ASTM F957-91(R2018) pdf free download

ASTM F957-91(R2018) pdf free download.Standard Specification for Gong, Sound Signaling
1. Scope
1.1 This specification covers gongs for use on ships 100 m or more in length, as required by International Regulations (see Appendix X1). 1.2 For consistency with International Regulations, all mea- surements are in SI units. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Materials and Manufacture
4.1 Materials: 4.1.1 The gong cylinder, brackets, clapper rod, “U” bracket, washers, and clapper support pin shall be of stainless steel, in accordance with Specification A167, UNS number S31600. 4.1.2 The clapper mass shall be of cast alloy steel in accordance with Specification A276, UNS S31600. 4.1.3 The support bolt, nut, flat washer, and cotter pins shall be of stainless steel compatible with the other materials. 4.2 Welding: 4.2.1 Welding shall be of the type and sizes shown in Fig. 1 and Fig. 2, and in accordance with Standard AWS D1.1. 4.3 Manufacture: 4.3.1 Fig. 1 shows the general arrangement ofthe assembled gong, as well as details of the gong cylinder. Fig. 2 shows details of the brackets, clapper, and miscellaneous fittings. 4.3.2 The gong cylinder may be made from two pieces welded together, instead of one piece. Two piece construction shall be annealed to remove residual stresses. 4.3.3 Sharp corners and edges of the cylinder shall be broken. 4.3.4 The two brackets shall be welded together before being welded to the cylinder. The flanged ends of the brackets may be left straight and not shaped to the cylinder. 4.3.5 The clapper mass shall be welded to the clapper rod before forming the second eye. 4.4 Extra Parts: 4.4.1 Two extra supporting nuts and flat washers shall be furnished with each gong.
X1.1 For general information, the following is quoted from U. S. Coast Guard Commandant Instruction M16672.2A: Navigation Rules, International-Inland. X1.1.1 Division II, Part D, Rule 33—Equipment for Sound Signals: X1.1.1.1 A vessel of 12 m or more in length shall be provided with a whistle and a bell and a vessel of 100 m or more in length shall, in addition, be provided with a gong, the tone and sound of which cannot be confused with that of the bell. The whistle, bell, and gong shall comply with the specifications in Annex III to these regulations. The bell or gong, or both, may be replaced by other equipment having the same respective sound characteristics, provided that manual sounding of the required signals shall always be possible. X1.1.1.2 A vessel of less than 12 m in length shall not be obliged to carry the sound signalling appliances prescribed in X1.2.1 of this rule but if she does not, she shall be provided with some other means of making an efficient sound signal. X1.1.2 Division II, Part E, Annex III—Technical Details of Sound Signal Appliances: International Rules: X1.1.2.1 Whistles (not germane to this specification. Therefore, not quoted). X1.1.2.2 Bell or Gong: (a) Intensity of Signal—A bell or gong, or other device having similar sound characteristics shall produce a sound pressure level of not less than 110 dB at a distance of 1 m from it.