• MBTA Red Line runaway train from Braintree Station

  • Discussion relating to commuter rail, light rail, and subway operations of the MBTA.
Discussion relating to commuter rail, light rail, and subway operations of the MBTA.

Moderators: sery2831, CRail

  by MaineCoonCat
 
Disney Guy wrote:Another approach would be to modify the bypass switch so a reverser key is needed to flip that switch with.
Any reason that wouldn't be an elegant solution? How tough/costly would that be?
  by Head-end View
 
Re; danib62's post above, could the train have reached a higher speed than 25mph, after coasting down the hill into Quincy Adams station? Kind of like the way a roller coaster works?
  by wyeknot108
 
litz wrote:What dispatcher did was get everything else out of the way, then shut down the power once they knew the line ahead was clear. That's the only way to prevent an accident in a case like this, with the conditions present.
I disagree. They could have just cut power from Braintree to North Quincy (or JFK) stopping the runaway train *immediately* (and obviously any other train in that area). The verbage about not wanting to inconvenience other riders doesn't pass the sniff test: the runaway train only had ~50 passengers (read: kinda empty at 6:08AM) - did the Wollaston train have some insane bulk of early-morning commuters on their way to emergency heart surgery or something?!?!

I don't necessarily have issues with the steps that were taken (e.g. clearing the rail then cutting the power) - but the "inconvenience" story in the face of a 25-40mph runaway train is kind of ridiculous. There is something more to the story. The OCC's shut-down procedure worked. *But* what if the 25-40mph train hit a patron on the platform at Quincy Adams, Quincy Center, Wollaston or North Quincy as it blazed through those stations "full-speed" with no warning and no breaking? Then the clear-the-tracks-no-inconvenience solution might have had dire and catastrophic consequences.

I don't know the third rail shut-down lag-time - that factor may have dictated the necessity to express trains to clear space - but it can't have been a commuter convenience issue taking precedence over a gigantic safety disaster. The train ran under power for 9 minutes; surely the third rail could have been cut sooner?
  by diburning
 
If there were trains in front of it beyond unpowered stopping distance (no braking) of the runaway train, then cutting the power with those trains there as well would make them sitting ducks when the runaway rolled through. So yes, it would make sense to clear the tracks first so that when the power was cut, it gave the runaway plenty of room to coast to a stop.
  by typesix
 
wyeknot108 wrote: I disagree. They could have just cut power from Braintree to North Quincy (or JFK) stopping the runaway train *immediately* (and obviously any other train in that area).
Trains can coast very long distances without power. I've seen this on the Riverside line with some operators, the train gets up to speed after a station stop and then coasts the rest of way to the next station with little or no reduction from running speed. Even curves barely made a difference.
  by sery2831
 
Disney Guy wrote:Trackside trip arms could be reinstalled, but a trackside indicator light aka re-installed wayside block signal at each one would be needed to reduce operator errors given that the cab signal unit is at a different viewing angle from the trip arm.
Trips and ATO do not work together. As in this case, the switch outside the cab and under the train is the same as securing a trip arm stuck in the down position. The operator was bypassing a stop signal. So if you had ATO and trips, the trip arm would have to be tied down and the bypass switch would have to activated. The same incident could occur in theory.

Moving the bypass switch to somewhere inside the train outside the operating cab in this series of the cars seems to me the solution here.
  by danib62
 
typesix wrote:Here's a Globe story on how the train was stopped:

http://www.bostonglobe.com/metro/2015/1 ... story.html
The people working in OCC at the time this happened should be given some sort of commendation. They really averted a disaster here.
  by Disney Guy
 
I see the first of many change order$ for safety "improvements" to the CNR car order. How much will it cost?
If the contractor used (United States of) American bidding and negotiation techniques and now felt that it significantly underbid the contact, then it would pad the cost of adding each additional change order just a tad to help make up for any now anticipated cost overrun for which the fixed price nature of the contract would otherwise force it to absorb.
  by Disney Guy
 
... but it can't have been a commuter convenience issue taking precedence over a gigantic safety disaster. ...
N.B.
Next inbound Ashmont train to hold at JFK so fleeing Braintree trains (visible from the Ashmont branch platform) could have the interlock to the subway (tunnel in Boston Elevated Railway terminology).
Braintree trains ahead of the runaway going express perhaps past Andrew (and then neatly stacking up in consecutive blocks).
The runaway train looking to waiting patrons like one more express skipping their stop.
No inbound train service on Braintree branch for at least an hour, except perhaps (adding insult to injury) the rescue train express from Braintree to reach the stopped runaway train, pushing it to the next station (JFK) and then getting to the yards (Cabot).
  by jboutiet
 
Out of curiosity... what would have happened here if the trainsets involved were DMUs rather than 3rd rail? How would they have stopped a DMU?
  by MCL1981
 
jboutiet wrote:Out of curiosity... what would have happened here if the trainsets involved were DMUs rather than 3rd rail? How would they have stopped a DMU?
If I'm reading this right, the bypass switch he flipped bypasses both ATC and trip-stop levers. If that's the case, I don't see any other way than a derail. Either run ahead and set a portable derail, or align it into a switch that has a derail built into it. Going at 25+mph, that might not be pretty.

I suppose you could put another train in front of it like they did in Unstoppable, however it didn't work out so well in the movie...
  by danib62
 
MCL1981 wrote: If I'm reading this right, the bypass switch he flipped bypasses both ATC and trip-stop levers. If that's the case, I don't see any other way than a derail. Either run ahead and set a portable derail, or align it into a switch that has a derail built into it. Going at 25+mph, that might not be pretty.

I suppose you could put another train in front of it like they did in Unstoppable, however it didn't work out so well in the movie...
The bypass switch actually wouldn't have effected the trip-stop lever, they're different systems. Getting around a faulty trip-stop used to require "keying-by". One of the actions the dispatcher took when he found out about the runaway train was to scramble crews from Cabot to set up trip stops by JFK/UMass
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