The USN Casablanca Class CVE's and Ashland Class LSD's had two simple Skinner Unaflow engines, each powering one propellor shaft. The ships had condensers. On the Ashland Class, displacement was 7930 tons loaded, horsepower on each shaft was 3700 and the combined 7400 HP was good for 17 knots. The ships were commissioned 1943-1944 and were active until the late 1960's.

C&O/PM carferry City of Midland 41 had two simple Unaflows while postwar C&O boats Spartan and Badger have two steeple compound Unaflows.

EMD 567's are uniflow engines but the flow is reversed from a Skinner steam Unaflow. On an EMD, the intake air enters through ports cleared by the piston at the bottom of the stroke and the exhauset exits through poppet valves at the top of the cylinder. On a Skinner, fresh steam enters through the poppet valves and exhaust steam exits through the ports.

For those keeping score at home, "uniflow" is the generic term for this type of engine while "Unaflow" is Skinner's trademark for their product.

Phil Mulligan

you'd think itd still be less efficient than some sort of compounding

The two C&O boats are compounds. Skinner specialized in equipping Lakers with their Unaflow engines. They were considered as efficient as diesels in spite of needing both a fire room and an engine room.

The Ashland Class LSD's were USN's last seagoing ships with reciprocating steam engines.

Phil Mulligan

We've discussed some of the diesel-engine conversion to steam in this thread from a couple of years ago:

http://www.rypn.org/forums/viewtopic.php?f=1&t=42240

Note that Matt Janssen has some of the original files for the CE-635 in his possession. I saw some of the details many years ago but didn't appreciate the specific details of the converted powerplant, as my interest was in different positive-displacement expansion.

At EPRI it was determined that a positive-displacement expander could be preferable to a turbine in applications that ran an appreciable part of the time at 'high turndown' (in other words, part load only). That specifically referred to compression-ignition vs. gas turbine, but some of the problems are generic to practical turbines.

A good way around the difficulties with high mass flow at relatively low turbine rpm was considered by PRR in the late 1940s in the form of the Bowes drive, the thing that made the Ingalls 2000hp passenger unit so interesting. This changed the V1 turbine from an interesting development of the Q2 into a much more practical road locomotive. What it did NOT do was solve the tremendous water rate and losses associated with atmospheric pressure turbine exhaust, something which had already limited the pure-mechanical V1 to something only slightly over 100 miles water range with substantial water-tender capacity. Later somewhat 'crayonista' promotion of the dual-turbine locomotive as 9000hp (or greater!) only would have made the water-rate problem vs. the practical range of something like F units even more striking.

Something I think a larger ACE locomotive might have benefited from was a proportional version of Holcroft-Anderson 'recompression' -- this used a second asynchronous engine to recompress exhaust steam to where it could be 'lossily' cooled to retain the latent heat of evaporation in a condenser with purposely-leaky tube to plate fit (so that the 'excess' heat could be more quickly lost, as in several of the turbine-electric designs in the first half of the 20th Century, without enormous heat-transfer surface and large amounts of fan forced cooling)

In practice, any appreciably sized condensing locomotive has to be able to work under conditions where full condensing is not possible. That was never demonstrated for the ACE3000, even at its relatively minuscule horsepower output (for so large a 4-8-4). I thought part of the solution might to be to supply some part of the locomotive water as 'greywater' (recovered from industrial or public sources at lower cost) which would be the thing preferentially evaporated in order to keep the mass of treated and deoxygenated water in a high-pressure turbine setup relatively preserved..

All this stuff is squarely in the historic-preservation category now: the people I know still in steam-turbine electric development are using different approaches.

Regardless of what anybody says about this venture, it was pretty cool watching a steam locomotive hauling a fully loaded coal train down the main line in the 1980's. Unfortunately I never saw it except on videos, but the video is one of my favorites. I would also like to thank Ross for at least putting the idea out there. This idea had the potential to bring back the steam locomotive. Very eager to read about your up coming book and would like a autographed copy.

