| Revision as of 10:09, 19 June 2002 editMaury Markowitz (talk | contribs)Administrators76,090 editsNo edit summary← Previous edit | Revision as of 10:18, 19 June 2002 edit undoMaury Markowitz (talk | contribs)Administrators76,090 edits Comparison with German designs, and more about the various versionsNext edit → | ||
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| However this plan left a large gap between 700hp and 1,500hp. To fill the gap work was started on a new 1,100hp class design as the ''PV-12'' -- PV for "private venture" as they received no money for work on the project. It first flew on the front of a ] biplane in 1935, using the new ] system then in vogue. This system proved to be somewhat suspect, and when supplies of ] (''Prestone'') from the ] became available, the engine was switched to this system instead. | However this plan left a large gap between 700hp and 1,500hp. To fill the gap work was started on a new 1,100hp class design as the ''PV-12'' -- PV for "private venture" as they received no money for work on the project. It first flew on the front of a ] biplane in 1935, using the new ] system then in vogue. This system proved to be somewhat suspect, and when supplies of ] (''Prestone'') from the ] became available, the engine was switched to this system instead. | ||
| The next year the fighter competition resulted in two planes utterly dependant on supplies of the PV-12, namely the ] and ]. With no other modern fighters on the drawing boards, the PV-12 was catapulted to the top of the supply chain and became the ''Merlin''. First widely delivered as the 1,030hp Merlin II |
The next year the fighter competition resulted in two planes utterly dependant on supplies of the PV-12, namely the ] and ]. With no other modern fighters on the drawing boards, the PV-12 was catapulted to the top of the supply chain and became the ''Merlin''. First widely delivered as the 1,030hp Merlin II in 1938, production was ramped up quickly. | ||
| Early Merlins were considered to be rather unreliable, but their importance was too great for this to be left alone. Rolls introduced a quality control program to address this, which consisted of taking random engines right off the assembly line and running them continously at full power until they broke. They were then disassembled to find out what part failed, and that part was redesigned to be stronger. After |
Early Merlins were considered to be rather unreliable, but their importance was too great for this to be left alone. Rolls introduced a quality control program to address this, which consisted of taking random engines right off the assembly line and running them continously at full power until they broke. They were then disassembled to find out what part failed, and that part was redesigned to be stronger. After a few years of this the Merlin matured into one of the most reliable aero engines in the world, allowing themselves to run at full power for entire eight hour bombing missions without complaint. | ||
| As it turns out the Peregrine saw use in only one plane, the ]. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature as Rolls spent all of their time troubleshooting the Merlin. Likewise the Vulture was used in the superlative ] and ], but proved to be completely unreliable. With higher power gasolines available from the US the Merlin was soon pushing into the 1,500hp range on its own, and both engines were cancelled in 1943. | As it turns out the Peregrine saw use in only one plane, the ]. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature as Rolls spent all of their time troubleshooting the Merlin. Likewise the Vulture was used in the superlative ] and ], but proved to be completely unreliable. With higher power gasolines available from the US the Merlin was soon pushing into the 1,500hp range on its own, and both engines were cancelled in 1943. | ||
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| Most of the upgrades to the Merlin were the result of ever-increasing ] ratings in the aviation fuel available from the US. At the start of the war the engine ran on the then-standard 87 octane ] and could supply just over 1,000hp from it's 27l displacement (compared to 1,100hp from the 34l ]). | Most of the upgrades to the Merlin were the result of ever-increasing ] ratings in the aviation fuel available from the US. At the start of the war the engine ran on the then-standard 87 octane ] and could supply just over 1,000hp from it's 27l displacement (compared to 1,100hp from the 34l ]). | ||
| The next major version was the XX which ran on 100 octane fuel. This allowed it to be run at higher compressions, which they achieved by increasing the "boost" from the ]. The result was the otherwise similar engine delivering 1,300hp. | The next major version was the XX which ran on 100 octane fuel. This allowed it to be run at higher compressions, which they achieved by increasing the "boost" from the ]. The result was the otherwise similar engine delivering 1,300hp. This process continued, with later versions running on ever-increasing octane ratings, delivering ever-increasing power ratings. By the end of the war the "little" engine was delivering over 1,600hp in common versions, and peaks of 2,000hp. | ||
| The engine was considered to be so important to the war effort that blueprints were sent to the ] for safekeeping, to be handed over in case of ]'s captipulation. When this was no longer an issue, in 1943 the ] company started production in the ] as the V-1650, originally for use in US-built Spitfires. The V-1650 was so much better than its US counterpart (the Allison V-1570) that it would replace that engine in the ], which then went to become one of the best fighters of the war. | |||
| which allowed it to be "boosted" to higher levels by its ] and the otherwise similar engine could now deliver 1,300hp. Another boost in octane and a new two-stage supercharger resulted in the | |||
| In comparison the ] had no similar ability to increase octane ratings, and had to continually introduce larger and larger engines to keep up. The result was that their planes had considerably worse power-to-weight ratios than the Merlin powered planes they faced, and the continual complete change in engines meant they never had enough to go around. The lack of engines was one of the major problems for the Luftwaffe, from the mid 1930's right until the end of the war. | |||
| ⚫ | It could be said that the old myth that Merlin would return to save Britain at its time of greatest need was proved correct. Strictly speaking, however, the Merlin name came from the sea bird rather than King Arthur's ]. | ||
| ⚫ | For this reason the engine is often considered to be one of the main factors in winning the war for the ]. It could be said that the old myth that Merlin would return to save Britain at its time of greatest need was proved correct. Strictly speaking, however, the Merlin name came from the sea bird rather than King Arthur's ]. | ||
| ''Links:'' | ''Links:'' | ||
Revision as of 10:18, 19 June 2002
The Merlin is an aircraft engine built in WWII by Rolls Royce. It was one of the best engines in the world, and powered many of the greatest planes of the war.
