Bomber B
Encyclopedia
Bomber B was a German
military aircraft design competition dating to just before the start of World War II
to develop a second-generation high-speed bomber
that would both be a direct successor to the Schnellbomber
design philosophy, and to replace all medium and heavy bombers then in service with the Luftwaffe
. The Reich Air Ministry
was so hopeful about the outcome that more modest projects were generally cancelled outright, so when the project eventually failed to deliver a working design, the Luftwaffe was left with hopelessly outdated aircraft.
, confident in its ability to produce aviation engines, opted for four-engine designs with heavy defensive firepower, as seen in the B-17 Flying Fortress. The United Kingdom
and Germany did not have this luxury. Both were severely constrained in engine production and tried to make do with two-engine designs. Both also invested heavily in a new generation of much more powerful engines, powerplants much like the American hyper engine
concept of the 1930s, which would provide the needed power for B-17-sized aircraft powered by only two engines, an approach the United States never used.
By the late 1930s, the new high-power engines started to appear, and both the British and Germans drew up designs based on them. The Avro Manchester
proved to be a poor performer in practice, but when it and the Handley Page HP.66 were reworked with four smaller Rolls-Royce Merlin
engines, resulting in the Avro Lancaster
and Handley Page Halifax
, they had two truly useful heavy bomber
s. This same transformation from two very powerful engines to four more producible powerplants was also attempted by Nazi Germany
with the Heinkel He 177
, but in a much later timeframe by the late summer of 1943, with the quartet of DB 603
-powered He 177B four engined prototypes successfully starting their flight tests by the end of 1943.
had started the competition for the first purpose-designed schnellbomber
, a bomber fast enough to simply outrun the defending fighters. It was thought that, with the limited power available, the bomber's two engines would mean it would always be faster than a single-engined fighter. This point was "proven" in the 1936 Air Races in Zürich
, where the Dornier Do 17
outran contemporary fighter designs from across Europe.
Later that year, the Reich Air Ministry selected the Junkers Ju 88
over a number of competitors to become their first purpose-designed schnellbomber. However the tradeoffs made for speed were serious; the Ju 88 was a small aircraft, carrying a fairly light load in its small bomb bay. This could be addressed by adding additional load on external racks, but doing so dramatically reduced performance due to increased drag. In addition, the limited engine power meant that the plane could not lift a reasonable warload and the fuel needed to carry it any distance, dramatically limiting its combat effectiveness. In order to make up for its shortcomings, a number of slower aircraft, such as the Heinkel He 111
and Dornier Do 17
, were pressed into service to fill particular performance niches, a problem no one in the Luftwaffe was at all happy with.
The Ju 88 was just entering service when Germany's own high-power "hyper engine
" class powerplants started bench testing. Daimler-Benz
offered the DB 604
, designed with a quartet of six-cylinder-long cylinder banks as an X engine
liquid-cooled powerplant, and Junkers their Jumo 222 six-bank, liquid-cooled, 24-cylinder "radial" style engine, both of which planned on delivering 2,500 hp (1840 kW) to start with. Compared to the Jumo 211
s in the Ju 88, a pair of such engines in a bomber's airframe would more than double the power when compared to a pair of the earlier inverted V12 powerplants, upwards to 5,000 hp (3680 kW). With this sort of power, a significantly more capable design could be built, one with considerably larger internal space for a much large bombload, more fuel for longer range, and even better speed.
Junkers had been studying dramatically more capable versions of the Ju 88 powered by their relatively compact Jumo 222, or the four-crankshaft Jumo 223
diesel aviation engine design from late 1937. No serious work was undertaken, but after Heinrich Hertel left Heinkel
and joined Junkers in 1939, the EF 74 design was submitted to the RLM in May 1939. Accordingly the RLM sent out the specifications for Bomber B in July 1939, the Ju 88 retroactively becoming Bomber A, which was also an RLM designation initially used on June 3, 1936 for a heavy bomber concept, starting the Heinkel aircraft project that would eventually become the Heinkel He 177
. Bomber B called for a new medium bomber with a maximum speed of 600 km/h (375 mph), able to carry a bomb load of 4000 kg (8,820 lb) to any part of Britain
from bases in France
or Norway
. To improve crew performance and defensive firepower, the designs were to have a pressurized cabin with remote control armament. With the extended range, larger payload and better performance, the Bomber B design would replace all existing bombers in service.
