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  • Johnson bar

  • Discussion of steam locomotives from all manufacturers and railroads
Discussion of steam locomotives from all manufacturers and railroads

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 #33803  by joatmon
 
Does anyone out there know the history behind the steam engine reversing mechanism being called the "Johnson bar"? I'd greatly appreciate this bit of trivia.

 #47636  by steemtrayn
 
According to Freeman Hubbard's "Encyclopedia of North American Railroads", the origin of the term "Johnson Bar" is lost in history, but probably was named for an official of the Baldwin Locomotive Works.
 #50992  by pjb
 
:-) Millwrights use a long lever with a steel flattenned lip. The latter is placed under the machine ( or other heavy object ) they are moving , and the lifting action of pressing the lever down moves the object a few inches or so . Like a roofers shovel; this lip, at the end near the handle, has a projecting triangular web, that provides the fulcrum. They usually, at least today, also have a pair of small wheels under the business end, in order to facilitate moving this big lever around without alot of effort or damaging floor surfaces.
As you pry up using this device, the small wheels lift off the floor as the illiuded to projection strikes the floor. Hence, the lever is fixed and will not
roll about on the wheels. This is called a "Johnson Bar", by the tradesman, and in the catalogs offering commercial tools.

The railroad industry version of this type tool is smaller. Carmen, and warehousemen called them 'come-alongs', which isn't very exact since
that suggests pulling; and actually, - you don't do that when using
these car movers.

Good-Luck, PJ

 #167235  by CabooseKid
 
I think the johnson bar he is refering to is the one in locomotives. And yes, the history of this device is lost, but i am guessing it was named for its inventor, kinda like the westinghouse air brake....

 #167546  by steemtrayn
 
I once read in an airplane magazine that a Johnson bar on a plane is used to control the pitch of the propeller blades, and that it got it's name from the reverse lever on a steam locomotive.

 #173228  by ek2179
 
It's not clear who Johnson was, but "Johnson Bar" refers to the long "armstrong" reverse levers that extended up through the cab floor with the big quadrant for latching it. The term has been used for the smaller reverse levers used on more modern engines to operate the various air-powered reverse cylinders. But not often.

ek2179
 #201458  by pjb
 
:-D EK you are correct as to what was called a "Johnson Bar", in a
steam loco. My point regarding that was that the tool antedates the
the existence of locomotives , and the name is adapted from the
similarity in appearance to the tools looks and application.

Similar big lever bars held in a floor mounted quadrant from which
the bar extended to a trailing truck apparatus, were used in weight transfer
devices. For instance, there was one on the Milwaukee Road's 1889 built
4-6-2s ( that were the first Pacifics built here , and probably in the
world). These locos became 4-6-0's and ran more than half a century
in that guise. The trailing truck had trouble staying entracked while
backing in its original incarnation. There is also a symbiotic
relationship between cardazzi trailing trucks and those hernia inducing
weight transfer levers and beams, because many of them were also
equipped for weight transferring functions.
Good-Luck, PJB

 #205006  by general440
 
I cannot believe that the Johnson Bar has caused such confusion. This should clear things up.http://www.locomotivegeneral.com/gauges.html The Johnson Bar is in the lower right hand corner
 #207968  by pjb
 
:-) General 440:
With all due respect- there is no confusion here whatsoever. We all
knew what the Johnson Bar(s) did in steam locomotives. If you read
the initial post, you would see the question was with respect to the origin
of it's name, not its function.
Good-Luck,PJB

 #223662  by pennsy
 
Hi All,

The Johnson Bar is essentially the transmission of the steamer. It controls the direction of travel, forward, reverse, neutral, and also can be positioned for the " company notch". That would be the position on the quadrant that matches the transmission's output to the load, the length and weight of the train. The Company Notch would be the most economical position for the train to be run.

 #223801  by O-6-O
 
pennsy; In your analogy the Johnson bar isn't the transmission its the
gear shift selector much like one in your car. The "transmission" on a
steam locomotive is the valve gear. My father who had a little bit of a
warped sense of humor told me the name Johnson bar comes from the
part of the engineer that hits it in a collision. LOL.

 #245069  by BR&P
 
OK, while we're discussing meanings, I had understood the "Company Notch" was way down forward, working full stroke. Less efficient and harder on the fireman's back, but meaning the locomotive was dragging everything they could hang behind her (and thereby making money for the company). Yes? No?
 #245130  by pjb
 
:-D
With respect to nomenclature: That is a correct meaning for
comp'ny notch.
As to the rest of it, that is all subjective. Most
(probably all, but couldn't prove it) locos would have run out of
steam under conditions described of having all the tonnage tied on
that could be started, and then ran wide open down the road.
Good-Luck, PJB

 #245148  by pennsy
 
Hi All,

Company Notch definitions are all somewhat subjective is correct. It is not the same position, engine to engine, or even length of train to length of train. It is the position that is MOST economical for the company. It will produce the correct horsepower required for the load and conserve as much water and fuel as possible. It is driven by economics.

 #245223  by BR&P
 
"that is a correct meaning for company notch"

Which one - the most efficient, or the hardest working?