The UP 4000 class

[AggroJones]

The Union Pacific 4-8-8-4 may be a glorified Yellowstone with a better tracking pony truck. [:0] Think about it. Not as an insult, but if you look at the stats, the BigBoy is very similar to all the yellowstones. Check the numbers. In appearance as well. Imagine, it could have been the Union Pacific 2-8-8-4. [:I] That extra lead truck axle doesn't make it a totally unique locomotive.
The "mightiest steam engine of all time", could have been a slighly larger Yellowstone.

Whats the point? Don't know. I just find it intresting to think of it like that.

[Anonymous]

NOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!

Okay, it looks so but the Bigboy´s are constructed from the Challenger´s

Take a look to Challenger´s, built before and after the Bigboy´s and you will see the similarity to the Bigboy´s.

Both were constructed by the famous UP technican Otto Jabelmann and ALCO´s construction department.

[Anonymous]

Actually 4015,

They Built the Challenger's, THen they built the Big Boy's. The Big Boy's worked so well, that they redesigned the Challengers.

Then its the DM&IR 2-8-8-4s that look alot like the Big Boy's. This could be partly becasue these were constructed during WWII and the War Department had a cap on developing any new technology not geared toward the war effort. It would have been just a simple matter for Alco to take the now stock Big Boy deisgns, tweak them in a few places for the DM&IR and whala, instead of designing and developing a new locomotive from scratch. Its a locomotive derived from existing specifications.

I think it would be an easy thing to model a DM&IR 2-8-8-4 from a Big Boy. The big thing would be changing it to a two wheel pilot truck, and shortening up the pliot. That would be pretty much the extent of the modifications. As for the other 2-8-8-4s they were made by Baldwin (Originally for the Northern Pacific) and thust have very little resemblence to a Big Boy.

James

[Martin4]

The UP 4000 class includes Big Boys and Cab Forwards: are these a "backward" version of the Big Boy ? The style and size seem comparable.

Martin
Québec City

[Anonymous]

The UP 4000 class DOES NOT include the Southern Pacific Cab Forwards. The Cab Forwards came in 2-6-6-2, 2-8-8-2, 4-8-8-2, and 2-8-8-4 variaties, all which were built by (I think) Baldwin. Besides, UP never owned a Cab Forward, so why would they be in the same class?

[nfmisso]

QUOTE: Originally posted by Martin4

The UP 4000 class includes Big Boys and Cab Forwards: are these a "backward" version of the Big Boy ? The style and size seem comparable.

Martin;

The UP did not have any Cab-Forwards - those were SP.

[AggroJones]

[Martin4]

Sorry
when I saw the road numbers in the 4200 series on some Cab Forward pictures (both prototype and models) I never realized those were not UP units. I was just seeing some similitude in design. UP had about every kind of locomotive that existed so I thought they had those Cab Forwards too.

Martin