BMW Strahlbomber I / P.1 Jet-Powered Heavy Bomber Concept
The Strahlbomber I heavy bomber was a conceptual design put forth by BMW to help sell its upcoming 018 series turbojet engine during World War 2.
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In the years leading up to World War 2 (1939-1945) the German Luftwaffe mistakenly neglected heavy bomber types while its future enemies pushed several classic designs through. When the war arrived in Europe, the Luftwaffe was forced to make do with a collection of medium-class bombers like the Dornier Do 17, the Junkers Ju 88 and the Heinkel He 111 (all detailed elsewhere on this site). The push for heavy bomber platforms came much too late for the service, particularly as air superiority changed in favor of the Allies and the German focus landed squarely on defensive-minded fighters and interceptors.
It was in 1944 that BMW began work on an all-new in-house turbojet engine which was intended to see considerable operational service through an all-jet bomber force being planned by the Luftwaffe for 1947. To help sell aeronautical engineers on the merits of the new, more powerful and reliable engine, company personnel arranged four heavy bomber conceptual designs based on the upcoming BMW 018 system. The power afforded by a collection of these engines theoretically allowed for greater payloads taken over longer distances than seen in conventional prop-powered bombers like the American Boeing B-17 "Flying Fortress, the Consolidated B-24 "Liberator", and the British Avro Lancaster. The BMW intent was not to deliver a new bomber to the Air Ministry, per se, but rather sell a design that would rely on the engines it would be making.
One of the four designs fleshed out by BMW engineers was the "Strahlbomber I". It utilized a swept-back wing planform (the wings shoulder-mounted on the fuselage), a single vertical tail fin and no horizontal tailplanes. The cockpit - seating two crew (assumed back-to-back) - was fitted at the extreme front end of the fuselage with fuel, avionics, bomb stores and the like installed in the center-aft section of the airframe. The fuselage tapered towards the tail in the usual way and proposed armament became 2 x 30mm MK 108 rear-facing cannons intended to counter the threat posed by trailing intercepting aircraft. It would mostly be aimed by way of periscope or similar in-direct method and fired remotely by the rear crewman.
The original Strahlbomber I design called for no less than 6 x BMW 003 turbojet engines of 1,764 lb thrust each with the later intent being that 4 x BMW 018 turbojets would be substituted in their place, these offering upwards of 7,500 lb of thrust each. A large collection of turbojet engines in a single design was a common feature of early jet aircraft - the engines were thirsty and generally seen as unreliable despite their promise of enhanced performance.
The Strahlbomber I had to fit all six of its engines into the design so two were paired within each wing and aspirated through a shared intake built into the wing leading edges. The engines exhausted from the wing trailing edges in individual exhaust rings. The remaining set of turbojets were then positioned well-forward, straddling the nose / cockpit section of the aircraft, which was thought to improve aircraft and crew survivability.
Beyond its proposed defensive armament scheme, the Strahlbomber I held little beyond its speed to escape an optimistic intercepting enemy - the bomber was estimated a maximum speed of 510 miles per hour with the original 003 engine set, and this was assumed to be faster once the more powerful 018 units were in play. Range was another estimated quality, this reaching out to 1,600 miles or more with a modest bomb load in tow and a service ceiling going beyond 30,000 feet was envisioned - necessitating a pressurized cabin for the crew.
Internally, the bomber was to hold provision for up to 8,000 lb of conventional drop bombs. This could be reduced some to improve operational range. At any rate, the aircraft would have clearly outclassed its prop-driven Allied bomber counterparts and then some through both bombload and over-battlefield capability.
With that said, the Strahlbomber I never materialized into any viable mockup or prototype form. It served as intended - a selling measure for a BMW product. The 018 was never readied before the end of the war in Europe came during May of 1945 and the existing work on the engine was captured and dissected by the Americans in the months following.
The other three submissions encountered the same fate: "Strahlbomber II" was more of a true flying wing in that it lacked any sort of tailplanes and attempted considerable wing-body blending. The BMW "High-Speed Bomber" utilized a unique gull-wing style mainplane with over-under engine nacelles carried just outboard of the wingroots. the cockpit, mainplane and engines were all to be situated well ahead of midships in this design. The final form, the BMW "02B", took on a most unique arrangement in that it had swept-forward wing mainplanes and held a pair of turbojet engines over and away from the cockpit by the nose. This was perhaps one of the more doubtful entries in the series considering the aeronautical challenges that would have laid ahead in testing.