Baker Valve Gear

Thu Feb 12 11:17:32 EST 2015

Ed,
I have seen those links in the Walschaerts VG with dimples in them where an engine tends to operate. 

Roger HuberDeer Creek Locomotive Works

      From: NW Mailing List <nw-mailing-list at nwhs.org>
 To: NW Mailing List <nw-mailing-list at nwhs.org> 
 Sent: Wednesday, February 11, 2015 4:53 PM
 Subject: Re: Baker Valve Gear

Roger -  The trouble with going into reverse wasn’t with theWalschaerts on those roads – it was with the Baker.  The CG 4-8-4s wereequipped with Walschaerts.  The center of their quadrants were blanked offbecause of engineers tending to hook the engines up too high which had bad effects on main rod back ends, etc., not associated with going intoreverse. The late Walter Dove who ran the 4501 when it was firstresurrected in 1964 was notorious for hooking the engine up too hign; I’vewitnessed him running a hot back end on the 4501 which has Walschaerts and Consolidation 722, which had Southern (722 probably won’t run again, but 630 hasthe same valve gear); I had witnessed the same effect on a Y-6 on the BristolLine from the same cause. The popularity of Walschaerts VG, I’m convinced, had alot to do with it being cheaper to put on the locomotive than Baker.  OldEgide Walschaerts’ patent on the valve gear probably expired before the turn ofthe 20th Century, and anybody who wanted to design it and put it on a locomotivecould do so.   I had a MP guy off the Boston and Maine lament to meabout the cost of buying Baker.  (Penny wise, , ,) But it had that sliding link block in a curved link(the Stephenson VG also had the links and link blocks) which was a little morecomplicated to maintain than Baker, all of whose connections were radial andtherefore simple pins and bushings which could be maintained on a simple lathe(later McGill “Multirol” needle bearings). IMHO, which might not be worth much, N&W likedBaker because when it was put right it would stay right, and when it got out ofkilter a journeyman machinist could put it right using a lathe; in other words,it was a precise valve gear that would stay that way under all conditions.  It functioned just as well on an M as it did on a J;N&W’s Mechanical Engineers depended upon Baker to operate satisfactorily onits fastest passenger locomotive, which operated at a driving wheel RPM farfaster than any of the other engines you might want to make comparisonwith.  The only failure of a J relating to valve gear that I ever heard ofwas not the fault of the valve gear per se but of the powerreverse.  But N&W’s maintenance standards were pretty high, includingreverse linkages. The New York Central was another Baker road; it hadhundreds of Mohawks, Hudsons and all its Niagaras so equipped; its early Hudsonsthat came with Walschaerts were changed to Baker, and if I’m not mistaken sowere the Mohawks.  They also had a bunch of H-10 Mikados with Baker, sinceLima seemed to favor it. Ed King  

From: NW Mailing List via NW-Mailing-ListSent: Wednesday, February 11, 2015 10:35 AMTo: NW Mailing List Subject: Re: Baker Valve Gear This is a very interesting topic. I hadnever heard that the Walschaerts would jump into reverse before. Possibly so.
 It seems, though, that Walschaerts wasa more common VG than Baker throughout this country and the world. I alsounderstood that Baker required a royalty payment and was more complex andheavier with many more parts than WVG. Perhaps that could explain the popularityof the WVG? Personally I prefer the looks of the Baker and I'm glad to see N&W favored that type VG. I read someplace that the Bakerlong travel (their term) was a very rugged VG and was more than able towithstand the forces generated by the more modern engines hence it's morefrequent use in the declining years of huge super powered engines. Who really knows? I'm sure EdKing, Louis Newton and Mr. Jeffries are about the best sources of info aroundthough. Maybe the WVG issue was why alot of that type gear on many roads was operated with the screw wheel setup? Iunderstand it gave the engineer very precise control of the VG. Very interestingdiscussion! Roger HuberDeer Creek Locomotive Works
From: NW Mailing List<nw-mailing-list at nwhs.org>
To: NW Mailing List<nw-mailing-list at nwhs.org> 
Sent: Wednesday, February 11, 2015 7:24AM
Subject: Re: Baker ValveGear
 Bob -  I’ve heard of this problem on theSouthern.  Engineers who tended to hook their engines up too close to center complained that it went into reverse, which might have been explained bytoo much slop in the reverse linkage.  Engineers in the south seemed to benoted for this; when the CG got their 4-8-4s it was noted that a half-dozen orso notches either side of center on the reverse quadrant were blanked off so anengineer couldn’t latch the lever that close to center. I don’t know that RF&P had thatmuch Baker experience; if I recall correctly the only Baker engines they hadwere the 2-8-4s and the ex-N&W K-3s.  Correct me if I’m wrong; therecould have been some early Baker enginers . . . EdKing 

From: NW Mailing List Sent: Tuesday, February 10, 2015 10:33 PMTo: nw-mailing-list at nwhs.org Subject: Baker Valve Gear Ed -
 I recall hearing from someone a whileback that the RF&P and maybe Southern had problems with the Baker gear as ittended to screw up when set near center. Maybe it was a specific class orapplication, 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 advantageof what Baker had to offer in its attributes vs. Walschert or others. Does any of this ring any sort of bellto your knowledge area? Thanks. Bob Cohen 
I don't think anydevelopment of Baker Valve Gear occurred in the sense that you?re thinking about.  The N&W got dissatisfied with Walschaerts gear early on withthe E-1 Pacifics and M-1 4-8-0s, both of which (according to a long-time MPofficial 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 referredto a treatise on valve gear in the ARROW entitled ?Monkey Motion?.

There was a predecessor of the Baker Valve Gear knownas 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.  TheBaker-Pilliod gear supposedly gave quicker valve events for any given cutoff butwas quite complicated.  A simplified version of this gear, known simply asthe Baker Valve Gear (Abner D. Baker invented the gear, it was marketed by thePilliod Company of Ohio) came out about 1911 and N&W adopted it asstandard.  The Baker Valve Gear was patented and had to be obtained fromthe Pilliod Company.  Some railroads didn?t think it was worthwhile. N&W obviously thought it was worth the cost.

Asfar as development was concerned, the Baker gear offered the advantage ofproviding a longer valve travel without introducing excessive angularities intothe valve gear.  After 1911 N&W never used another valve gear. The A of 1936 used Baker gear with a long valve travel.  The onlyrefinement thereafter was the application of McGill ?Multirol? needle bearingsfor all the connections in the gear.

When the Jcame 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 J?s big valveshelped 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 speedsrequired driving wheel RPM in excess of 535, almost unheard of elsewhere. (Charles Faris designed the counterbalancing for the J; his figures were checkedby Voyce C. Glaze whose workbooks are at the N&WHS Archives; the J mighthave been the most perfectly counterbalanced steam locomotive ever built,anywhere, anytime).

I hope this is helpful.

Ed King

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