A Hypothetical on an Improperly Set Crossover Switch

[Anonymous]

Let's say for this hypothetical we have a double track mainline with
a crossover switch at the point from where we are viewing this. A
freight train is travelling westbound on "track 1". The switch here
is set on "track 1" for a crossover, but the second switch is still
set in straight "track 2" mode. What would happen? I know that
modern computer technology would most likely never allow this to
happen, but let's say there was this glitch. Would the flanges upon
entry press the 2nd switch into the correct position as a last
second emergency safety measure, or would there be a derailment?

[Anonymous]

At slow speed there is a good chance the wheels would pu***he switch point into position and let the train pass through with the connecting rod being bent. That is essentially how a spring switch works. At high speed the train could derail.

Larry

[railman]

seconding cnwrwyman's remarks here...

at slow speeds, like on a model railroad, the weight would more than likely pu***he switch. Faster, and there could be trouble.

[BR60103]

Chessking: modern computer technology does not enter into it. The are large parts of railway that aren't wired. The CN line from London to Windsor, Ont. is "dark territory". A few years ago a track crew left a crossover set for the crossing (both switches, I think) and a Passenger train came along, went through the crossover and derailed into a string of cars standing on a third track. The crew's last act was to radio a warning to another train that was appoaching from the other direction.

[CliqueofOne]

In the spring of 1999 at Thamesville, Ontario, Canada there was such a switch that was in the wrong position. This unfortunately resulted in the deaths of two railway employees. This could have been worse. Much worse. The train that derailed was an eastbound Via. On the other track was a westbound Via. One of my coworkers was on that westbound Via that stopped in time. In 2000 I was involved on the CTC project on this section of dark territory. I stood at the former switch location. Seen where the former back track was. I saw the wreaths. I saw debris that was still there a year later. I know a few of the employees mentioned. It is something I'll never forget.

Some sites with a little info;
http://danger-ahead.railfan.net/reports/rep99/thamesville_02.html
http://www.tc.gc.ca/mediaroom/releases/nat/1999/99_h037e.htm
http://www.tsb.gc.ca/en/media/communiques/rail/2001/comm_r99h0007.asp
http://www.transport2000.ca/Hotlines/hl010407.htm


This is the site worth looking at;
http://www.tsb.gc.ca/en/reports/rail/1999/r99h0007/r99h0007.asp

Signal Mechanic. Signal Department. Canadian National Railways.

[Anonymous]

QUOTE: Originally posted by BR60103

Chessking: modern computer technology does not enter into it. The are large parts of railway that aren't wired.

My apologies here. I forgot to mention in this hypo that the switches were "automatic", not "manual".

[Anonymous]

QUOTE: Originally posted by railman

[#welcome]welcome to the forums, chessking. May your hours in the forum be fun and enjoyable!

Thanks for the warm welcome [:)] This forum is going to be fun and informative. I'm more likely going to be the question rather than answer, because I don't have a tremendous amount of railroad knowledge ... and if I don't have an answer, I will not BS my way through the thread.

[Anonymous]

My bad with the railroad terminology.

Yes M.W. , very right on. But in the thread's origin, it was stated, "a glitch". Now however unlikely this is to occur is irrelevant so long as the condition is or has been an existing possibility.

What would happen to the switch itself, not the signaling.

Thanks.

[Anonymous]

Actually, thanks for pointing out what you say some consider trivial:

You Wrote:

"By the way, "double track" means current-of-traffic running, either dark or ABS signaled, one-way only, e.g., northward on one track and southward on the other. "Two main track" means that it is CTC, either way on either track, both tracks signaled in both directions. It may seem like a trivial distinction, but it is not. It's a piece of nomenclature that has strict meaning in railroads and among railroaders."

I didn't know this, and I've been rambling on for years saying "double track mainline" for the CSX line passing through Rochester. So it's "two main track".

Everyone can learn something from anyone!

