Section 8 Anchor windlass design and testing

8.1.1 A windlass, capstan or winch used for handling anchors, suitable for the size of chain cable required by Pt 3, Ch 5, 6 Anchor cable and complying with the following criteria is to be fitted. Where Owners require equipment significantly in excess of Rule requirements, it is their responsibility to specify increased windlass power.

8.1.2 The design, construction and testing of windlasses are to conform with a relevant National or International Standard or code of practice acceptable to LR. To be considered acceptable, the standard, or code of practice, is to specify criteria for evaluation of stresses, performance and testing.

8.1.3 Operation and maintenance procedures for the anchor windlass are to be incorporated in the vessel operations manual.

8.1.4 Windlasses may be hand or power operated, subject to the requirements of Pt 3, Ch 5, 8.4 Windlass design 8.4.3.

8.1.5 Where steel wire rope is used in lieu of chain cable, a suitable winch with sufficient drum capacity to store the length of wire rope fitted is to be provided.

8.1.6 The windlass, anchoring capstans and winches are to be of types approved by LR.

8.1.7 On craft equipped with anchors having a mass of over 50 kg windlass(es) of sufficient power and suitable for the type and size of chain cable are to be fitted. Arrangements with anchor davits will be specially considered.

8.3.1 Materials used in the construction of torque-transmitting and load-bearing parts of windlasses are to comply with LR's Rules for the Manufacture, Testing and Certification of Materials, July 2022 or an appropriate National or International Standard acceptable to LR, provided that the Standard gives reasonable equivalence to the requirements of LR. The proposed materials are to be indicated in the construction plans and are to be approved in connection with the design. All such materials are to be certified by the material manufacturers and are to be traceable to the manufacturers’ certificates.

8.3.2 Weld joint designs are to be shown in the submitted construction plans and are to be appraised in association with the approval of the windlass design in accordance with an appropriate National or International Standard acceptable to LR. .

8.3.3 Welding procedures, welding consumables and welders are to comply with the LR Rules for the Manufacture, Testing and Certification of Materials, July 2022 or an appropriate National or International Standard acceptable to LR.

8.3.4 The degree of non-destructive examination of welds and post-weld heat treatment, if any, are to be specified and submitted for consideration.

8.4.1 In addition to the requirements of the National or International Standard or code of practice acceptable to LR (see Pt 3, Ch 5, 8.1 General 8.1.2) the following performance requirements are to be complied with:

1. Holding Loads: Calculations are to be made to show that, in the holding condition (single anchor, brake fully applied and chain cable lifter declutched) and under a load equal to 80 per cent of the specified minimum breaking strength of the chain cable, the maximum stress in each load bearing component will not exceed the maximum permissible yield. For installations fitted with a chain cable stopper, 45 per cent of the specified minimum breaking strength of the chain cable may instead be used for the calculation.
2. Inertia Loads: The design of the drive train, including prime mover, reduction gears, bearings, clutches, shafts, cable lifter and bolting is to consider the dynamic effects of sudden stopping and starting of the prime mover or chain cable, so as to limit inertial load.
3. Continuous Duty Pull: The windlass is to have sufficient power to exert a continuous duty pull , Z_cont1, over a period of 30 minutes corresponding to the grade and diameter, d_c, of the chain cables as follows:
   1. for specified design anchorage depths up to 82,5 m when using ordinary stockless anchors: :

      Chain cable grade	Zcont1 (N)
      U1	37,5d c 2
      U2	42,5d c 2
      U3	47,5d c 2
      unit of d	mm

   2. for specified design anchorage depths greater than 82,5 m a continuous duty pull Z_cont2 is:
      
      where

      dc	=	is the chain diameter, in mm
      Da	=	is the specified design anchorage depth, in metres

   The anchor masses are assumed to be the masses as given in Table 5.6.1 Chain cable. The value of Z_cont is based on the hoisting of one anchor at a time, assumes that the effects of buoyancy and hawse pipe efficiency (assumed to be 70 per cent) have been accounted for. In general, stresses in each torque-transmitting component are not to exceed 40 per cent of yield strength (or 0,2 per cent proof stress) of the material under these loading conditions.

