Section 7 Equipment

7.1.1 To entitle a ship to the figure 1 in its character of classification, equipment in accordance with the requirements of Table 13.7.1 Equipment requirements is to be provided. The regulations governing the assignment of the character figure 1 for equipment are given in Pt 1, Ch 2, 2 Character of classification and class notations.

7.1.2 For ships intended to be operated only in suitable areas or conditions which have been agreed by the Committee, as defined in Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.6 to Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.10, equipment differing from these requirements may be approved if considered suitable for the particular service on which the ship is to be engaged, see also Table 13.7.1 Equipment requirements.

7.1.3 Where the Committee has agreed that anchoring and mooring equipment need not be fitted in view of the particular service of the ship, the character letter N will be assigned, see also Pt 1, Ch 2, 2.2 Character symbols 2.2.2.

7.1.4 Where the ship is intended to perform its primary designed service function only while it is anchored, moored, towed or linked, the character letter T will be assigned, see also Pt 1, Ch 2, 2.2 Character symbols 2.2.2.

7.1.5 For classification purposes, the character figure 1, or either of the character letters N or T, is to be assigned.

7.1.6 The anchoring equipment required herewith is intended for temporary mooring of a ship within a harbour or sheltered areas when the ship is awaiting berth, tide, etc. It is designed to hold a ship only in good holding ground conditions to avoid dragging of the anchor. In poor holding ground, the holding power of the anchors would be significantly reduced.

7.1.7 It is assumed that under normal circumstances a ship uses only one bower anchor and chain cable at a time.

7.1.8 All anchors and chain cables are to be tested at establishments and on machines recognised by the Committee and under the supervision of LR’s Surveyors or other Officers recognised by the Committee, and in accordance with Ch 10 Equipment for Mooring and Anchoring of the Rules for Materials.

7.1.9 Test certificates showing particulars of weights of anchors, or size and weight of cable and of the test loads are applied to be furnished. These certificates are to be examined by the Surveyors when the anchors and cables are placed on board the ship.

7.1.10 Steel wire and fibre ropes are to be tested as required by Ch 10 Equipment for Mooring and Anchoring of the Rules for Materials.

7.2.1 Anchors are to be of an approved design. The design of all anchor heads is to be such as to minimise stress concentrations, and in particular, the radii on all parts of cast anchor heads are to be as large as possible, especially where there is considerable change of section.

7.2.2 Anchors which must be specially laid the right way up, or which require the fluke angle or profile to be adjusted for varying types of sea bed, will not generally be approved for normal ship use, but may be accepted for offshore units, floating cranes, etc. In such cases suitable tests may be required.

7.2.3 The mass of each bower anchor given in Table 13.7.2 Equipment - Bower anchors and chain cables is for anchors of equal mass. The masses of individual anchors may vary by ± 7 per cent of the masses given in the Table, provided that the total mass of the anchors is not less than would have been required for anchors of equal mass.

7.2.4 The mass of the head, including pins and fittings, of an ordinary stockless anchor is to be not less than 60 per cent of the total mass of the anchor.

7.2.5 When stocked bower or stream anchors are to be used, the mass excluding the stock is to be not less than 80 per cent of the mass given in Table 13.7.2 Equipment - Bower anchors and chain cables for ordinary stockless bower anchors. The mass of the stock is to be 25 per cent of the total mass of the anchor, including the shackle, etc. but excluding the stock.

7.2.6 It is recommended that anchor lashings, e.g. a ‘devil’s claw’, be fitted to hold the anchor tight against the hull or the anchor pocket. Anchor lashings are to be designed to resist at least a load corresponding to twice the anchor mass plus 10 m of cable without exceeding 40 per cent of the yield strength of the material.

7.3.1 When high holding power anchors are used as bower anchors, the mass of each such anchor may be 75 per cent of the mass given in the Table for ordinary stockless bower anchors.

7.3.2 Anchor designs for which approval is sought as high holding power anchors are to be tested at sea to show that they have holding powers of at least twice those of approved standard stockless anchors of the same mass. For holding power test requirements relating to high holding power anchors, see Ch 10, 1.3 Anchor holding power tests for HHP and SHHP anchors of the Rules for the Manufacture, Testing and Certification of Materials, July 2022.

7.3.3 The anchor is to be suitable for the ship’s use and is not to require prior adjustment or special placement on the sea bottom.

