O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Gotha WD 11
   The WD 11 was the next development in the twin-engined torpedo aircraft series after the WD 7. It was a considerably bigger aeroplane, and its engines drove pusher airscrews. Some thirteen aircraft of this type were delivered between March and July 1917. Engines, two 160 h.p. Mercedes D III. Span, 22.51 m. (73 ft. 10 3/8 in.). Length, 13.43 m. (44 ft. 0 7/8 in.). Height, 4.75 m. (15 ft. 1 7/8 in.). Area, 103.4 sq.m. (1,117 sq.ft.). Weights: Empty, 2,437 kg. (5,361 lb.). Loaded, 3,583 kg. (7,883 lb.). Speed 120 km.hr. (75 m.p.h.). Climb, 1,000 m. (3,280 ft.) in 12 min. Armament, torpedo carried under fuselage; one Parabellum machine-gun in nose.

J.Herris Gotha Aircraft of WWI (A Centennial Perspective on Great War Airplanes 6)

Gotha WD11

   Ordered on 9 March 1916 and designed by Rosner as a torpedo bomber, the WD11 resembled the earlier WD7 but was a much larger aircraft. The WD11 was powered by two 160 hp Mercedes D.III engines and was equipped to carry one Whitehead G/125 torpedo under the fuselage. All WD11 torpedo bombers were flown by a two-man crew, and the observer in the front cockpit had a flexible Parabellum LMG 14 machine gun.
   After flight tests at the SVK, the prototype WD11, Marine Number 679, was used to train aircrews at the Sonderkommando Flensburg. Three more production batches followed the prototype; the first was a batch of five, Marine Numbers 991-995, followed by a batch of three, Marine Numbers 1211-1213, followed by a final batch of eight, Marine Numbers 1372-1379, for a total of 17 airplanes.
   WD11 torpedo bombers were operational in the Baltic and North Sea, but they were reported to be underpowered - the Gotha G-types of similar size and weight had 260 hp Mercedes D.IVa engines - and too lightly built for the severe demands put on them.
   Torpedo attacks proved very difficult and required ideal sea and weather conditions. A drag rod under the fuselage was lowered prior to the attack; it was a device to measure height over the water, and the pilot had to maintain an altitude of 5 meters for torpedo release. Optical height measuring devices were also tested. Because of the difficulty of torpedo attacks coupled with the vulnerability of the aircraft to ship-board anti-aircraft guns, torpedo attacks were soon abandoned and the WD11s were modified to carry ten 50-kg bombs or a single Teka anti-shipping mine.

Gotha WD11 Specifications
Engines: 2 x 160 hp Mercedes D.III
Wing: Span Upper 22.50 m
Span Lower 21.00 m
Area 104 m2
General: Length 13.45 m
Height 4.75 m
Empty Weight 2146 kg
Loaded Weight 3583 kg
Maximum Speed: 120 km/h
Climb: 1000m 12 min
1500m 20 min
Service Ceiling: 3200 m
Range: 500 km


Gotha Seaplane Production Summary
Type Ordered Marine Numbers Remarks
WD11 17 679, 991-995, 1211-1213, 1372-1379 Torpedo bomber, flew operational sorties

M.Schmeelke "Torpedo Los!" (Aeronaut)

