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.
Read more from The LA Times.
is that contradictory to anyone else?
It all goes back to what kind of operations does the park have. My assumption is that Disneyland has professional operators who have a significant amount of control over their rides, and therefore it isn't unexpected for the operators to be able to perform such operations as resetting the block system and transferring trains.
--Dave Althoff, Jr.
Big Thunder has been around a lot longer too...more chances for that to happen. But whether the monitors were sufficient, it probably boils down to human error.
In any event, this is most unfortunate news. I was fortunate enough to take a swing on it a couple weekends back. The line moved really fast given the crowd at the park. I guess I'll avoid it until they get the trains back in shape.
Also, giving ride operators that amount of control and responsibility helps develop pride and job satisfaction. Ride ops can certainly handle the responsibility given proper training. My pilot on a recent commuter flight wasn't much older than your typical CP ride op!
Although the crash at BTMRR is unfortunate, the way the rides are operated show just how good operations are at both Disney and CP. Especially CP since they are seasonal, and they seem to avoid the mishaps that have cursed Disney lately.*** This post was edited by Pete 4/8/2004 3:24:47 PM ***
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 real question is...does it make sense to control a ride this way? I say no. I understand the need to shut down power to things like the lifts etc. in an e-stop situation, but why should the computer go brain dead too? In an e-stop, all brakes should come on, the lifts should stop, and the computer should go into a holding pattern not unlike the "pause" function on a video game....still keeping track of the last known location of each train. A park shouldn't have to evacuate an entire ride, and go through a lengthy restart procedure.
Especially in this case where #1, it's a busy park that can't afford to have long downtimes and should have rides up and running quickly and #2, it's been e-stopped for something minor as a gate being opened. Evacuate an entire ride because a guest opened a gate? That's like shooting a fly with a bazooka.
Here's a story on how the whole "Manual" operation works. (This is about the Tornado at Adventure Land, Iowa. Still fully manual. Semi-Manual skid breaks (uses a button to control them), two trains (although only one is usually used), and the trains are PTC Buzzbar, Three row per car. It doesn't have a block. The story will have two trains running.
1. The operators check the restraints, give the thumbs up. The train is out of the station.
2. The operators want to add another train. So, they will stop the train early on the final breaks, after the passengers are out. (The operator could also stop the train on the lift, also.)
3. The operators hears a ringing, telling the operator that the train is getting near.
4. The operator breaks the train, and lets the people out.
5. The operator cycles the train again, and stops the train on the breaks, or stops the train on the lift.
6. The transfer must be manually adjusted to allow the train on.
7. The operator releases the breaks from the transfer shed, and allows the train into the station.
8. Operator restarts lift, and all is well. (Lift is continually running)
9. Operator hears ringing bell. Dispatches train, gets ready to stop train.
It's as easy as that. All the operator would have to do on multiple block coasters, it monitor the sensors more closely.
the computer should go into a holding pattern not unlike the "pause" function on a video game....still keeping track of the last known location of each train.
You did not just compare a coaster to your X-Box...
What if the issue was CAUSED my the computer losing track of a train? What would you do in that situation? An e-stop is the overall best solution to cover the multitube of problems that can happen.
You are misunderstanding Rob. I tried to be clear, but let me state it again another way. I didn't say the computer should do the pause thing INSTEAD of an E-stop. And I never suggested that the ride stay in motion. But what should happen is that once the ride has come to a halt due to an e-stop, the computer should keep track of all trains at all times...whether the ride is in automatic or manual mode. The way it is now, once an e-stop has happened, the computer loses all memory of where the trains are. Which condition sounds more unsafe to you?
So for something minor and totally unrelated to a catastrophic failure such as you described...such as a person opening a gate, you still have to evacuate the entire ride and spend the next hour moving trains around in a risky manner just to reboot the thing. Does that make sense? To me it doesn't. Not if it's something minor.
"On many rides (caveat: I am not familiar with BTMRR), when the E-stop is pressed, the power is turned off....Either way, when the power comes back on, the computer is totally confused."
The rides that I work on do not shutdown the computer in control of the ride in any case. An e-stop will shut down all motors, pumps, etc. and close all brakes, but the computer is still fully aware of the position of all ride units. However, in manual mode, it is always possible to run the ride units into each other, because there is only limited safety in manual mode. At the park I work at, ride operators are only allowed to control the ride in "automatic mode". Any other mode is reserved for maintenence personnel. Furthermore, while it is possible for the computer or PLC to have a serious unrecoverable error, on rides that have no "resting position" (simulators come down to rest on their own, most coasters have no such position) there are always two computers constantly comparing data and double checking each other for discrepancies. Therefore, for the most part, it still knows the position of all ride units, but may also have "ghosts" (it thinks a unit is there, but actually is not) based on the erroneous data. The ghosts can be cleared in a maintenance mode, in most cases.*** This post was edited by RideTech 4/11/2004 10:10:18 PM ***
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