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Start Your Engines

Many years ago, I was testing a diesel engine that was to be used in a total-energy package for a U.S. Navy ship. The ship had been designed and built to a rejected heat rate of 4 million Btuh from each of the ship's four engines.

During my testing, I calculated the heat that was rejected to the cooling water and then to the waste-heat system. The most heat I was able to measure from an engine was about 2.75 million Btuh. Shortly after a report that included my testing data was issued, I was called to a meeting in Washington, D.C. None of my managers bothered to accompany me. It soon dawned on me that I was alone in my opinion, and I would be defending the data.

The big question was, “If the engine manufacturer said the engine should produce 4 million Btuh, and we are getting only 2.75 million Btuh, where is the heat going?” At the time, the only answer I could come up with was, “Up the stack.” This did not seem to reassure the 20 other people in the meeting.

At that point, one of the attendees brought out a diesel-engine reference book. It had percentages of heat rejected into the air, cooling system, and exhaust. The percentages were in close agreement with my data. Suddenly, I was not the focus of attention.

After the meeting, I asked to see the source of the 4-million-Btuh figure. It essentially was a one-sentence letter from the engine manufacturer's marketing department stating the rejected heat rate was 4 million Btuh. There were no curves or other data. As a result of this test, a fifth engine was installed in every ship.
Dave Hall
Oceanside, Calif.

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