EDWIN DROOD
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O
ver the last fifteen years, professional productions of musicals
have set a new standard of spectacle. Towadays, audiences for college and
university productions of musicals like Into
the Jl7oods, Big River, and Grand Hotel expect
to see technical feats similar to what was done
in the Broadway productions. Such was the
case in the tah State University Theatre production of The MJlstelJI ojEdwin Drood. The
designer and director agreed to use one of the
Broadway production scenic devices-a
treadmill which carried several actors twenty
feet across the set in both directions and at
varying speeds. Buildillg this professionallooking device on our less-than-professional
budget was the challenge given to the technical
director and shop staff.
Our research into the engineering of
treadmjlJs began with a look at exercise treadmills. We first contacted Weslo Industries
whose exercise treadmills employ a rubber
conveyor belt running over a specially coated
and uniquely fabricated under-belt surface.
Weslo's engineers connected us with a source
for conveyor belts, Mol Belting. One of Mol
Belting's engineers suggested a belt 18 inches
\vide and forty feet long to meet our design requirements and limited funds. As it turned out,
the $450.00 factory-spliced belting loop would
be the most expensive part of the project.
Our best source of information for figuring out the mechanics of the Drood treadmjlJ
carne from the farming community. Study of
potato piler conveyor systems determined
many of the construction techniques and materials we used.
The treadmill frame employed three inch
channel iron for side rails to support the several hundred pounds of actor weight the belt
would transport. The channel iron rails were
supported with 11h-inch 12 gauge square steel
BrULe Duerden
tubing cut to a four inch length creating an
eight inch step up onto the platform. 11h-inch
square tube was also used to span between the
channel iron and support a structural deck of
3/4-inch plywood.
One of the key elements in engineering an
efficient treadmill is providillg a very low-friction surface on the horizontal decking that
supports the weight of the transported actors
as they move horizontally on the belt. Keeping
friction to a minimum between the weighted
moving belt and the under-belt decking keeps
the power demands on the motor at sensible
levels and also keeps the treadmill moving
smoothly. The specialized under-belt surface
used in Weslo's exercise treadmills was prohibitively expensive given our budget, but as
we discovered, it was also unnecessary. We
found an adequately slick, yet inexpensive under-belt material in white 1/4-inch tile board.
This Masonite product is available at most
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