7.3.4 High holding power anchors are to be of a design that will ensure that the anchors will take effective hold of the sea bed without undue delay and will remain stable, for holding forces up to those required by Pt 3, Ch 13, 7.3 High holding power anchors 7.3.2, irrespective of the angle or position at which they first settle on the sea bed when dropped from a normal type of hawse pipe. In case of doubt, a demonstration of these abilities may be required.

7.4.1 An easy lead of the cables from the windlass to the anchors and chain lockers is to be arranged.

7.4.2 Chain cables may be of mild steel, special quality steel or extra quality steel in accordance with the requirements of Ch 10 Equipment for Mooring and Anchoring of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 and are to be graded in accordance with Table 13.7.3 Chain cable steel grades. The total length of chain cable given in Table 13.7.2 Equipment - Bower anchors and chain cables is to be divided in approximately equal parts between the two bower anchors.

7.4.3 Grade U1 material having a tensile stress of less than 400 N/mm² is not to be used in association with high holding power anchors. Grade U3 material is to be used only for chain 20,5 mm or more in diameter.

7.4.4 Where stream anchors are used in association with chain cable, this cable may be either stud link or short link. Also for Equipment Number ≤ 90, short link chain cables may be used for bower anchors as an alternative to stud link chain cables.

7.4.5 The form and proportion of links and shackles are to be in accordance with Ch 10 Equipment for Mooring and Anchoring of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 .

7.4.6 Where Owners require equipment for anchoring at depths greater than 82,5 m and up to 120 m, the recommendations specified in Pt 3, Ch 13, 10 Anchoring equipment in deep and unsheltered water shall be complied with.

7.4.8 Wire ropes or chain cable are to be used for stream anchors as specified by Table 13.7.4 Equipment – Stream anchors, stream wires, towlines and mooring lines.

7.4.10 Where wire rope is used in lieu of chain cable for anchoring, galvanised wire rope with an independent wire core in accordance with Ch 10, 6 Steel wire ropes of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 is to be used. Wire rope terminal fittings are to comply with an acceptable code or standard. The strength of terminations, connecting fittings, shackles or links is not to be less than that of the anchor line.

7.4.11 The chain locker is to be of adequate capacity and depth to provide an easy direct lead of the cables through the chain pipes and facilitate self-stowing of the cables. The chain locker is to be provided with an internal division so that the port and starboard chain cables can be separately stowed.

7.4.12 The chain locker boundaries are to be watertight up to the weather deck. Where the means of access to the chain locker is located below the weather deck, the access cover and its securing arrangement in general are to be in accordance with recognised standards for watertight manhole with bolted covers (e.g. ISO 5894 Ships and marine technology – Manholes with bolted covers). Butterfly nuts and/or hinged bolts are prohibited as the securing mechanism for the access cover.

7.4.13 The chain locker is to be provided with adequate drainage facilities.

7.5.1 It is recommended that the ship design minimum breaking load, length and number of mooring lines provided on board ships with equipment number of less than or equal to 2000 be not less than those specified in Table 13.7.4 Equipment – Stream anchors, stream wires, towlines and mooring lines. The Equipment Number is to be calculated in accordance with Pt 3, Ch 1, 7.1 Calculation of Equipment Number. Deck cargoes at the ship nominal capacity condition are to be included in the determination of side-projected area A to be used in this sub-Section including the equipment number calculations. The nominal capacity condition is defined in Pt 3, Ch 13, 9.1 General 9.1.7 and the ship design minimum breaking load is defined in Pt 3, Ch 13, 9.1 General 9.1.8.

7.5.2 It is the Owner and designer’s responsibility to ensure the adequacy of the mooring equipment. The adequacy of minimum recommended mooring lines in this sub-section needs to be verified based on assessments carried out for the individual mooring arrangement, expected shore-side mooring facilities and design environmental conditions for the berth.

7.5.4 It is permitted to reduce the individual mooring line lengths specified by Table 13.7.4 Equipment – Stream anchors, stream wires, towlines and mooring lines by up to 7 per cent provided the total length of mooring lines is not less than the total length, if all the lines were of equal given lengths.

