This is an old revision of this page, as edited by Maury Markowitz (talk | contribs) at 09:52, 19 June 2002. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 09:52, 19 June 2002 by Maury Markowitz (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)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 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 in the 1,030hp Merlin II, the engine would undergo a huge series of modifications over the war.
As it turns out the Peregrine saw use in only one plane, the Westland Whirlwind. Although it 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 fact the early Merlins were considered to be unreliable as well, 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 engines off the assembly line at random 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 year of this the Merlin matured into one of the most reliable engines in the world, allowing themselves to run at full power for entire bombing missions.
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.