s8film40
Well-Known Member
I believe if I remember right it the for the MAPO system to work it has to be a closed circuit but when your on the spur track it's an open circuit. It's mentioned in the NTSB report interviews how it works. The technology is really dated.
It is possible for the MAPO/MBS system to work on a spur line, in fact Disney has done this and had it working for a period of time in the past. The big misunderstanding is that the system is not intended to alert drivers of proximity to another train but rather to alert them of a certain distance of safe beamway. It is a "fail safe" system so it is not looking for other trains but rather clear unblocked signals from the immediate track ahead. In lieu of these clear unblocked signals it will put the train into a safer state requiring the driver to use overrides to move the train as well as placing restrictions on speed. This mode of driving requires the driver to ask permission so that clearance can be double checked and requires the driver to drive with greater caution as there is an audible alarm as well as having to continuously hold a button. A spurn line is not part of normal operation and so really shouldn't have these transmitters on it as you want these restrictions placed on the train when it is moving from line to line.