cable 61 extends from the bracket 66 over the sheave 55 to an inner end 74 of the movable boom section 12c when the winch 48 is energized the cable 60 pulls the movable boom section 12b from the retracted position shown in fig2 to the extended position shown in fig3 the outward movement of the section 12b also causes the cable 61 to pull the outer section 12c of the boom assembly from the retracted position shown in fig2 to the extended position shown in fig3 the winches 48 50 each include a pressure release brake not shown which prevents rotational movement of the winches when they are not energized the cable 62 extends from the winch 49 over the sheave 56 to the winch 50 when the winch 49 is actuated and the winch 50 is free wheeling the trolley 43 is moved from the position shown in fig2 to the position shown in fig3 and the pipeline assembly 11 is moved from the folded position shown in fig1 to an extended position where the outer end of the pipe 22 extends over the outer end of the boom assembly 12 when the winch 50 is actuated and the winch 49 is free wheeling the trolley 43 and the pipeline 11 moves from the extended position back to the folded position shown in fig1 when the winch 50 is locked the winch 48 is free wheeling and the winch 49 is actuated the boom sections 12c and 12b are retracted back into the fixed boom section 12a by the winch 49 thereby moving the boom from the extended position shown in fig3 to.