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

nw-mailing-list at nwhs.org nw-mailing-list at nwhs.org
Tue Oct 25 17:34:43 EDT 2005



>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

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

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