Arado
, Dornier
, Focke-Wulf
and Junkers all responded with designs, and Henschel later added its own entry (the Hs 130
). However, it was clear even at this point that the call for designs was to some extent a formality, as the Junkers design had already been selected for production. The Ar 340 was dropped in the design stage and Do 317
was relegated to low-priority development, while prototype orders were placed for the Fw 191
and the Ju 288
. With the Focke-Wulf and Dornier projects as first and second backups, the Technisches-Amt technical development office of the RLM
started using these other designs as experimental testbeds. For instance, as the aircraft would be operating at high altitudes, they suggested that all hydraulic systems on the Fw 191 be replaced with electrical ones instead to avoid the possibility of freezing up. However this dramatically increased the complexity of wiring the planes, and the chance that one of the many motors would fail was considerable. But that was not terribly important—it was felt that the Junkers design would work anyway.
power output class engines, the 24-cylinder, six-bank Jumo 222 or the 24-cylinder four-bank DB 604 X engine
, were ready to be installed. Instead of waiting, both teams decided to power their prototypes with the BMW 801
radial engine
, although with 900 hp less per engine, the planes would be seriously underpowered. The first 222s did not arrive until October 1941, and by this point the DB project had already been cancelled. By May 1942, things were getting desperate, and it was suggested that the Daimler-Benz DB 606 be used instead, even though it was considerably larger and heavier. Prototypes of both designs with these engines were ordered, although the Fw was just getting into the air with the 801s at this point and the 288 was showing a continual tendency to break its landing gear on touchdown. Desperation set in at the RLM, who had no other designs "in the pipeline" to fill the gap left if Bomber B did not work, even though some minor designs like the Henschel Hs 130
, usually powered with two DB 603 or 605 engines, and the Dornier Do 317
, itself being tried with the "coupled" DB 606 or 610 "power systems" in some airframes, roundly derided in August 1942 by Reichsmarschall Hermann Goering as "welded-together engines", were being considered. A slightly improved Ju 88-based on the Ju 88B design-was ordered as the Ju 188
, and several prototypes of "stretched" versions of existing bomber designs with four engines were also ordered.
In June 1943, the T-Amt finally gave up; by this point, even if the Jumo 222 started working reliably, as it had begun to do so in the summer of 1943, a shortage of the metals needed for the high-temperature alloys it used meant it would not be able to enter production anyway. The Bomber B project was a massive and astoundingly expensive venture that delivered nothing, while also serving to ensure that no other designs were available in late 1943, when their existing twin-engined medium bombers started to become hopelessly outdated.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
military aircraft design competition dating to just before the start of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
to develop a second-generation high-speed bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
that would both be a direct successor to the Schnellbomber
Schnellbomber
A Schnellbomber is a high-speed bomber. The concept developed in the 1930s when it was believed that a very fast bomber could simply outrun its enemies....
design philosophy, and to replace all medium and heavy bombers then in service with the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
. The Reich Air Ministry
Reich Air Ministry
thumb|300px|The Ministry of Aviation, December 1938The Ministry of Aviation was a government department during the period of Nazi Germany...
was so hopeful about the outcome that more modest projects were generally cancelled outright, so when the project eventually failed to deliver a working design, the Luftwaffe was left with hopelessly outdated aircraft.
Background
The main problem for aircraft designers in the 1930s was a lack of engine power. Construction methods had progressed to the point where airframes could be built to any required size, but the engines needed to lift them were not available. The U.S.United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, confident in its ability to produce aviation engines, opted for four-engine designs with heavy defensive firepower, as seen in the B-17 Flying Fortress. The United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and Germany did not have this luxury. Both were severely constrained in engine production and tried to make do with two-engine designs. Both also invested heavily in a new generation of much more powerful engines, powerplants much like the American hyper engine
Hyper engine
The hyper engine was a 1930s study project by the United States Army Air Corps to develop a high-performance aircraft engine that would be equal to or better than the aircraft and engines then under development in Europe...
concept of the 1930s, which would provide the needed power for B-17-sized aircraft powered by only two engines, an approach the United States never used.