Prior to the war Rolls had been planning to have two main engines through the late 1930's and into the 1940's. The 700hp Peregrine was a updated development of the earlier V-12 Kestral which had been used to great success in a number of 1930's designs. Two Peregrine's bolted into an X-24 would create the 1,700hp Vulture, for use in larger planes like bombers. There was also the possibility that the famous R engine from the Supermarine racing planes could be developed into a 1,500hp class engine of its own, itself a development of the Buzzard, a scaled up Kestral.
However this plan left a large gap between 700hp and 1,500hp. To fill the gap work was started on a new 1,100hp class design as the PV-12 -- PV for "private venture" as they received no money for work on the project. It first flew on the front of a Hawker Hart biplane in 1935, using the new evaporative cooling system then in vogue. This system proved to be somewhat suspect, and when supplies of Ethylene Glycol (Prestone) from the US became available, the engine was switched to this system instead.
The next year the fighter competition resulted in two planes utterly dependant on supplies of the PV-12, namely the Hawker Hurricane and Supermarine Spitfire. With no other modern fighters on the drawing boards, the PV-12 was catapulted to the top of the supply chain and became the Merlin. First widely delivered as the 1,030hp Merlin II in 1938, production was ramped up quickly.
Early Merlins were considered to be rather unreliable, but their importance was too great for this to be left alone. Rolls introduced a quality control program to address this, which consisted of taking random engines right off the assembly line and running them continously at full power until they broke. They were then disassembled to find out what part failed, and that part was redesigned to be stronger. After a few years of this the Merlin matured into one of the most reliable aero engines in the world, allowing themselves to run at full power for entire eight hour bombing missions without complaint.
As it turns out the Peregrine saw use in only one plane, the Westland Whirlwind. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature as Rolls spent all of their time troubleshooting the Merlin. Likewise the Vulture was used in the superlative Hawker Tornado and Avro Manchester, but proved to be completely unreliable. With higher power gasolines available from the US the Merlin was soon pushing into the 1,500hp range on its own, and both engines were cancelled in 1943.
Most of the upgrades to the Merlin were the result of ever-increasing octane ratings in the aviation fuel available from the US. At the start of the war the engine ran on the then-standard 87 octane avgas and could supply just over 1,000hp from it's 27l displacement (compared to 1,100hp from the 34l DB 601).
The next major version was the XX which ran on 100 octane fuel. This allowed it to be run at higher compressions, which they achieved by increasing the "boost" from the supercharger. The result was the otherwise similar engine delivering 1,300hp. This process continued, with later versions running on ever-increasing octane ratings, delivering ever-increasing power ratings. By the end of the war the "little" engine was delivering over 1,600hp in common versions, and peaks of 2,000hp.
The engine was considered to be so important to the war effort that blueprints were sent to the US for safekeeping, to be handed over in case of England's captipulation. When this was no longer an issue, in 1943 the Packard company started production in the US as the V-1650, originally for use in US-built Spitfires. The V-1650 was so much better than its US counterpart (the Allison V-1570) that it would replace that engine in the P-51 Mustang, which then went to become one of the best fighters of the war.
In comparison the Luftwaffe had no similar ability to increase octane ratings, and had to continually introduce larger and larger engines to keep up. The result was that their planes had considerably worse power-to-weight ratios than the Merlin powered planes they faced, and the continual complete change in engines meant they never had enough to go around. The lack of engines was one of the major problems for the Luftwaffe, from the mid 1930's right until the end of the war.
For this reason the engine is often considered to be one of the main factors in winning the war for the Allies. It could be said that the old myth that Merlin would return to save Britain at its time of greatest need was proved correct. Strictly speaking, however, the Merlin name came from the sea bird rather than King Arthur's legendary magician.
Links: