Southern Pacific MT-4 4-8-2 trailing wheel diameter?

Trains Magazine Steam & Preservation
1

Does anyone have handy the diameter of the wheels on the trailing truck of SP’s MT-4 class 4-8-2s? They look like they were unusually large:

2

These engines had Franklin C-1 boosters, which as I recall could have something like 51" wheels. A relatively quick way to get answers would be to contact these guys:

https://riverraisinmodels.com/spMountains.html

or check one of the references they cite at the end of that page. (Surprisingly, steamlocomotive.com does not appear to reference the leading or trailing-wheel diameters in their page on the MT classes…)

Ask Ed over on the MR forums; he’ll have an answer PDQ.

3

From the drawings in the Model Railroader Steam locomotive Cyclopeda, 51" diameter on the trailing wheels on the SP MT class.

Yes, a bit bigger than the typical mid 40’s size of most such trailing trucks.

Sheldon

4

Thank you! Yes, steamlocomotive.com was where I went first. I only turn to you guys as a last resort (I know there’s a book on the MT mountains out there, but it retails for north of $100).

Thanks for the confirmation!

5

From Page 9 of Robert J. Church’s book "The 4300 4-8-2’s - Southern Pacific’s Mt-Class Locomotives":

Lead truck - 36" diameter

Drivers - 73" diameter

Trailing truck - 51" diameter

The lead truck had solid-center wheels, the drivers were spoked wheels and the trailing truck had spoked wheels.

Page 19 has an excellent photo of the trailing truck and booster engine for a brand new Mt-3 number 4344 4-8-2 under construction in the Sacramento shops that is being placed on its wheels.

6

Wait wait… what? We’re NEW BUILDING an MT-3?

Edit Nevermind, I read that wrong. My heart leapt into my throat for a second. I thought we were doing something… British. Sigh.

7

If anyone’s still paying attention to this thread, I had a few more questions about the MT-4s/SP (and didn’t want to spam up the forum asking them).

  • Did the MT-4s run north out of San Francisco to Portland? Or were they pretty much exclusively Donner Pass/Sunset Route beasts?
  • Daylights didn’t run to Portland until the late 40s, correct? Prior to that, it was the Cascade (which had a completely different, more traditional trainset)? Thanks!
8

I am not much of a SP nerd. I believe the SP initiated the Shasta Daylight after the War with new lightweight trainsets that were powered by Alco PA-1’s.

I have no knowledge concerning the routes that the MT-4’s were used on.

9

Here is Mt-4 4348 at Portland Union Station in 1932:

http://espee.railfan.net/nonindex/steam-02/4348_sp-steam-mt04-joe_strapac.jpg

10

Here is Mt-4 4353 on freight in the Bay Area in 1953:

http://espee.railfan.net/nonindex/steam-02/4353_sp-steam-mt04-gene_deimling.jpg

11

Here is Mt-3 4329 in Oakridge, Oregon in 1940 or 1941:

http://espee.railfan.net/nonindex/steam-02/4329_sp-steam-mt03-joe_strapac.jpg

12

Awesome, thank you (sorry it took me a while to get back!).