Those two might be looking for Malcolm and his camera....

I also first thought it was in way of preparing for something, but I dismissed that thought because there is no crew member in sight, except for the two on the starboard bridge wing, which seem not to be very about what is going on. The age of the picture is decisive, but otherwise you might have said that it looks that they are checking their phones.

Normally once a ship reaches like in this case a secure river passage preparations are being made by the deck crew for the arrival in port. That includes a hatch opening without any delay when alongside. Therefore the wires are changed from the cargo derricks to the hatch cover system to open (very well visible in this clear shot from Malcolm, 3 hatches, 3 derricks, 3 ropes).
To reverse this again without any time loss when sailing helping ropes are used to quicken this up.
So this ropes are only in place when the derricks were up and the wires were changed to open or close the hatches.
There have been easier systems around but existing methods were seldom changed.
Hope I was clear enough,
Brgds, Manfred

Thanks Manfred, I read what you write but my lack of technical knowledge in this field prevents me to understand the words. So the the two ropes are swinging freely irrespective the weather? They cannot be secured in any way?

@pieter:
The hoisting wires from the derrick (cargo) winches are fixed to open the hatches when the ship is alongside.
When the opening of the hatches is through the ropes will help to get the hoisting wires back through the upper cargo block without having to lower the derrick.
Brgds, Manfred

Interesting couple of ropes swinging loose there.