Ford Aerospace Division: Tanks for the Memories
If you have been following my posts you may have seen that I spent my last three years at Ford (2004-2007) working as an automatic transmission cooling engineer. I also started my engineering career working on cooling.
I worked for Chrysler Defense, Inc., as an automatic transmission engineer from 1980-1982. Early in 1982 we were sold to General Dynamics.
About this time Ford Aerospace Division won a contract over General Dynamics to build a new anti aircraft turret that would be mounted on an . The M48 was a Korean war era tank, that had been updated to 1960’s technology.
It was capable of 15 mph cross country. Once the new turret was installed it weighed about five tons more than it did as a tank. So the cross country speed was probably degraded, but if it was tested nobody told me.
This was designed to support the then brand new M1 Abrams Main Battle Tank. The M1 was capable of 35 mph cross country. Who ever thought that a 15 mph support vehicle could help protect a 35 mph tank?
Chrysler Defense had made the M48 and did the upgrades. Now that we were owned by General Dynamics, they owned the M48. Remember how Ford won the contract over General Dynamics? Now General Dynamics assigned me to analyze the cooling on the M48 with respect to the added weight, and the fact that Ford redesigned the grilles, which changed the opening from 10 square feet to 3 square feet.
I spent three weeks with paper, pencil, and my trusty calculator (at least we were past slide rules!) doing a cooling analysis. At the end of this work I concluded that both the engine and transmission will be above our temperature limits by about 30 degrees F.
This started a firestorm of finger pointing. Ford claimed that General Dynamics was lying because we had lost the contract to Ford. My management stood by my analysis. The Army only knew one way to find out who was right. Test it.
I spent two weeks at the Army’s Aberdeen, MD, proving ground. We had an M48 with the modified grill and a towable dynamometer. This dynamometer was mounted on a truck chassis. A BIG truck chassis. I think it was built on the same chassis that the strip mine off road dump trucks use.
The tires were about 7 feet tall. There was a ladder to climb into the cab. The cab was wide enough for the driver and a three person bench next to him. We also had a trailer dynamometer towed behind the truck. To test an M1 they used TWO of these trucks with two trailers!
We had a two mile long test track with a circle at each end to turn around. The worst case cooling was at 2.3 mph. This created a high speed ratio (a lot of slip in the torque converter) and created a TON of heat! We had to run the test until the temperatures stabilized. One lap of the test track took two hours.
As we came back past the garage we would all climb out of the cab, go into the garage for a few minutes break, and climb back in. All of this while the test was still running at 2.3 mph. My normal walking pace is about 3 mph, so you can see how slow this was going.
I was rather nervous during the whole two weeks that I was there. I was very relieved when the Army gave us the official results. Both the engine and transmission had exceeded the temperature limits by 29 degrees F! I had a big celebration that night.
This test, and the 15 mph cross country speed, plus the fact that the turret was not able to actually pass any of it’s functional tests, meant that this program never made it to production.
And after this I never heard of Ford Aerospace Division again. It certainly didn’t exist when I came to Ford in 1988.
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M48A5 Tank photo courtesy of Andy Doyle via Flickr & M1 Abrams MBT photo courtesy of Ed Uthman via Flickr.