This is a motor minesweeper of one of the 'R' groups, there were nine different groups totalling nearly 300 boats, many builders were involved but most were built by two companies : Abeking and Rasmussen at Lemwerder and Schlichting at Travemunde.
Sizes varied from L 26 B 4.4 Dr 1.2 mtrs and 63 tons dispalacemet for the earlier boats to L 41 B 6 Draft 1.8 and displacemet 160-170 ton for the later boats
Machinery varied from twin MAN Diesels driving twin Voith-Schneider cycloidal propulsion units, 1,800 SHP 21 knots, to twin MAN shaft driven props with 3,750.
Similarly armamnt varied from two single 20mm Oerlikons, a single 37mm and three 20mm guns, building started in 1929 and went on to 1945.
They were number according to there build series the R1 group was 1 to 16, R17 was 17-24, R25 25-40, R41 41-129, R130 130-150, R 151 151-217, R218 218-300 R301 301 -312 and finally the R401 group 401-448
The above boat is obviously a WW2 survivor, roughly half the boats survived with 48 going to the USA, the USSR got 45, Denmark 24, Britain 11, Netherlands 8 and Norway 4. I cannot pin down exactly which type she is but is obviously one of the later series, sticking my neck out I think the R41 group
These little ships were built by either Abeking and Rasmussen at Lemwerder or Schlichting at Travemunde. L37.8 B 5.80 Dr 1.4 mts Displt 125 tonnes
machinery : Twin screw MAN Diesels 1,800 BHP 20 knots
Post war when the dust had settle a substantial number of these boats were returned to Germany and I think this is one of those craft
Thankyou Davie, Steve & Stefan you are great shiphistorians.
A look in Erich Groner's "Die deutschen Kriegsschiffe 1815-1945" came up with the following: Build 1944.
Commissioned 26/1 1944 as R 134.
Transferred as a war indemnity to U.S.A. 1/11 1947.
Returned to Bundesmarine, Germany 1956 as W 68 MERKUR
If she is the R134 that makes her one of the next series to the R41 the R130 group, these were identical in all except the length which was just over 3 mts longer at 41.1 mts and the displacement was 150 tonnes. She retained the 900 BHP MAN Diesels and so was a little slower at 19 knots
I*ve got a chronicle named "40 years German Minewarfare Flotilla". It says FGS Merkur was the former KM R135 and was recommissioned June 6th 1956 in the 1st GE MS SQN. October 10th 1956 she became part of the 3rd GE MS SQN with home base Wilhelmshaven. In August 1958 the squadron moved to Kiel. She was decommissioned around 1962 when the R-Boats were replaced by the fast minesweepers of the Schuetze- or 340/341-Class.