dehusman NorthWest State of the art 1880. Pretty much extinct in the US (as long as you don't count DTC).
NorthWest
State of the art 1880. Pretty much extinct in the US (as long as you don't count DTC).
DTC or TWC as implemented by today's Class 1's is integrated with the carriers Computer Aided Dispatching Systems. Those systems keep track of the block authorities issues and are programmed to prevent overlapping block authority. To issue an authority, the Dispatcher defines the block limits he intends to give the train, when the authority is issued it is issued to a specific train with a specific engine number - it is transmitted to the crew in a rule book defined format and then repeated by the crew back to the Dispatcher who must account for all the wording before the authority is Complete and Effective. Authorities may be issued in a single or both directions. Authorities issued in both directions can only be released in their entirety. Authorities issued in a single direction may have territory BEHIND the train released back to the Dispatcher. Authorities may have their direction changed with both the crew and the computer being updated with the changes when a change is required or requested.
If a Dispatcher attempts to issue an authority into territory already authorized to another authority - the CADS won't let the authority be created.
The biggest problem on high volume DTC/TWC territory (that is not backstopped with ABS Signalling - truly DARK territory) is for the Dispatcher to release territory in error - thus allowing CADS to create authority into track space where the other train still operates as they have proper authority.
Never too old to have a happy childhood!
NorthWestOne of the station masters in the telephonic block system has admitted he wrongly allowed one train to enter the block. And we're bashing 2MT CTC as unsafe. This system being used for 60+ trains a day on a single track is lunacy in the 2010s!
Dave H. Painted side goes up. My website : wnbranch.com
And other than a few seaside pockets, south of Rome is a very poor area.
C&NW, CA&E, MILW, CGW and IC fan
NorthWest The fact that manual block signalling survives on a busy mainline in a first world country in 2016 is simply insane.
The fact that manual block signalling survives on a busy mainline in a first world country in 2016 is simply insane.
They already have plenty of better systems-they've failed to implement one here for some reason. Just the savings in labor costs should be enough to pay for it.
NorthWest My understanding is that there is a dispatcher to 'herd the cats' in a way that allows trains to travel the line in a timely fashion by communicating with the station masters about meets. However this system has a single point of failure in the station master, who is supposed to agree with the other on what trains are allowed to enter the block between them. As there is no backup safety system, station masters allowing two trains into the same block results in this.
My understanding is that there is a dispatcher to 'herd the cats' in a way that allows trains to travel the line in a timely fashion by communicating with the station masters about meets. However this system has a single point of failure in the station master, who is supposed to agree with the other on what trains are allowed to enter the block between them. As there is no backup safety system, station masters allowing two trains into the same block results in this.
Johnny
NorthWest http://www.bbc.com/news/world-europe-36792246 One of the station masters in the telephonic block system has admitted he wrongly allowed one train to enter the block. And we're bashing 2MT CTC as unsafe. This system being used for 60+ trains a day on a single track is lunacy in the 2010s!
http://www.bbc.com/news/world-europe-36792246
One of the station masters in the telephonic block system has admitted he wrongly allowed one train to enter the block.
And we're bashing 2MT CTC as unsafe. This system being used for 60+ trains a day on a single track is lunacy in the 2010s!
Which now leads to the question, Was the 'stationmaster' operating with independent authority or was he responsible to some higher authority that had responsibility for the entire line?
schlimm As far as these crashes go, how do you know what speeds the two trains were going in Panhandle TX? My point is high weight, stronger buffers, etc. (i.e., a PzKpfw VI on rails) didn't help much in all of the examples. Dead is dead.
As far as these crashes go, how do you know what speeds the two trains were going in Panhandle TX? My point is high weight, stronger buffers, etc. (i.e., a PzKpfw VI on rails) didn't help much in all of the examples. Dead is dead.
Thanks to Chris / CopCarSS for my avatar.
Above a certain point, kinetic energy makes a collision unsurvivable as the equipment cannot adequately dissipate it. However, this point does appear to be higher for US equipment than European equipment. There is a certain speed range where a US car might be survivable, but the European one not.
The count is now 27 dead, sadly.
Parts of the line are upgraded to double track, but this section had yet to be. The line is apparently still telephonic block signalling, which is a safety nightmare with little redundancy!
I gather the private Italian line in the under-funded south was always single track.
tree68At one time, automobiles were designed as virtual tanks (ie, armored vehicles). Then it was discovered that while the vehicles didn't fare badly in collisions, the people inside were much worse off, as they kept going after the vehicle stopped. Seat belts made only a minimal difference, essentially changing the nature of injuries. Now cars are built with "crumple zones" to use up some of the energy of the collision and soften the blow for the passengers.
