Atlantic Coast Line R-1 4-8-4's

[nw-mailing-list at nwhs.org]

>Ladies and Gentlemen,

>I'd think that N&W's K-3 counterbalancing problems were far more a factor 

>in

>lessons learned when designing the J than anything that occurred on the ACL

>with their Baldwin R-1's (or any other non-N&W designed locomotive for that

>matter).

>

>Ed Painter Jr ; Narrows, Va (currently Russellville, AR)



Ed,

No doubt N&W learned plenty from the K-3's, but the balancing problems with 
the K-3's were never corrected so they only provided a lesson in what NOT to 
do.

The ACL R-1's were modern, high-speed 4-8-4's which were balanced according 
to the latest AAR guidance (which was theoretically at least something all 
the railroads followed, not just Baldwin and/or the ACL).  The balancing 
problem was corrected by modifications to the engines after extensive study 
of the problem.  Hence, the R-1's showed both the problem and how to correct 
it.

Another point is that it wasn't any big mystery why the K-3's had problems- 
a low-drivered 4-8-2 with a LONG main rod is just gonna be really hard to 
balance satisfactorily.  The deal with the ACL engines is that they weren't 
expected to have any problems.  They unfortunately showed that the theory 
(or at least the recommendations) hadn't kept up with the real world.

It's been written that the N&W design team looked at all the other existing 
4-8-4 designs while designing the J's, and the ACL's engines would have 
certainly been among the 4-8-4's the studied.  Given that the J's used a 
whole range of innovations to ensure they didn't have balance problems (see 
Bill Withuhn's article in "Railfan" some years ago) and were suitable for 
higher speeds than any other 70" drivered engine ever built, it only makes 
sense that the N&W design team studied the R-1's too.

Regards,
Hugh