Alton & Southern 0-10-0 14 at E. St. Louis, Illinois, 10/11/36. It had over 96,000 lbs. tractive effort with the booster cut in. Not sure if the light colored areas were aluminum, graphite, white or another hue. A&S 0-8-0 12 survives at MOT, but this one got away.

http://abpr2.railfan.net/abprphoto.cgi? ... t+s14a.jpg

A fellow employee who once worked at E. St. Louis in the 1970s said they were advised to carry a sidearm in the yard there..

Bob, IIRC, the rods on these engines were aluminum, so I'll bet the boiler & cylinder jackets were too.

Why are the first two axles on the tender tied together with side rods?

Ted.

Looks to me as if it was a booster of some kind. Anyone out there want to chime in and back me up or correct me if I am wrong?

First, are you sure about the alloy rods?
Second, and perhaps I should start a new thread
but what was the history of alloy rod use. I only
recall a Pennsy K4 I think that tried them.

A&S 14 did have a tender truck booster, a two cylinder engine geared to one axle with side rods to drive the other axle. They were so-so common on heavy switchers and hump engines, to contribute tractive effort at low speeds. The booster was separately controlled by its own throttle valve.

Since the A&S was owned by Alcoa at the time, engine 14 made extensive use of aluminum components. There is an article on the loco in the trade press of the era. Even the bell was made of aluminum, no doubt it sounded like a dishpan. The rods application was not particularly successful, as aluminum doesn't have the right characteristics for loco side rod use. Might be too stiff. Only a few such applications were done, and were not repeated.

Perhaps one of the readers more familiar with metallurgy could comment on the comparable characteristics of steel vs. aluminum in this use.

Aluminum rods are sometimes used in automotive applications, but for racing only. The reason is failure due to fatigue; that is, failure due to repeated, cyclic stress. Aluminum has a much lower fatigue strength than steel. A steel connecting rod can be designed to have (within limits) "infinite" life. An aluminum connecting rod has a definite, limited life before it will fail due to fatigue.

This is tolerable for something like connecting rods in a racing engine in which the rods can be replaced after every few races, but hardly the characteristic you'd want in a steam locomotive connecting rod.

When were these engines retired and scrapped? As much as the Missabe liked huge, ten-coupled switchers did they ever consider purchasing any of these? They would have looked right at home in the Proctor yard......

Don C.