Some observations
...after many years of maintaining hydraulic systems on Navire systems
All Navire loading/vechular ramp/doors when in use are suspended by the lowering & heaving sets of wires and hydraulically controlled to maintain auto tension
The are not designed to rest unaided on a wharf or pier as the forces between the door/ramp pivot to the vessel could shear
This is why hydraulic auto tension maintains constant load pressure of the ramp/door on the loading point
This auto tension compensates when for example a 200 tonne vehicle moves from the vehicle load on the wharf to the same 200 tonne load being transferred to the vessel
Naturally auto tension also compensates for tidal movement
In cases where loading schedules may stop for eg., a night shift, it would be common practice to raise the ramp/door off the wharf/pier and leave it suspended by the lowering & heaving sets of wires, then shut the hydraulic system down until change of shift when the door/ramp was lowered to engage the wharf/pier the to engage auto tension......
At ~~ 4 seconds into the video, the lowering & heaving sets of wires on the Port side ramp/ door are clearly
slack hence auto tension was not functioning
Usually, any such Naviere type ramp/door must not be lowered until the vessel has completed it's berthing and is at rest
It is common for such vessels to haul itself along a wharf to a revised berthing position without the need for the assistance of a Tug Boat
With the Tug Boat appearing and pressing the Ferry to the wharf suggests that the berthing was not complete
The authority to move the vessel would or should been under the directions of the Master
The authority to lower the Naviere ramp/door would have been that of the Officer of the Watch, however being responsible to the master
1. Obviously the chain of Command
was not maintained......
2. Maintaining the auto tension hydraulic system would have required ~~ 250 kW of input power...and this is supplied by the vessels diesel generators....to save precious $, Reports have emerged that dodgy operators are using such Naviere type ramp/door systems without auto tension
My best guess is that points 1. and 2. ......were a contributor's in the event..............Derek