Do You Know the Rapid Replacement Method for the Luffing Rope of Large Crawler Cranes?

When lifting extremely heavy loads, large crawler cranes require the use of a superlift mast. During frequent luffing operations, the luffing rope of the crane is prone to wear and wire breakage, necessitating its replacement.

1. Traditional Method for Replacing the Luffing Rope of Crawler Cranes

In the traditional method, replacing the luffing rope involves first dismantling the superlift main boom and then lowering the superlift mast to the ground before the rope can be replaced. This entire process takes at least two days. Considering the high rental costs of large cranes, project timelines, and site constraints, a simpler and more efficient method for replacing the luffing rope is essential.

2. Rapid Method for Replacing the Luffing Rope of Crawler Cranes

(1) Lowering the Main Boom and Superlift Mast

First, lower the main boom to the ground and support it steadily with sleepers. During lowering, pay attention to the positioning of the hook to prevent the main Hoist Rope from derailing and to avoid the hook tipping over and damaging the main hoist rope. Next, lower the superlift mast to as low a height as possible without making contact with the main boom. Finally, disconnect the superlift luffing pulley group from the main boom lacing.

(2) Connecting the New and Old Ropes

First, release the luffing winch rope to lower the luffing pulley group steadily onto the main boom. Securely lash and fix the luffing pulley group to the main boom to prevent it from swinging during the process of reeving the new and old ropes. Next, cut the luffing rope connected to the wedge socket at the head of the superlift mast to facilitate the connection of the new and old ropes. Before cutting, securely bind both sides of the cut point with hemp rope to prevent the rope from whipping due to tension release after cutting. Then, weld a nut onto each end of the new and old luffing ropes. Finally, position the new rope and its drum in front of the superlift main boom. Use an iron wire to wrap back and forth between the nuts on the ends of the new and old ropes, connecting them. The connection should allow free movement to pass smoothly through the pulley group.

(3) Reeving the Luffing Rope

First, slowly operate the luffing winch, allowing the old luffing rope to pull the new rope through the pulley group until the new rope reaches the luffing winch drum. Then, use a hemp rope to pull and secure the new rope. Next, disconnect the iron Wire Connecting the new and old ropes. Finally, release the luffing winch, pull out all the old winch rope from the drum, and coil it on the ground.

(4) Winding the New Rope

First, fix the end of the new rope to the luffing drum. Then, rotate the luffing winch drum to wind the new rope along the groove onto the drum. During the first layer winding, use a small hammer and a crowbar to ensure the luffing rope is tightly wound. Continue operating the luffing drum until an appropriate length of rope remains at the other end of the superlift luffing pulley group, sufficient for installing the wedge socket of the luffing pulley group. Finally, attach the wedge socket to the other end of the new rope and fix the wedge socket to the head of the superlift mast. This replacement method completes the luffing rope replacement in just half a day. It avoids the procedures of dismantling and reinstalling the main boom of the large crawler crane during luffing rope replacement and eliminates the complex task of reeving the superlift luffing pulley group again, saving both time and costs.