Tuesday, July 7, 2009

Possible Monorail Crash Explanation

Screamscape has an excellent article up today explaining how the monorail crash likely happened. Bear in mind that this is purely speculation but it is based on a number of sources and is, best I can tell, the most plausible explanation I have heard.

From Screamscape...

Despite the reports from guests who were nearby when it happened, it seems that WDW Monorail accident happened completely backwards from how it was first envisioned. It was really Monorail Pink that was moving backwards into the station at maximum reverse power, which collided into Monorail Purple which is now thought to have been stationary at the time. So yes... the death of the pilot was actually caused by Monorail Pink, but it wasn’t entirely that pilot’s fault either.

From the breakdown of several stories that have flooded by inbox in the last 12 hours or so, the blame all comes down from a major miscommunication between Central Monorail Control and the Monorail Shop while they were directing Monorail Pink through the procedure to take the switch beam from the Epcot line over to the Magic Kingdom expressway beam, before heading back to the shop for the night. The way it was explained to me is basic form is that Monorail Pink pulled forward out of the station, as if it were going to Epcot, and came to the stop somewhere just past the switch track. Here is where the communication problem comes up, as the Shop apparently controls the switch tracks and communicated something to the Central control booth (at the TTC) that the switch track has been moved. Central instructed Pink that they were clear to reverse onto the switch track, which instead struck right into Purple inside the station. However I’ve heard that no one from the platform crew was in the booth where one of them should have been during this kind of procedure, where they could visually check on things and could have called off Monorail Pink before it was too late.

The normal system that prevents accidents from happening (MAPO) was in an “overide” mode at the time, which is standard procedure anytime monorails are switched from one beam to another. At this point in time the pilot of Monorail Pink was pretty much going on the word of the control tower that everything was normal. Even though they have rearview mirrors, the darkness in this area of the track combined with the curve of the beam itself were a big factor. In fact if you look at the aerial photo I’ve “borrowed” here to display the area of the accident, you can see that way the switch beam curves here alongside the main beam, it would be very difficult for the pilot to tell from “feel” that they had not switched to the right beam.

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