4. Overload Capability: The windlass prime mover is to be able to provide, for a period of at least two minutes, the necessary temporary overload capacity for breaking out the anchor. This temporary overload capacity is to be a pull equal to the greater of:

   1. short term pull:

      1,5 times the continuous duty pull as defined in Pt 3, Ch 13, 8.4 Windlass design 8.4.1.(c), or

   2. anchor breakout pull:

      
      where:

      Lc	=	is the total length of chain cable on board, in metres, as given by Table 5.6.1 Chain cable
      W a	=	is the mass of bower anchor(kg) as given in Table 5.5.1 Anchors.

   Note The speed in this period may be lower than normal.
5. Hoisting Speed: The mean speed of the chain cable during hoisting of the anchor and cable is to be 0,15 m/s.
6. Brake Capacity: The capacity of the windlass brake is to be sufficient to stop the anchor and chain cable when paying out the chain cable in a controlled manner. Where a chain cable stopper is not fitted, the brake is to produce a torque capable of withstanding a pull equal to 80 per cent of the specified minimum breaking strength of the chain cable without any permanent deformation of strength members and without brake slip. Where a chain cable stopper is fitted, 45 per cent of the breaking strength may instead be applied. The following simplified formula is to be used to calculate the required brake capacity:

   K _b d _c ² (44 − 0,08d _c) N

   where K _b is given in Table 5.8.1 Values of K_b .

8.4.2 As an alternative to conducting the engineering analyses required by Pt 3, Ch 5, 8.4 Windlass design 8.4.1, approval of the windlass mechanical design can be based on a type test, in which case the testing procedure is to be submitted for consideration.

8.4.3 Calculations for torque transmitting components are to be based on 1500 hours of operation with a nominal load spectrum factor of K_m = 1,0. Alternatively unlimited hours with a nominal load spectrum factor of K_m = 0,8 can be applied.

8.4.4 The following criteria are to be used for gearing design:

1. Torque is to be based on the performance criteria specified in Pt 3, Ch 5, 8.4 Windlass design 8.4.1.

2. The use of an equivalent torque, T_eq, for dynamic strength calculations is acceptable but the derivation is to be submitted to LR for consideration.

3. The application factor for dynamic strength calculation, K_A, is to be 1,15.

4. Calculations are to be based on 1500 hours of operation.

5. The static torque is to be 1,5 x T _n where T_n is the nominal torque.

6. The minimum factors of safety for load capacity of spur and helical gears, as derived using ISO 6336 or a relevant National or International standard acceptable to LR, are to be 1,5 for bending stress and 0,6 for contact stress.

Gears intended to transmit power greater than 100 kW are to be certified by LR, and the gears are to meet the requirements of Pt 11, Ch 1 Gearing.

8.5.1 Hand-operated windlasses are only acceptable if the effort required at the handle does not exceed 150N for raising one anchor at a speed of not less than 2 m/min and making about thirty turns of the handle per minute.

8.5.2 windlasses suitable for operation by hand as well as by external power are to be so constructed that the power drive cannot activate the hand drive.

8.5.3 Where a chain stopper is fitted, the windlass braking system is to have sufficient brake capacity to ensure safe stopping when paying out the anchor and chain. It is the Master's responsibility to ensure that the chain stopper is in use when riding at anchor. At clearly visible locations on the bridge and adjacent to the windlass control position, the following notice is to be displayed adjacent to the windlass control position, and at clearly visible locations on the bridge if the windlass can be operated remotely:

'The brake is rated to permit controlled descent of the anchor and chain only. The chain stopper is to be used at all times whilst riding at anchor.'

In all other cases the windlass is to be capable of providing a continuous duty pull as required by Pt 3, Ch 5, 8.4 Windlass design 8.4.1.(c).

