1.36D MISCELLANEOUS METALWORK (Continued) D. Standard designs of spiral stairways are shown on the following drawings: Reference E. A ladder is used where it is necessary to ascend or descend at an angle (1) Maximum length for single ladder, 30 feet. (2) Minimum clear width from center line of ladder to either side, 15 inches. (3) Clearances as indicated on Drawing No. 103-D-6. (4) Ladders greater than 25 feet long should be equipped with a cage or basket; however, where these ladders are used infrequently, the question of installing cages should be determined on the basis of individual requirements. F. Designs of ladders are indicated on the following drawings: Ladders Reference |