The Gray Marine Opposed Piston Diesel

I mentioned last week that I picked up a bunch of drawings recently, and in the group was a microfilm reel with a rather interesting engine…

Yup, it is indeed an opposed piston engine, and an experimental US Navy engine at that.. And I can not find one single thing about this engine online, anywhere. Gray Marine is pretty well known for the work they did during WWII, specifically with the Detroit Diesel 6-71. Gray Marine would take engines built by Detroit, and convert them to marine use, one of which being the 64HN9 – a 6-71 with a high output governor, used on the Higgins Boat: The LCVP, or Landing Craft Vehicle Personnel.

I cant say I know alot about Gray, but I do know that they would commonly take off the shelf engines (like the 6-71 above), convert them to marine use, and slap their name on it with a new model number.

So, just what is the deal with this engine? Well, I have no idea, and I really hope some of the viewers can help with this one. I have never seen an opposed piston engine like this one. Its a 2 cylinder opposed piston, but note that each crankshaft (4 of them!) drives a bevel gear set, which in turn drives the main center shaft. Holy moving parts, Batman, this thing could almost give a Napier Deltic a run for its money. On the back end, is a reverse gear.

Unfortunately, I have not spotted a spec sheet yet in the drawings. It is not a very big engine though, only 26 1/2″ tall and only about 64″ long. So it could not have been that much of a powerhouse..

These are pretty big drawings, so click on them to see the full size. The one top view had to be spliced together from 4 separate ones.

So, anyone with ideas on this thing…comment or email!

Old Advertising V

Click for Larger

This week, we have one of the many George Drake designed, Gulfport built 102’2″ tugs for the Navy. In the early 1940’s, Cleveland Diesel began building tugs on spec. for the upcoming war. The design was a simple harbor tug, with 4 state rooms, large crew fo’c’sle, central galley and a single head. Under the hood, the tugs had a Cleveland 12-278 engine driving an 800kW generator, powering a 1000HP propulsion motor. The design was later revised with a slightly different interior arrangement, and the wheelhouse raised up a bit. Quite a number of these tugs were built for the Navy as YT’s, and after the war, the design became one of Gulfport Shipbuildings “stock” designs. At some point TAMS Inc. acquired the design from George Drake, and kept it in the catalog so to speak. A large number of these tugs – essentially all the same, in cookie cutter fashion, were built for the commercial towing industry into the 1960’s.

The tug in the advertisement, is the YT 174 “Allaquippa”, built by Gulfport in 1941. She was struck from the Navy in 1969, and apparently sunk in the mid 1990s.

From “Diesel Electric Vessels Powered by Cleveland Diesel”