Positive Train Control (PTC)

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

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Re: Positive Train Control (PTC)

Postby Dick H » Thu Dec 05, 2013 5:44 pm

While the MM&A line through Canada where the crude oil train disaster
occurred will never see PTC, there are numerous main lines in the USA
hosting haz-mat unit trains, general freight with sizeable cuts of haz-mat
and passenger trains. These train pass through congested urban areas, as
well as out in the prarie. So PTC can increase the safety of freight shipment,
as well as passenger trains.

It has appeared that most, if not all, the railroads, big and small, treated the
unit haz-mat trains in the same manner as a general freight train with mostly
empties and no haz-mat cars, such as leaving them unattended on main lines
and the like. Unfortunately, it took a disaster to get these trains some extra
safety considerations. While no railroad wants a major haz-mat incident, the
9-5 bean counters are always out there with suggestions on cutting corners.
They are no where around at midnight, when things go bad, really bad...
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Re: Positive Train Control (PTC)

Postby BostonUrbEx » Thu Dec 05, 2013 7:48 pm

newpylong wrote:You cannot quantify the cost of a human life.


This is done all the time. Even the EPA has a value on the average human life where it says it is not worth the cost to go beyond a certain point to protect lives. And I think you'd be reckless to not set up priorities based upon how many people you're saving and at what cost. Arborway's post makes the most important point in this whole thread.
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Re: Positive Train Control (PTC)

Postby Adirondacker » Thu Dec 05, 2013 10:44 pm

CRail wrote:....New diesel trains operated in excess of 100mph over stick rail with wayside signals...


And crashed into each other because when the train ahead of the one traveling at 100 miles an hour had to make an unscheduled stop the engineer in the following train didn't have enough time to brake when he saw the stop signal. You need cab signals starting at around 80 so the engineer ( and the automatic train stop if there is one ) have enough time to stop.

CRail wrote:This is in reference to the mandate requiring all trains operating over 69mph be equipped with cab signals which, at the time, barely existed


Trains operating at 80 or higher which is where 79 MPH comes into the discussions. Cab signals were widely used at the time. and were a mature technology.
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Re: Positive Train Control (PTC)

Postby CRail » Thu Dec 05, 2013 11:03 pm

Signals then didn't go from clear to stop, as they don't today, so I'm not buying that wayside signals contributed to crashes. Provide some NTSB (or comparable) reports suggesting so and we can discuss them. Otherwise, moving right along...

Sorry, 79, not 69... My point is unchanged. The world has much faster trains than us, and we are, on average, behind where we were in the 1950s (60+ years later and we carry passengers a whopping 15mph faster than we did when streamlined diesels were cutting edge). Railroads elsewhere did not dissipate like ours did, so there was clearly an unnatural force there. I firmly believe, and will continue to do so, that it's the same unnatural force shoving PTC down our throats. If 'safety' were really the main concern here, how about putting policies in place which make sure crews are provided with adequate rest and break periods so they're comfortable in their 'safety sensitive' positions. There's that 'money' thing again. Greater off time means a greater work force, and break periods means we may have to pay the same amount for less productivity. $afety Fir$t! THAT is my point, which is in support of Arborwayfan's excellent one, and they both stand.
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Re: Positive Train Control (PTC)

Postby gokeefe » Thu Dec 05, 2013 11:38 pm

CRail wrote:Railroads elsewhere did not dissipate like ours did, so there was clearly an unnatural force there.


Railroads "elsewhere" were owned by the government. During the 50s and 60s the overegulation that started with the Hepburn Act in 1906 became completely unbearable. The government refused to deregulate the railroads until they were bankrupt and the rest since the Staggers Act is "history".

Could there have been special interests who encouraged this scenario? Absolutely but the fact of the matter is that during that period of time oil was cheap, interstate highways were new and uncongested, jet planes were faster, and the railroads were terribly burdened by 100 years of overbuilt infrastructure that was overregulated to boot.

Positive Train Control is a safety improvement that has been on the priority list of the National Transportation Safety Board for over 20 years. Accident after accident have caused tremendous loss of life and economic damage which could have been prevented or mitigated had working PTC systems been installed. Railroads remain the single most important means of freight transportation in the U.S., they cannot be replaced and their role in the movement of bulk hazardous materials and along with large numbers of commuters in some parts of this country is essential. All of this being the case and given the concerns of this day and age PTC is an understandable necessity.
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Re: Positive Train Control (PTC)

Postby MBTA3247 » Fri Dec 06, 2013 9:29 am

newpylong wrote:The number of accidents that could have been prevented or reduced by PTC is too large to list. Human error is unavoidable.

The number I've seen reported is that PTC would prevent about 4% of the accidents that occur on modern railroads. It doesn't do anything to prevent accidents caused by broken wheelsets, broken rails, heat kinks, etc, which account for the majority of wrecks.
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Re: Positive Train Control (PTC)

Postby TrainManTy » Fri Dec 06, 2013 11:21 am

Adirondacker wrote:
CRail wrote:....New diesel trains operated in excess of 100mph over stick rail with wayside signals...


And crashed into each other because when the train ahead of the one traveling at 100 miles an hour had to make an unscheduled stop the engineer in the following train didn't have enough time to brake when he saw the stop signal. You need cab signals starting at around 80 so the engineer ( and the automatic train stop if there is one ) have enough time to stop.


That's a signal spacing/block length problem. Cab signals and ATS on the same length blocks would cause the exact same results, as all the reports I've read said that the engineer of the Exposition Flyer applied the brakes as soon as he saw the approach signal. You need blocks that are long enough to allow a train running at MAS to stop safely at the second signal. Or Advance Approach signals (on NORAC, these aren't just an early heads-up for crews but require an immediate reduction to Limited Speed).

My understanding is that the 79mph restriction was designed to force the railroads to adopt the new equipment mandated by the law in order to maintain their current speeds. Unfortunately, it didn't quite work that way and many railroads simply ran their trains slower.
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All posts are my personal opinion. I do not speak for any organizations on this board.
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Re: Positive Train Control (PTC)

Postby ns3010 » Tue Dec 10, 2013 4:38 pm

Bid 222-13, closing 1/7/14:

The MBTA is issuing this Request for Comment to facilitate the finalization of the specification in conjunction with leaders in the industry for Positive Train Control (PTC) System.
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Re: Positive Train Control (PTC)

Postby 8th Notch » Fri Mar 21, 2014 5:24 pm

From what I was told in recert class, the PTC deadline for the T was pushed back to 2018 from the original 2015 deadline. Not to say I told you so... :wink:
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