Patent ID: 7455187

Claim:
A traveling crane comprising: a base machine having a boom derrickably attached thereto at one end of the boom and a jib derrickably attached to the other end of the boom; and a jib derricking device for raising and lowering the jib, the jib derricking device comprising: a jib derricking winch for derricking the jib; a jib derricking rope wound/rewound by the jib derricking winch; lower and upper spreaders around which the jib derricking rope is routed for raising and lowering the jib; a strut attached to the top of the boom rotatably about a horizontal axis in a fore-and-aft direction; a jib guyline connecting the strut to the jib; and a strut guyline connecting the strut to the upper spreader, wherein during assembling/disassembling of the crane, the upper spreader is constructed to move along the upper surface of the boom between a position adjacent to a boom anchor and a position, at which the strut guyline is fixed and unfixed, adjacent to a far end of the boom, and wherein the upper spreader is provided with support legs arranged to protrude downwardly for supporting the spreader on the boom with support leg guide members arranged on the upper surface of the boom for guiding the support legs.