Baker gear hooked up near center

[NW Mailing List]

Ed:

You hit the nail on the head as to the main engines I heard about; the RF&P
Berkshires and the story came from a Southern shop man who knew and/or
heard what you describe. That RF&P only had 10 of them and they were war
babies all helped spell their end, all too soon, never minding no roller
bearings or not enough.

The CG solution for the Baker gear I had never heard but you are far more
learned in that field than I. I am an observer and asker and then I sit
back and await you guys who have really gotten into it to answer the
question. And so you have done here again, as you have so many time
previously. Thank you, a thousand times, thank you. You have simplified the
issue to where my little pea-picking brain can comprehend and understand it.

And as a follow up to that, I then gather that N&W removed the slop in the
linkage for the great successes they had? That would seem the logical
answer but who knows and your insight would be helpful.

I still have not really figured out the Rube Goldberg apparatus aka
Southern Valve Gear. Why go thru all those additional gyrations when the
solution is already there with previous inventions, but then again, my
query as to why reinvent the wheel is the issue I guess?

Thanks for the help.

Bob Cohen



Bob -

I have heard of this problem on the Southern.  Engineers who tended to hook
their engines up too close to center complained that it went into reverse,
which might have been explained by too much slop in the reverse linkage.
Engineers in the south seemed to be noted for this; when the CG got their
4-8-4s it was noted that a half-dozen or so notches either side of center
on the reverse quadrant were blanked off so an engineer could not latch the
lever that close to center.

I do not know that RF&P had that much Baker experience; if I recall
correctly the only Baker engines they had were the 2-8-4s and the ex-N&W
K-3s.  Correct me if I am wrong; there could have been some early Baker
enginers . . .

EdKing

From: NW Mailing List
Sent: Tuesday, February 10, 2015 10:33 PM
To: nw-mailing-list at nwhs.org
Subject: Baker Valve Gear

Ed -


I recall hearing from someone a while back that the RF&P and maybe Southern
had problems with the Baker gear as it tended to screw up when set near
center. Maybe it was a specific class or application, I don't know, but I
heard that and it came from a solid source. That said, obviously N&W
figured things out nicely and took full advantage of what Baker had to
offer in its attributes vs. Walschert or others.

Does any of this ring any sort of bell to your knowledge area?

Thanks.

Bob Cohen



I don't think any development of Baker Valve Gear occurred in the sense
that you are thinking about.  The N&W got dissatisfied with Walschaerts
gear early on with the E-1 Pacifics and M-1 4-8-0s, both of which
(according to a long-time MP official who was a mentor of mine) that
promoted rapid link block wear.  The M-2s were slightly better, as were the
Z-1 2-6-6-2s.  You are referred to a treatise on valve gear in the ARROW
entitled ?Monkey Motion?.

There was a predecessor of the Baker Valve Gear known as the Baker-Pilliod
gear; it was applied as an experiment to class A 4-6-0 #89.  It was used on
the first E-2 Pacifics of 1910.  The Baker-Pilliod gear supposedly gave
quicker valve events for any given cutoff but was quite complicated.  A
simplified version of this gear, known simply as the Baker Valve Gear
(Abner D. Baker invented the gear, it was marketed by the Pilliod Company
of Ohio) came out about 1911 and N&W adopted it as standard.  The Baker
Valve Gear was patented and had to be obtained from the Pilliod Company.
Some railroads did not think it was worthwhile.  N&W obviously thought it
was worth the cost.

As far as development was concerned, the Baker gear offered the advantage
of providing a longer valve travel without introducing excessive
angularities into the valve gear.  After 1911 N&W never used another valve
gear.  The A of 1936 used Baker gear with a long valve travel.  The only
refinement thereafter was the application of McGill, Multirol, needle
bearings for all the connections in the gear.

When the J came along, I don?t think there was any question of using any
other valve gear, or using poppet valves.  The Baker valve gear driving the
Js big valves helped the engine to attain speeds of over 110 MPH (read Dave
Stephenson?s treatises in the ARROW about the 610 tests on the PRR).  Such
speeds required driving wheel RPM in excess of 535, almost unheard of
elsewhere.  (Charles Faris designed the counterbalancing for the J; his
figures were checked by Voyce C. Glaze whose workbooks are at the N&WHS
Archives; the J might have been the most perfectly counterbalanced steam
locomotive ever built, anywhere, anytime).

I hope this is helpful.

Ed King
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