By the late 1930s, the new high-power engines started to appear, and both the British and Germans drew up designs based on them. The Avro Manchester
Avro Manchester
|-See also:-References:NotesCitationsBibliography* Buttler, Tony. British Secret Projects: Fighters and Bombers 1935–1950. Hickley, UK: Midland Publishing, 2004. ISBN 978-1857801798....
proved to be a poor performer in practice, but when it and the Handley Page HP.66 were reworked with four smaller Rolls-Royce Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
engines, resulting in the Avro Lancaster
Avro Lancaster
The Avro Lancaster is a British four-engined Second World War heavy bomber made initially by Avro for the Royal Air Force . It first saw active service in 1942, and together with the Handley Page Halifax it was one of the main heavy bombers of the RAF, the RCAF, and squadrons from other...
and Handley Page Halifax
Handley Page Halifax
The Handley Page Halifax was one of the British front-line, four-engined heavy bombers of the Royal Air Force during the Second World War. A contemporary of the famous Avro Lancaster, the Halifax remained in service until the end of the war, performing a variety of duties in addition to bombing...
, they had two truly useful heavy bomber
Heavy bomber
A heavy bomber is a bomber aircraft of the largest size and load carrying capacity, and usually the longest range.In New START, the term "heavy bomber" is used for two types of bombers:*one with a range greater than 8,000 kilometers...
s. This same transformation from two very powerful engines to four more producible powerplants was also attempted by Nazi Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
with the Heinkel He 177
Heinkel He 177
The Heinkel He 177 Greif was the only operational long-range bomber to be operated by the Luftwaffe. Starting its existence as Germany's first purpose-built heavy bomber just before the war, and built in large numbers during World War II, it was also mistakenly tasked, right from its beginnings,...
, but in a much later timeframe by the late summer of 1943, with the quartet of DB 603
Daimler-Benz DB 603
|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9* Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989. ISBN 0-517-67964-7...
-powered He 177B four engined prototypes successfully starting their flight tests by the end of 1943.
The Schnellbomber concept
In 1936, the Reich Air MinistryReich Air Ministry
thumb|300px|The Ministry of Aviation, December 1938The Ministry of Aviation was a government department during the period of Nazi Germany...
had started the competition for the first purpose-designed schnellbomber
Schnellbomber
A Schnellbomber is a high-speed bomber. The concept developed in the 1930s when it was believed that a very fast bomber could simply outrun its enemies....
, a bomber fast enough to simply outrun the defending fighters. It was thought that, with the limited power available, the bomber's two engines would mean it would always be faster than a single-engined fighter. This point was "proven" in the 1936 Air Races in Zürich
Zürich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...
, where the Dornier Do 17
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...
outran contemporary fighter designs from across Europe.
Junkers Ju 88
The Junkers Ju 88 was a World War II German Luftwaffe twin-engine, multi-role aircraft. Designed by Hugo Junkers' company through the services of two American aviation engineers in the mid-1930s, it suffered from a number of technical problems during the later stages of its development and early...
over a number of competitors to become their first purpose-designed schnellbomber. However the tradeoffs made for speed were serious; the Ju 88 was a small aircraft, carrying a fairly light load in its small bomb bay. This could be addressed by adding additional load on external racks, but doing so dramatically reduced performance due to increased drag. In addition, the limited engine power meant that the plane could not lift a reasonable warload and the fuel needed to carry it any distance, dramatically limiting its combat effectiveness. In order to make up for its shortcomings, a number of slower aircraft, such as the Heinkel He 111
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...
and Dornier Do 17
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...
, were pressed into service to fill particular performance niches, a problem no one in the Luftwaffe was at all happy with.
The Ju 88 was just entering service when Germany's own high-power "hyper engine
Hyper engine
The hyper engine was a 1930s study project by the United States Army Air Corps to develop a high-performance aircraft engine that would be equal to or better than the aircraft and engines then under development in Europe...
