Thank you all for the help, once in a while it happens, that you really come across rare and interesting ships and whereas I was very happy to see what I thought was an "old coaster of the 50ies" I found to have seen an military auxiliary ship, which was found proof on many russian websites which deal with all kinds of Navy and ex Navy ships.
This here is also needed to be seen by the admin, who has mistakenly put this ship into the category for pipelayers. Sometimes, it is a hell of a search to find something out, but it is worth it.
More info under the photo now, thanks to very nice international cooperation and this is, what makes shipspotting.com unique and also in such special cases.
Greetings,
Cornelia