The Merlin in Perpective-the combat years

[USCANAM]

A friend and a fellow Roll-Royce Owners Club (RROC) member, knowing of my interest in aviation, loaned me this most interesting book.
If you are interested in Experimental aircraft, WWII, either, or both, this book on the Roll-Royce Merlin engines is a must read, as the books points out, just about everything developed for WWII aviation was experimental. The need for aircraft was so intense, that all you had to do was prove to a group that it might fulfill a particular need, and it was ordered. Development would start as the planes and engines were flying,
In perspective, one might suggest that the Merlin engine was one of the most important developments that the Allies received.

As I might conclude, there is a chance that my wife might never had been born had President Truman not decided to end the war quickly with the dropping of the Atomic bombs, as my wife’s father had been fighting in the Pacific, and surely would have been involved in the Allied attack on Japan had they not surrendered. Who know is he would have survived. She was born in 1946.
Likewise, many readers of this posting, might not be here had the Merlin not been fitted to the P51s that were able to escort the Allied bombers to their targets, and greatly reduce the number of bomber losses.
Who know how many of your fathers, and grandfathers survived because of this engine.

The Merlin was the powerplant for the Hurricane, and Spitfire fighters which managed to win the Battle of Britain. Had Germany succeeded in destroying British air power, and had been able to invade and occupy England, the Allies would not have had a jumping off point for the Liberation of Europe. Who knows what the world would look like now.
It’s amazing how the visions of a few gifted men altered our world.

The author of this book, Alec Harvey-Bailey started with R/R shortly before WWII, and remained for over 40 years. However, his father had been a senior executive with the company for most of his life.
It is not a large book, measuring about 5â€￾x8â€￾ and less than 3/8â€￾ thick, however the print is small, and there are many photos, drawings, and factory prints.

A few facts from the book.

Development of this engine started in 1934 when Royce (Rolls had died in a aircraft accident years earlier) saw war clouds developing, deemed such an engine would be necessary if Britain was to have any chance of survival. They used their experience gained from the Schneider Trophy winning engines at the end of the 20’s to help develop the Merlin.
I first saw a Merlin engine over 50 years ago when I majored in Aircraft at Central Tech in Toronto. It was a cut-away that would rotate slowly by an electric motor, and was undoubtedly used during the war to train mechanics. I do remember what a beautifully built engine it was. It was fascinating to watch parts moving through the cutouts. I still remember it.

Total Production was about 160,000, with Packard building 60,000 in Scotland.
There were 52 different Marks produced for 19 different aircraft.
There were over 50,000 engines repaired and put back into service.
Fighter engines in 1939 lasted about 240 hours, and this improved to 300/360 in 1944/45
Bomber engines in 1939 lasted about 300 hours, and improved to 360/420 in 1944/45
Transport engines would last about 480/500 hours.

The engine was 27 litres (1650 cu.in.) and had a compression ratio of 6:1.
Combat power in 1939 with the Merlin III was 1030 hp @ 3000 rpm with 6.25 lb boost, and would maintain this power to 16,000 feet. Horsepower was .6 per cubic inch.
By 1944 the Merlin 66 had 2050 hp @ 3000 rpm with 25 lb boost, and could maintain this power up to 36,000 feet. Horsepower was 1.24 per cubic inch.

The book covers the development right through to the end of the war.
Most interesting is that just about every part in the engine had a problem at one time, and the book goes into detail about some of the fixes. Obviously, it helped if the pilot could nurse the aircraft back so the engineers could trace the failure.
A common problem was the crankcase would crack on a forced landing, and they could salvage the case by welding the cracks, and installing a steel brace which is documented and illustrated.
Distortion of the case while under load would cause some drives to fail. The cures are covered.
One has to mentally picture these British engineers surveying the problems with a pipe in one hand and a cup of tea in the other, but they got the job done. These were basically kids flying these fighters, and with a lot of bullets attempting to knock them out of the air, they didn’t need their engines to fail and accomplish the same mission.

Also covered was the problems that the P51’s had when flying slow to keep with the bombers they were escorting.
The topic, as has appeared on this forum, as to manifold pressure vs. rpm is covered. This was debated even then.
Covered also , is the comparison between the relatively simple air cooled bulky radial, and the sleek compact liquid cooled, more complex V12 Merlins.

There is a chance that this book is out of print, but a web search if you’re interested might find you one.
This issue I was loaned was published in 1983 by the Roll-Royce Heritage Trust, PO Box 31, Derby England.
Another source might be the Roll Royce Owners Club Website. They have an on-line store with a large selection on books. A phone number is listed on the site.
I’d say well worth the effort to find one.

Cheers
Jack
RV9A
79 hours

[Spike]

Now that sounds like a nifty book.