Automatic train protection on the Green Line?

What's the central subway and what is deadman?

Ricky Smith wrote:What's the central subway and what is deadman?

A deadman is a switch of some kind (usually a footpedal or button on the controller - sometimes the controller itself doubles as the deadman) that has to be pressed down before the vehicle will move. If it gets released (which it is assumed will happen if the motorman becomes incapacitated), it shuts off power to the traction motors and throws the brakes into emergency.

My understanding is that the central subway is the Green Line from Boylston Street to Haymarket (aka the Tremont Street Subway), though it might include the Boylston Street Subway as well.

MBTA3247 wrote: A deadman is a switch of some kind (usually a footpedal or button on the controller - sometimes the controller itself doubles as the deadman) that has to be pressed down before the vehicle will move. If it gets released (which it is assumed will happen if the motorman becomes incapacitated), it shuts off power to the traction motors and throws the brakes into emergency.

So on older red, orange, and blue line trains does the driver have to keep the deadman controller down even when stopped? Or does he release it when he stops?

-Dan

MBTA3247 wrote:

Ricky Smith wrote:What's the central subway and what is deadman?

A deadman is a switch of some kind (usually a footpedal or button on the controller - sometimes the controller itself doubles as the deadman) that has to be pressed down before the vehicle will move. If it gets released (which it is assumed will happen if the motorman becomes incapacitated), it shuts off power to the traction motors and throws the brakes into emergency.

When the LRVs were young, they had a deadman where you had to grip the handle and pull the bottom half up. This caused the operators to put an elastic or a tie wrap around the handle to avoid accidental emergency stops. The engineers quickly redesigned the handle to work with downward pressure from the top.

My understanding is that the central subway is the Green Line from Boylston Street to Haymarket (aka the Tremont Street Subway), though it might include the Boylston Street Subway as well.

Actually, the central subway is the entire underground portion plus the Lechmere Viaduct. Beck in the days when many cars from Divisions 1, 2, 3, 5, 6, 7 and 9 mingled there, the subway was a seperate division, Division 8, which had supervisory powers but no cars or operators of its own. Between 1916 and 1924 cars from East Boston (Division 4) also came under its umbrella. This in turn evolved from the day when all surface trackage in Downtown Boston was also controlled by Division 8.

Gerry6309 wrote: When the LRVs were young, they had a deadman where you had to grip the handle and pull the bottom half up. This caused the operators to put an elastic or a tie wrap around the handle to avoid accidental emergency stops. The engineers quickly redesigned the handle to work with downward pressure from the top.

I'm not sure how something that screams "BAD ERGONOMICS" could have been approved. I know Boeing didn't have any experience with light rail, but that is just a little crazy.

Arborway wrote: I'm not sure how something that screams "BAD ERGONOMICS" could have been approved. I know Boeing didn't have any experience with light rail, but that is just a little crazy.

True Boeing is definately better @ building airplanes, I'm a strong supporter of the 787 Dreamliner and can't wait for it to come out...

Is Kinky-Sharyo going to build our next green line cars?

-Dan

Last July Consultants were to submit proposals for being selected to perform an analysis for the application of a Positive Train Control System on the Green Line. Does any one know whether a Consultant was selected and the progress of the project?

Given the recent safety record of the Green Line, I'm surprised by the somewhat lackadaisical (or downright negative) attitude here towards some sort of ATO system. Seems to me that something has to change. Maybe that can be done with operator training and a couple more signals in critical spots (how about blind curves that are currently in the middle of a block...didn't that contribute to the crash that killed the operator within the last couple years?). And making sure the rules are followed to the letter. If ATO will cripple the system then fine, but let's not do nothing. Just my opinion.

Here is a report from July.

http://www3.whdh.com/news/articles/sports/BO117928/

Given the recent safety record of the Green Line, I'm surprised by the somewhat lackadaisical (or downright negative) attitude here towards some sort of ATO system. Seems to me that something has to change. Maybe that can be done with operator training and a couple more signals in critical spots (how about blind curves that are currently in the middle of a block...didn't that contribute to the crash that killed the operator within the last couple years?). And making sure the rules are followed to the letter. If ATO will cripple the system then fine, but let's not do nothing. Just my opinion.

Not only will ATO cripple the system, so will following the rules to the letter. As I have been told by a former MBTA manager the (T) Union has great leverage because they can carry out rulebook slowdowns which are just as effective as a strike for tying the system up in knots. Much of the Green Line is effectively run "on sight" with non-absolute signals serving as "suggestions". While there might be an argument on the higher speed segments, in the tunnels sight operation results in near maximum throughput even if it does result in the occasional fender bender. Philly used to work the same way until they put in the CTBC after a few minor mishaps. The result is a near doubling of trip times during the peak periods. Anyone who performs a rational risk analysis will accept a slight increase in the chance of suffering an injury in a bump up in return for getting to their destination in a timely fashion. Even with the lose rules on the green line its still safer than say driving or even walking on Boston roads.

