UP 3985 Challenger

[Anonymous]

I posted this on the regular Trains forum and realized this one might be more appropriate...
I was looking through one of my books and saw a series of pictures of UP 3985, a Challenger type steam locomotive. On the engineer's side, just in front of the rear truck, about adult shoulder height from the ground, are two hand wheels sticking out from the side of the locomotive. Are they handbrakes? I haven't seen controls like that on any other steam locomotive....

Erik