Abstract: The device comprises a detachable sling consisting of an upper part and a lower part. The upper part carries a self-propelled trolley. The lower part of the sling is articulated by links with supporting shoes also articulated to each other by links. The shoes are arranged symmetrically with relation to the longitudinal axis of the pipeline and are moved by hydraulic cylinders, both ends of each cylinder connecting the lower part of the sling with one of the shoes by means of ball joints. Both parts of the sling are interconnected with each other by projections and slots installed, respectively, on the upper and lower parts of the sling.