Wayner's book "Freight Car Pictorial" shows a war surplus Army flatcar
in use to haul municipal trash seen at Council Bluffs on the U.P. ca.
1971. It clearly has truss rods.I know this is "the exception that
proves the rule",but I think Richard is right about there never being a
specific ban on truss rods. Of course the rules on age of underframes
would have weeded out any cars from the 1920's and earlier that had
truss rods, (assuming there were any such still in service) by the late
1960's.I saw a few vertical staff brake wheels when I first started
railfanning in the early 1970's,but they were rare by then.They were
pretty common on non-revenue equipment on C&O and NYC in my area
(Detroit, MI)however.

Larry King
<lrkdbn@...>