For the life of me I can't see why so many people get worked up about things that have such an amazingly low probability of actually impacting them.

I have to agree, the last thing the green line needs is something else to slow it down. Anyone who is screaming for more safety and saying the occasional bump isnt an acceptable risk can't possibly depend on the trolleys at peak periods. I would bet if you interview the riding public they would say the same thing. Trolleys are more like buses then rapid transit, and fender-benders happen all the time with them.

The only place I could see see some sort of protection is out on the D, where the speeds are high enough to enable a serious crash (as we have seen). I cant see anything other then trip arms being necessary though. (perhaps a trip arm entering frequent accident spots as well, ie government center westbound and the boylston curve.)

Every serious accident on the green line (within the last few years) has been the result of red signal violations. The current signal system serves the line well, the only change (well, one of two changes, but I'll get to that) I really think would help the situation is giving the signal the ability to force a train to stop (like on the blue line and in NYC). I don't think mechanical trip arms are feasible, however an absolute stop feature is certainly possible. This would have no effect whatsoever on the line under normal operation, it would only come into effect when a red signal is violated. I don't see why a time delay feature couldn't also be implemented to allow cars to pass a red after a minute as the rule allows.

The other issue which I suspect is a factor (which would become much worse with ATO) is that operator training is abysmal. Operators are required to know JUST ENOUGH about the systems they operate to get through the day. It is the T's intent to keep them ignorant about anything beyond the minimum so that they don't try to solve a problem themselves. If anything goes unusual, they don't want you to fix it, want you to stop and ask for help. This leads to incompetence, and carelessness, which in turn creates a danger for the operators and the passengers. ATO only multiplies this factor, and in my opinion is very bad. The big wreck in DC recently would probably not have happened if it weren't for the issues I speak of here, that proves the dangers which are imposed when we rely on a computerized system.

Human error exists, therefore it is reasonable to have systems to aid the human and catch mistakes, but eliminating the human interaction from the operation is a terrible idea, and this is what the Red and Orange lines have done. Doing it to the green line could be even more catastrophic.

FP10 wrote: Trolleys are more like buses then rapid transit, and fender-benders happen all the time with them.)

I agree. Buses dont have ANY safety mechanisms and work in mixed traffic. Trolleys shouldn't require anything more than the signals buses use. Yes, bumps happen....but the green line is still safer than driving a car.

One thing is a train running at 200mph. A green line train rolling along at 17mph doesn't need anything to make it slower.

I know it's not ATO, but I laugh when I see what they're doing in LA....it's ridiculous. You have a bunch of crazy people crying for safety...and you get enough overkill to bankrupt a project. Imaging having to deal with crap like this here! It would ruin Boston.

http://www.youtube.com/watch?v=6HBOP_76m3s
http://www.youtube.com/watch?v=ee93yveCDGM


Now...if ATO meant that that green line trains could run without drivers....that would be great! 24 hour service, better headways..... maybe in 50 years computers will be smart enough to make emergency decissions like a human can.

(quoted from the Youtube page mentioned above)
"Some people cannot imagine that pedestrians will be able to escape the reaper on the Metro Gold Line Eastside Extension in Los Angeles. It seems simple enough in this video. "

Who does not know that the Brooklyn Dodgers were originally known as the Brooklyn Trolley Dodgers?

Also, shortly after Katrina, there was concern that evacuees staying at the Superdome would have run-ins with the light rail line running nearby, the latter then having a notoriously high collision rate. Except the evacuees were already familiar with light rail, in their native New Orleans (Canal St, Carrollton Ave., etc.)

Closer to home, I remember in an earlier lifetime the PCC's screaming (figuratively as well as squealing) out of Government Center around the curve towards Park St. To this day the signals at that curve are extremely close together, and it appears as if a red signal and a stopped train could be closer than the brakes could stop the train if the operator is not careful going through the first green signal. (A quick fix could be had there by making that first signal soutbound out of Govt. Center yellow-yellow-red instead of green-yellow-red.)

Isn't an ATO system supposed to try to mimic following rules to the letter? Then, if following rules to the letter will cripple the system, it therefore follows that an ATO system must do likewise.

The R-160s are 85,000 lbs - 122,000 is the AW3 weight.

LRVs historically have track brakes, which can REALLY stop a train fast.

The other thing about R/T stuff Vs freight - the electric/electronic actuation on transit cars means MUCH faster response. In the old days on the MP type MUs on the LIRR, it was a known fact that they stopped a lot longer without the electric assist they had.

I'd be more worried about the MBTA's commuter fleet - like most FRA operations, the braking performance on that stuff isn't anything to write home about (Metra is about the bottom of the bucket - their emergency rate is less than full service on the LIRR/Metro-North stuff). Funny how the FRA's supposedly do concerned about safety, yet doesn't mandate braking rates that non regulated stock has had for decades...