There are at least two very different aspects of deceleration here, addressed with very different technical approaches for different purposes.
As demonstrated most memorably by Princess Diana's accident, high-speed trauma even with very expensive 'crumple zones' -- the best that Dieter Zetsche's company could build -- can be extraordinarily lethal. It is a sometimes-unrecognized fact that the only mass that has to be decelerated for survivability is the mass of the passenger. This is why inertia-reel and 'pretensioned' seat belts, and to a lesser extent those abortions of NHTSA prioritization pyrotechnic air bags, work as well as they do; they smooth the deceleration rate of the different critical parts of the human body, and limit it over a permissible range of motion. Even then, they can't 'reach inside' to stabilize the aorta, the cervical vertebrae, and other 'weak spots' that produce medical syndromes.
All the 'crumple zones' do is 'pre-smooth' the peak deceleration rate in collisions to what the personal deceleration means can accommodate. Note how well this works in recent Formula I racing, where the cars are often reduced to fragments of carbon-fiber tub ... but the drivers walk away or relatively quickly recover.
The 'other half' of the problem with older, heavier cars is not so much that they 'don't crumple and absorb energy' as that they have inertia of their own. When something much heavier, like a bus or train, hits them, there is significantly more spot deformation at the point of contact. But more significantly in many accidents, the inertia of the vehicle becomes concentrated at part of the structure that is not designed to take the load -- for example, when a car skids and then collides with an obstruction meeting its side or driver's door. Then you may have 6000lb at some nontrivial speed impelling the driver or passenger against something relatively unmoving, or worse yet 'sharp' like that idiot California toll office that killed the "Porsche girl", or the guy wires on some power poles.
I think it might be pointed out that Miller's 'paired' approach to railroad-car safety is just as applicable, and basically just as correct, today as it was more than a century ago. You keep the cars in line; you provide robust and effective anticlimbing between them; you keep them from rolling over or accordioning; and you armor the ends enough to prevent mutual crushing or telescoping.
Then we can start taking up Bella et al's desire to protect passengers who need to be decelerated inside a train that is being kept intact. She thinks seat belts will accomplish that; I know decidedly otherwise. But I think a strong case can be made that if we keep the train relatively upright and connected, and the shells unbreached, and the windows from popping out and ejecting people, we'd have much more survivable accidents than we do now.
schlimmThe N. Philly and Yonkers crashes also suggest stronger FRA standards do not offer much additional protection.
That is a bit like saying that a crash helmet does not offer much additional protection because Chris Reeve damaged his cervical spine while wearing one.
Most of the loss of life in the Amtrak 188 crash was the result of a lateral impact against a catenary support, which bent the car involved like a beer can in a direction it was never meant to be stressed and then tore it open. No FRA passenger-car standard would have changed that -- it might even be possible that the armored FRA cab standard for locomotives would not have withstood such an impact.
The recent vehicle crash involving third-rail penetration likewise does not reflect a problem with FRA buff standards or car-end "armoring"
The BNSF crash in Oklahoma, even if we allow for the almost impossibly-high instantaneous contact speed (very close to what was achieved in the Gunpow collision in the late '80s) involved much higher inertial mass. No FRA standard would have preserved cab integrity, perhaps even in the refuge zones, under such conditions, and I suspect there is a point where regardless of careful design there is enough force in an accident to 'make the rubble bounce' enough -- or enough times, in effect -- to destroy any safety-device integrity, even those that purport to displace "meeting ends" to avoid structural override and 'telescoping' or penetration.
My impression of the Yonkers wreck was that much of the damage came as the cars rolled or came out of line; neither of those effects have much to do with buff standards or car-end protection.
From what I have seen of the Italian wreck so far, it was a straight-line collision with most of the debris seemingly close to the centerline of the track. This is not so much one train telescoping the other as both trains shredding into confetti. That to me is an indication of very insufficient collision protection.
Yes, the double tracking would have helped. They just didn't get it done quite fast enough as things have turned out.
What a horror. Nothing left of the head ends of both trains but tinfoil.
Prayers for the victims and their families. May God give them all peace.
