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Picture a 4" diameter steel pipe, about 3/32"
thickness, about 20' long. One end has a hitch coupler welded to it. Starting
about 2' back from the hitch, there are 6' aluminum 'outriggers' or cross
members about every two feet to the end of the pipe. These 'outriggers' are
constructed of two pieces sheet aluminum (same as the skin) formed into a 'C'
shape about six inches high and six feet or so long, then riveted back-to-back
to make an 'I-beam' shape... ][. A four inch diameter hole is cut into
each of these outriggers which allows them to be slipped onto the pipe. When
they're in final position, the steel pipe and aluminum outriggers are attached
with flimsy little pieces of sheet metal bent into an 'L' shape, rivetted to the
steel pipe with brass rivets (slows the bi-metal corrosion).
a 5/8" plywood subfloor is mounted to the
outriggers, which stand about 3/4" above the pipe, requiring wooden 'spacers'
every few feet along the pipe.
a 'U'-shaped channel of aluminum sheet metal is
mounted around the edge of the subfloor, to which the monocoque (shell) is
riveted.
this makes for a very lightweight trailer -
suitable for towing behind the typically low-powered family cars of the
immediate post WWII era at the then-typical 'highway' speeds of 40-50 mph (no
interstates/freeways yet, ICYDK).
However, after a few years of bouncing along the
highways and byways of this great land of ours, things can start to get ugly
down there under the old asbestos tiles, particularly if there's been any floor
rot or plywood de-lamination. Once the floor begins to flex, it's only a matter
of time before the whole thing starts to come apart. One way to tell if there's
a problem is to grab ahold of the hitch, and see if the pipe will
'rotate'.
In renovating his old pipe-frame trailer, Bud
Cooper replaced the pipe/outriggers with a steel ladder-frame, and
replaced the axle and spring suspension with a new style Henschen dura-torque
axle/suspension. He left a length of the original pipe frame exposed at the
rear, for appearance' sake.
I'm doing something similar - but using square-tube
aluminum to construct a kind of 'buttressed-ladder-frame' which
will be mounted to a new henschen axle. The original pipe will slide
into the aluminum frame, secured with rubber bushings and steel
bolts, so that once it's all together, it will appear to be completely
original.
Tuna
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