jack braking

[Paul Ivsin]

The LogisticsWorld Glossary
(http://www.logisticsworld.com/logistics/wxj.htm) claims that "jack brake"
is the general term for any braking-assistance device, and a Jake Brake(tm)
is a specialized type of jack brake.  I cannot, however, find any other
source that makes this distinction, and have found a couple cases where the
terms are used interchangably.

A Google search on ' "jake brake" ordinance ' pulls up dozens of city/county
meeting minutes from around the US, with the consistent theme of noise
versus safety.  There appear to be a couple cases where towns have convinced
the state DOT to prohibit jake braking along stretches of highway nearby,
which may have been what you encountered.

Unless you want to invoke the Peltzman Effect, I can't find anything about
the possible dangers of the device.  The overwhelming consensus seems to be
that they are very effective in slowing down semis.

Paul

...
Paul Ivsin
paul at ivsin.com
...
----- Original Message -----
From: "Rudolph C Troike" <rtroike at U.ARIZONA.EDU>
To: <ADS-L at LISTSERV.UGA.EDU>
Sent: Sunday, September 30, 2001 12:34 AM
Subject: jack braking


I'm guessing that the meaning of "jack braking" is the same as that for
"jake braking" given recently, but I'd like to know if anyone can confirm
it. I encountered the term on a sign on a highway in western Oklahoma,
miles from anywhere, and couldn't see any particular reason for it other
than that the terrain at that point was a roller-coaster series of hills
up and down. However, I'm not sure from the description of "jake braking"
given why there would be a prohibition against it in such wide-open
spaces. I inferred from the description that it might be objected to
because of the noise, but this obviously does not apply here. I'm still
wondering why it was proscribed in this context. Could it be dangerous?

        Rudy