Fatal Talgo Derailment in Spain

[jis]

In a related matter, my Swiss friend says Swiss engineers run red lights on their mountain railways routinely. They do it and get away with it and then one day a guy does it and has a headon collision. Do authorities discipline staff who do risky things?

Unless your friends are familiar with the rulebook that describes what each of the signal aspect means, they have no way of knowing whether it is legal to pass a red signal under certain circumstances or not.

For example, under NORAC rules in the US, a block signal can be passed at restricting speed after stopping at it (and for certain freight trains they are now even allowed to roll past one at restricting speed). This is done many dozens of times, safely, each day on the NEC, specially on the main line tracks leading into Penn Station from LI, where you will see a line of LIRR and Amtrak trains proceeding slowly essentially nose to tail. Same is the case through the Hudson tubes. Although in Hudson tubes they may be going faster than a crawl because they are actually under block signal control using extremely short blocks, and no trackside signals. They can see the allowed speed at any time on the APU of the cab signaling system in the cab.

Anyway, Red over Red (or simple single Red with no other numbers or lights on) means absolute stop at Home signals. But just a red at a block signal (with a number under the signal head) essentially means proceed at restricting speed ready and able to stop at any obstruction on the track.

Just to illustrate how difficult it can be for a novice unfamiliar with the rules to understand what is going on...... Just yesterday when I arrived at Metropark on an Acela, an NJT train was holding at the Home Signal at Menlo on track 1 for the Acela to cross over from track 2 to track 1 in front of it and make the station platform. What the NJT was seeing at the signal was a Red with no other light on the signal lit and no number plate on the signal - meaning Home Signal, "absolute stop". The Acela had red over flashing green meaning Limited Clear cross over at cab speed and then clear ahead. So it crossed over and stopped at the platform.

As soon as the Acela cleared the interlocking, the dispatcher reset the switch and "fleeted" track 1 straight, which means essentially what was an absolute Home signal, turned into a Block signal, denoted by a white number plate light lighting up next to and slightly below the signal head. As soon as that happened, the NJT train started off at slow speed and crawled upto the end of the platform right behind the Acela.

As soon as the Acela left, the NJT crawled in behind it maybe 100 yards separating them, to make the platform.

Someone unfamiliar with the rules would have been going berserk thinking a red signal was passed by the engineer. "Man did you see that? He just passed a red signal. He really ought to be disciplined. It is so unsafe to pass a red signal" etc. etc.

Well, yes. He did pass a red signal, that by the rule book in force is supposed to be passed. That is the way it is supposed to work, and it is perfectly safe as long as the rules are followed.

 

[jis]

Look at the video. As the heavy lead diesel plows into the ballast, the passenger carrying cars were pushed into it by a combination of momentum and the trailing diesel unit. A string of soda cans crushed between two bricks.

It should be quite revealing to see the actual sequence that they come up with in the investigation.
The front 4 or so cars actually went way past the bridge and lodged themselves in the gully by the track. The pileup was starting at about the 5th car. Don;t know the exact mechanism that caused one of those cars to get lodged more firmly in the ballast than the others and cause the rest to pile in onto it.

So it looks like it was more of a case of several soda cans crushed between a lodged soda can and a brick, with one sode can jumping up and out of the way too!

 

[Swadian Hardcore]

Not particularly. Given that the engineer is in the front, they're probably more likely to be injured when running into something. Chase, Bayou Canot, Capitol Limited/MARC collision are just a few...
Edit: Came across this link while reading about Bayou Canot - firsthand account from one of the conductors. Short, but EXCELLENT read that puts a human face on the disaster:

http://www.gcwriters.org/destruction_of_amtrak.htm

I think the only reason this engineer survided while so many passengers died is because the leading unit was not the first to leave track, and it was pulled off by the cars behind it. When pulled off, it seems that the rear of the leading unit impacted first, with the front following in, so the engineer suffered less force than in a collision.