Mr. Rowland,
Looking forward to your book. Placing this information in a single-source book will be very helpful. We can see from some of the responses on this thread that the internet is no place for sustained sensible discussion.
The ACE 3000 tests followed a line of steam locomotive testing going back to the beginning. There was obviously a strong steam following in the mechanical departments of the railways, even as diesel technology was showing its worth.
Here in Canada, both major companies had enough faithful steam men to be able to try holding back the diesels right to the end.
Canadian Pacific went all the way with its multi-pressure No. 8000. It also experimented with all-welded boilers on some G5 class Pacifics, and was building new steam power after many North American roads had passed it by.
Canadian National experimented with Mountain Type No. 6020 in 1940, and many of these experiments were applied to newer power. CNR also experimented with poppet valves in Northern Type No. 6184, Dunn Valve Gear, and a variety of experiments in smoke deflection, including full streamlining.
Earlier companies like Grand Trunk, Intercolonial, and others experimented with several versions of compounding, Allfree-Hobart valves,Cleveland Uniflow Cylinders, and any number of valve/reverse gears.
One might assume that the railways kept records of all these experiments to compare with standard technology. Sadly, today's histories often simply say, the changes worked as expected, and that was that. It would be wonderful to see some of the detailed reports, and the on-the-road data from these experiments.
Some of this might have present-day applications -- how did the CPR's welded boilers pan out over time, for example? Did they compare well with riveted boilers, or were they failures?
Perhaps much of this mechanical department material is lost forever. Your data is not. Thank you for the effort in assembling this material in a coherent fashion for posterity.

That's ok. Whether you are a fan or foe, the Ross Rowland story needs to be told. I am VERY pleased to hear his book is finally forthcoming!

I'd agree with Kevin that I've never heard that as a sole reason for N&W to dieselize. To my knowledge, it was the lack of replacement specialty parts, which, no doubt, Roanoke Shops could have easily made.

But one of the primary reasons the N&W dieselized like it did appears to be Stuart Saunders. Saunders, even then, was angling for Presidency of the biggest railroad; the Pennsy. I strongly suspect that Saunders was readily kowtowing to his Pennsy buddies (since they were big investors in the N&W) early in the game to "modernize his railroad" to be like the Pennsy, and make them look with favor upon him to bring him in as the Pennsy president. C.E. Pond, N&W Manager of Motive Power at the time told me that they scrapped a lot of good steam engines, and tons of parts to dieselize. Not to mention all the money they saved eliminating jobs.

Agreed that the diesels were easier on the track, but I've never seen any kind of evidence that this was used as a basis of acquiring the Virginian. The Virginian's easier grade was coveted by N&W since the mid 1920s, but the State SCC turned down a merger in 1925 wanting to keep the competition. By the mid 1950s, it was a totally different regime in the state.

The money saved with reduced maintenance, as well as removal of a lot of double track made it look better. But I can say that as late as the 1990s, I know of dispatchers cursing Saunders for taking out the double track.

I think Saunders Pennsy connections early in the game has never really been discussed. Once he took over the Presidency, he knew that R.H. Smith's extremely well maintained N&W could slack off track and other maintenance without any real ill effects for a few years, and that money goes to the bottom line, making it look that much better. So, how did him being President of the Pennsy work out after all that?

Ken Miller

Can't remember where I read that, but track maintenance savings (including single tracking) was a big factor and I suppose the total savings included a lot of different things, including manpower, spare parts, etc.
Since some of the locomotives were almost brand new (1953) scrapping of them seems like a wasteful practice.
The "lost engines" that I saw in the scrapyard in Roanoke in 1964 were already stripped hulks only, at the most, 6 or 7 years after retirement.

