The three basic types are the Apex (fabricated rectangular grid), Morton
(punched round holes), and Gypsum (punched and stretched into diamond
holes). Other companies have made running boards (Blaw-Knox for instance),
but I don't recall what they look like. Didn't the Blaw-Knox look like an
Apex?

Yes, Blaw-Knox and Apex are both interlocking rectangular grids.

Another rare type is the "Alan Wood" solid running board with diamond
tread -- not unlike diesel walkways. These were used on PRR X37's and
I think may have been used on some eastern cabooses.


Tim O'Connor <timoconnor@...>
Sterling, Massachusetts