7.5.5 As an alternative to the minimum recommendations for mooring lines prescribed in this sub-Section, the minimum recommendations for mooring lines may be determined by direct mooring analysis in accordance with the procedure given in Appendix A of IACS Recommendation 10 Chain Anchoring, Mooring and Towing Equipment.

7.6.1 The recommended ship design minimum breaking load, length and number of mooring lines for ships with equipment number greater than 2000, calculated in accordance with Pt 3, Ch 1, 7.1 Calculation of Equipment Number are provided in this sub-Section. Deck cargoes at the ship nominal capacity condition are to be included in the determination of side-projected area A to be used in the equipment number calculations. The nominal capacity condition is defined in Pt 3, Ch 13, 9.1 General 9.1.7 and the ship design minimum breaking load is defined in Pt 3, Ch 13, 9.1 General 9.1.8.

7.6.5 The maximum wind speed V_w is representative of the mean wind speed over a 30 second period from any direction and at a height of 10 m above the ground. The current speed considered is a representative of the maximum current speed acting on bow or stern (±10°) at a depth of one-half of the mean draught. Furthermore, it is considered that the ships are moored to solid piers that provide shielding against cross currents.

7.6.6 Additional loads caused by higher wind or current speeds, cross currents, additional wave loads, or reduced shielding from non-solid piers, for example are to be specially considered. Consideration is also to be given to the fact that unfavourable mooring layouts can significantly increase the loads on individual mooring lines.

Figure 13.7.1 Typical mooring arrangement

7.6.10 The total number of head, stern and breast lines is specified as:

n

=

where

A1

=

side projected area as defined by Pt 3, Ch 13, 7.6 Mooring lines (Equipment Number > 2000) 7.6.3

However, for oil tankers, chemical tankers, bulk carriers and ore carriers the total number of head, stern and breast lines is to be taken as:

n

=

The total number of head, stern and breast lines is to be rounded to the nearest whole number. The number may be increased or decreased in conjunction with an adjustment to the ship design minimum breaking load. The adjusted ship design minimum breaking load, , is to be taken as:

	=
	=

where

MBLSD	=	MBL SD or , if the intended ship design minimum breaking load is different as provided by Pt 3, Ch 13, 7.6 Mooring lines (Equipment Number > 2000) 7.6.8 or Pt 3, Ch 13, 7.6 Mooring lines (Equipment Number > 2000) 7.6.9
n	=	number of lines for the considered ship type as calculated by the above formula without rounding
n**	=	increased or decreased total number of head, stern and breast lines

Vice versa, the ship design minimum breaking load of head, stern and breast lines may be increased or decreased in conjunction with an adjustment to the number of lines.

7.6.12 The length of mooring lines is to be taken as 200 m. It is permitted to reduce the length of individual mooring line by up to 7 per cent provided that the total length of mooring lines is not less than the total length, if all the lines were of equal given lengths.

7.6.13 As an alternative to the minimum recommendations for mooring lines prescribed in this sub-Section, the minimum recommendations for mooring lines may be determined by direct mooring analysis in accordance with the procedure given in Appendix A of IACS Recommendation 10 ‘Chain Anchoring, Mooring and Towing Equipment’.

7.7.1 The recommendations with respect to the mooring arrangement and mooring winches are provided by this sub-Section.

7.7.2 Mooring lines in the same service (e.g. breast lines) are to be of the same characteristics in terms of strength and elasticity.

7.7.3 As far as possible, a sufficient number of mooring winches is to be fitted so as to allow all mooring lines to be belayed on winches. This allows for an efficient distribution of the load to all mooring lines in the same service and for the mooring lines to shed the load before they break. If the mooring arrangement is designed such that mooring lines are partly to be belayed on bitts or bollards, it is to be understood that these lines may not be as effective as the mooring lines belayed on winches.

7.7.4 In the case of ships with Rule length L greater than 90 m, all ropes having breaking strengths in excess of 736,0 kN and used in normal mooring operations are to be handled by, and stored on, suitably designed winches. Alternative methods of storing shall give due consideration to the difficulties experienced in manually handling ropes having breaking strengths in excess of 490,0 kN.

7.7.5 The mooring winch is to be fitted with brakes, the holding capacity of which is sufficient to prevent unreeling of the mooring line when the rope tension is equal to 80 per cent of the ship design minimum breaking load of the rope as fitted on the first layer. The winch is to be fitted with brakes that will allow for the reliable setting of the brake rendering load.

