• Discussion of steam locomotives from all manufacturers and railroads
Discussion of steam locomotives from all manufacturers and railroads

Moderators: Typewriters, slide rules

  by rlsteam
Visit my "Big Boys and Challengers Gallery," www.forecyte.com/bigboys , for some action shots in the 1950s.
  by us.trains
rlsteam wrote:Visit my "Big Boys and Challengers Gallery," www.forecyte.com/bigboys , for some action shots in the 1950s.
Many thanks for your link, very beautiful pictures as I like. Your web site is very interesting too I will explore it and link it in mine.

  by FourTwelveTwo

Have you purchased "The Big Boy Portraits" book? It's a mixture of roster and action shots, but there are many angles and views not normally seen in other publications.

I share your love for these machines!


  by JeffK
Bonjour! Vous écrivez bien l'anglais - mieux que je puis écrire en français.

Comment se fait-il que vous vous intéressez aux locos américains?
  by x-press

In old 1950's footage I have seen of the UP 4000-class engines, an overhead view of the steam turret shows TWO vents releasing steam. Neither one is the generator, which is ahead and to the left. I know the blowdown separator is up there somewhere, but the "thing" I thought was the separator doesn't seem to be doing anything in the shot (no steam). One vent is located just ahead of the cab, the other just ahead of it and to the left, still on the dome.

Does anyone know what these are?

Thanks in advance!

  by tacomalarry
I enjoy photos of Big boy and S.P. cab fowareds
Mr Stewart from tacoma

I bought full drawings of the Bigboy about two years ago from the folks that put up this site. At the time I paid 30 dollars. I just went there and dont see the offer but if you contact them I'm sure they could direct you on how to purchase the disk. It contains all the mechanical drawings used to build the bigboys including drawings made obsolete during the process of constructing the series. I dont have the disk in front of me but there are hundreds of drawings on the disk. I'm sure your questions would be answered and maybe more questions would be raised. I love going through them to figure out how things work.
  by tacomalarry
I enjoy photos of big boy the Best UP made
big steam fan Lawrence
  by pennsy
Got this one of # 4012. Enjoy. Had to give you a photo in full color.
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  by joeburgard540
I know this answer is a long time in coming...but here you go. :-D

The two plumes of steam coming from near the steam turret casing are the exhausts from the Pyle-National turbo-generator and the cold water centrifugal pump (mounted underneath the fireman's side of the cab). The centrifugal pump (Elesco type TP) pumped water from the tender to the exhaust steam injector (located underneath the running boards on the fireman's side of the smokebox).

  by joeburgard540
Does anyone know for certain what the maximum cut-off was for the Big Boys in both forward and reverse (if the figures are different)? I'd assume it would be about the same as Challenger #3985 since they both use the 12" ALCO Type "M" power reverse and had very similiar designs.

I just revisited #4018 in Dallas, but the cab is locked so I couldn't see the reverse quadrant. I asked one of the employees, but he didn't have the keys.

Are any of the reverse quadrants clearly visible on any of the Big Boys that are on display?

  by Typewriters
Cutoff on the UP 4000's was 81% maximum, forward - haven't found a figure for reverse yet.

Comparable figures between the 4000's and the 3950-3969 include lap, lead and overall valve travel. RME lists the 4000's as having been equipped with ALCO Special Type H reverse, and the 3950's with Type H.

-Will Davis