1941 Quartermaster Corps lingo

[G S C]

I have heard Johnson rod used, in reference to fictitious car repairs,
as in:  The Johnson rod was broken, and had to be replaced.

A quick search on Alta Vista turned up the following references to
Johnson bar.  There is no explanation of the derivation of the term
(although that question was asked at one hobbyists' site), but it is
associated with various forms of transportation, and one military (Navy)
usage:

Military usage, with reference to soap:
http://homepage2.rconnect.com/mbrey/chap8b.html
"Saturdays were reserved for cleaning the floors and we referred to them
as field days. We would 'Johnson Bar' the floors to remove the black
marks that built up all week from the heavy foot traffic. I'm not sure
what the derivation of the term Johnson Bar is, but it was a tough job
removing the marks."

Railroad usage:
http://www.trainweb.org/railwaytechnical/st-vs-de.html
"We can limit the amount of steam going to the cylinders by leaving the
intake valves open for less of the stroke. We close the intake valves
earlier in the stroke. We
'cut off' the flow of steam to cylinders early. This is exactly what the
cut off lever (sometimes called a Johnson Bar in the US and a Reversing
Lever in the UK) does.
When an engineer adjusts the cut off lever, 'notches up the cut off',
'hooks up the Johnson bar', he is limiting the amount of steam going to
the cylinders."

Clearly illustrated at (in a vintage RR photo):
http://www.reuben.org/sansom/photo2.asp

Reference to trucking:
http://www.ortrucking.org/safety/combo.htm
"5. You should use the trailer hand valve (trolly valve, johnson bar)
when:
a. Stopping.
b. To correct a trailer that is starting to jack knife.
c. To test the trailer brakes.
d. All of the above."

http://www.aone.com/~robert/truck6.html
"Truck tractors classically have a Johnson bar hand brake handle on the
right
side of the steering wheel for activating the trailer brakes only, but
this vehicle has a second 2-way Johnson bar on the left. It is sort of a
knee basher when you get in
the truck, but believe it or not this control is actually a steering
brake control. That's right, this truck has steering brakes. Pull the
lever one way and it sets the right
rear brakes and the other way and it sets the left brakes."

References to aircraft:
http://jpaul.gwdi.com/osh_art.htm
http://www.lavida.com/mooney3.html

George S. Cole   gscole at ark.ship.edu
Shippensburg University