[bdeutsch]

Living near Sacramento, we have had the opportunity to see one of these with some regularity. As I recall, UP still maintains a running version out of one of their yards in Wyoming (might be off on exact location). Some of the following info may not be 100% accurate, but it is close.

Of note, they were able to generate about 6,000HP (+/-) per locomotive. Diesel-Electric locomotives built by GE or EMD only recently were able to attain a similar HP rating (kind of interesting if you think about it.)

Challenger class locomotives were built in two two configurations, cab forward (one of which is kept in the California Railroad Museum here in Sacramento) and of course the more traditional cab location. Main reason for the cab forward design was to avoid some of the breathing problems engineers had going through long tunnels in Sierras.

I think they were considered 4-8-8-4 types...these things are absolutely magnificent when under steam..