Rolls-Royce Heritage Trust
Historical Series Reviews - Page 06

The History of the Rolls-Royce RB211 Turbofan Engine
by Philip C Ruffles

Softbound, 295mm x 210mm x 20mm, 326 pages
ISBN: 978-1-872922-48-5
Rolls-Royce Heritage Trust
P.O. Box 31
Derby DE24 8BJ

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335 photos/illustrations

Rolls-Royce Heritage Trust Historical Series No.47
Reviewed by Douglas Culy, 16 January 2015

The book has a very large amount of detail, and is a blow-by-blow account of taking engine power from the subscale RB203 Trent II's 9,730 lb-t to the RB178-16 demonstrator at 24,750 lb-t to the RB211-6 at 33,500 lb-t (at most), to the RB211-22 at 40,000 lb-t (only for a few seconds, so as to avoid cremating the engine, while these early -22s averaged about 35,000 lb-t), to the RB211-22B averaging 38,500 lb-t versus a commitment to Lockheed of 38,000 for flight-test engines (the production contract was for 40,600 lb-t) to the RB211-22C at 42,000 lb-t, to the RB211-524B at 50,000 lb-t, to the RB211-535C at 37,400 lb-t, to the Trent 600/700 at 67,500 lb-t, to the Trent 800 at 91,600 lb-t, to the Trent XWB at 93,000 lb-t, and to intermediate powers for other Trents, obtained by scaling the core. After the -22C program, the challenges were easily handled, but Ruffles shows the -22 and -22B to be the engines that almost killed Rolls-Royce.

Ruffles was a development engineer, given varied responsibilities at increasingly higher levels in the Company, having joined R-R shortly before the start of studies leading to the RB211. He was intimately involved in the RB211 program. He shows that the Hyfil composite fan blade was only the 'straw that broke the camel's back' (the low-pressure-compressor vanes and the front bearing housing were also glass-reinforced plastic). The larger problem areas were: burning of the combustor, high-pressure (HP) turbine nozzles (limiting turbine inlet temperature) and HP turbine blades; and excessive leakage through most of the labyrinth seals between the three rotating spools and the static structure. Ruffles then tells of the long effort to resolve field problems, since the test hours were not sufficient to find the really short-life components. The discussion of these major problems and their solutions is thoroughly done in terms of the detail design aspects of several features of each of the suffering parts.

The usually ordinary problem of weight was complicated by having to add much weight to move the engine mounts from the core-engine case to the fan case. Accommodating airframe weight growth came after the R-R bankruptcy.

Bankruptcy was brought about by cost growth in the program, sales decline of R-R overall business, admittedly poor management of development, the need to force Lockheed to come to terms on modifying a contract that had become impossible to meet, and R-R's poor cash position after just completing development of the Adour engine. Though not mentioned in the book, R-R was ALSO working on the: civil and military Speys, the RB193 for the VAK191 fighter (which was cancelled just after the bankruptcy), RB199 program (which was started before the -22 version had begun and continued after bankruptcy). Total company sales in 1968, the year of the RB211 program start, was near 60 million pounds, and investment in the 211 program by the time of bankruptcy filing was near 200 million pounds. Inflation and real material/labor increases had raised the cost of production engines by 69%. The book separately uses the terms "Launch Costs" and "R&D Costs". They are not differentially defined, but this reviewer thinks that R&D means engineering development alone, and Launch includes manufacturing tooling and possible initial spares.

Ruffles shows that R-R had good intelligence on what competitors Pratt & Whitney and General Electric were doing, and that this in turn motivated R-R to push harder on its programs. Many participating engineers and managers are discussed and shown, suggesting to this reader that frequently changing leadership contributed to management problems.

In summary, the history of the RB211 is very much a handbook for the development engineer, and the most detailed history of a development program that this retired development engineer has seen since he entered the business 54 years ago.

However, The History of the Rolls-Royce RB211 Turbofan Engine is a complex book, requiring several reads to grasp all that is included, a task is greatly complicated by the LACK OF AN INDEX. This reader encountered many small glitches in the book (typos, misspellings, etc.). Ruffles made a number of comments that assumed the reader was well acquainted with R-R facilities and their uses. He also naturally used British vernacular, some of which is very hard for Americans to understand. The writing seemed to have been hurriedly done, and the editing was sloppy or non-existent.

In spite of the above problems, this reader still highly recommends the book … with the caveat: be warned.