Overmod After a pause of respect for the dead and dying: Victrola1 The U. K. Mirror's report. http://www.mirror.co.uk/news/world-news/italy-train-crash-12-dead-8403500 I noted this comment: The Mayor of Corato, Massimo Mazzilli wrote on Facebook: “The disaster is like a plane crash.” Again we have light vehicles, insufficiently designed for absorbing collision impact, coming apart disastrously While there are some on this forum that scoff at hidebound US insistence on heavier construction for passenger equipment, I wonder how passengers in this incident might have fared had the equipment met FRA buff standards. I
After a pause of respect for the dead and dying:
Victrola1 The U. K. Mirror's report. http://www.mirror.co.uk/news/world-news/italy-train-crash-12-dead-8403500
http://www.mirror.co.uk/news/world-news/italy-train-crash-12-dead-8403500
I noted this comment:
The Mayor of Corato, Massimo Mazzilli wrote on Facebook: “The disaster is like a plane crash.”
Again we have light vehicles, insufficiently designed for absorbing collision impact, coming apart disastrously
While there are some on this forum that scoff at hidebound US insistence on heavier construction for passenger equipment, I wonder how passengers in this incident might have fared had the equipment met FRA buff standards. I
Although in general I agree with you, two recent incidents (MN and ATK) with FRA compliant equipment haven't looked too much better.
schlimm Overmod I wonder how passengers in this incident might have fared had the equipment met FRA buff standards. At those speeds, you seriously think heavier equipment would have reduced casualties significantly? The BNSF crash in OK suggests not. The N. Philly and Yonkers crashes also suggest stronger FRA standards do not offer much additional protection. Although the cause is unknown, it is likely either a failure by dispatcher, the control system used or some engineer error. Double track would help, too.
Overmod I wonder how passengers in this incident might have fared had the equipment met FRA buff standards.
At those speeds, you seriously think heavier equipment would have reduced casualties significantly? The BNSF crash in OK suggests not. The N. Philly and Yonkers crashes also suggest stronger FRA standards do not offer much additional protection. Although the cause is unknown, it is likely either a failure by dispatcher, the control system used or some engineer error. Double track would help, too.
schlimmAt those speeds, you seriously think heavier equipment would have reduced casualties significantly?
At one time, automobiles were designed as virtual tanks (ie, armored vehicles). Then it was discovered that while the vehicles didn't fare badly in collisions, the people inside were much worse off, as they kept going after the vehicle stopped. Seat belts made only a minimal difference, essentially changing the nature of injuries. Now cars are built with "crumple zones" to use up some of the energy of the collision and soften the blow for the passengers.
To a point, "secondary collisions" have become less of a factor.
Even then, beyond a certain speed, you're pretty much doomed.
The problem with that approach for rail cars is that you'd be using up potential revenue space.
Recall that Ford found it cheaper to pay the claims than to fix the problem with the Pinto fuel tank - dollars and cents speak loudly.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
schlimm Overmod At those speeds, you seriously think heavier equipment would have reduced casualties significantly? The BNSF crash in OK suggests not. The N. Philly and Yonkers crashes also suggest stronger FRA standards do not offer much additional protection. Although the cause is unknown, it is likely either a failure by dispatcher, the control system used or some engineer error. Double track would help, too.
Overmod
In a phone interview with state TV, Ferrotramviaria director general Massimo Nitti said the dynamics of what went wrong are still to be determined, but it is clear "one of the trains wasn't supposed to be there" at the same time as the other.
OvermodI wonder how passengers in this incident might have fared had the equipment met FRA buff standards.
Very little of the first two cars of either train are recognizable.
No freight equipment involved. The two trains were an Alstom Coradia EMU and a Stadler Flirt EMU both operated by Ferrotramviaria SpA, operating on track owned by Ferrotramviaria. Closing speed unknown although both vehicles are designed for 100 mph (160kph) speeds.
Victrola1The U. K. Mirror's report. http://www.mirror.co.uk/news/world-news/italy-train-crash-12-dead-8403500
Again we have light vehicles, insufficiently designed for absorbing collision impact, coming apart disastrously -- so the 'plane crash' simile is appropriate in more than one sense.
While there are some on this forum that scoff at hidebound US insistence on heavier construction for passenger equipment, I wonder how passengers in this incident might have fared had the equipment met FRA buff standards. It is also a cautionary tale that time or operating separation between 'light rail' and freight equipment is not a guarantee of passenger safety...
The U. K. Mirror's report.
Hit the translate button on this one.
http://bari.repubblica.it/cronaca/2016/07/12/news/puglia_scontro_fra_treni_tra_andria_e_corato_morti_e_decine_di_feriti-143896174/?ref=HREA-1
There are in coming reports of a head on crash between two passenger trains.
https://www.facebook.com/skynews/videos/1395747907106469/
Sorry for the Facebook reference.
try this one instead.
http://news.sky.com/story/deadly-head-on-train-collision-in-italy-10499381
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