In a message dated 7/7/02 9:53:17 PM Pacific Daylight Time,
jaley@... writes:

<< Gene doesn't give
dimensions in his handouts, but the brake wheel on my IM R-40-23 (which
happened to be handy) is also 1'11", so I suppose that this is
"reasonably" in scale for a freight car.>>

Jeff,

The most common diameter of the verticle hand wheel was 22" in diameter, so
you're real close with the given measurements. The test rack for geared hand
brakes was designed for a 22" wheel with notes for construction of parts for
other size wheels.

I don't believe the AAR ever actually mandated a common size of the wheel
itself, but many of the other dimensions, along with the pattern for the
mounting holes (gear box) were listed as "standards" so railroad repair shops
could supply replacements. The shafts, mounting holes, and so forth were all
designed so various designs were interchangeable.

Regards,

Guy Wilber
Sparks, Nevada