Okay, I realize I am somewhat of a newbie to the hobby and trains. But I know the wheel configurations of many different steam engines. In the larger articulated engines I know of the 2-6-6-2, 2-6-6-4, 2-8-8-4 and others but I was surprised to see this one. I was surfing the web and found a webpage called Southern Steam Engines. It was a compilation of mostly black and white photos taken from the 20s through the 40s of steam power used by Southern. On there, they had three pictures of Southern #4002, a 2-6-8-0 wheel configuration. That wheel configuration I had never heard of. Anyone ever hear or know more about engines with these wheel stats? I also learned that Southern ran quite a few 2-8-8-2s. I didn't think they had. Here is a link to the site if you want to browse it. http://southern.railfan.net/images/archive/southern/steam/steam.html And, here is a pic (dated 1924 I think) of the beast I found within:
After a little more internet research, I found the following Wikipedia site that explains a little more. Says Great Northern Railway and Southern Railway were the only two in this country to run this wheel configuration. Here is the link: http://en.wikipedia.org/wiki/2-6-8-0 Still, I had never heard of one like this before so I found it rather interesting! I bet you won't find a model (RTR) in any scale of one of these... Dean
Dean, I can only guess (operative word) that designers were concerned that low-pressure cylinders could not output the same energy as high-pressure cylinders, so had them power only three axles instead of the four as with the high-pressure engine. Design engineers of 125 years ago didn't have such niceities as computers, calculators, or even slide rules to help with their designs. Consequently, every calculation was done by hand, based on gut-feel concepts that seemed logical at the time. Reminds me of the old cartoon showing an engineer walking away from a pile of smoldering wreakage..."Oh Well, Back to the Drawing Board".
Mr. Dean, I wonder if that wheel arrangement had a name attached to it such as did the Big Boy, Challenger, Allegheny, etc. ?? :question:
I am not really sure. I know they were built by Baldwin and that they were articulated in the same way the Mallets were articulated, according to Wikipedia. Again, I had never seen or heard of one before this so I found them a bit interesting. Dean
Dean, actually the 2-6-8-0 in your photo is a Mallet compound design, i.e. it used the steam twice with the high pressure cylinders exhausting into the low pressure cylinders. Mallets were distinguishable by having the low pressure engine in front, and the high pressure engine in the rear. The Mallet's low pressure cylinders were almost twice the size of the high pressure cylinders. Also the early Mallets used slide valves on the low pressure cylinders, and piston valves on the high pressure cylinders, which has always puzzled me because a slide valve is far less efficient than a piston valve. BTW, an "articulated" locomotive only means that it has two engines with a pivot between them. The rear engine is fixed under the boiler and the front engine slides back and forth under the boiler.
Ah' now your talking about one thats dear to my heart,although its the Great Northern 2-6-8-0 thats my alltime favorite the GN. had a large number of them some being rebuilt in to the most powerful 2-8-2s ever built.And oh yes there were quite a few models of these engines produced by PFM Oriental and Challenger models. i have one of the latter pictured below
