There are now 3 steam locomotives operating with full Lempor exhausts in the U.S.; one on the Mt. Washington Cog Railway in New Hampshire and now 2 more on the Grand Canyon Railway in Arizona. A forth locomotive features a partial Lempor exhaust system; it operates at Greenfield Village in Michigan.The Lempor Ejector was developed by Ing. L. D. Porta of Argentina, best known in the U.S. for his work during the 1980's with American Coal Enterprises. A Lempor basically consists of a carefully proportioned exhaust stack combined with a set of 4 steam nozzles. It can also be expanded to double and even triple stack configurations. The Lempor significantly improves the drafting of steam locomotives compared to conventional exhaust arrangements. The Lempor was first applied to locomotives in Argentina in the 1950's, and was later used in South Africa by David Wardale. It has since been applied to numerous tourist locomotives in the U.K. where it has proven its worth in providing increased power and better fuel and water economy.The Lempor at Mt. Washington was installed on No. 9 "Waumbek" in 2004 and has been operating succesfully since that time. This locomotive was covered in an article by Dave Lathrop on RYPN earlier this year. Grand Canyon Railway locomotives no. 4960 and no. 29 were recently fitted with Lempors and are operating well. Read more about these locomotives and see photos on the "News" section of my page at the link below.http://www.trainweb.org/tusp/news/news.htmlA partial Lempor exhaust (stack only) was installed on locomotive no. 1 ("Edison") at Greenfield Village in Michigan some time ago where it is also working well. (See http://www.trainweb.org/tusp/news/news_arc.html#GREEN for more info.)

Yes, and I wouldn't be surprised to see some more similar innovative retrofits on the way.....dave

With the intent of starting a “brisk” discussion rather than a flame war….How does a retrofit of this type effect the historic preservation of a locomotive?It makes sense on the Mt Washington Cog line, who have continued a tradition of building and operating steam, and probably works on the Grand Canyon which is steam passenger railroad rather than a museum, but why the Henry Ford?To what extent is this a reversible modification?

Discussing away:Entirely reversable. Take new stuff off, put old stuff back. This isn't about historic preservation, but rather about operation. The two points of view are probably 99% mutually exclusive, as historic fabric is continually lost in an operating artifact. To the extent that the artifact is only adequately interpreted as a useful item in operation, preserving the experience requires sacrificing the historic fabric. Of course, generally, a middle road is found somewhere, where new materials are mated with historic as necessary. Just how the new stuff is crafted and installed is the gist of the matter. Given most of the Henry Ford stuff has been highly modified to recreate artifacts from other stuff, that decision was made decades ago. Of course, you could argue that the earlier alterations provide a historical context into museum management of its era, making the faked stuff historic in its own right......dave

Randy,As Dave says, all these retrofits are entirely reversible. In fact, on most (all?) of the tourist line Lempor retrofits I'm aware of, the modification is invisible from the exterior of the locomotive. This is done by designing a Lempor stack to fit within the existing "stock" smokestack. Sometimes this results in a somewhat compromised design, but so far at least the results even under these circumstances have been very good. Even a more radical Lempor installation, in which a complete larger smokestack or even dual stacks were installed would be fairly easy to reverse- smokeboxes are cut and patched pretty regularly on operating steamers. No modifications would be required to the cylinder castings for even a dual Lempor installation.As I understand it, the installation on "Edison" was intended to correct a poorly steaming locomotive, and it was very successful in this regard.

Hugh -Is the engineering for the Lempor Exhaust system available? We are to the point with this Southern Ks Class locomotive being rebuilt at TVRM to where we could incorporate this technology. I would be most interested in doing so.When we were rebuilding USATC Class As 610 back in the late 1980's we researched the Giesel Ejector but could not find enough engineering to support the design of one. If the late Mr. Porta left enough of the engineering behind to support continued designs, I would feel one way to honor his memory would be to continue to utlitize his work to continually improve our steamers.

Dr. Portas' paper on the subject is contained en toto within Hughs' site. Unfortunately, the design process looks to be anything but a straight number crunch. This seems like an obvious application for a CFD program that didn't exist when Dr. Porta first wrote the paper. I googled the subject and quickly found a number of outfits that cite a capability to perform the design work.Better yet-why not contact the owners of the modified engines to see where they sourced the engineering from ? Dave

So maybe you can tell me, with all the attention to new design ideas at Mt. Washington, why are they still operating with fixed cutoff on those engines? Their back pressure at load is so great they have an exhaust bypass valve to atmosphere.I would think these engines would benefit greatly from variable admission or compounding (remember these are 4 cylinder engines operating at high rpm).

Mark and Hugh - I gotta make a trip out west for a few days - why don't we collaborate when I return? dave

softwerklex:That's a good question about the lack of variable cutoff valve gear. I imagine the primary reason is because designing and building 4 sets of Walschaerts (or whatever) would be a BIG project. It may be planned for the future.You are exactly right about the necessity for an exhaust by-pass valve. If you visit Roger Hahn's website: http://members.aol.com/belpaire/mtwash.htm (link also included in my news story) and look about 3/4's of the way down the page you'll see a photo of the revised exhaust bypass valve arrangement on Waumbek.

Don't forget a common shay has 3 sets of stephenson valve gear.