@Manfred,
The mentioned voyage from Yokohama to Bremen tells me that she was then engaged in the VNS Holland-East Asia Service.
You are absolutely right about her being partly loaded. There can be several reasons for that, one of them is a change in service which happened often.
For fun I did some checks:
25-05-70, passed Mauritius for Rotterdam (last port was S'pore),
02-06-70, 270 miles WSW from Walvis Bay,
09-06-70, Dakar
15-06-70, 115 miles SW of Isle of Wight.
Next day arrival at Rotterdam.
The ports in the NWE region in this service were: Rotterdam, Bremen, (sometimes Bremerhaven), Hamburg and Antwerp. This coastal trip (or kustreis as we called it) took 14 days to the max.
A month later she was back in Rotterdam with her cargo gear operational again.
What I expect, based on experience, that she went partly loaded straight into the shipyard to carry out several surveys, including the cargo gear.
If we want to be 100% sure, we will have to ask the chief officer or bosun who were on board 50 years ago.
But that might be a problem.

@Bob.
It looks to me that all loose gear was removed upon arrival Rotterdam. Span wires, runners and guys including all blocks, i.e. mast head span blocks, derrick heel blocks, derrick cargo blocks, span blocks and guy blocks are not visible.
The cargo tackles of the two heavy derricks are still in place under their tarpaulin covers.
The span trunnions on the mast cross-tree are clearly visible.

1 month later
http://www.shipspotting.com/gallery/photo.php?lid=3044805

Has the rigging been completely removed or has it not just been lashed closely to the derricks, masts and kingposts?

At swtk: Quote "Nice job to do that at sea", no doubt about that but she is not at sea but in the North Europe-range inbound R`dam, even partly loaded as it looks. Further cargo operations will be difficult it seems.

Exactly Denis. Why removing it? But it was often done as I was told.
When I was at sea (since 78) it was not done anymore.
But what I suggested here on another location: it could be possible that the cargo gear had to undergo her quadrennial survey, and it was good practice in those days to overhaul all the blocks. Nice job to do that at sea.

Why removing it?

With all rigging removed from her derricks for the crossing. What a job to make the gear operational again!