"the Navy didnÂ’t have any combatants with reciprocating engines in WWII."

If I remember correctly the anti-submarine escort carriers were powered by 5-cylinder Skinner Unaflow reciprocating engines. These are a lot like the engines that were used in the last three Pere Marquette and C&O Lake Michigan car ferries of 1941 (City of Midland 41) and 1951 (Badger and Spartan). I believe the Midland's engines were steeple compound Unaflows (it is now cut down into a barge, bringing continuous Pere Marquette steam operation to an end, except for PM 1225).

The Skinner engine has only inlet valves, the exhaust passages being in the cylinder walls, kind of like a two-stroke Diesel. The Skinner is so much like a Diesel, in fact, that the Skinner Engine Company of Erie, PA, makes a business of converting old EMD 567 engine blocks into steam engines.

To learn more about these carriers, I STRONGLY recommend "U-505" by Adm. Daniel V. Gallery. It's a great book, with detailed histories of the U.S.S. Guadalcanal and the U-boat that's now at the Chicago Museum of Science and Industry. The appendix that describes how money was raised to install the boat is a good primer for museum fund-raising generally. The story of the German U-boat crew and officers is remarkable. And you will split a gut laughing at the story of the giant beach ball that the British navy tried to de-fuse.

Aarne H. Frobom
The Steam Railroading Institute
P. O. Box 665
Owosso, MI 48867-0665

froboma@mdot.state.mi.us

I recomment the Dictionary of American Fighting Ships online at http://www.hazegray.org/danfs/ for a history of USN ships. The online edition is a volunteer transcription of an official USN publication.

A friend served aboard USS Iredell County (LST-839) in Vietnam. She was a WWII LST and had two GM diesels. He was not in engineering, but I suspect they were the naval version of a 12-567. They relied on those 20-some year old engines to propel them all around the Pacific.

An earlier posting on a command ship had put him near some of the Ashland (LSD-1) class LSD's (Landing Shop Dock) and he noted they were the last commissioned USN ships with recips. I believe the power plant(s) were Skinner Unaflows.

The Electric City Trolley Museum Association

From my understanding (and watching the powerplant on campus) it take quite a while to bring a cold turbine up to full power from cold

how did the reciprocating engines compare in this aspect??

btrue@vt.edu

> "the Navy didnÂ’t have any combatants
> with reciprocating engines in WWII."

> If I remember correctly the anti-submarine
> escort carriers were powered by 5-cylinder
> Skinner Unaflow reciprocating engines. These
> are a lot like the engines that were used in
> the last three Pere Marquette and C&O
> Lake Michigan car ferries of 1941 (City of
> Midland 41) and 1951 (Badger and Spartan). I
> believe the Midland's engines were steeple
> compound Unaflows (it is now cut down into a
> barge, bringing continuous Pere Marquette
> steam operation to an end, except for PM
> 1225).

Oh, yes, right you are. I forgot all about them. However, I will make a pitiful attempt to defend myself by saying that I was thinking about "real" up-and-down engines with the wide open machinery, and the oiler up to his elbows in flying parts feeling the bearing temps. I always thought that the Skinners were honorary internal combustion engines with their enclosed crank cases, and pressurized lubrication systems. That's no fun at all.

Realize that steam turbines are rather long machines with very tight clearances between the tips of the turbine blades and the housing and shaft.

Usually, the turbine is "rolled" first at very low speeds with a starting motor to evenly heat the rotor and shaft, and prevent it from sagging in the middle. Once the rotor has been rolled for a specified period of time, it is then brought up to low speed (around 200 RPM), and checked to make sure it is not developing any unusual vibrations. I believe equipment checks are also made at this time.

After everything checks out, it is then brought up to full speed. (If it is a turbo-generator used to generate 60MHz AC power, it will turn at 3600 or 1800 RPM, depending on the number of poles in the generator.)

On the other hand, steam engines are mostly made up of massive castings, and do not operate at anything near the speeds of a steam turbine. So, I believe they are brought up to speed very quickly.

BTW, while failure of a steam engine could cause damage to the engine and maybe something/someone nearby, a large steam turbine-generator turning at 1800+ RPM can scatter parts for quite some distance should it decide to throw blades. Another good reason to be careful on startup.

-James Hefner
Hebrews 10:20a

> From my understanding (and watching the
> powerplant on campus) it take quite a while
> to bring a cold turbine up to full power
> from cold

> how did the reciprocating engines compare in
> this aspect??


Surviving World Steam Locomotives
james1@pernet.net

> Usually, the turbine is "rolled"
> first at very low speeds with a starting
> motor

...opps, that should be "turning gear", not "starting motor". Must be infernal combustion sickness....

Surviving World Steam Locomotives
james1@pernet.net

> I recomment the Dictionary of American
> Fighting Ships online at
> http://www.hazegray.org/danfs/ for a history
> of USN ships. The online edition is a
> volunteer transcription of an official USN
> publication.

Thank you for the location of transcription. Some of my information came from my printed copies of the Dictionary of American Fighting Ships. But, I'm missing the final few volumes (without looking mine go though "s").

By the way, I recall reading that when the Santa Fe bought war surplus 567's they found out that some ran "backwards." This was because of their use in Navy craft. Santa Fe had to buy new cam shafts for the engines.

Brian Norden

bnorden49@earthlink.net

Brian,
The same was true for a lot of the GMC 6-71s. Depending on the application, they were set up for counter or clockwise rotation. On ships and boats they like to have the screws (if two) rotating counter to each other. I would suspect that this could be the same for the FM units used in submarines.

Robert@trainorders.com

Sort of like counter-rotating aircraft propellers?
-Angie.


Ladypardus@cs.com