NFPA 1931-1999 Standard on Design of and Design Verification Test for Fire Department Ground Ladders

NFPA 1931-1999 Standard on Design of and Design Verification Test for Fire Department Ground Ladders. 2-32.2 Folding roof hook assemblies shall be attached to the beams in a manner that does not appreciably weaken the beams, 2-4 Additional Requirements for Extension Ladders Only. These design reqLsrements shall be m addition to the desii requrements specified w Section 2-1. 2-4 .1 Construction. 2-4.1.1 Extension ladders shall be constructed with a permanentty affixed stop that is installed by the manufacturer. The stop shall prevent ladders from overextending. The manufacturer shall determine the location of this permanently affixed stop to ensure that the test requirements of this standard are met when the ladder is extended to maximum extended length. 2-4.1.2 Extension ladders shall not be constructed in a manner or method that necessitates the elimination of a rung on any section. Exception: One of the lower two rungs of the fly section shall be permitted to be replaced by the steel cross bar of a halyard- actuated rung lock system. 2-4.1.3 Extension ladders shall be constructed in a manner so that the rungs of each section shall align with the rungs of other sections when the ladder is extended and pawis are engaged. 2-4.2 Length. 2-4.2.1 The designated length of an extension ladder shall be the maximum extended length along the beams on one side exduding any butt spur. The minus tolerance of the designated length shall not exceed 6 In. (152 mm). In length. 2-43 WIdth. 2-4.2.2 Attic extension ladders shall not exceed 16 ft (4.9 m) 2-4.3.1 Extension ladders shall have a minimum inside width between beams on any section of at ioast 16 in. (406 mm). 2-4.3.2 Attic extension ladders shall have a minimum inside width between beams on any section of not less than 7 in. (190 mm). 2-4.4 Hardware. Hardware shall meet the minimum strength requirements of the ground ladders component parts. Hardware shall be corrosion resistant or protected against corrosion. 2-4.5 Halyard and Pulley. 2-4.5.1 Extension ladders over 16 ft (4.9 m) in designated length shall be equipped with a halyard and pulley system. 2-4.5.2 The pulley shall be attached to the ladder in a manner so as not to appreciably weaken either the rungs or the beams. 2-4.5.3 The pulley shall not be less than 1114 in. (32 mm) in diameter, measured at the base of the sleeve. 2-4.5.4 The halyard shall not be less than...