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The story of the BV 155 began at Messerschmitt in the spring of 1942. A requirement had arisen for a carrier-based single-seat fighter to be based aboard the aircraft carrier Graf Zeppelin, then under construction. In response, Messerschmitt proposed the Me 409, later renamed Me 155. In the interest of economy and simplicity, it was to use as many Messerschmitt Bf 109 components as possible, being basically a navalized version of the earlier Messerschmitt fighter.

The Me 155 was to be powered by a DB 605A-1 liquid-cooled engine of 1,475 PS (1,455 hp, 1,085 kW). The fuselage was more or less that of the standard Bf 109G, but with an entirely new wing. The undercarriage retracted inwards into wing wells, providing the wider track required for safe carrier landings. Standard naval equipment such as folding wings, catapult spools, and arrester gear were to be fitted. Proposed armament was an engine mounted 20 mm MG 151 cannon and two 20 mm MG 151 cannons and two 13 mm (.51 in) MG 131 machine guns in the wings. It had an estimated maximum speed of 649 km/h (403 mph). Three variants were worked out, the Me 155A with one Junkers Jumo 213, the Me 155B powered by a DB 628, which was basically a DB 605A with a two-stage mechanical supercharger with an induction cooler, and the Me 155C with one DB 605A.

Detail design of the Me 155 was complete by September 1942. However, the numerous delays in the Graf Zeppelin seemed to indicate that the completion of the carrier would be at least two years away. Messerschmitt was told to shelve the Me 155 project for the indefinite future. Work on the Graf Zeppelin carrier was eventually abandoned.

Me 155A
In order that all of that work on the Me 155 project not go entirely to waste, Messerschmitt adapted its design in November 1942 to match a Luftwaffe requirement for a fast single seat bomber. A single 1,000 kg (2,210 lb) SC1000 bomb was to be carried. All of the carrier equipment and most of the armament was removed from the aircraft. Additional fuel tanks were provided and an elongated, non-retractable tailwheel was added to provide ground clearance for the large bomb. The proposal was designated Me 155A in late 1942.[2]

Me 155B
By the end of 1942, the increasing number of USAAF bombing raids and intelligence coming in about the new American B-29 bomber led the Luftwaffe to revive development of the Me 155B. The engine was to be the DB 628, which was basically a DB 605A with a two-stage mechanical supercharger with an induction cooler. A pressurized cabin was to be provided. It was estimated that a service ceiling of 14,097 m (46,250 ft) could be attained.

A converted Bf 109G adapted to take the DB 628 engine flew in May 1942 and attained an altitude of 15,500 m (50,850 ft). However, the Technische Amt concluded that a DB 603A engine with an exhaust-driven turbosupercharger was more promising. The DB 603A provided 1,201 kW (1,610 hp) for takeoff and 1,081 kW (1,450 hp) at 15,000 m (49,210 ft). This engine change required that the fuselage be elongated in order to house the turbosupercharger aft of the pressure cabin. Exhaust gases were carried to the turbosupercharger via external ducts. Air was drawn in through via a ventral trough aft of the wing. Standard Bf 109G wings were to be fitted outboard of a new, long-span, untapered wing center section. Other parts were scavenged from existing Messerschmitt designs – the vertical tail was from the Me 209, and the horizontal tail and the undercarriage were taken from the Bf 109G. The resulting revision of the Me 155B was designated P.1091 by Messerschmitt.

In August 1943, the RLM realised that Messerschmitt was over-committed and transferred the design work to Blohm & Voss. The design team there came to the conclusion that the existing Messerschmitt design had too many weaknesses and a complete redesign would be necessary.

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