As I recall, Magnum was the first one to install a wind-speed sensor on top of lift back when I worked there in '91 or '92. It rolled-back in the pretzel.
Also, I've seen Gemini after valleying a couple times. And a friend was a test rider on it when it rolled back. I think Gemini is probably the ride most prone to do that, cause the turns are relatively high, and the train goes slow on them even when warm.
One of the ride ops told me Raptor went back and forth in the valley for 10 minutes before it finally came to a stop.
According to the official Raptor manual:
"if the wind speed is greater than 20 mph, an empty train must not be dispatched from the station. If the wind speed is greater than 30 mph and the wind is blowing directly off the bay, Raptor must be closed immediately but without dispatching an empty train"
Found this next line interesting:
"Management reserves the right to override this call depending on the wind direction, temperature and speed of the trains"
When I worked on Raptor and we had simular wind conditions we wouldn't even dispatch a train until it was full. We even ran 1 train operations to insure a heavier train. I know we "used" guests as weight on more than one occasion just to get a train back to the station, then we would let them off on the runway.
Not wind related, but on Sunday night, they would not dispatch Jr. Gemini without at least 14 kids. Even with the full train, I didn't think my son was going to make it back to the station. Jr. Gemini doesn't come to mind when I think of a coaster not being able to complete its circuit, but that train made it by the slimmest of margins.
I think Magnum is relatively safe since the re-profiling, though I suppose if the trims were on hard anything is possible. I'm trying to think of who was on the train... but there was one miserable bonus weekend in maybe 1999 where they went down to one train (which they did again Saturday) and we barely made it over the second hill. I thought for sure we'd "Ocean Motion" at the bottom of the first drop, but we made it. I forget what the crew said our lap time was, but it was apparently outside the normal parameters for operation. Slowest, yet most memorable Magnum rides I've had.
I've always wondered what it'd be like to play ocean motion on Magnum, or any other ride for that matter.
I think I would get sick of rocking back and forth after about 2 minutes. 10 minutes would probably feel like an eternity. I guess I could handle it on Magnum of MF because the seats are at least comfortable and open, but Raptor or Mantis would suck.
The only ride I've ever seen valley was a DV (GAm's, IIRC)...it was funny seeing a coaster rolling back and forth in the station like that. Whatever the problem was, I was happy to see the ride re-opened withon an hour or so....that was the day I caught my credit lap... :)
Other than that, witnessed a couple rollbacks, one on Ka, one on TTD...and a couple *near-valley moments* on some kiddie coasters (BB's comes to mind, LOL).
^ What you witnessed was a Tower 1 miscatch. The train was running too slow and didn't make it high enough to catch on the catch car. There are brakes at the bottom of the boomerang that stop it so it doesnt valley somewhere else. Maintenence comes out and releases the brakes. Train rolls back and forth a few minutes. When it stops, they bring the catch car down to the station and hook it up. Then test it and reopen.
Tower 2 is basically the same except the train would stop between the loop and Tower 2. After the train stopped rolling back and forth, they would winch it up about 10 feet since the Tower 2 catch car is not able to come all the way down.
SFGAm Shock Wave said: There are brakes at the bottom of the boomerang that stop it so it doesnt valley somewhere else.
The brakes are there purely to dampen the train's pendulum motion, not to prevent valleying in other sections. Even running at full speed, the train barely makes it over the second half of the cobra roll on the return trip, so to suggest that it clears that, doesn't make it high enough on Tower 1 to catch the car, and then makes it back over the first half of the cobra roll is preposterous.