Baker gear hooked up near center

[NW Mailing List]

Maybe the "slop" issue is why N&W used needle bearings in the Baker gear in their later locos . . . 

pete groom
> On Feb 11, 2015, at 6:17 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> 
> 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 <mailto: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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