Current through Register Vol. 54, No.43, October 26, 2024
Section 6.19 - Needle beam scaffolds(a)Platforms. Where the space between needle beams is 12 feet or less, the platform shall be composed of planks at least 10 inches wide and 2 inches thick. Where the span is over 12 feet the cross section of the two planks shall be increased in proportion. Platforms shall not be more than 6 feet in width. In all cases where not nailed or otherwise secured, planks shall be at least 2 feet longer than the span bridged and a hole shall be bored through both ends of every plank. The hole shall be not less than 6 inches from the end and a 5/8 inch bolt at least 8 inches in length shall be placed in it and provided with a tightly fitting nut. The planks shall be laid on the beams with the bolts outside. Where the planks are to be used in a steeply inclined position, they shall be provided with cleats at least 1 3/4 by 2 inches in cross section, spaced not more than 8 inches apart. Provision shall be made for the use of guardrails and toeboards.(b)Needle beams. All needle beams shall be plainly marked to prevent their use for any other purpose. Care shall be taken in handling them to prevent falls and ensuing defects. When the space between needle beams is 12 feet or less, wood needle beams shall be at least 3 inches by 8 inches in cross section with the longer dimension vertical and shall be increased in size when longer or when required for the loads they are to support. Needle beams shall always be in one length, and spliced or built-up beams shall not be used. Provision shall be made to prevent the supporting ropes from slipping over the ends of the beams.(c)Pipe needle beams. Pipe needle beams shall be of unspliced wrought iron or steel pipe, painted and free from rust or scale. When the scaffold span is not more than 12 feet, the pipe shall be at least 3 1/2 inches in diameter; if the span is more than 12 feet and not more than 16 feet, the pipe shall be at least 4 inches in diameter; over 16 feet, the diameter of the pipe shall be correspondingly increased.(d)Ropes. The ropes shall be attached to the needle beams by what is known as a "scaffold hitch" or some other equally effective method, the loose end being firmly tied to a supporting rope by a bowline knot. The rope shall be at least 1 inch in diameter and shall be increased proportionately to the size of the load. The supporting rope shall not be attached to the needle beam at a point less than 1 foot from the end of the beam. In other respects the rope shall conform with the requirements set forth in § 6.31 (relating to cables, ropes, block and tackle).(e)Protection. Protection shall be afforded as set forth in § 6.32 (relating to protection).