LAB TECHNICIAN

The AiResearch Manufacturing Company of California, a Division of the GarrettCorporation, was manufacturing three small gas turbine engines in October 1951 when I becamean employee. They were Gas Turbine Compressor Unit, Model GTC43/44-5, Gas TurbinePower Unit, Model GTP70-10 and Gas Turbine Compressor Unit, Model GTC85-70. I startedworking as a laboratory technician on Project Engineer Cliff Farrell’s Model GTC43/44-6. This was a “dual bleed” unit which differed from the -5 in that it incorporated two bleed valves. Thecompressor bleed valve (same as the -5) functioned with a second thermally controlled valvelocated downstream of the combustor. The two valves mixed air/gas from the sources to providean increased bleed air temperature.

I learned how to operate the unit and performed much of the development test operations.Everything progressed normally as we conducted testing in the open air test cells. Thearrangement of the test facility was two test bays on each side of a common control room. Fourunits of various configurations could be operated from one of the control panels located at eachcorner of the control room. All instrumentation and operational controls were located at thesestations. Working in this environment wasn’t too bad; there was enough shelter keep dry whenraining, and temperature was not a problem in Southern California.

Low temperature environmental testing was required and that presented a problem, forthe low temperature facility could not handle a unit of gas turbine size. To perform this test, alarge wooden box was set up just outside of the low ambient test facility. Controlled temperatureair ducts were routed to the box. The objective was to maintain a positive pressure on the testchamber while subjecting the test unit to cold soaking and operation.. Unit controls andinstrumentation were provided just outside of the test box. After the GTC43/44-6 was installedin the temporary test facility, the setup was checked out at existing ambient. Operating atextreme ambient temperatures was initiated by pumped cold air into the box until minus 65F wasattained, where the unit had to soak for a specified time before a start and operation sequencewas initiated.

During this soaking period, I had some time to watch and talk with the facilitytechnicians. I noticed that every once-in- awhile one of them would go to a gallon can and downa large green pepper. I had always enjoyed a good pepper, for back home in Arkansas, mygrandfather would plant his peppers (those long red ones) in his garden the very first thing in thespring. So I asked if I could have a pepper, which they, joyfully, encouraged that I do! Displaying my knowledge on pepper eating, I select a very large one. I put the whole thing in mymouth, discarded the stem and attempted to chew. I could not do a very good job, only broke itup a little when the large mass slipped down! Everything went well for a while, then the pepperexploded with a heat index that I had never experienced! This was my first encounter withjalapeno peppers and another lesson in Spanish/Mexican. But I continue to be a fan of jalapenopeppers.

It came time to perform a minus 65F start. I initiated the start sequence and away shewent! Excessive turbine inlet temperature, no stopping at governed speed, right past over speedprotection and very bad noise! Disassembly revealed a severely damage hot end. The pneumaticgovernor/speed control system did not function very well in the humid LA atmosphere. Duringseveral ambient cycles prior to the soaking period, moisture collected in the pneumatic control

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system which became inoperative due to internal ice formation. This was my first turbine melt down. Very embarrassing and Cliff was very upset.

Late in my laboratory experience, we had to tear out all of the instrumentation plumbingand electrical wiring from the unit test stand to the panels and consoles in the control room. AlRomanin, Bill Caan and I learned what a mercury magnetic was (a broom and a dust pan). Theplumbing for all of the mercury manometers was routed to the test room via a covered ditch in the floor. Over the years of testing the ditch was loaded with mercury spills. We gathered themercury and placed it in flasks. A full flask weighs 90 pounds. Did you know that a man can lifta 90 pound flask and place it on his shoulder and carry if away, but he cannot do the same thingwith one that is only a third full? Why, because when he attempts to place it on his shoulder therapid movement of the mercury to the opposite end tears the flask from his hands and there ismore mercury to sweep up! We participated in this clean up for some time and regardless of thefears expressed today, no one suffered from this exposure.

My last assignment as a Lab Technician was to help build and operate Test Cell 10. Thisfacility was temporary and was dedicated to testing of turbochargers. A new project utilizing Dr.von der Nuell’s (one of the German engineers brought over to the states after the war) knowledgeand back ground in this field. He was well recognized in the field of supercharging internalcombustion engines. He was the author of several books and had been a university professorteaching the subject.

Test Cell 10 was located in the back of AiResearch laboratory area at the very edge of theLos Angeles Airport (corner of Sepulveda and Century). Prefabricated sound proof panels wereutilized to construct the enclosure for the housing of instrumentation, controls and personnel. The test units were located outside on a concrete slab, i.e., it was an open air test facility. Thecompressed air supply was furnished by a very large Ingersol Rand, trailer mounted, dieselengine driven, Roots type compressor. It was a temporary arrangement!

Preston Holland was the leadman and I was his only helper. It was a small and austereproject! After we assembled and checked out the facility, the first development unit was placedunder test. We had much trouble with vibration and none of the development engineers up toand including von der Nuell could resolve theproblem. Now von der Nuell had fired Mr.Douglas, his Project Engineer, just prior to startingthe test program. I do not know the reason; butsuspect that von der Nuell’s Prussian attitudecaused a problem.

The turbocharger design utilized a radialcompressor driven by a radial inflow turbine wheel. The two elements were mounted on a commonshaft which was supported by two oil lubricatedbearings. The general arrangement of aturbocharger is shown in this cross section.

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To solve the vibration problem, von der Nuell had to call Douglas back as a consultant atan exorbitant cost. The first thing Douglas required was the removal of everything attached tothe test unit. Then he ordered the pounding of the pyramid shaped pedestal (1/4 inch thickwelded steel fabrication) with a lead mallet. From these data, he established the resonantfrequency of the test stand. He worked for several days, made a good sum of money and finallyrequired the installation of vibration deadening material on the test unit pedestal. It was poeticjustice that he was able to return and prove his worth

We had everything going well and required a second shift, as a result I met Paul Mitchell. Paul was a professional football player. I understood that he had originally played for the NewYork Giants and had been traded to the Chicago Bears. He had just finished the season with theBears. He had an arrangement with AiResearch to work in the off-season and preferred swingshift. So with this ideal arrangement, he became the swing shift leadman; I do not recall who hishelper was.

I shall never forget this big man, standing in the test cell door with his head against thetop of the door opening and his shoulder rubbing both sides of the door frame, telling us aboutone of his games. He said, that when he broke out of the huddle, assumed his position andlooked across the line, “There was a great big SOB!” I have often wondered just how big theother guy was, for I was standing there aghast, looking up and nodding my agreement with everything this very large guy said.

Paul finished up the year with us and returned to his football playing. He returned toAiResearch after his retirement from football and ultimately became a vice president in thecustomer support area. Big men always move up in the business world!

As for the turbocharger project, I maintained an interest in its growth after I moved toPhoenix. During an orientation visit to Los Angeles many years later, I was able to see theproduction line in action in the old Engineering Building on 96 and Arbor Vitae. Jim Cazier,th

Manager of the AiResearch Industrial Division, had really shaped it into the only true productionfacility in the Garrett Corporation at that time. I watched material come in, progress down a linewith very few personnel in attendance as turbocharger were assembled, tested and packaged fordelivery. It was impressive. The turbocharger product line grew into a billion dollar business.

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