Does anyone out there know if there were any steam locomotives that had both slide valves and power reverse? I ask this because I have started the 'rebuild/update' project on my MDC moguls. I did buy the power reverse details, but I am wondering if there were ever any rebuilds where the shops left the slide valves but added power reverse. While many locomotives had their slide valves replaced with piston or poppet valves when rebuilt, there were more than a few old steam locomotives that retained their slide valves though various rebuildings until they went off to the scrap pile in the 1950s, but depsite my searches, I have never been able to find a photograph of both sides of the same locomotive that had slide vlaves so that I could determine if it had power reverse. If anyone knows about or can come up with a photograph of an old steam locomotive with both power reverse and slide valves, I would appreciate it. I do not want to try to change the steam chests on the MDC locomotives.
I know what a power reverse is, and how they work. Have heard the term slide valve. But what would they look like? Boxcab E50
Well, I'm pretty sure this is not the answer you were looking for, but there were a lot of Mallet locos built in North America with slide valves on the LP engine, and power reverse. Of the types you are probably talking about, there were probably more than a few turn of the century hogs that were built with slide valves, stephenson gear, and later had power reverse added. Former Great Western number 75 is one example, I think. (or maybe it was the 51?)
BoxcabE50, slide valves were flat like a bread pan turned up side down. There was a slot in the top (bottom of the pan) where steam could always enter from a hole in the steam chest to fill this pan. The length of the pan was just long enough to close over both holes, one at each end in the cylinder below. In this "centered" position, steam pressure would act as a brake and lock the drivers up. When this sliding valve (the pan) was moved the least little bit foreword, steam was allowed to go through the pan enter one of the holes in the cylinder and force the piston to pull on the drivers. This would very slowly roll the engine forward, and with the full total power of the boiler pressure at that! No first gear was needed. Shove this flat valve in reverse and the engine would suddenly be going the other way! It was smooth as silk! Flat valves were about the size of a card table, so were quite heavy. Not good at high speeds. The piston valves were much smaller and lighter to pass the same volume of steam, and could work at high speeds without breaking the piston rod on the valve gear. Power reverse gear was added to slide valve engines during terminal re-builds, but I don't think any engines were manufactured new with slide valves operated by a powered foreword/reverse system. I could be wrong about the new ones, but I do remember that long handled manual reverse lever on a 2-6-0 that had the old flat slide valves. That old tea kettle was built back in "nineteen ought and two AeeDee" as they said it back then too. That's in the year 1902AD for you young scalers that don't remember when years were "BC" or "AD". [ 07. January 2005, 20:59: Message edited by: watash ]
Thanks for thehelp, gentlemen. GM on theRailwire found a photograph of a Reading Company camelback 0-8-0 with slide valves and power reverse. Interestingly, on the camelback, the power reverse cylinder is right over the steam cylinders. SO, I added my power reverse details to my 'rebuilt' MDC moguls. I have done two so far, and am learning new things all the time. One thing that I learned was that I forgot to bend back the pilot ladder sides on the first one (I used the Gold Medal steam dress-up kit), so the first one does look a bit curious, but the second one is better. Now, for the third one.
Flash: I do not have the equipment or know-how to poast photographs. I will see if I can get someone to photograph them and post them. Someone else here wants to see the MT body mounts. I should add that I also added a generator to my updated moguls.