7.7.6 For powered winches the maximum hauling tension which can be applied to the mooring line (the reeled first layer) is to be not less than 2/9, nor to be more than, 1/3, of the rope's ship design minimum breaking load. For automatic winches these figures apply when the winch is set to the maximum power with automatic control.

7.7.7 For powered winches on automatic control, the rendering tension which the winch can exert on the mooring line (the reeled first layer) is not to exceed 1,5 times, nor be less than 1,05 times, the hauling tension for that particular power setting of the winch. The winch is to be marked with the range of rope strengths for which it is designed.

7.7.8 Mooring lines are to have a straight lead from the mooring drum to the fairlead as far as practicable.

7.7.9 When a mooring line changes direction, the contact surface on the fitting shall have a large radius so as to minimise the wear experienced by the mooring lines. Recommendations from the rope manufacturer for the intended rope type are also to be complied with.

7.8.1 The recommended towlines are given in Table 13.7.4 Equipment – Stream anchors, stream wires, towlines and mooring lines and are intended as ship’s own towline, for being towed by a tug or another ship. It is the Owner and designer's responsibility to ensure the adequacy of towing lines based on assessments carried out for the individual towing arrangement. This sub-Section also provides recommendations with respect to the towing arrangement.

7.8.2 The equipment number used for the selection of the towline is to be calculated in accordance with Pt 3, Ch 1, 7.1 Calculation of Equipment Number. Deck cargo as given by the Loading Manual is to be included in the determination of side-projected area A to be used in the equipment number calculations.

7.8.3 Towing lines are to be led through a closed chock. The use of open fairleads with rollers or closed roller fairleads is to be avoided.

7.8.4 For the purpose of towing, it is recommended to provide at least one chock close to centreline of the ship forward and aft. It is also beneficial to provide additional chocks on port and starboard side at the transom and at the bow.

7.8.5 Towing lines are to have a straight lead from the towing bitt or bollard to the chock.

7.8.6 For the purpose of towing, bitts or bollards serving a chock are to be located slightly offset and at a distance of at least 2 m away from the chock, see Figure 13.7.2 Typical towing arrangement.

7.8.7 Attention is to be given to the arrangement of the equipment for towing and mooring operations in order to prevent interference of mooring and towing lines as far as practicable. It is beneficial to provide dedicated towing arrangements separate from the mooring equipment.

Figure 13.7.2 Typical towing arrangement

7.8.8 For emergency towing arrangements for tankers, reference is made to Pt 3, Ch 13, 12 Emergency towing arrangements. For all ships other than tankers, towing arrangements of sufficient strength are to be provided fore and aft, as defined by ‘other towing service’ in Pt 3, Ch 13, 9.2 Towing.

7.9.1 Towlines and mooring lines are to be of wire, natural fibre or synthetic fibre construction or of a mixture of wire and fibre. For synthetic fibre ropes it is recommended that lines with reduced risk of recoil (snap-back) be used to mitigate the risk of injuries or fatalities in the case mooring line failure.

7.9.2 Notwithstanding the strength recommendations in Pt 3, Ch 13, 7.5 Mooring lines (Equipment Number ≤ 2000), Pt 3, Ch 13, 7.6 Mooring lines (Equipment Number > 2000) and Pt 3, Ch 13, 7.8 Towline and towing arrangement, no fibre rope shall be less than 20 mm in diameter. For polyamide ropes the line design break force is to be increased by 20 per cent and for other synthetic ropes by 10 per cent to account for strength loss due to, among other causes, aging and wear. The line design break force is defined in Pt 3, Ch 13, 9.1 General 9.1.9.

7.9.3 Wire ropes used for towlines and mooring lines are generally to be of a flexible construction with not less than 144 wires in six strands with seven fibre cores for strengths up to 490 kN, and 222 wires in six strands with one fibre core for strengths exceeding 490 kN. The wires laid round the fibre centre of each strand are to be made up in not less than two layers.

7.9.4 Wire ropes for towlines and mooring lines used in association with mooring winches (on which the rope is stored on the winch drum) are to be of suitable construction.

7.9.5 The towing and mooring lines are to be tested in accordance with Ch 10, 6 Steel wire ropes and Ch 10, 7 Fibre ropes of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 for wire ropes and fibre ropes, respectively.