Rolls-Royce Heritage Trust
Historical Series Reviews - Page 01
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The Merlin in
Perspective
- Softbound, 208 x 148 x 11 mm, 204 pages Rolls-Royce Heritage Trust (ML-71) Recommended Retail Price: 100 photos/illustrations |
Reviewed by Kimble D. McCutcheon
Rolls-Royce Heritage Trust Historical Series No. 2
Alec Harvey-Bailey was in charge of Merlin engine defect investigation during WWII. In addition to examination of damaged engines, his role also involved development of engineering improvements and repairs. Harvey-Bailey made numerous visits to active squadrons and even flew aircraft when it was necessary to become familiar with particular problems.
Between 1939 and 1945 the Merlin was used in 19 different types of operational service aircraft plus large families of Spitfires and Mosquitoes. There were Merlin variants with single-stage single-speed superchargers, single-stage two-speed superchargers, and two-stage two-speed superchargers with intercooling. Ratings ranged from 1,000 hp to over 2,000 hp, with specific weight improving from 1.4 to 0.8 lb/hp. More that 160,000 Merlins were built.
The Merlin, like any engine, was not without its problems. Much of the book deals with the Rolls-Royce response, which was direct and swift engineering action, remedial action on production or repair, or getting a grip on squadron maintenance and/or operational problems. Single-engine installations and the Lancaster were relatively trouble-free, but the close proximity of propellers to the wing leading edge of the Halifax and to the fuselage of the Mosquito led to vibration and reduction gear difficulties.
The Merlin in Perspective is filled with details concerning Merlin development as specific issues were addressed. Examples include backfires, bearing failures and propeller reduction gears. Seemingly insignificant design changes sometimes produced counterintuitive side effects. As a result it was Rolls-Royce policy to immediately address even the smallest details.
The book has numerous drawings of engine components. It also provides several appendices with pictures of engines and the aircraft they powered as well as tables specifications for the Merlin Mark numbers. It is a must for any fan of the Merlin.
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Olympus Softbound, 210 x 148 x 11 mm, 185 pages Rolls-Royce Heritage Trust Recommended Retail Price: 106 photographs/illustrations |
Reviewed by Kimble D. McCutcheon
Rolls-Royce Heritage Trust Historical Series No. 15
This book grew from its author’s attempt to record the highlights of a largely uneventful test flying career, where his association with the Olympus was a far more interesting story than the flying. The Olympus, Bristol’s first turbojet, was designed to power bombers flying at more than 500 mph and 40,000 ft. During its 50-plus year life its thrust rating grew from 9,140 lbT to 38,000 lbT. The book was written to mark the 40th anniversary of the Olympus’ first run. The second edition is expanded to cover the demise of Concorde supersonic airliner.
Bristol got off to a slow start in turbojets. In 1946 when the first layouts of what was to become Olympus were started, Bristol had no operating experience with pure jets. The Project Office was run by Charles Marchant, and a staff of two—Sam Robinson, a designer and Gordon Lewis, a young graduate engineer. A target thrust of about 9,000 lbT was needed to achieve the 500 mph and 40,000 ft goals and this would required a compressor pressure ratio of at least 9:1, which at the time was unheard of. Bristol Chief Engineer Frank Owner hoped to achieve this pressure ratio using a split-compressor design with a 10-stage axial compressor feeding a centrifugal second stage. Problems associated with the centrifugal stage ultimately resulted in two axial stages, each driven by a separate turbine. A cannular combustor, believed to have first been used on the Olympus, kept engine diameter under 40”. At that time annular combustors were beyond the state of the art.
Dr. (later Sir) Stanley Hooker joined Bristol in January of 1949, and after he replaced Frank Owner as Chief Engineer about 18 months later, the Olympus program took off. The Olympus saw extensive service in the Vulcan bomber. Bristol gained supersonic experience by working on Olympus development for the TSR2, which positioned the company and its descendents (Bristol-Siddeley, Rolls-Royce) to produce the Olympus 593 for the Concorde. In addition to aviation applications, over 250 Olympus engines have been used in marine applications, and over 300 sold for industrial power generation.
The chapter covering Olympus 593 development for use in the Concorde is both awe-inspiring in terms of the airplane’s capabilities and tragic in its documentation of the events that led to the Concords’ withdrawal from airline service. However, despite the troubles that challenged Concorde, the Olympus engine displayed a nearly perfect service record in airline service.
More reviews coming soon
