Whoa!
I too hope everyone is OK, but I am real concerned for the engineers of both trains.
This day and age, how do 2 freight trains get dispatched so they can have a head-on collision?
According to the first article (I think it was that one), a similar accident happened in 2013 and they said it was because a switch wasn't set properly by the conductor.
I don't see how that's possible... Almost all switches these days are controlled by the Dispatcher in whatever city they are in. At NS the dispatchers are located in the city the division is named after.. e.g. Harrisburg Division is in Harrisburg, Pittsburgh Division in Pittsburgh, Dearborn Division in Dearborn. Some I'm not sure of though. Such as the Lake Division.
Their are quite a few hand thrown switches still.. The person who throws the switches is in charge of reporting them "Lined and Locked Normal".. At NS we are instructed by the Engineer to "Double Check the Switches and any Derails". Then the dispatcher will get his or her railroad.
I kinda figured human error as the most likely cause.
While it's not set in stone yet. I would guess this.
Does anyone know if the signals are bi-directional?
Both tracks are bidirectionally signaled CTC according to postings from a guy who used to be a dispatcher in that division (on trainorders).
Jishnu I don't believe much on TO.com.. This is one. Simply cause you can be a Dispatcher in one division but only be qualified to work 1 desk out of say 8. Unless he was an Assistant Chief or Chief Dispatcher... Then ya gotta know all you're division!
Bi-Directional signaling is more commonly known as "261" referring to Rule 261 of many rule books which states train can run in both directions on that track.. One Direction (No not the boy band) Is known as (251 N,S,E,W) Signaled in one direction North, South, East, or West. Or there is "271" signaled both directions BUT you need a Track Authority or Track Warrant for your Movement. One more to throw in there.. "171" Dark Territory... No signals govern movement. Movement is governed by Track Authority only.
I'm way ignorant of signalling standards. Is it possible for each train to enter a block at the same time, so neither would have a red indicator? Even so, wouldn't both trains have yellow indicators? In other words, if both trains were at speed, wouldn't there need to be human error on both ends?
Doesn't the dispatcher have a display where he or she can see indications of train movements? In other words, shouldn't the dispatcher have a visual indication of two trains approaching each other on the same track? (This is not the same thing as necessarily having time to react, depending on when the second train entered the track.)
Yes. Such train would receive a "Restricting Signal". At NS a restricting signal is either of the following governed by at least NORAC signals.. A signal that is Red with a NUMBER PLATE, red over steady yellow, or on a Dwarf signal steady yellow. These signals can NOT be received at an Interlocking with the EXCEPTION of Red over yellow. Should a dwarf signal be in place the steady yellow will rule.
I'm way ignorant of signalling standards. Is it possible for each train to enter a block at the same time, so neither would have a red indicator? Even so, wouldn't both trains have yellow indicators? In other words, if both trains were at speed, wouldn't there need to be human error on both ends?
Doesn't the dispatcher have a display where he or she can see indications of train movements? In other words, shouldn't the dispatcher have a visual indication of two trains approaching each other on the same track? (This is not the same thing as necessarily having time to react, depending on when the second train entered the track.)
no, because a signal does not automatically turn green when the track is unoccupied.
It additionally requires the positive approval of a scheduler who sets a path.
If the block is green at both ends, this would imply there are two paths into that block simultaneously and the interlocking should prevent that.
While it doesn't turn green some will go up to Approach then Clear. If the signal is an "automatic", non interlocking signal, it may just go dark. In which case it will use "approach lighting". Meaning the signal will display the proper indication when the train enters the block and once the train has passed will go dark again. Some interlocking use this. I know of one that does and one that did. Most interlocking are consistently lit.
But generally yes the dispatcher will have to have a train lined up to such a point.
What do you expect from the news agencies.
