German Naval Radar

Updated 17 October
5. Battleships
Scharnhorst Class Bismarck Class

A) Scharnhorst Class

In November 1939 both these vessels were equipped with an 81.5cm (368MHz) FuMO 22 situated in an additional tower above the forward rangefinder tower. The 2m x 6m mattress antenna on the front of the tower rotated with the 10.5m rangefinders so the result from both instruments could be compared. During their stay at Brest in the summer 1941 they were fitted with a FuMO 27 on the after rangefinder tower and for their 'Channel dash' in 1942 both were probably equipped with a passive Palau antenna on a small frame at the back of their rangefinder tower, which thus operated in the reciprocal direction to the rangefinder and the active FuMO. 

During a refit in Germany Scharnhorst received a new FuMO 26 or 27 set, with a 2m x 4m mattress antenna, under which was a smaller frame for the two rows of vertical and horizontal Timor dipoles serving the passive FuMB 4 Samos set.

To follow standard German practice there should also have been passive Sumatra antennas somewhere on the screen around the foretop rangefinder platform; however, they cannot be traced in any photography. It can also be assumed that they carried a small omni-directional round dipole FuMB 3 Bali, but the antenna for this set is to small to be clearly identified. It would have been fitted on the top of the foremast or on a yardarm.

Picture 5.1
The FuMO 22 antenna (2m x 6m) fitted on a new tower above the foretop rangefinder tower in November 1939. The structure is crowned by an open battle-observer's post, Scharnhorst and Gneisenau being the only German capital ships to have this 'open' type.  Also shown (in the plan view) are the butterfly-shaped Sumatra antennas probably fitted for the 'Channel dash' in 1942.


Picture 5.2
The foretop as modified in February 1942 with a square radar tower and the observer's post. The upper antenna is probably for FuMO 26 or 27 (2m x 6m) and the lower antenna the Timor frame for the FuMB 4 Samos.

Picture 5.3
The after rangefinder tower with its vertically polarized FuMO 27 antenna (2m x 4m), fitted in the summer of 1941.

B) Bismarck Class

As the added weight of the radar tower resulted in a critical surplus load on the sensitive bearing engines of the rangefinder tower, both these battleships were fitted with enlarged towers, for all three gunnery rangefinders, housing both a FuMO 23 and the optical equipment. The installation of a fourth mattress antenna on the front of Bismarck's conning tower is the subject of controversy in German literature. The dimension of the structure appear to indicate that it had two rows of dipoles for active or passive detection, but the clarifying details are obscured in all photographs by a canvas cover.

The Tirpitz was re-equipped while she was based in Norway as part of the German standby force. Probably in January 1942 the foretop rangefinder tower was topped with an additional radar tower, carrying a FuMO 27 mattress antenna and a smaller frame, for the Timor antennas, above it. The sides and the rear of the radar tower were fitted with Sumatra antennas. In about the spring or summer of 1944 Tirpitz received an enlarged 3m x 6m mattress antenna, probably for FuMO 26. Careful examination of Tirpitz photographs reveals a small frame of a pole on top of the foretop tower, later moved to a bracket on the foremast to avoid interference with the FuMO 26. It is possible that this was either an experimental installation of FuMO 30 or the later standard frame for the Palau dipoles serving a FuMB 6. The addition of a trainable antenna frame to supplement the fixed antennas seems logical, but this would be the only appearance of a FuMO 30 on a German surface unit, it having originally been developed to submarines.

Again in the spring or summer of 1944, the third AA director, fitted just abaft the mainmast (German nickname 'Wackeltopf') was raised by 2m and equipped with an AA gunnery radar, probably Würzburg-C or Würzburg-D. As previously mentioned the Würzburg had originally been developed for the Luftwaffe, but it was later navalised for the German Navy's AA shore batteries under the following designation: FMG 39T/C (later FuSE 62C) Würzburg-C became the Navy FuMO 212, and FMG 39T/D (later FuSE 62D) Würzburg-D became the Navy FuMO 213. This reveals a fact that has not previously been published.

Tirpitz had the most sophisticated radar equipment of all the larger German surface units. However, without interviewing eye-witnesses we cannot know that these sets were not experimental, nor how effective they were under battle conditions. In this connection it would be most interesting to read British intelligence reports on the ship and to see Torstein Raaby's photographs of her. Torstein Raaby, who became famous after the war as member of Thor Heyerdahl's Kon Tiki expedition, was with the Norwegian resistance during the war and for ten months the spent much of his time on the top of the church tower of the Village of Alta watching the movements of the German capital ships lying in Kaa Fjord. He had a radio set, and camera with a telephoto lens, and his detailed reports to the British helped to ensure the ultimate destruction of the Tirpitz. As far as I know, his photographs have never been published, so where are they now?


Picture 5.4

The after 10.5m rangefinder tower with FuMO 23 antennas (Tirpitz only 1940 - 12 Nov 1944).

The third 3-D, stabilized AA director with the 3m diameter parabolic dish antenna of FuMO 212 or 213. The base ring on the director was raised 2m in the spring/summer of 1944 (Tirpitz only).


Picture 5.5

(C) Foretop 10.5m rangefinder tower and FuMO 23 antenna, 1940 - 12 Jan 1942.

(D) Forward 7m rangefinder tower and FuMO23 antenna, 1940 - 12 Nov 1944 (Tirpitz).

(E) Possible FuMO 21 dipoles in Bismarck, not definite proof for this assumption.



Picture 5.6

Foretop rangefinder tower crowned by an additional radar office, with FuMO 27 antenna, and topped by observer's post. 
On the short pole on the roof of the radar hut is the Timor antenna of FuMO 4 Samos, January 1942 - Spring/Summer 1944.

Picture 5.7

Foretop tower and radar hut supporting the large FuMO 26 antenna. FuMO 30 Hohentwiel placed on the foremast, Spring/Summer 1944 - 12 November 1944. 

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