Beacon Junction (Green Line) Derailment 6/8/2019

[MBTA3247]

I was discussing this with one of the other members at Seashore Trolley Museum (a retired T inspector) on Saturday afternoon. According to him, the switch at Beacon Junction defaults to the normal position (ie, straight thru for the C line) unless an outbound D train has approached it and the route isn't blocked by an inbound C train. Definitely a recipe for a speeding train to hit the switch before it finishes throwing and have the front truck go straight and the other trucks go left.

[Disney Guy]

"Would a signal have detected the switch?"

The signal at the switch remains (should remain) double red until the switch(s) are in position and the track chosen is clear and red (double red) signals are showing for all conflicting movements.

Although the required block headed by a yellow signal prior to the red signal is shorter than one train length, the red signal is in full view at least two additional 3 car plus length blocks upstream.

An improvement might be to not throw the switch for the diverging track if a train is approaching at speed.

Otherwise, the switch might finish throwing but the train might derail after going into the turn too fast.

It is also good practice for (at this location) the outbound switch to throw to the C route if not already, before an inbound C train is cleared through.