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What
makes a Pretzel click?
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Pretzel's
patented single-rail powered ride system originally
used a three-sided length of channel iron with
an insulated secondary rail placed within the
recess. With constant hard use, the need for
a stronger, more dependable track led to the
change to T-rail of the type used for mining
cars,
modified by adding the insulated 'live' rail.
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The
main rail was the conduit of the neutral side
of the circuit; the live rail was the 'hot'
side.The 110vac current was transmitted
to the motor via the trackwheel and contact
wiper.
Pretzel
cars ran on 12 pound rail (12 pounds to the
running yard) obtained from the West Virginia
Iron and Steel Co. of Huntington, WV and sometimes
purchased through the Morris Wheeler Co. of
Philadelphia.
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| "In
the early days, they used to take a 24-foot piece
of track and bend it this way and that. When I
came on in '46, I used to make a 6-foot and 3-foot
circle and put live rail on the outside and live
rail on the inside. So when you turn on the inside,
the live rail is on the inside. When you go around
this way, the live rail is on the outside. I’d
make up the design and they’d go down there and
put it together. We’d ship all the pieces and
when they’d get there, they’d put them all together
like a Lionel train. That was the thing with the
dark ride; we could go into any old or used building
and put a ride in there." |
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Standard Pretzel car undercarriage in production for nearly
40 years.
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"Originally,
that track was 1 X 2" channel iron and we had fiber washers
in there. And we used a 1/8 by ½ inch strip in the side and
put a bolt through there and insulated that. But that didn’t
work out, that wasn’t heavy enough. We put that in Ramagosa’s
ride. I went down there and worked all night. We finally got
the ride going. Then we got the railroad iron where we got fiber
insulators. We had a machine to squeeze the clips together to
hold the live rail. We had to create the 3/8" X 3/4"
live rail, cut 1/16" short to join together with the bond plate. |
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Then we'd mill it
out where it fit into the clip. The bending machine used three
rollers and could bend as tight a curve as you wanted. We'd make
all of that by hand at the shop; bend the track, weld the clips
onto it. We even wound our own springs. When I started full-time,
that's when we went to the standard track sections, just straights
and six-foot radius half and quarter curves. That did away with
all those odd pieces." |
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Pretzel's
spare parts catalog was a board-mounted display of every
component of the undercarriage of the car, including
axle, bearings, trackwheel, yoke, drive wheel, contact
wiper and crescent, motor mount and transmission casting,
drive ratchets, pawls, gears and hardware. Wheels and
other parts were finished by the L. E. Hettinger Machine
Works. "Louie" Hettinger's shop was right
next door to the Pretzel building and was eventually
acquired by the company. The heavy drive gears were
specially produced for Pretzel using a custom tooth
spacing and pitch. The large Pretzel shapes on the sides
of the cars were sand cast at a local foundry, then
finished and painted at the Pretzel shop. Wax Brothers,
a furniture upholstery shop, made the seat cushions
for the rides, and the cars were spray painted by Boswick's
auto body shop. |
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Most makers of dark ride cars, such as Traver/Chambers and Allen
Herschell, generally used the method of powering only the right-hand
rear wheel while allowing the left-hand wheel to turn freely on
its axle. This compensated for the difference in the turn radius
between each of the wheels when the cars went into curves. But
cars such as Traver's, with rubber-tired wheels, would experience
more wear on the driven wheel.
Although Pretzel's initial patent indicated a similar design,
almost as soon as they went into production this was changed to
a dual-wheel differential. Two five-spoked ratchet plates were
affixed to the gear-driven axle which interfaced with a spring-loaded
drive pin located within each wheel. With this arrangement, the
outer wheel on a turn in either left or right directions was free
to rotate at the faster speed necessary to negotiate the larger
outside radius. The torque would be shifted to the inner wheel
at the shorter inner radius which had traction with the floor.
When the car moved onto straight track, the speed of the wheels
would equalize and the drive pins would engage the two ratchets,
powering both wheels together. This, plus the use of wide steel
casters, resulted in more balanced wheel wear.
During a turn, the slipping of the drive pin against the ratchet
teeth in the outer wheel, which was then turning more rapidly
than the axle, gave the Pretzel cars their characteristic clicking
sound. |
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