The strenth of up-stops

Dave: is that why the B&M hyper stations don't seem to have rails?

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Be polite and ignore the idiots. - rollergator
"It was like that when I got here."
"I'll procrastinate later."

Stations have perfectly ordinary rails. Perhaps you didn't notice because the train space is so much wider than the track?

What B&M do with their hypers and their stand-ups (probably with the floorless coasters as well) is to use a row of wheels down the center to support the weight and a couple of angle irons on either side to keep the train level. I'm not certain, but on the inverteds there are extra casters on the train so that when the train is sitting in the storage area the wheel carriers can be completely (all six wheels per) clear of the track for service. I'm not sure about the track-on-the-bottom coasters. :)

--Dave Althoff, Jr.

Dave, just curious how does the upstops being used as the road wheels on the transfer track work? Is the whole wheel assembly actually above the track (upstops riding on top of the track) instead of the usual wheel assembly going around the rails?

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So you believe that you are studying us, then kindly explain why you are the ones trapped in your seats.

The Demon was back in 1996, not 3 years ago. It held in the inversion for almost 4 hours

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I am one.
I am Turbo.

FOF: That's exactly how it works on Mean Streak. The storage track has three track sections on it. One section is conventional wood coaster track; the other two sections are a pair of angle-iron rails set well below the normal track height. When they transfer a train off, they slide the transfer table over to line up with an angle-iron track and roll the train off. The train rolls off of the wood track and onto the angle-iron, rolling on the upstop wheels.

Can't do that with the Arrow Runaway Train coasters; they don't have upstop wheels (except Magnum). I don't think that would work with the Arrow loopers either, as many of those have brackets under the two of the up-stops to serve as sensor flags.

--Dave Althoff, Jr.

Well, you *could* do it with an Arrow runaway train... you'd just have to shove really hard :)

Turbo, The Demon incident wasn't three years ago, but it wasn't '96, either. It was '98. I remember riding the thing only a week or two later during my gradeschool class trip, and being just a tad worried that the same thing would happen.

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I hear America screaming...

B&M hypers have a similar system to the inverts that takes the load off the main wheels in the car barn.

While the bearing in the middle of the wheel determines the short term mechanical strength of the wheel, wheel diameter is critical in determining the life of both the wheel and the bearing. A larger wheel heats less which give longer tire life and turns a lower RPM which gives longer bearing life.

There are 2 big factors that cause upstops to need to be less sturdy than running wheels. First, the upstops are carrying a load much less of the time. Second, running wheels have to deal with forces of 3 to 5 G's on many coasters. Upstops are limited to a little over 1 G.

In either case, rollercoaster wheels are limited in thier design by the many cycles of stress that occur during operation, not by one time static loading. A wheel, bearing, and axle that can be turned and slammed around all season has no problem holding the static weight of a train if it is stuck upside down.
*** This post was edited by Jim Fisher 2/6/2003 11:52:52 PM ***