LAB TECHNICIAN
The AiResearch Manufacturing Company of California, a Division of the Garrett
Corporation, was manufacturing three small gas turbine engines in October 1951 when I became
an employee. They were Gas Turbine Compressor Unit, Model GTC43/44-5, Gas Turbine
Power Unit, Model GTP70-10 and Gas Turbine Compressor Unit, Model GTC85-70. I started
working 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. The
compressor bleed valve (same as the -5) functioned with a second thermally controlled valve
located downstream of the combustor. The two valves mixed air/gas from the sources to provide
an 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. The
arrangement of the test facility was two test bays on each side of a common control room. Four
units of various configurations could be operated from one of the control panels located at each
corner of the control room. All instrumentation and operational controls were located at these
stations. Working in this environment wasn’t too bad; there was enough shelter keep dry when
raining, and temperature was not a problem in Southern California.
Low temperature environmental testing was required and that presented a problem, for
the low temperature facility could not handle a unit of gas turbine size. To perform this test, a
large wooden box was set up just outside of the low ambient test facility. Controlled temperature
air ducts were routed to the box. The objective was to maintain a positive pressure on the test
chamber while subjecting the test unit to cold soaking and operation.. Unit controls and
instrumentation were provided just outside of the test box. After the GTC43/44-6 was installed
in the temporary test facility, the setup was checked out at existing ambient. Operating at
extreme ambient temperatures was initiated by pumped cold air into the box until minus 65F was
attained, where the unit had to soak for a specified time before a start and operation sequence
was initiated.
During this soaking period, I had some time to watch and talk with the facility
technicians. I noticed that every once-in- awhile one of them would go to a gallon can and down
a large green pepper. I had always enjoyed a good pepper, for back home in Arkansas, my
grandfather would plant his peppers (those long red ones) in his garden the very first thing in the
spring. 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 my
mouth, discarded the stem and attempted to chew. I could not do a very good job, only broke it
up a little when the large mass slipped down! Everything went well for a while, then the pepper
exploded with a heat index that I had never experienced! This was my first encounter with
jalapeno peppers and another lesson in Spanish/Mexican. But I continue to be a fan of jalapeno
peppers.
It came time to perform a minus 65F start. I initiated the start sequence and away she
went! Excessive turbine inlet temperature, no stopping at governed speed, right past over speed
protection and very bad noise! Disassembly revealed a severely damage hot end. The pneumatic
governor/speed control system did not function very well in the humid LA atmosphere. During
several 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 plumbing
and electrical wiring from the unit test stand to the panels and consoles in the control room. Al
Romanin, Bill Caan and I learned what a mercury magnetic was (a broom and a dust pan). The
plumbing 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 the
mercury and placed it in flasks. A full flask weighs 90 pounds. Did you know that a man can lift
a 90 pound flask and place it on his shoulder and carry if away, but he cannot do the same thing
with one that is only a third full? Why, because when he attempts to place it on his shoulder the
rapid movement of the mercury to the opposite end tears the flask from his hands and there is
more mercury to sweep up! We participated in this clean up for some time and regardless of the
fears expressed today, no one suffered from this exposure.
My last assignment as a Lab Technician was to help build and operate Test Cell 10. This
facility 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) knowledge
and back ground in this field. He was well recognized in the field of supercharging internal
combustion engines. He was the author of several books and had been a university professor
teaching the subject.
Test Cell 10 was located in the back of AiResearch laboratory area at the very edge of the
Los Angeles Airport (corner of Sepulveda and Century). Prefabricated sound proof panels were
utilized 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. The
compressed air supply was furnished by a very large Ingersol Rand, trailer mounted, diesel
engine 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 austere
project! After we assembled and checked out the facility, the first development unit was placed
under test. We had much trouble with vibration and none of the development engineers up to
and including von der Nuell could resolve the
problem. Now von der Nuell had fired Mr.
Douglas, his Project Engineer, just prior to starting
the test program. I do not know the reason; but
suspect that von der Nuell’s Prussian attitude
caused a problem.
The turbocharger design utilized a radial
compressor driven by a radial inflow turbine wheel.
The two elements were mounted on a common
shaft which was supported by two oil lubricated
bearings. The general arrangement of a
turbocharger 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 at
an exorbitant cost. The first thing Douglas required was the removal of everything attached to
the test unit. Then he ordered the pounding of the pyramid shaped pedestal (1/4 inch thick
welded steel fabrication) with a lead mallet. From these data, he established the resonant
frequency of the test stand. He worked for several days, made a good sum of money and finally
required the installation of vibration deadening material on the test unit pedestal. It was poetic
justice 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 New
York Giants and had been traded to the Chicago Bears. He had just finished the season with the
Bears. He had an arrangement with AiResearch to work in the off-season and preferred swing
shift. So with this ideal arrangement, he became the swing shift leadman; I do not recall who his
helper was.
I shall never forget this big man, standing in the test cell door with his head against the
top of the door opening and his shoulder rubbing both sides of the door frame, telling us about
one of his games. He said, that when he broke out of the huddle, assumed his position and
looked across the line, “There was a great big SOB!” I have often wondered just how big the
other guy was, for I was standing there aghast, looking up and nodding my agreement with every
thing this very large guy said.
Paul finished up the year with us and returned to his football playing. He returned to
AiResearch after his retirement from football and ultimately became a vice president in the
customer 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 to
Phoenix. During an orientation visit to Los Angeles many years later, I was able to see the
production line in action in the old Engineering Building on 96th and Arbor Vitae. Jim Cazier,
Manager of the AiResearch Industrial Division, had really shaped it into the only true production
facility in the Garrett Corporation at that time. I watched material come in, progress down a line
with very few personnel in attendance as turbocharger were assembled, tested and packaged for
delivery. It was impressive. The turbocharger product line grew into a billion dollar business.
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