Here is the story behind this engine. GM came up with this engine, to replace diesel engines in tractor and trailer rigs, during the 1973 Oil embargo. They developed the motor, and installed it into 2 rigs. Sent them out to drive back and forth, from East coast to West coast until the engine failed. The drivers soon had to report to the project manager, that they were now the proud recipients of the most expensive T&T speeding tickets, in every state they drove through. Soon, both lost the privilege to drive. Other drivers took over. The fuel consumption was a killer. Something around 30 gal an hour. Back to the drawing board. GM came up with Regen Wheels. 6-7 thousand bucks per wheel. Two big, huge, heavy wheels that were hung on both sides of the engine. They turned at 17 RPM. When you looked at them from the side, it looked like the wheels were made up of rolled up cardboard. They were made of some exotic metal that could take the heat of the output turbine exhaust. As long as they turned at 17 RPM. There was two seals, (at 1,800 bucks a shot) that sealed the input and output sides of the burner assembly. The exhaust gases were funneled through half of the Regen wheel, to warm up the wheel. The input ambient air was drawn though the other side of the super hot wheel to heat up the incoming air going into the burner chamber. Imparting much energie by doing so. As long as they turned at 17 RPM. Back on the road they went, destroying all speed ticket records and proving that the regen wheels worked. It now only ate 17 GPH. GM also found that the engines tended to self destruct at 1000 + or - hours. Like clock work. The oil embargo ended, and GM dumped the whole thing on Allison Turbine Company. They refined it a bit, but it still ate too much fuel. THEN, came the Patriot Missile System. They had a power need of 150 KW generator, with a very stable frequency and voltage output. Allison shouted "Pick me! Pick me! and got the contract. Had the Army wanted a 300 KW gen set, Allison would have sold them the same motor. This baby is a monster. The Israeli Gov. bought some, to install in a Special Patrol Boat, thereby having the fastet Patrol Boat in the Mediterranean, for several years. It had three of these things, each driving a direct drive screw. In 1985 when I came along into the Patriot world, the Army had 103 motors. They planned to need 84 in Europe, and 2 floats in my shop. There were 6 in Ft. Bliss, and 2 floats. And 2 in the School House in Ft, Belvoir for training. Total of 96. The motors were overhauled at Tooele Depot. They did a poor job of overhauling this engine. That led to 3 engines being totally written off. So we now had 3, count em, 3 spare engines. At the end of the 80's, NATO started to down size, the requirement for 7 BN's Patriot, of 6 firing Battery's was cut first in half, the reduced to one Bn Patriot in Germany, consisting of 3 firing Batters each. But by then, the turbine gen set was on its way out, Unreliability, high cost and problems procuring repair parts killed it. The 150 KW replacement was Deutz powered gen set.