Blohm & Voss BV 155 - Me 155B

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 envisage a pressing need for an effective high-altitude interceptor. Messerschmitt adapted its design to this requirement under the designation 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.

In August 1943, the Technische Amt decided that Messerschmitt was over-committed, and they decided to transfer the work on the design to Blohm & Voss. After some initial study, the Blohm & Voss design team deemed that the existing Messerschmitt design had too many weaknesses. Several months of argument and finger-pointing between the Messerschmitt transition team and the Blohm & Voss designers followed. Friction between the two teams got steadily worse. In the event, no meeting of the minds was possible, and the Technische Amt eventually decided to throw Messerschmitt off the project entirely, and turn it entirely over to Blohm & Voss.