ISO 13729:2012 download free.Ships and marine technology – Ships mooring and towing fittings – Closed chocks.
ISO 13729 specifies the design. stze and technical requirements for dosed chocks Installed to lead the moorwig and towing rope of a ship.
2 Normative references
The following referenced documents are indispensab’e for the application of ISO 13729 For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IMO Circijar MSCCirc.1175, Guidance on shØboani towing and moonrg equipment
3 Terms and definitions
For the purposes of ISO 13729, the following terms and definitions apply.
3.1
sat. working lead
SW’.
maximum load en kN on the rope that should normally be applied in ser’vce condItions
4 Classification
4.1 Type
The closed chock is to be classified by its installation site as foliows:
— Type A – Deck-mounted closed chock;
— Type B — Bulwark-mounted closed chock.
4.2 NomInal sizes
The nominal sizes, L x H x 1) of closed chocks are denoted by reference to the width and heiit of the openmg and depth of the chock in millimetres. For the closed chocks having the same size, the alphabetical character is followed by nominal stze for the different SWL.
The nominal sizes are:
25Oc2GOx214, 300x250x286. 350x250x333. 400x250x381. 450x250x381, 500x250x381, 400x250x428.
450x250x428. 500x250x428. 5OOx4OO428, 500x250x525A. 500x400x525A, 5OO25Ox525B, 500x400x5258
5 Dimensions
Closed chocks have dimensions and particulars In accordance with Tables 1 and 2. and Figures 1 and 2
6 Materials
The following inatenal is to be used for manufacturing the closed chocks:
— Chock: steel casting material having a yield point of not less than 235 t’Umm or equivalent
The carbon contents of the steel casting shall not be more than 023 % considering weldability.
7 Construction
The foundation of the dosed chocks shall be determined by considering the actual load decbon The foundation and welding connections to the hut shall be guaranteed reliable transmission of the maximum loading of the closed chocks to hull construction without any plastic deformation or cracks.
8 Manufacturing and Inspection
8.1 All surfaces of the dosed chocks tncludrng welding shall be free from any visible flaws or inperfections.
82 All surfaces In contact with the ropes shall be free from surface roughness or irregularities likely to cause damage to the ropes by abrasion.
8.3 The dosed chocks shall be coated externally with an anti-corrosion protective fInish.
9 MarkIng
9.1 The SWI. intended for the use of the closed chocks shall be noted in the towing and mooring plan avallable on board for the guidance of the shipmaster. as specified in MSC/Circ.1175.
92 The actual SWLon board shall be determined by considering the foundation and under deck reintorcemeni and It shall be marked on the towing and moorIng plan. The actual SM. shall not be over the SM. indicated In the International Standard.
9.3 The dosed chocks shall be dearly marked with their SWL by weld bead or equivalent. The SM. shall be expressed in tonnes (letter T) and be placed so that it is not obscured duainq operation of the fitting.
EXAMPLE SWL XXXI
9.4 the SWL mark shall b. provided on the foundation of the chock or on deck.
9.5 The radii of edges and corners not shown In Figure 1 shall be of rmnitnum 25 mm.