171. Crawling boards.- The employer shall ensure at a construction site of a building or other construction work that- (a) all crawling boards used for work on steep roofs are of adequate strength, made of sound material and of the type approved for the purpose of their use as per relevant national standards; (b) crawling board referred to in clause (a) are kept in good repairs and inspected by a responsible person before being taken into use; (c) crawling board referred to in clause (a) is secured to a steep roof on which it is used by ridge hooks or other effective means; (d) a firmly fastened life line of adequate strength is strung beside each crawling board referred to in clause (a) throughout its length while using such crawling boards. | 
