Union Pacific 3985

Thanks Paul I'll pass it along.
---
Can't wait to see if you find the article!

 

I found the discussion that I was talking about the other day and found that it references this website which sums it up nicely (see the charts for "articulated locomotives"):

http://www.steamlocomotive.com/misc/largest.shtml#art

I was incorrect about the discussion topic. ; They were discussing which one was the physically largest and which one was the most powerful. ; The charts on the website above show that while the Big Boy (listed as "UP 4-8-8-4) was not the physically largest or the most powerful, it consistently placed. ; Also, if you remove the experimental locomotives like the N&W Jawn Henry, the C&O M1, and the Virginian XA, the Big Boy places higher on the lists and in the case of length, it wins the category. ;

If you look at total weight (including the tender) the Big Boy places second behind the experimental C&O M1. ; If you eliminate the above mentioned experimental locomotives, the Big Boy places second behind the Erie P-1 "Triplex" locomotives in the weight category, excluding the tender. ; The "Triplex" can be also be argued to be experimental since only 3 were made. ; But since they were successfully used for 13 years by the Erie in pusher service on steep grades, you can argue that they were not experimental. ; To further muddy the argument, if you look at the weight on the drivers which is an important factor in keeping the drivers from slipping, the Big Boy is beat by a couple of regular production locomotives from other railroads.

When the discussion changes to most powerful, the Big Boy actually places at the bottom of the list for "most pulling force" (tractive effort) and 5th in the "most powerful" (horespower) list behind several regular production models from other railroads.

So, it is clearly not the "most powerful" and may or may not be the "biggest regular production locomotive" depending on which weight category you use in the definition and how you argue the Erie Triplex.

 

and yet union pacific has quietly let it pass unchallenged for many years that they were the kings of big power. especially looking at those diesels they tried a few years back, called centenniels?, turned out to be too big to be practical

 

Interesting. I'm new to the train world so it's nice to find some things out!