"Recent Developments in the Unaflow Locomotive" is the headline found over an article in the June 24, 1922, edition of Railway Age. "The Stumpf Unaflow Locomotive Company, Syracuse, N. Y., is now arranging for installations in this country."
The article mentions Stumpf unaflow locomotives in use in Europe. Did any North American railroads experiment with the concept?
Go to page 1727 of the link to find the article cited.
https://books.google.com/books?id=IQIjAQAAMAAJ&printsec=frontcover&dq=Railway+Age+ebook&hl=en&sa=X&ei=esvkVKLmJtW0yAT-sYH4AQ&ved=0CDAQ6AEwAA#v=onepage&q&f=true
The only Unaflow engines with which I am familiar were built by the Skinner Engine Co. for Pere Marquette/C&O on "City of Midland 41", "Spartan" and "Badger".
For the uninitiated and those interested, there were a ton more than just those two installations (Edit: And let's not forget about the Pere Marquette 21 & 22, two additional Great Lakes carferrys that were lengthened and repowered with Skinner Unaflows in the early 1950's, nor the City of Midland 41 that pioneered their use on carferries.).
The 50 strong Casablanca class of escort carrier used the Skinner Unaflow for the most famous example. They're the most numerous class of aircraft carrier ever built.
In addition, several newbuild Canadian lake freighters utilized the engine in the early 1950's with one still steaming with it until it was sadly retired at the end of the 2011 season due to Algoma Central modifying plans that Upper Lakes Shipping had to repower her with a diesel to get several decades more of use out of her (ULS ordered an engine and scheduled shipyard time for installation, but Algoma's acquisition of the fleet ended that plan despite her hull apparently being in perfect shape).
And several American lake freighters were repowered with it during the 1950's. One of which, the St. Mary's Challenger from 1906, steamed with it until the end of the 2013 sailing season before being cut down to a barge during the 13/14 winter layup.
And the cable laying ships Neptune and the Albert J. Myer were equipped with the engine. When repowered in the early 1980's, they were the final USN vessels with a reciprocating steam plant.
The Ashland and Casa Grande classes of Landing Ship Dock assault vessels are another notable user of the Skinner, with one, the former USS Comstock, still in commission today in the navy of Taiwan.
Was a fairly popular engine in the 1940's and 1950's such as on New York ferry boats, even though all rail experiments with Uniflows were failures. They were slow, but reliable, efficient, and very quiet compared to even geared steam turbines.
Even saw use for stationary power generation in some factories (And the Uniflow may yet again make a return for such duties).
It appears the unaflow was successful in marine and stationary applications. Like the turbine, the unaflow steam locomotive was not a success.
I am not a mechanical engineer. Does anyone know what problems kept the unaflow steam locomotive from being a success?
Wiki is our friend:
http://en.wikipedia.org/wiki/Uniflow_steam_engine
LensCapOn Wiki is our friend: Uniflow steam engine From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Uniflow_steam_engine
Victrola1 It appears the unaflow was successful in marine and stationary applications. Like the turbine, the unaflow steam locomotive was not a success.
I really hope that I don't have this backwards in my mind, but for those that may be wondering why two different names are appearing in this thread, the story as related to me is that this style of engine is referred to as a Uniflow.
Unaflow is the trade name for a type of Uniflow engine (Both in simple and compound forms) that was designed, produced, and marketed by the Skinner Marine Engine Co. during the 1930's-1950's primarily for marine applications.
I believe that all rail experiments predate the Unaflow, so technically speaking, the correct word to use in reference to such experiments would be the generic type name of Uniflow.
While all such steam engines are Uniflows, only some are Unaflows.
Uniflow engines had the advantage of a quick response time. This would explain why PM/C&O installed them in their carferries and why other ferry operators used them in their boats.
The Unaflow uniflow locomotive article cited from 1922 shows poppet valves being utilized to control steam flow. Other postings on steam locomotives have discussed problems with poppet valves. Could poppet valves be a major reason for railroads not adopting uniflow locomotives?
Matt Jansen, an engineer who has been very involved with Wasatch Railroad Contractors in the Steam locomotive restoration business, started a company in the early 2000's called Vapor Locomotive which specialized in engineering support for Skinner Uniflow engines.
In addition to promoting the design for stationary power applications he proposed building a steam electric locomotive by rebuilding an existing diesel unit with a Skinner engine replacing the diesel prime mover. He wanted to market the design to industrial users who generated large amounts of solid biomass as a byproduct such as forest product industries, ethanol producers, etc..
Unfortunately the company website doesn't exist anymore and I presume they closed shop..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
http://babel.hathitrust.org/cgi/pt?id=uc2.ark:/13960/t59c6tr57;view=1up;seq=9
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