While definitely not the sole factor, parts supplies were a serious consideration. Roanoke Shops could have likely made virtually any part for a steamer, but it may have been cost prohibitive. N&W would have had to pay licensing fees to produce these specialty items (Baker valve gear, Worthington feedwater heaters, piston rings, etc.). This would have certainly adversely affected the balance sheet in the steam vs. diesel debate.

One specific item I remember reading about that affected steam production well before the end of steam were Worthington feedwater heaters. N&W wanted the largest size SA type feedwater heaters for the last batch of Y-6b’s. Worthington had already started curtailing production and told them they could only provide the next smaller size. You can imagine this situation would get steadily worse.

It may pay to remember that there were places diesels eased track maintenance, and places diesels made track worse. The shorter wheelbase of a diesel truck, and the lack of any need to impose lateral a la Voyce Glaze to permit less overbalance, were in the contemporary diesels' favor; the much greater lateral inertia 'down low' and some of the characteristics of contemporary six-wheel trucks with nose-suspended motors, not so much. I never found it surprising that there were areas 614, one of the best of the late 4-8-4 designs, was superior to contemporary Flexicoils (or other types N&W might use on six-motor power). I look forward to seeing technical detail on the specifics of comparison with GM two-axle swing-hanger "Blomberg" trucks with D77s, which I think by ~1985 to have proper dampers including yaw damping.

I think much of the effect of overbalance augment is somewhat misunderstood. As long as you stay well under the critical point where inertial and thrust-component force up equals force from weight through the equalization system down, the hammer-blow was not 'hammering' but sinusoidal; good angled cross-balancing and lightweight rods, as on 614T, reasonably solved that issue up to a speed that I hope Mr. Rowland can finally divulge in his book. What I'd like to see is an instrumented comparison of 614 against a modern radial truck with softer primary and stiff lateral secondary, like the HTCR-II or later; the results will still be interesting...

Was there any real question that the primary point of the dieselization was to decrease overhead plant and equipment, and get rid of "excess manpower"? That was a principal reason almost everywhere else in the East, most of it less than a decade earlier, and by the time Saunders went after his pieces of silver the true savings would have been well-shared and well-known by people in actual operating positions, not just lawyers. A fun consideration can be gotten by carefully reading the trade press and looking at the corporate activity in key specialty-supply firms like American Arch and the rest of the interlocked industry: firms were reinventing themselves in other areas or agreeing to wind up their affairs to stop loss for stockholders ... but still asking very much full price (or being dog-in-the-manger) about patent rights or trade secrets in producing alternatives. Not that it would have 'staved off' widespread dieselization, which would assuredly have come quickly after 1970 of necessity, but it ought to have made the extended retirement of steam that had been forecast in the '40s to have happened in more places and circumstances.

One of the important objectives of the month long Jan. 1985 614T program was to show the 2 senior software writers from Foster Wheeler what the real life environment of a steam locomotive was in real time.

Remember the ACE 3000 was to have been a computer controlled locomotive with no human involvement in the trailing units. That meant that the software had to be able to respond to all of the things that can come up out on the road. A few examples....1. the feedwater system stops delivering make up water into the boiler, 2. the stoker worm jams on account of a 36" pipe wrench found its was into the trough, 3. on a very hard pull the sanders stop working on wet rail resulting in excessive slipping, 4. there is a system failure resulting in loss of commands from the lead locomotive, 5. due to a hose failure there is a huge loss of water reserve, 6. malfunctioning safety valves cause boiler over pressure of 75 lbs. ( 375 vs. dwp 300 ) , 7. Due to extreme cold ( wind chills of minus 40F) feedwater line freezes.

Those are just a few. I'm sure you can imagine many more. Remember it might be something that " almost never" happens but that doesn't mean it can't or won't and it has to be handled.

I can testify that if nothing else came out of the effort the education those two men got would have made it worthwhile.

There's a great deal can be learned in a class room setting, but there are some things that can only be learned by living the experience in real time.

Thanks, Ross Rowland