Sorry....
...I didn't explain myself properly
All wire sheaved hydraulically powered vessel ramps are
driven down......not any free fall of wire....the force [hydraulic pressure] is set by the counterbalance valve and is a greater setting than required for hoisting or raising up....the reason for this is if hydraulic power is lost, the ramp will lock up and not free fall out of control to the wharf
This is why the audible sound of the ramp being lowered is always greater than the sound of the ramp being raised
Derek