ASTM F957-91(2023) PDF

ABSTRACT This specification covers gongs for use on ships of certain length, as required by International Regulations. The gong cylinder, brackets, clapper rod, "U" bracket, washers, and clapper support pin shall be made of stainless steel. The clapper mass shall be made of cast alloy steel. In addition, the support bolt, nut, flat washer, and cotter pins shall be made of stainless steel compatible with the other materials. The general arrangement of the assembled gong, as well as details of the gong cylinder, brackets, clapper, and miscellaneous fittings are presented. The sound characteristics of these gongs shall be determined by an acoustic test. These gongs shall be free from cracks, burrs, sharp cutting edges, and other defects affecting their life, appearance, and serviceability. 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 measurements 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 accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.