" class powerplants started bench testing. Daimler-Benz
Daimler-Benz
Daimler-Benz AG was a German manufacturer of automobiles, motor vehicles, and internal combustion engines; founded in 1926. An Agreement of Mutual Interest - which was valid until year 2000 - was signed on 1 May 1924 between Karl Benz's Benz & Cie., and Daimler Motoren Gesellschaft, which had...
offered the DB 604
Daimler-Benz DB 604
|-See also:-Bibliography:* Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
, designed with a quartet of six-cylinder-long cylinder banks as an X engine
X engine
An X engine is a piston engine comprising twinned V-block engines horizontally opposed to each other. Thus, the cylinders are arranged in four banks, driving a common crankshaft. Viewed head-on, this would appear as an X...
liquid-cooled powerplant, and Junkers their Jumo 222 six-bank, liquid-cooled, 24-cylinder "radial" style engine, both of which planned on delivering 2,500 hp (1840 kW) to start with. Compared to the Jumo 211
Junkers Jumo 211
|-See also:-References:* Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989. ISBN 0-517-67964-7-External links:*...
s in the Ju 88, a pair of such engines in a bomber's airframe would more than double the power when compared to a pair of the earlier inverted V12 powerplants, upwards to 5,000 hp (3680 kW). With this sort of power, a significantly more capable design could be built, one with considerably larger internal space for a much large bombload, more fuel for longer range, and even better speed.
The Bomber B project
Junkers Jumo 223
The Junkers Jumo 223 was an experimental 24-cylinder aircraft engine based on the Junkers Jumo 205. Like the Jumo 205, it was an opposed piston two-stroke diesel engine. It had four banks of six cylinders in a rhomboid configuration, with four crankshafts one at each vertex of the rhombus, and 48...
diesel aviation engine design from late 1937. No serious work was undertaken, but after Heinrich Hertel left Heinkel
Heinkel
Heinkel Flugzeugwerke was a German aircraft manufacturing company founded by and named after Ernst Heinkel. It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight.-History:...
and joined Junkers in 1939, the EF 74 design was submitted to the RLM in May 1939. Accordingly the RLM sent out the specifications for Bomber B in July 1939, the Ju 88 retroactively becoming Bomber A, which was also an RLM designation initially used on June 3, 1936 for a heavy bomber concept, starting the Heinkel aircraft project that would eventually become the Heinkel He 177
Heinkel He 177
The Heinkel He 177 Greif was the only operational long-range bomber to be operated by the Luftwaffe. Starting its existence as Germany's first purpose-built heavy bomber just before the war, and built in large numbers during World War II, it was also mistakenly tasked, right from its beginnings,...
. Bomber B called for a new medium bomber with a maximum speed of 600 km/h (375 mph), able to carry a bomb load of 4000 kg (8,820 lb) to any part of Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
from bases in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
or Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
. To improve crew performance and defensive firepower, the designs were to have a pressurized cabin with remote control armament. With the extended range, larger payload and better performance, the Bomber B design would replace all existing bombers in service.
Arado
Arado Flugzeugwerke
Arado Flugzeugwerke was a German aircraft manufacturer, originally established as the Warnemünde factory of the Flugzeugbau Friedrichshafen firm, that produced military hydroplanes during the First World War.-History:...
, Dornier
Dornier
Dornier may refer to:* Claudius Dornier , German aircraft designer and builder** Dornier Flugzeugwerke, German aircraft manufacturer founded in 1914 by Claudius Dornier* Dornier Consulting, international consulting and project management company...
, Focke-Wulf
Focke-Wulf
Focke-Wulf Flugzeugbau AG was a German manufacturer of civil and military aircraft before and during World War II. Many of the company's successful fighter aircraft designs were slight modifications of the Focke-Wulf Fw 190.-History:...
and Junkers all responded with designs, and Henschel later added its own entry (the Hs 130
Henschel Hs 130
- See also :- References :NotesBibliography* Donald, David.. Warplanes of the Luftwaffe. London:Aerospace, 1999. ISBN 1 874023 56 5.* Dressel, Joachim and Griel, Manfred. Bombers of the Luftwaffe. London:Arms and Armour Press, 1994. ISBN 1-85409-140-9.* Green, William. War Planes of the Second...
). However, it was clear even at this point that the call for designs was to some extent a formality, as the Junkers design had already been selected for production. The Ar 340 was dropped in the design stage and Do 317
Dornier Do 317
-Do 317B:-See also:-References:*Griehl, M. Dornier Do 217-317-417: an Operation History. Airlife, 1991.*Green, W. Warplanes of the Third Reich. Galahad Books, 1986....
was relegated to low-priority development, while prototype orders were placed for the Fw 191
Focke-Wulf Fw 191
The Focke-Wulf Fw 191 was a prototype German bomber of World War II. Two versions were intended to be produced, a twin-engine version using the Junkers Jumo 222 engine and a four-engine variant which was to have used the smaller Daimler-Benz DB 605 engine...
and the Ju 288
Junkers Ju 288
|-See also:-References:NotesBibliography* Hitchcock, Thomas H. Junkers 288 . Acton, MA: Monogram Aviation Publications, 1974. ISBN 0-914144-02-2.-External links:...