German Torpedo Aircraft

Gothaer Waggonfabrik AG, Gotha

  With the Gotha company already having gained experience in designing twin-engine bombers, the RMA subsequently ordered the company to build a T-aircraft in February 1915. Dipl.-Ing. Karl Rosner, the chief designer of Abteilung II at Gotha, delivered the type WD7 (Marine No. 119) to the SVK in January 1916. Although the 119 was not yet a torpedo aircraft, it is considered to be the forerunner of the later Gotha torpedo aircraft. Tests of the 119 at Warnemunde were successful and the RMA ordered a series of other torpedo training aircraft, the Gotha WD7 (No. 670 - 676). They, too, were unable to drop torpedoes, as they were equipped with bracing struts between the floats. By August 1916, all seven Gotha WD7s had been delivered to the SVK and were later used as training aircraft at both Kiel-Holtenau and Flensburg. With the Gotha WD7 (670) practical innovations were made again and again by the SVK. At Warnemunde, various engine installations were also tried, with 130 hp Hiero engines from Austria-Hungary being temporarily installed. In February 1916, the RMA placed a further order with the Gothaer Waggonfabrik, for the type WD11. The WD11 (Marine No. 679) had for the first time a recess for the torpedo, the so-called torpedo trough, on the underside of the fuselage. In this trough-like recess, the torpedo was coupled into the holding device at a 50 degree angle. An advantage of the WD11 was the seating position of the torpedo layer in the fuselage bow, with the pilot sitting directly behind him, shifted to the right. This made it possible to communicate easily. WD11 No.679 was followed by further orders for Gotha WD11 aircraft with Navy Nos. 991-995, 1211-1213, and 1372-1379. But before the torpedo aircraft could be considered "front-ready", i.e., suitable for frontline use, there was still a long way to go. In the documents of the Seaplane Test Command (SVK) and the Torpedo Test Command (TVK) there are many reports regarding these details. Items involved were not only the basic construction, but particularly the struts from the fuselage to the floats, the torpedo and mine mount on the fuselage, as well as the armament. The engines were also replaced more frequently; the Gotha WD7 (675 and 676) received more powerful 120 hp Argus engines instead of the 100 hp Daimler. The WD7 (676) was still at Warnemunde in June 1917 and was used to test a movable 2 cm Becker cannon mounted in the bow position of the aircraft. On the WD11 (679) tail-heaviness had to be addressed and the motors received new acetylene starters. On 17 October aircraft No. 679 was accepted by the Maritime Aircraft Acceptance Commission (SAK) and handed over to the Special Command Edler in Flensburg. However, it was damaged there on October 31, 1916 and had to be returned to Warnemunde for repair. It was not until 5 December 1916 that the Gotha WD7 (679) arrived again at the SoKo in Flensburg.
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  Acceptance of Gotha WD11 series (991-995) to Warnemunde went off without any major problems. Delivered in March 1917, WD11 No. 991 was ready for acceptance by April 1917. This was followed by the remaining aircraft thru May 1917, after having been installed with the Anschutz-Gyro-Inclinometer in airframe Nos. 991, 992, 993, and 996. The third series of the Gotha WD11 (1211-1213) were delivered to Warnemunde in June 1917. With WD11, Marine No. 1211, the height detection device of the company Fa. Optische-Signale m.b.H. Berlin and the Arnhem communication apparatus were tested in May 1917. The on-board telephone headset/microphone system allowed for clear communication between the pilot and the torpedo layer during the flight without auditory interference.
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  In August 1917 Gotha WD14 (1415) and WD11 (1378) could be handed over to the front stations of the North Sea. The Gotha WD11 (1377) was equipped with navigation lights for the first time, red and green lights on the wingtips and a white one at the end of the fuselage which were clearly visible at several hundred meters, but they could be dimmed from the cockpit by use of a rotary switch. The G-planes of the Gothaer-Werke had reached series maturity by the summer of 1917, so there was little to change in the subsequent series. During testing at Warnemunde, the I.T-Staffel tested the Gotha aircraft during a relay exercise at Flensburg in August 1917 and the crews were very satisfied with the aircraft. In October and November 1917, WD14 Marine Nos. 1418 to 1428 were delivered to Warnemunde. The WD14, Navy No. 1429, followed in December 1917, the delay was due to the subsequent installation of the onboard communication equipment (Arnheim's communication apparatus), with which the three-man crew could communicate during the flight. The Gotha WD14, from No. 1617, became the 17th machine to receive a modified fuselage. In the fuselage nose, the rotating LVG gun ring was installed in the machine gunner's position. In addition, 10 x 10 kg of bombs could be carried, placed in boxes in the front of the fuselage.


Gotha WD11 Specifications
Engines: 2 x 160 hp Mercedes D.III
Wing: Span Upper 22.50 m
Span Lower 21.00 m
Area 104 m2
General: Length 13.45 m
Height 4.75 m
Empty Weight 2146 kg
Loaded Weight 3583 kg
Maximum Speed: 120 km/h
Climb: 1000m 12 min
1500m 20 min
Service Ceiling: 3200 m
Range: 500 km



Gotha Torpedo Bomber Production
Type Qty Marine Numbers Notes
WD11 1 679 Prototype.
   5 991-995
   3 1211-1213
   8 1372-1379


German Torpedo Bomber Production
Type Albatros W.5 Gotha WD11 Gotha WD14 Brandenburg GW Friedrichshafen FF41AT
Number 5 17 52* 21 8
* 69 ordered, production was curtailed by the Armistice.
There were a number of prototype torpedo bombers; this table shows only production types. The Albatros W.5 was produced in the smallest quantity of any production type, an indication of its relative merit. The Gotha WD14 received by far the largest orders. It was also the only aircraft in the table powered by 200 hp Benz Bz.IV engines; the others were all underpowered by 150 hp Benz Bz.III engines.

M.Dusing German Aviation Industry in WWI. Volume 1 (A Centennial Perspective on Great War Airplanes 84)

Gothaer Waggonfabrik A.-G., Gotha (Go)

Aircraft Development:

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  The particular success of the G-planes led to the construction of torpedo planes at the instigation of the Navy Department. The types WD11 and WD14 were developed.
  WD11 was initially a biplane based on the proven WD8 type with 2 x 160 HP Daimler engines, mounted on the lower wings to the left and right of the fuselage. To accommodate the torpedoes, the fuselage was provided with a recess on its lower side.
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