Was: ACL R-1 4-8-4's; Now Locomotive Counterbalancing

[nw-mailing-list at nwhs.org]

>Hugh,

>

>Our paths cross again on another message board!

>

>One thing that has always mystified me regarding

>Baldwin's well publicised counterbalancing problems

>both with ACL's R1s and New Haven's 4-6-4s: why

>didn't Alco and Lima have similar problems during the

>late 1930's? Did they discover that the recommended

>AAR methods were deficient for more modern power and

>change their procedures accordingly? If so, then N&W

>could have also independently changed its methods to

>bypass the problems Baldwin had. Or, as you

>suggested, N&W could have noted the ACL 4-8-4 problems

>and reacted directly.

>

>Dave Stephenson



Hi Dave,

I guess I should have joined this list a long time ago- it looks like a good 
one.

That's a very good question.  The only Lima engines I've read about with 
balancing problems were the C&O T-1's.  Some time after their delivery, 
these engines were evidently retrofitted with lighter-weight rods and 
reciprocating components and possibly other mods which corrected, or at 
least reduced the problem.  The Pennsy ran into the same problems in the 
40's when they built copies of the T-1's to the original blueprints, 
ignoring the improvements made by the C&O!

Interestingly, Richard Prince mentions Alco in the section on the ACL R-1s 
in his book on the ACL.  Evidently ALCO, or at least the UP chose to ignore 
the AAR design guidance and use less counterbalance material than 
recommended on their 4-8-4's (in 1937) and on their later 4-6-6-4's and 
4-8-8-4's.  This would seem to show that they had either already run into 
problems or suspected that problems would occur.  According to Prince, the 
UP engines didn't exhibit balancing problems.

I've often thought that these problems cropped up at the worst possible time 
for steam; for instance, the ACL never again purchased new steam power after 
the ordeal they went through the R-1's and these problems probably convinced 
some other railways that reciprocating steam had just "reached its limits".

According to what Bill Withuhn wrote, the N&W design team went a lot farther 
than Baldwin and the ACL did to ensure the J's worked properly.  As I 
recall, they had all drivers cross-balanced (not just the mains as 
recommended by the AAR), they added no "overbalance" material to the main 
drivers (which was used to correct the reciprocating balance), and of course 
they had the leading and trailing trucks with very strong centering springs 
to eliminate any tendency for the engines to "nose".

I just have to figure the N&W at least sat up and took notice when the R-1's 
developed a lot of unexpected problems.  The J was a significantly bigger 
and heavier engine with much smaller drivers, longer stroke (32" vs. 30") 
and was expected to be capable of similar speeds, all of which would have 
made proper balancing VERY important.  They obviously did their homework.

Good Steaming,
Hugh Odom
The Ultimate Steam Page
http://www.trainweb.org/tusp/