Disneyland's Big Thunder Mountain Railroad has riderless accident
Posted Wednesday, April 7, 2004 8:20 AM | Contributed by Jeff
California officials have ordered additional training for the crew of Big Thunder Mountain Railroad at Disneyland after a routine reset of the ride resulted in the collision of two trains. A report says procedures were not correctly followed. This is the same ride where a mechanical defect resulted in the separation of a train resulting in the death of a rider in September.
I don't know what it involves, but except for Mine Ride and Gemini, adding trains looks pretty straight forward. I know that they need mechanics there to restart Wildcat, which similarly has a whole mess of blocks.
Wildcat not only has a whole mess of blocks, it also has conditions that won't self-clear...a complicated way of saying that sometimes the cars have to be pushed to get them going again.
My point is that my observation of Cedar Point is that the crews start up, shut down, transfer trains, and clear fault-stops. When I have seen Maintenance request a train be pulled off, it was the Operations people who did it for them. The ride operators are trained professionals who are perfectly capable of performing such operations on their ride. We see that at Cedar Point; there is no reason not to expect as much from Disney...in fact I would expect it more from Disney because of the year-round operation of the park: their ride operators may be not just professional, but career professional ride operators.
One of the problems is that even though the control booth has a gazillion monitors, the operators don't have a clear view of the entire ride. Not only that, the monitors are B&W...might be easy to miss a train in one of the views.
I'm under the impression this wasn't just a matter of re-starting the ride or adding/removing trains, but actually cycling trains around in manual (maintenance) mode. I don't believe Cedar Point operators have the ability to cycle trains in manual mode, but that does appear to be the case here. I don't see any reason why ride ops should ever need the ability to use a manual mode (unless a ride is completely manual, that is).
It´s strange... it´s supposed that the coasters have a PLC that controls the coaster and avoids this kind of incidents. I don´t know if this coaster doesn´t have a Computer but maybe this could help to avoid this kind of problems.
But is that really cycling trains around the course in manual mode? I mean, sure cars are being manually backed up, but I'd argue that's a bit different than actually cycling trains in manual mode, which basically mean blocks are effectively turned off.
On many rides (caveat: I am not familiar with BTMRR), when the E-stop is pressed, the power is turned off. This may happen because Something Bad™ happened, or it may happen because the ride operators intentionally shut the ride down to make sure that Bad Things™ didn't happen while the transfer switch was open. Either way, when the power comes back on, the computer is totally confused. The operators can look around, using monitors, or by hiking out to the brake runs, or whatever, and know where the trains are. The computer, on the other hand, is stuck in its little cave under the station, where it can't see a darned thing. In an effort to do the Right Thing™ it just makes the assumption that all blocks are occupied until someone tells it otherwise. The operators manually indicate that a train can advance, and as the trains go around, they check out of the blocks they're really in, and the system resets. But doing the reset requires that the operators give the computer the proper information so that it doesn't accidentally crunch trains together.
Right - I understand that. What I'm saying is that generally ride-ops don't have the power to reset an e-stop. If they can at Cedar Point, that's news to me. Because of instances like this, however, I see no reason why ride-ops need that power.
-Nate*** This post was edited by coasterdude318 4/8/2004 12:54:45 AM ***