8.6.2 Where Pt 3, Ch 5, 8.6 Alternative windlass design requirements for Special Service Craft for restricted service 8.6.1 applies, the windlass overload capacity is to meet the requirement of the short-term pull as defined in Pt 3, Ch 5, 8.4 Windlass design 8.4.1.(d) using the continuous duty pull defined in Pt 3, Ch 5, 8.6 Alternative windlass design requirements for Special Service Craft for restricted service 8.6.1.

8.6.3 All aspects of windlass design except those referenced above are to meet the requirements of Pt 3, Ch 5, 8.4 Windlass design.

8.7.1 Hydraulic systems, where employed for driving windlasses are to comply with the requirements of Pt 15, Ch 3, 6 Lubricating/hydraulic oil systems.

8.8.1 Electric motors are to meet the requirements of Pt 16, Ch 2, 9 Rotating machines. Motors exposed to weather are to have enclosures suitable for their location, see also Pt 16, Ch 2, 1.11 Location and construction 1.11.1.

8.8.2 Motor branch circuits are to be protected in accordance with the applicable Rules, and cable sizing is to be in accordance with the requirements of the Pt 16, Ch 2, 11 Electric cables, optical fibre cables and busbar trunking systems (busways).

8.9.1 All control devices are to be capable of being controlled from readily accessible positions and protected against unintentional operation.

8.9.2 The maximum travel of the levers is not to exceed 600 mm if movable in one direction only, or 300 mm to either side from a central position if movable in both directions.

8.9.3 Wherever practical, the lever is to move in the direction of the intended movement. If this cannot be achieved, then it is to move towards the right when hauling and towards the left when paying out.

8.9.4 For lever-operated brakes, the brake is to engage when the lever is pulled and disengage when the lever is pushed. The physical effort on the brake for the operator is not to exceed 160 N.

8.9.5 For pedal-operated brakes, the maximum travel is not to exceed 250 mm and the physical effort for the operator is not to exceed 320 N.

8.9.6 The handwheel or crankhandle is to actuate the brake when turned clockwise and release it when turned counterclockwise. The physical effort for the operator is not to exceed 250 N for speed regulation and 500 N at any moment.

8.9.7 When not provided with automatic sequential control, separate push-buttons are to be provided for each direction of operation.

8.9.8 The push-buttons are to actuate the machinery when depressed, and stop and effectively brake the machinery when released.

8.9.9 The above-mentioned individual push-buttons may be replaced by two ‘start’ and ‘stop’ push-buttons.

8.9.10 Control systems, whether electric, pneumatic or hydraulic, are to comply with the general requirements of Pt 6, Ch 1, 2 General requirements.

8.10.1 Where applicable, moving parts of windlass machinery are to be provided with suitable railings and/or guards to prevent injury to personnel.

8.10.2 Protection is to be provided for preventing persons from coming into contact with surfaces having temperatures over 50°C.

8.10.3 Steel surfaces not protected by lubricant are to be protected by a coating in accordance with the requirements of a relevant National or International Standard acceptable to LR.

8.10.4 For arrangements of power transmission systems and relief requirements, see Pt 5, Ch 14, 9.1 General of the Rules for Ships.

8.10.5 Electrical cables installed in exposed locations on open deck are to be provided with effective mechanical protection.

8.10.6 Means are to be provided to contain potential debris resulting from severe damage of the prime mover due to over-speed in the event of uncontrolled rendering of the cable, particularly when an axial piston type hydraulic motor forms the prime mover.

8.10.7 An arrangement to release the anchor and chain in the event of windlass power failure is to be provided. Windlasses are to be fitted with couplings which are capable of disengaging between the cable lifter and the drive shaft. Hydraulically or electrically operated couplings are to be capable of being disengaged manually.