Look at the video. As the heavy lead diesel plows into the ballast, the passenger carrying cars were pushed into it by a combination of momentum and the trailing diesel unit. A string of soda cans crushed between two bricks.

I don't get how this correalates to the security video. Elaborate?

 

[hake]

The video appears to show that the third vehicle (a passenger car and presumably a single axle talgo type vehicle) was forced up and sideways towards the outside of the curve. It looked as if the train formation was subject to buckling (presumably due to compressive stresses in rear). Could it have been that the braking effort was stronger in the leading vehicles than at the rear of the train? What is the delay of braking effect in talgo rear vehicles compared with the lead vehicles, especially when a very strong brake application is made?

Many years ago, I worked on control systems. This led me to distrust active control systems (such as talgo wheelsets are reported to controlled by) in certain situations where extreme duress operating conditions are possible. What befell this talgo was surely outside a predictable performance envelope and so wheelset control system behaviour could not be safely anticipated. The behaviour of passive systems can be more realistically be forecasted. Simplicity is a virtue and there are likely too many variables in the talgo model, brilliantly ingenious though the work of José Luis López Gómez might be. Give me nice predictable bogie system anytime.

I would also observe that a talgo possesses fewer axles than a bogie equipped train. Flange forces are therefore likely to be greater with a consequent greater possibility that wheels will cross over the railhead. In that exceptional circumstance, I would far prefer wheels and axles to be single assemblies. One must always design for the exceptional circumstance.

 

[cirdan]

Does anything on trains give the engineer a better chance than passengers of escaping injury or death?

Often, when a crash is imminent, engineers can jump out of the train, or can leave their cab and seek refuge inside the locomotive, an area where chnaces of survival are greater. On cab cars they can run inside the passenger compartment. So if you ever see an engineer running from the cab and through the passenger area, you'd be well advised to run with him.

 

[Bob Dylan]

Does anything on trains give the engineer a better chance than passengers of escaping injury or death?

Often, when a crash is imminent, engineers can jump out of the train, or can leave their cab and seek refuge inside the locomotive, an area where chnaces of survival are greater. On cab cars they can run inside the passenger compartment. So if you ever see an engineer running from the cab and through the passenger area, you'd be well advised to run with him.

Similar to if you see a Pilot come out of the Cockpit with a Parachute you're in a heap of trouble!

 

[RRUserious]

Does anything on trains give the engineer a better chance than passengers of escaping injury or death?

Often, when a crash is imminent, engineers can jump out of the train, or can leave their cab and seek refuge inside the locomotive, an area where chnaces of survival are greater. On cab cars they can run inside the passenger compartment. So if you ever see an engineer running from the cab and through the passenger area, you'd be well advised to run with him.

Similar to if you see a Pilot come out of the Cockpit with a Parachute you're in a heap of trouble!

Pretty humorous. Makes me wonder if that has ever happened since the 1930s when commercial airline travel started off. We know that the captain of the Costa Concordia left his ship with passengers still on board. But a airline captain parachuting from a crashing plane?

 

[Swadian Hardcore]

Does anything on trains give the engineer a better chance than passengers of escaping injury or death?

Often, when a crash is imminent, engineers can jump out of the train, or can leave their cab and seek refuge inside the locomotive, an area where chnaces of survival are greater. On cab cars they can run inside the passenger compartment. So if you ever see an engineer running from the cab and through the passenger area, you'd be well advised to run with him.

Like at the 1988 Paris train collision? When the brakes failed on a commuter train and the engineer ran back to the last car with all his passengers before the train smahed into another commuter train pakred in the station.

 

[RRUserious]

I guess when all you can do is save your life, it seems pretty sensible to do that.

 

[John Bredin]

Yes, but have the courtesy to do your best Gandalf or Dr. Who imitation and yell RUN!!! as you run for your own life.

 

[RRUserious]

Or "follow me as fast as you can move!!!"