Preface 2008

The current models of aviation engines on transpacific flights develop about 90,000 pounds of thrust, power generation gas turbines have broken the 450 megawatt gas turbine barrier, and gas turbines are now being used on cruise ships. Gas turbines have come a long way since my first meeting with them. At that point over thirty years ago, we waited a day for the casing on an old 20 kilowatt Brown Boveri to cool sufficiently for us to be lowered by rope harness into the intake for an inspection.

Most end users do not part easily with their old workhorses, so many of them are still around. The Rolls Royce Avon fleet on the Alaska pipeline, the huge number of globally installed General Electric Frame 5s (the original version, not the newly introduced model), the myriad of Solar Centaurs and Saturns everywhere in the world that needed “just about 3,000 or 1,000 horses” for a pipeline or oil and gas application, the many models of Pratt and Whitney’s JT8D that still make up one of the world’s largest commercial aircraft engine fleet. They work reliably, if inefficiently by today’s standards, surrounded by a work force that can often hear the slightest whimper of distress from their machine—often because they rarely hear one. To some extent, these turbines owe their longevity to the continual design development in the form of service bulletins, decreed “mandatory” or “optional” by their manufacturers. I use quotation marks, as sometimes there are manufacturers who have used the “mandatory” label as a means of upgrading end-user fleets for their own revenue extension. Rather than actual end-user power requirements, the OEM’s motivation was to lower the number of configurations that required a stock of spares, and other profit-motivated objectives. And then other times, as with the JT8D, the bulletins developed took a generic 9,000 pound thrust engine, born in the 1950s to just under 20,000 pounds thrust by the 1980s with one of the most enviable safety records for a gas turbine fleet. Many land based gas turbines, like the old GE Frame 5 have a proven record of specific steam injection designs raising their power output by 20–25%.

There are many types of basic applications of gas turbines. There are land, sea, and air gas turbines. On land, there are power generation and mechanical drive gas turbines. In aviation, there are large commercial, high-performance military, mid-range commercial, small fixed-wing, and helicopter engines, maintained to commercial or military specifications. At sea, there are large vessel turbines and smaller ferry turbines. There are offshore applications that must incorporate the sturdiness associated with land use turbines, with the light weight associated with aviation applications, with the corrosion resistance associated with marine applications.

There are many types of engineers who are fortunate enough to work with gas turbines. There are end users and OEMs (original equipment manufacturers). Gas turbine specialists and turbomachinery specialists who work on all rotating machinery. Overall systems and project engineers. And manufacturer design specialists who will work on one major turbine component all of their working lives.

There is an indefinable quality about gas turbines that favors those that who somehow develop an instinct for them, regardless of working years spent or formal education accumulated. I have watched humble mechanics point the way for befuddled technical gurus. There are brilliant design engineers who can miss a misalignment source that a millwright can spot blindfolded. There are some engineers who can actually troubleshoot a practical problem, and others who can’t.

With gas turbines, there are systems design and specification, commissioning, troubleshooting, failure analysis, retrofit and reengineering, training, technical writing, design development, repair and overhaul, fleet management, and regular operations functions. I have been singularly fortunate in that I have run that entire gauntlet back and forth in power generation, oil and gas, process, military aviation, and commercial aviation on three different continents. No credit to my astuteness: the state of the world kept moving me on (politics is a good thing sometimes).

One flash of discernment, however, did make it possible for me to hold all of that exposure together not just as a cohesive whole, but one where all sectors could gain from each other. Then in the Canadian Air Force, I was about to take on all the six helicopter engine fleets the Canadian military branches flew. The presentation before me at the 1984 annual American Society of Mechanical Engineers International Gas Turbine Institute meeting (ASME IGTI’s “TurboExpo”) featured an offshore oil and gas man who was displaying the control panel that ruled a platform. In Canada, we had just “piggybacked” on the US F-18 fighter program with a few of the same. The F-18’s F-404 General Electric engine had a condition monitoring system that was, to say the least, intriguing. It occurred to me that the panel displayed on the screen was very similar to the one on the HUD (head up display) of the F-18.

And so a “joint” ASME IGTI session that I ran annually from 1985 through 2003, patiently assisted by luminaries like Jim Hartsel (one of the General Electric turbine engineers most responsible for the superior performance of the F-404 and the T700), was born. The committee sponsors included the Aircraft Engine, Controls, Instrumentation & Diagnostics; Materials, Metallurgy & Manufacturing; Marine, and Electric Utilities committees. The idea is to get land, sea, and air people to learn from each others’ experiences. It works. The panel has hosted some of the best brains from commercial and military aviation, power generation, oil and gas, manufacturing, process and petrochemical, performance analysis, marine applications, metallurgical development, and controls instrumentation and diagnostics. Those attendees who are fortunate enough to show up have benefited enormously. It has given aspects of my work a rare flair that is attributable to the company I have been blessed to keep.

This book represents much of the expertise in the gas turbine field available today. It is 80–90% adapted and edited from many brilliant sources and about 10% is original writing. That latter portion serves to give the reader a point of reference that they can measure the extent of their agreement—or disagreement—against. It’s practice for when you have to make decisions that your underwriters, insurance company, and mechanics may challenge. The book avoids the just-one-application bias (say, just mechanical drive or just power generation or just aviation or just plain theory) that all other gas turbine books I know of adopt.

Gas turbine engineers in all sectors, disciplines, and specialties, who looked at the draft, have told me they found its contents useful. Just as importantly, they gleaned information from others’ applications. So besides imparting applications and basic design knowledge, this book is meant to get readers to think across disciplines, across land, sea, and air to the heart of this demanding, powerful, and infinitely variable mistress—the gas turbine.