency does
not allow time for deliberation. Accordingly, the procedures should be practiced beforehand.
4.2 Limitation during towing operation
4.2.1 Not all ships have the same degree of shipboard equipment, so there may be limits to possible
towing procedures. Nevertheless, the intention of this International Standard is to predetermine what
can be accomplished.
4.2.2 The towing load should not exceed the safe working loads of deck fittings and the allowable
working load of that deck structure as shown in Figures C.1 and C.2. When heavy weather which will
significantly increase the towing load is forecasted, special considerations are to be paid to the towing
speed, towing line arrangement, and the ship’s stability.
4.2.3 The loading points on stand-rollers are so high that great bending moments are generally
transferred to the supporting structures. Consequently, stand-rollers are not to be used in towing line
arrangement as far as practicable.
2 © ISO 2012 – All rights reserved

4.3 Master’s response
4.3.1 The master of a ship or ship owner’s representative, when recognizing that the ship is in distress
and may need towing assistance, should make the initial notification of the incident to the following parties:
a) Flag states;
b) Nearest Coastal state; and
c) Other relevant parties (shipper, insurer, company, authorities, etc.).
4.3.2 The master should complete Tables E.1 through E.4 and prepare to communicate with the towing
ship.
4.3.3 All information in Annexes C and D should be delivered to the towing ship.
4.3.4 The master should ensure that towing lines do not become taut until towing lines are tied to the
connection system of the towing ship and that everyone on deck has been notified.
4.3.5 When the power system on board is not available or alternative connection procedures are
introduced by the towing ship, the master should try to make the best decision possible considering the
ship’s current status in consultation with the towing ship.
4.3.6 When an alternative procedure is adopted, it should be clearly communicated to all crew.
4.3.7 The master should ensure that survival craft are made ready for use.
4.4 Safety considerations
4.4.1 The Chief Officer on the mooring deck should be in contact with the Bridge at all times.
4.4.2 Everyone on deck should be equipped with personnel life saving appliances and be alert to avoid
hazardous situations such as slips, trips, falls, etc.
4.4.3 All crew should be well informed of the work procedures and tasks.
4.4.4 When the towing line becomes strained in tension, all on-deck staff should be evacuated to a
safe location.
4.4.5 The crew should have a good knowledge of equipment stowage locations and their accessibility.
Any identified improvements to stowage arrangements should be implemented.
4.4.6 While engaged in towing operations, the minimum number of crew essential to carry out duties
are to be on deck, and they should never be exposed to a rope or wire under tension or load. Wherever
possible, the deck should be cleared of crew while towing.
4.4.7 Regular maintenance of emergency towing equipment is of utmost importance for emergency
readiness.
4.5 Towing preparations
4.5.1 The towed ship is to display the navigation lights, shapes and, if manned, make sound signals
required by the International Regulations for Preventing Collisions at Sea, 1972, as amended. Due
consideration should be given to the reliability of the lights and sound signals and their ability to function
for the duration of the voyage.
4.5.2 Prior to sailing, the watertight integrity of the towed ship should be confirmed by an inspection of
the closing arrangement for all hatches, valves, air pipes, and other openings through which water might
enter. It should also be confirmed that any watertight doors or other closing arrangements within the hull
are securely closed and that any portable closing plates are in place.
4.5.3 The securing arrangements and weather protection for the cargo, equipment and store carried on
the towed ship should be carefully examined to ensure that they are adequate for the voyage.
4.5.4 When appropriate, the rudder should be secured in the amidships position and measures should
be taken to prevent the propeller shaft from turning.
4.5.5 The towed ship should be at a suitable draught for the intended voyage.
4.5.6 The towed ship should have adequate intact stability in all the loading and ballast conditions to
be used during the voyage.
4.5.7 Life saving appliances in the form of lifejackets and lifebuoys should be provided whenever
personnel are likely to be on board the towed ship even if only for short periods of time. When personnel
are expected to remain on board for longer periods of time, life rafts should be provided. Other life
saving appliances, including distress signals, fire appliances and radio equipment, including means of
communication with the towing ship, should be provided whenever the towed ship is continually manned.
5 Decision matrix for determining towing pattern
The towing pattern should be decided by the ship’s master, in consultation with the master of towing
ship, by using the following decision matrix (see Annexes A and B).
The ship should be towed from the bow as far as possible. If it is not possible to tow from the bow
because of grounding, collision, etc., towing from the stern may be selected as an alternative.
For determining the towing pattern, the following status and surrounding conditions should be taken
into account:
a) Ship’s position;
b) Weather and sea conditions;
c) Short-te
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