Braking question

Now what is that on the left track; on the very bottom there is a white half closed strip. What is that for?These are also found on wooden coasters, that white thing on the track.

The blue things are censors correct?

How does it estimate how fast the coaster is going so it knows how hard to squeeze?

Thanks if you can answer these questions.
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What in the world is in that bag?Watch u got in that bag!?!?!?!?!?!?!
[link edit. -j]

*** This post was edited by Jeff on 12/19/2001. ***

Now about those questions...

That white rail is a mounting rail for control hardware. Yes, the blue boxes are prox switches. That must be a piece of station track for them to use that many of them; I'm guessing that they are using a Millennium Force-like system of many small overlapping blocks in the station to allow multiple cars to move simultaneously through the station. If you look a little more closely at the photo, you should be able to see that the long line of prox switches is also mounted on a piece of that ]-shaped channel rail.

There are brakes on the track pieces in that photo as well. The brass-colored strips there between the prox switches and the rail are the brake caliper surface; harder to see is the brake caliper itself, painted black. "Behind" each caliper, that is, appearing to be on the opposite side of the rail, are the pneumatic actuator cylinders that push the brake open. Actually, from the track section on the right, it appears that the cylinders are directly below the rail. You can also tell the direction of travel in that photo, because only one end of the brake caliper is bent to form an alignment channel. See it? You can tell that the caliper is to be entered from the end opposite the camera, the far end of the track section.

I think these prox switches are not being used for speed control, but for position sensing. Where proxes are used for speed control, you will see two switches a short distance apart. Both are intended to be triggered by the same part of the train. Since the distance between the two switches is known, the PLC can determine the vehicle speed by counting the number of machine cycles between the time the first switch is triggered until the second switch is triggered. The more cycles, the slower the train is moving.

--Dave Althoff, Jr.
(fixed a character encoding mistake)

*** This post was edited by RideMan on 12/19/2001. ***

Regarding the "white strip" you mention, think of it this way...the rails (both top and bottom) are painted white. Where you see the grey stripes at is where the steel was left unpainted. This was done only where the wheels will actually make contact with the rails. The paint would wear off anyway with time and this keeps it from causing for the ride to lose it's smoothness.

You are correct that the blue objects are sensors..."proximity" sensors to be more exact. The computer measures how long it takes the train to pass from one prox to the next and applies braking pressure accordingly. This all, of course, happens in a few fractions of a second.

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James Draeger
"Legend is a wooden Jesus"

*** This post was edited by ACEerCG on 12/19/2001. ***