What is the true purpose of the quick drop feature on a PLM Caterpillar pipelayer? This feature is designed to drop the pipelayer load quickly in the case of a tipping danger. If the operator uses this feature for any other reason than an emergency situation, and stops a falling load before ground level when the hook control lever is in Quick Drop mode, it can cause further problems with the pipelayer down the road, reducing the life of a well operating machine, and costing you higher maintenance fees.
The Caterpillar T models (583T/587T) require you to move the lever up and slightly over to engage the quick drop. This motion has proved to be too easy to implement, causing operators to engage this safety feature unnecessarily triggering an overload condition in the winch.
On the Caterpillar PL83 and PL87, the operator does not need to move the lever to engage the quick drop. Push the red button (20) and hold down to allow the hook to fall freely, if necessary. Release the button to return to the neutral position. The button has to be returned to the neutral position before the hook operation can be restarted.
The Caterpillar PL61 has a slightly different technique. To perform a quick drop you push the lever all the way past the detent and depress the left yellow button. This will allow the hook to fall freely. When the hook control lever is released, the lever returns to the HOLD position. The hook will remain in place.