Description of maintenance work on thesuperstructure

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8.6 Hoist ropes

8.6.1 Checking the position of sheaves and rope drums

GDanger of accidents due to turning rope drum. Keep yourself and other people away from the turning rope drum. If you take hold of the turning rope drum, your fingers and hands could be crushed between the rope drum and hoisting gear frame or get caught and drawn in by the turning drum.

• Check the position of the hoist ropes(1) on the rope drums of the main hoist and the auxiliary hoist (additional equipment).

• Slowly turn the rope drum at least one turn in the lowering direction. Check the rope on the drum as you do this.

–The ropes must be uniformly wound onto the rope drum.

–The turns on the drum must have a uniform distance of 0 to 2 mm.

–The cross-over points must be offset by approx. 180°.

HThe upper layer of rope lies over the lower layer at the cross-over points.

• Check the position of the hoist ropes on the sheaves at the boom head and in the hook block.

• Check the sheaves for damage and wear, and check that they run freely.

GRisk of accidents from incorrectly set lowering limit switch!

Never turn the free rope end under the drum. Turns on the drum which are unwound when the rope drum is stationary can not be detected by the lowering limit switch. This causes the lowering limit switch to become set incorrectly and to switch off too late or not at all. In addition, the load may fall.

8.6.2 Checking the status

• Reeve the hoist rope on the hook block six times (à Operating instructions, chapter on Rigging work , section on Rigging work on the main boom ).

• Support the truck crane and enter the SLI code for the current rigging mode.

• Raise the boom and extend it fully.

• Unreel the hoist rope and check that the rope is not damaged or improperly reeled ( à Assessing thecondition of thehoist rope, p.8-37). When five turns are left on the rope drum, the lowering limit switch must switch off.

If the lowering limit switch does not switch off or switches off too late, it must be reset; à Setting the lowering limit switch, p.8-45.

• Check the mounting of the rope clamp(1) on the rope drum for damage and ensure that it is securely attached (tightening torque; à Special tightening torques, p.10-2).

• Check whether the hoist rope can be wound without kinking and flattening:

–The free end of the rope must protrude from the pocket(2).

• Check the rope securing device in the rope end clamp(2) for proper seating and correct positioning of rope.

The rope end clamp(1) must be attached to the free end of the rope and the rope must secured around the rope wedge(3).

Assessing thecondition of thehoist rope

HIf in doubt about damage assessment, always consult an expert.

To assess the condition of the hoist rope, you must be familiar with the following:

–the type of rope (crosslay rope or Lang’s lay rope), –the number of load bearing wires in the outer strand

–the rope diameter (à Operating instructions, chapter on Technical information, section on Superstructure).

In a crosslay rope(1), the wires run more or less in the longitudinal direction of the rope.

In a Lang’s lay rope(2), the wires run at an angle of approximately 45° to the longitudinal direction of the rope.

To calculate the number of bearing outer wires(1), count the number of outer strands of the rope and multiply by 7. H

If there are multiple layers of strands, only the outer layer is counted.