I'm old enough to remember The Supremes and I'm old enough to remember when The Supremes were still The Supremes and I'm old enough to remember when they sang:
"I remember mama said, You can't hurry love."
I took it to heart, but not to mind. It was Motown, the Sound of Young America.. It had the beat, you could dance to it, but live by it? I was in a hurry about everything.
The Supremes, or rather Holland-Dozier-Holland, were wrong. You can hurry love. What you can't hurry in this life is the National Transportation Safety Board (NTSB). Apparently.
Thursday, March 10, Caltrain train #506 overtook and collided with HRC XXX +2 (three pieces of on-track equipment) on the track at San Bruno, California. For those of you not familiar with, or too old to remember, San Bruno is right next to San Francisco International Airport.
There were injuries to the train's passengers and those riding the on-track equipment.
NTSB dispatched an investigative team, including the board's vice-chairman Bruce Landsberg who was quick to report that the PTC system and the PTC on-board equipment was functioning at the time of the accident, which seemed to add an element of mystery to the accident. Isn't PTC supposed to prevent this? Yes. Does it prevent this automatically, without human activation, and even against human failure?
No, no, and no.
Years ago, most railroads subject to the PTC installation requirement, decided that it would be--what? easier, more feasible, better??-- to install PTC as a system overlaying, and thus dependent upon, the legacy systems-- track circuits, manual block, track warrants-- that register occupancy and thus authorize or restrict following and opposing movements. PTC, in most cases, is not configured as a vital system, which is field resident as opposed to office resident. That means PTC does not on its own register track occupancy and thereby automatically allow or prevent train movements.
Yes, some PTC systems use GPS to provide the train with location information, but that is self-location for the train, and is not shared with other trains PTC systems. Besides, location is not occupancy. Location is information. Occupancy is a matter of life and death, hence vitality.
So... with that understanding, the underlying cause of this accident should be easy to determine. Since on-track maintenance equipment, unlike locomotives and train cars, cannot be relied upon to trigger the underlying system for registering occupancy (don't shunt, won't shunt, might not shunt), all railroads prohibit the movement of trains into a block of track occupied by such equipment. Reciprocally, in order to safely move such equipment, the train dispatcher must give permission, but only after
"blocking the signals," locking in the stop indication for both following and opposing movments. Thus the critical paths for this accident, absent a catastrophic failure of the vital signal system, are quite few and all involve human error.
Either the on-track maintenance equipment occupied the track without the train dispatcher's permission; or the employee-in-charge of the on-track equipment provided inaccurate information as to location, track, and time the equipment wanted to use the track; or the equipment was authorized to use an out of service track, but improperly obstructed (fouled) the adjacent in-service track; or the employee in charge improperly reported all the equipment "clear" of the track before the equipment was actually clear; or the train dispatcher forgot to properly block the signals; or the train dispatcher improperly removed the signal blocks; or there was a miscommunication about the status of the on-track maintenance equipment when one train dispatcher relieved the other of his/her duties.
In the course of my career on railroads, all these things have happened. It's always horrible.
And in every case, it is almost immediately evident where the error resides; what caused the accident; how it happened; who screwed up. Almost immediately, almost always, regardless of the type of legacy system used to register occupancy: ABS, TCS, ACS,TWC, DTC, MBS. Always different, always the same, always immediately. This, after all, is a vital failure of the railroad's commitment to safe train operations and if the cause is not immediately determined, train operations should be suspended until such cause is determined.
Which makes it more than a little odd that vice-chairman Landsberg states at about the 4:40 mark of his press-briefing, that it will be between fifteen and eighteen months before NTSB issues its final report. I presume this means it will take that long for NTSB to determine the primary cause of the accident.
Now there isn't a railroad in the country, and in the world I hope, that would allow its own investigating team to take 15-18 months to determine a cause, take remedial action, and revise or modify procedures that may be vulnerable to the errors that triggered this accident. There shouldn't be a railroad that would allow its investigating team more than 24 hours. We are dealing with the vital systems of the railroad-- the methods for authorizing and restricting authorizations for train movements.
So the NTSB has to provide a more rapid identification, evaluation, and reporting on the vital systems that may be involved in each specific accident.
That's one.
For two, several years ago, following the release of the NTSB report into the collision of an Amtrak train with MOW equipment at Chester, Pa., Steve Ditmeyer, who nursed the ARES positive train control system into operational status on the then BN railroad some 35 years ago, recommended that all MOW on-track equipment be fitted with GPS receivers. Then that location information could be integrated with existing train control systems to provide an occupancy indication of that equiipment when on or about the track, thus making it "visible" to the dispatcher.
Of course this would mean establishing that the reliability and accuracy of GPS information meet the safety-critical standards for a vital input to railroad operations, but the potential rate of error for using GPS identification of on-track maintenance equipment has to be less than the actual rate of error we suffer with now.
The funny thing, or not so funny, thing is, railroad have already equipped their on-track (and off-track) maintenance equipment with GPS locators, probably to track the time spent at Dunkin' Donuts. Definitely not so funny.
David Schanoes
March 13, 2022
NAME THAT TUNE
There's a rumor going aroud
Says you're gonna split
They say you're going away
It's a midnight blitz
But there's only good in leaving
With a suitcase full of load
Cause where's all the good times
With a pocket full of IOUs
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