Cooper Engines

[Jefecinco]

[Split from another thread on another topic, during which the topic of the Cooper engine was introduced. All comments about the Cooper engine are now moved to this thread--jimh]

...of the two main Cooper diesels driving generators for our the main electric motor (diesel-electric) we only had one operational diesel. If I remember correctly, the massive inline 6cyl Coopers were about 1,000hp each and spun at a max of 400RPM.

DT - Thanks for the story. I particularly enjoyed the insights into the Cooper engines. I've made the assumption that the Coopers you refer to were followed by the Cooper Bessemer line on which I received some excellent training in 1971. Our engines were in a fixed power plant and fired by natural gas with diesel pilot fuel. We had six engines turning 3 megawatt generators each. The were governed at 180 RPM although designed to run at 360 RPM. Cooling was via a six cell cedar cooling tower. During my year at the plant we never changed lubricating oil although the oil was sampled and tested frequently. Out of curiosity we used fiber optics to examine the combustion chambers on the first engine to log 4000 hours of operation. All we could see was a very small grey ash deposit atop the pistons. With four stroke engines running at 180 RPM you can hear each cylinder when it fires. That was the best designed diesel power plant I've seen.

[dtmackey]

I've made the assumption that the Coopers you refer to were followed by the Cooper Bessemer line on which I received some excellent training in 1971.

Yep, those were the Coopers I was referring to. We had the 6cyl versions and I believe they also had a 7 and 8 cyl offering in normally aspirated and also turbo. Ours spun at 360rpm and I believe had a max or 400rpm, but I'd be leery of spinning that amount of mass at those RPMs. After the SPAR drove over the ledge, the crank in one of the Coopers was bent and could not be run. The CG hired engineers to come in an evaluate and they determined that if they machined the main bearings to be oval in shape, it would allow the crank to spin. They spent months tearing it apart and machining the block and bearings while we sat in South Portland ME in Charlie status.

Upon assembly, they fired up the "fixed" Cooper and everything on the ship shook like crazy. The crank was flexing due to the bend and higher than normal bearing gaps they machined, so the Cooper was deemed unsafe for use by the CG and we had to operate on a single Cooper for months before being refitted with new diesels.



Here's a pic of me with one of the pistons, it measured around 14 - 16" in diameter and the stroke was somewhere in the 20 - 22" range. I'm going from memory, you may know the specifics better.

On the subject of big diesels, I was later transferring to Iwo Jima and spent a year of isolated duty out there at the Loran-C 9970 Master station for the Pacific. We had 26 guys and caught our own rainwater in the rainy season and stored it for up to 8 months, generated our own power with 4 large Cat diesels and powered a 1.8 Megawatt transmitter. I grabbed a valve from one of the old motors removed from service and dumped to rust in the sulfur filled air. I still have it and here's a pic of it on my kitchen floor next to a 1/2 of milk.



If you like CG history, this is a pretty cool link of the station on Iwo Jima.

http://www.loran-history.info/iwo_jima/iwo_jima.htm

D-

[Jefecinco]

DT - Our Coopers were turbocharged and I believe they were 12 cylinder. We lost a turbocharger due to an overspeed. We were operating in parallel with the local utility (Otter Tail ) with two engines running. Otter Tail went off-line during a blizzard and our commercial tie-breaker failed to open. Thus our engines instantly tried to take over powering our part of North Dakota and went to full fuel before the overload breaker tripped.

That was the only time we went completely dark except for battery lighting. Our Commanding General had to report to the Pentagon the next day in person to explain why a multi-billion dollar weapons system with 100% redundancy was unavailable for the two minutes required for our plant to get back on-line.

We replaced the tie-breaker and tweaked the relays so it functioned properly but never operated in parallel in inclement weather.

Ironically the reason we operated in parallel was if our plant went down Otter Tail could temporarily pick up the load.