This from micechat.com from a poster. It does make sense.
Hi guys,
I'm a former Mark VI railie, and I stay in touch with a fair number of folks in the department. Here's what I've heard. I'm going to stress that it's what I've heard, and I can't represent this as absolute fact. Take that for what it's worth.
The short, short version is that Monorail Central cleared Monorail Pink in reverse into the Concourse (the Epcot side of the TTC) station without being aware that Monorail Purple was still in the station. Pink was cleared with MAPO override, meaning that the driver would have disabled the anti-collision system (there are a variety of legitimate reasons for doing this), and would have been acting on faith that Central wouldn't have cleared him into a dangerous situation because it sometimes is difficult to see everything you'd want to in the cab mirrors, particularly at night on a curve such as the one he was backing along. For whatever reason, Purple just sat in the station without attempting to avoid the accident, and was struck by Pink moving at the full 15 mph allowed during MAPO override. From what I understand, the driver of Purple was a new transfer from another department. Why Central would not have made sure the station was clear before moving any trains is a bit of a mystery, but I've heard that no one was actually in the control console (the control tower-looking place at Concourse) at the time. To my knowledge, there were no electrical or mechanical problems in play here. Again, I have to stress that I'm relating what I've heard, and I was not there. This is a second-hand account from others more familiar with the situation.
Okay, speculation time.
Why would Purple have just sat in the station and let himself get hit? Well, it was a new driver from what I understand, and when Pink got close enough to trigger Purple's MAPO system, it's quite possible that the driver of Purple freaked a little bit (any time a driver gets an unexpected red MAPO light, it gets their attention), and was so intent on looking at his console trying to figure out what was going on that he simply did not see Pink barreling down on him. I suppose it's also possible that the Concourse station didn't have power at the time, preventing Purple from leaving, but I rather doubt that was the case.
Why would Central clear a train into an occupied station? Inattention, most likely. As I said, I'd heard that Central was not at the console at the time of the accident. IMO, if this is the case, it's the root cause of the accident and whoever was Central should be strung up.
Also, here's a little primer on how the anti-collision system on the WDW trains works, since there seems to be some confusion as to how the system works:
The system at Disney is called the MAPO system, or more precisely the Moving Blocklight System (MBS). It consists of a number of transmitters along the beam every 7-10 pylons or so that place RF signals of three different frequencies onto the positive buss bar (power rail), and a corresponding receiver in each train. The trains are wired with a capacitor that shorts the MAPO signals to ground, preventing any signals generated ahead of the train from getting past it. The transmitters are arranged sequentially around the beam- if any given transmitter is putting out frequency #1, then the next one will be emitting frequency #2, and the next one after that will have frequency #3. The one after that will be transmitting frequency #1 again, and the cycle continues all the way around the beam. The upshot of this is that in normal operation, the following distance should be such that there will be three or more transmitters between a given train and the train ahead of him, thus the following train will "see" all three frequencies, and the driver will have a green MBS light on his console. As he begins to get close to the leading train, there will only be two transmitters separating the trains, and the leading train will be shorting out the third MAPO frequency being generated by the next transmitter ahead of it. The following train will then see only two frequencies, and the yellow MBS light illuminates on the driver's console. This signals the driver that he needs to stop at the next designated holdpoint until his MBS indicator turns green again (i.e., the leading train has gone far enough away that there are now again three or more transmitters between the two trains). If the driver ignores the yellow MBS light and continues on, then the following train will only have one transmitter between it and the leading train. This triggers an emergency stop on the following train, with a big ol' blinking red light (a "red MAPO") to let the driver know he screwed up, and a corresponding entry is made in the train's daily event log. It's a reasonably fail-safe system, meaning that if there are problems with the system itself, it will result in a train being stopped instead of being allowed to continue into a dangerous situation. It's not rocket science, and is similar to moving blocklight systems used on subways and other similar systems. Being so simple, the system is pretty reliable, although it rarely can get a bit flaky during thunderstorms, resulting in the occasional yellow MBS light even though there may be a mile or more between trains.
However, there are a number of situations where the MAPO system needs to be turned off, and for that, there's a "MAPO override" button on the console, which allows the driver to do just that. When MAPO override is active, the train is limited to 15 mph, and the driver has to continue to hold the button down to keep the system overridden. Some examples of when the system needs to be overridden are when trains are on any of the spurlines (since they have no MAPO transmitters), or when trains are being switched between beams.
Anyway, regardless of what actually did happen, my thoughts go out to the family of the driver that died, and also to the driver of Pink, who I'm sure is living with his own awful grief. No one should have to deal with this kind of stuff for a crappy hourly position, and I hope that this sad event brings some (IMO) much-needed change in the Transportation Department management.
I am sad reading this story.