. With the Focke-Wulf and Dornier projects as first and second backups, the Technisches-Amt technical development office of the RLM
Reich Air Ministry
thumb|300px|The Ministry of Aviation, December 1938The Ministry of Aviation was a government department during the period of Nazi Germany...
started using these other designs as experimental testbeds. For instance, as the aircraft would be operating at high altitudes, they suggested that all hydraulic systems on the Fw 191 be replaced with electrical ones instead to avoid the possibility of freezing up. However this dramatically increased the complexity of wiring the planes, and the chance that one of the many motors would fail was considerable. But that was not terribly important—it was felt that the Junkers design would work anyway.
The end of the project
Prototype airframes of both designs were ready mid-1940, but in a taste of things to come, neither of the hyper engineHyper engine
The hyper engine was a 1930s study project by the United States Army Air Corps to develop a high-performance aircraft engine that would be equal to or better than the aircraft and engines then under development in Europe...
power output class engines, the 24-cylinder, six-bank Jumo 222 or the 24-cylinder four-bank DB 604 X engine
X engine
An X engine is a piston engine comprising twinned V-block engines horizontally opposed to each other. Thus, the cylinders are arranged in four banks, driving a common crankshaft. Viewed head-on, this would appear as an X...
, were ready to be installed. Instead of waiting, both teams decided to power their prototypes with the BMW 801
BMW 801
The BMW 801 was a powerful German air-cooled radial aircraft engine built by BMW and used in a number of German military aircraft of World War II. The engine's cylinders were in two rows of seven cylinders each, the bore and stroke were both 156 mm , giving a total capacity of 41.8 litres...
radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
, although with 900 hp less per engine, the planes would be seriously underpowered. The first 222s did not arrive until October 1941, and by this point the DB project had already been cancelled. By May 1942, things were getting desperate, and it was suggested that the Daimler-Benz DB 606 be used instead, even though it was considerably larger and heavier. Prototypes of both designs with these engines were ordered, although the Fw was just getting into the air with the 801s at this point and the 288 was showing a continual tendency to break its landing gear on touchdown. Desperation set in at the RLM, who had no other designs "in the pipeline" to fill the gap left if Bomber B did not work, even though some minor designs like the Henschel Hs 130
Henschel Hs 130
- See also :- References :NotesBibliography* Donald, David.. Warplanes of the Luftwaffe. London:Aerospace, 1999. ISBN 1 874023 56 5.* Dressel, Joachim and Griel, Manfred. Bombers of the Luftwaffe. London:Arms and Armour Press, 1994. ISBN 1-85409-140-9.* Green, William. War Planes of the Second...
, usually powered with two DB 603 or 605 engines, and the Dornier Do 317
Dornier Do 317
-Do 317B:-See also:-References:*Griehl, M. Dornier Do 217-317-417: an Operation History. Airlife, 1991.*Green, W. Warplanes of the Third Reich. Galahad Books, 1986....
, itself being tried with the "coupled" DB 606 or 610 "power systems" in some airframes, roundly derided in August 1942 by Reichsmarschall Hermann Goering as "welded-together engines", were being considered. A slightly improved Ju 88-based on the Ju 88B design-was ordered as the Ju 188
Junkers Ju 188
The Junkers Ju 188 was a German Luftwaffe high-performance medium bomber built during World War II, the planned follow-on to the famed Ju 88 with better performance and payload...
, and several prototypes of "stretched" versions of existing bomber designs with four engines were also ordered.
In June 1943, the T-Amt finally gave up; by this point, even if the Jumo 222 started working reliably, as it had begun to do so in the summer of 1943, a shortage of the metals needed for the high-temperature alloys it used meant it would not be able to enter production anyway. The Bomber B project was a massive and astoundingly expensive venture that delivered nothing, while also serving to ensure that no other designs were available in late 1943, when their existing twin-engined medium bombers started to become hopelessly outdated.