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The Blohm und Voss Bv 238 was the largest flying boat built during the Second World War, but only one prototype was completed and that was destroyed by Allied aircraft two months after its maiden flight.
Two different aircraft were given the Bv 238 designation. Blohm und Voss had experience of designing very large flying boats, having worked on the Blohm und Voss Bv 222 Wiking in the late 1930s. This was originally designed as passenger airliner, but became the largest flying boat to enter military service during the Second World War (admittedly in very small numbers).
Dr Ing Richard Vogt’s next large flying boat was a very large long range design produced in 1940 for Lufthanse. The P.200 would have been the second largest flying boat ever (behind the infamous Hughes ‘Spruce Goose’). It would have had a wingspan of 279ft, be powered by four engines and have a passenger capacity of 120.
This aircraft was abandoned in January 1941 to allow the company to focus on a new RLM request for a long-range multi-purpose flying boat, the first Bv 238. The new aircraft was to be a long range transport and reconnaissance aircraft, with the ability to be used as a bomber.
This aircraft was to be powered by four 2,500hp Junkers Jumo 223 Diesel engines. This was a highly experimental engine, of which only one prototype was ever built. Because the engine wasn’t expected to enter service for several years the first Bv 238 was thus abandoned early in 1941. Work on the Jumo 223 engine was cancelled in the following year.
Work on an entirely new design for the Bv 238 began in July 1941. This inherited its general layout and many features from the Bv 222, but was a much larger aircraft, 20ft longer, with a 50ft wider wingspan and twice as heavy. The design was accepted and four prototypes were ordered. The first three were to be prototypes for the Bv 238A and would be powered by six Daimler-Benz DB 603 liquid-cooled engines. The last would be the prototype for the Bv 238B and would use six BMW 801 air cooled radial engines.
The new aircraft was a high winged monoplane, with the six engines carried in nacelles that extended in front of the wing. The pilot’s cockpit was close to the pointed nose. It had wing tip floats that retracted inwiards. The wing had a tubular wing spar that supported the engines, contained the fuel and oil tanks. It had a high mounted tail, with the horizontal surfaces well above the top of the fuselage. The hull was tall but narrow, something that doesn’t always come across in photographs. It was designed for large scale manufacture, with as few complex elements as possible, and used no rare magnesium. The aim was to be able to build a Bv 238 hull in eight weeks.
Work on the new project made slow progress. The very large size of the new design clearly worried Dr Vogt, and the Flugtechnische Fertigungsgemeinschaft near Prague was ordered to build a quarter sized flying test bed, using the same design but powered by six 21hp engines and constructed from wood. Work on this FGP 227 began in 1942 but it wasn’t completed until 1944. It was then sabotaged by French POWs on its was to be tested at Travemunde, and repairs weren’t completed until September 1944, by which time very large flying boats were a very low priority! During its maiden flight the FGP 227 suffered from a fuel blockage and was damaged in the resulting forced landing.
Work on the full scale aircraft continued through 1942 and 1943, and work on the hull of the first prototype, Bv 238 V1, began in January 1944. Unsurprisingly work on this prototype was slow, and it wasn’t ready to fly until March 1945. By this time Blohm und Voss had dedicated 600,000 man hours to the project, and had built the jigs and tools required for mass production!
The Bv 238 V1 made its maiden flight in March 1945. After four test flights in that month it was declared to be fit for service. However the aircraft was destroyed by allied Mustangs on Lake Schaal (twenty miles to the south of Lubeck) only four days before the end of the war. There appears to be some disagreement on these dates, with some sources placing these events in 1944, but that would had required very quick construction if the January 1944 date for the start of work is accurate.
V1 was unarmed, but if it had entered production the Bv 238 was going to be heavily armed. It was to carry four turrets armed with four 13mm MG 131 machine guns each, one in the nose, one in the tail, and two one the trailing edge of the wings. Two pairs of MG 131s would be carried in beam stations in the side of the fuselage. Two 20mm MG 151 cannon would be carried in a dorsal turret. Bomb bays capable of carrying a total of 20 551lb bombs would have been built into the wings, and there would have been two weapons racks under each wing, each capable of carrying an LD 1200 torpedo, 2,250lb bomb, Hs 293 missile or BV 143 glide bomb.
Work had also begun on V2 and V3. At the end of the war V2 was at the Weser-Flugzeubau at Bremen and was 80% complete (Weserflug was the fourth largest aircraft producer in Germany during the war, but as it only built aircraft under licence isn’t well known). V3 was at Blohm und Voss’s factory at Finkenwerder (just to the west of Hamburg and now used for Airbus construction). The hull was 60% complete, the wings had only just been started.
In 1942 work began on a land based version of the Bv 238, the Bv 250. This would use the same Daimler-Benz DB 603 liquid-cooled engines as the V1. The flying boat elements of the lower hull would be removed giving it a level underside and a multi-wheel undercarriage installed. Four prototypes were ordered, and work had begun on producing some of its components by the end of the war. The Bv 250 would have had a slightly reduced wingspan but been slightly longer, would have been even heavier than the Bv 238, but was perhaps rather optimistically given higher estimated ranges and a similar top speed.
Blohn und Voss also produced a layout for a civil version, but got no further with that design.
Bv 238 V1 (unarmed)
Engine: Six Daimler-Benz DB 603 liquid-cooled engines
Power: 1,900hp each at take off
Crew: 12 (estimated as armament undecided)
Span: 197ft 4.75in
Length: 142ft 8.5in
Height: 43ft 11.5in
Empty weight: 111,985lb
Normal loaded weight: 154,325lb
Maximum take-off weight: 176,400lb
Max speed: 264mph at 19,685ft
Landing speed: 78mph
Max range: 3,788 miles (reconnaissance version)
Aircraft of the Luftwaffe 1935-1945, Jean-Denis G.G. Lepage.
Combines a good background history of the Luftwaffe with a comprehensive examination of its aircraft, from the biplanes of the mid 1930s to the main wartime aircraft and on to the seemingly unending range of experimental designs that wasted so much effort towards the end of the war. A useful general guide that provides an impressively wide range of information on almost every element of the Luftwaffe
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