8.10.8 The design of the windlass is to be such that the following requirements or equivalent arrangements will minimise the probability of the chain locker or forecastle being flooded in bad weather:

1. a weathertight connection can be made between the windlass bedplate, or its equivalent, and the upper end of the chain pipe, by means of a cover or seal, and
2. access to the chain pipe is adequate to permit the fitting of a cover or seal, of sufficient strength and proper design, over the chain pipe while the ship is at sea.

8.11.1 Windlasses are to be inspected during fabrication at the manufacturers’ facilities by a Surveyor for conformance with the approved plans. Acceptance tests, as specified in the specified Standard (see Pt 3, Ch 5, 8.1 General 8.1.2), are to be witnessed by the Surveyor and include the following tests, as a minimum:

1. No-load test. The windlass is to be run without load at nominal speed in each direction for a total of 30 minutes. If the windlass is provided with a gear change, an additional run in each direction for 5 minutes at each gear change is required.
2. Load test. The windlass is to be tested to verify that the continuous duty pull, overload capacity and hoisting speed as specified in Pt 3, Ch 5, 8.4 Windlass design 8.4.1 can be achieved.

   Where the manufacturer’s works does not have adequate facilities, these tests, including the adjustment of the overload protection, can be carried out on board ship. In these cases, functional testing in the manufacturer’s works is to be performed under no-load conditions.

3. Brake capacity test. The holding power of the brake is to be verified through testing if not verified by calculation.

8.11.2 Windlass performance characteristics specified in Pt 3, Ch 5, 8.11 Shop inspection and testing 8.11.1 are based on the following assumptions:

1. one cable lifter only is connected to the drive shaft;

2. continuous duty and short term pulls are measured at the cable lifter;

3. hawse pipe efficiency assumed to be 70 per cent.

8.12.1 Each windlass is to be tested under working conditions after installation on board to demonstrate satisfactory operation. Each unit is to be independently tested for braking, clutch functioning, lowering and hoisting of the chain cable and anchor, proper riding of the chain over the cable lifter, proper transit of the chain through the hawse pipe and the chain pipe, and effecting proper stowage of the chain and the anchor. It is to be confirmed that anchors properly seat in the stored position and that chain stoppers function as designed if fitted. The braking capacity is to be tested by intermittently paying out and holding the chain cable by means of the application of the brake.

8.12.2 The mean hoisting speed, as specified in Pt 3, Ch 5, 8.4 Windlass design 8.4.1.(e) is to be measured and verified. For testing purposes, the speed is to be measured over two shots of chain cable and initially with at least three shots of chain (82,5 m or 45 fathoms in length) and the anchor submerged and hanging free. Following trials, the ship will be eligible to be assigned a descriptive note specified design anchorage depth . . . metres, which will be entered in column 6 of the Register Book.

8.12.3 Load testing is to be carried out if this was not previously completed as required by Pt 3, Ch 5, 8.11 Shop inspection and testing 8.11.1.(b).

8.12.4 Where the depth of water in the trial area is inadequate, suitable equivalent simulating conditions will be considered as an alternative.

8.13.1 The windlass is to be permanently marked with the following information:

1. The size designation of the windlass (e.g. 100/3/45, where 100 is the nominal diameter of the chain cable in mm, 3 is the numeral in the chain cable steel grade U3, and 45 refers to the holding load expressed as a percentage of the chain cable breaking load).
2. Maximum anchorage depth, in metres.

8.14.1 The windlass is to be efficiently bedded and secured to the deck. The thickness of the deck in way of the windlass may need to be increased, and the supporting structure for the anchor windlass to be examined for the brake holding loads specified by Pt 3, Ch 5, 8.4 Windlass design 8.4.1. The allowable stresses specified in Table 5.6.3 Allowable stresses in windlass and chain stopper supporting structure are to be used to derive the net scantlings of the supporting structure. The capability of the supporting structure to withstand buckling is also to be assessed. Strength and buckling calculations are to be submitted for consideration. The structural design integrity of the bedplate is the responsibility of the Builder and windlass manufacturer.