BS ISO 13733:2020 pdf free.Ships and marine technology一Ship’s mooring and towing fittings一Universal fairleads with upper roller.
BS ISO 13733 1 Scope This document specifies the types, nominal sizes, dimensions and materials, as well as construction,manufacturing and marking requirements, for universal fairleads with upper roller(s) installed to lead the mooring rope of a ship.2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.IMO Circular MSC/Circ.1175, Guidance on shipboard towing and mooring equipment 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: 一ISO Online browsing platform: available at https://www.iso.org/obp 一IEC Electropedia: available at http://www.electropedia.org/ 4 Classification 4.1 Type Depending on the construction, universal fairleads shall be classified as belonging to one of the following four types: a) Type 4R: with one rope-passing opening;  b) Type 5RL: with one rope-passing opening with an additional guide roller on the left side; c) Type 5RR: with one rope-passing opening with an additional guide roller on the right side;d) Type 7R: with two rope-passing openings.4.2 Nominal sizes The nominal sizes, Dn, of universal fairleads are denoted by reference to the outside diameter of the main roller, in millimetres, in terms of the nearest number drawn from a basic series of preferred numbers. For the universal fairleads having the same roller diameter, the code, i.e. 4R, 5RL, 5RR or 7R, is followed by the nominal size for the different SWLs.9.1 The safe working load (SWL) for the intended use of the universal fairleads shall be noted in the towing and mooring plan available on board for the guidance of the shipmaster as specified in IMO circular MSC/Circ.1175. 9.2 The actual SWL on board shall be determined by considering the foundation and under deck reinforcement, and it shall be marked on the towing and mooring plan. The actual SWL shall not be over the SWL in this document. 9.3 The universal fairleads shall be clearly marked with their SWL by weld bead or equivalent. The SWL shall be expressed in tonnes (symbol ‘t’] and be placed so that it is not obscured during operation of the fitting. BS ISO 13733 pdf download.