[Hugh Jampton]

What will happen mainly depends on 3 things, the speed of the hypothetical train compared to the speed of the hypothetical switches, the hypothetical axle load and the amount of hypothetical wear of both the switch blade and the leading wheel on that side.

If the train is going faster than the switches permit it will probably derail at the first switch in the crossover, before it even gets to the improperly lined switch.

If the tain has a heavy locomotive at the front then it will run through the switch, breaking (or bending) the operating rod or breaking the switch machine (or forcing it off its mounting). In this case the train doesn't derail because the switch blade is forced into the trailing position. If it is a lighweight train then there is a danger that the flange will climb over the switch blade and derail the train. (I'd use Nadal's formula to asses the risk of this happening)

If the switch blade is worn then there is a chance that it will cut into the flange of the wheel causing the train to derail (we call this a Farringdon edge after a derailment that happened some years ago), or if the wheel is worn then there is a chance that the cotact angle between the flange and the switch blade is so low that the wheel can ride up over the switch blade. (again, I'd use Nadal to check this out)

[Junctionfan]

My grandmother was on a train from Toronto on RDCs when CN was still doing passenger service and they departed only to here BANG BANG. All of a sudden the conductor gets off and checks the tracks while the engineer radios dispatch to ask him if he aligned the switches right.

[Randy Stahl]

Sounds like one power switch is going to get run through, if there is no derailment alot of expensive machinery is gonna get busted up. I'd hate to be the engineer who passed a red signal and ran through the switch. I've seen train slack run in and shove a train through a power switch , I recall the engineer getting fired .
Randy

[jchnhtfd]

running through a switch set against you is going to damage the switch (not true on a model railroad, but this is the real world and things are very different!). What you hope is that the damage will be enough to keep the signals from clearing in lighted territory, or to be visible in dark territory. Otherwise, the next guy through in the facing direction is going on the ground, and will likely be annoyed. Or worse.

That's the very least that can happen in our hypothetical situation. The worst is an accident like the one CliqueofOne was talking about.

[mudchicken]

A run-through switch, damaged switch(*) componets and an angry PO'd roadmaster....

(*) any combination of Bent throw rods, bent transit clips, broken switch stand (unless it was a variable switch in a yard), broken $12,000 CTC switch machine, bent or warped points, ruined OTM, an unhappy DS or yardmaster that can't run trains and so on....

How fast are we going?

In terminals, this is a fairly common occurance on any railroad and is as much a people issue (i.e. brain-failure) as it is a technical issue.

[adrianspeeder]

Sounds like some shady underhandidness would be needed. What would be a good bribe for a section forman?

Adrianspeeder

[edblysard]

Chessking...
From a yard snake...
Odds are you couldnt run through the switch, in the situtation you described..
See Mr Hemphills remarks...unless the crew is wanting to get killed or fired, it dosnt happen.

Should note the GCOR has a rule than, if you line one end of a crossover, you must line to other end for the through movement.

So if you line one end for the normal movement, you have to line the other end for normal movement before you foul the end you just lined.

If you line one end for the reverse....you get the point.

Some older yards have what we refer to a flop over switches, or safety switches, which have a clutch inside, that allows them to be run through.

You shouldnt do that, but it does happen.

There are V switches, or variable switches, which are specificly designed to be run through in the trailing point movement, and do line themselves with the pressure of the wheel flanges.

Then there are spring switches, designed to be run through in the trailing point move, but line themselves back to the normal( straight) movement position after each wheel set passed through.

If you are the unlucky crew that splits a power switch, odds are the clutch inside will allow it to move into the trailing point move, but a lot depends on what splits the switch...a locomotive has enough mass and weight to force the points into the correct position, but say a cab car, well, that might get on the ground.

As for the wording on double track and main...the word main, when used by the dispatcher when he or she gives me permission to occupy the main, provides me not only authority to occupy, but also provides a measure of protection, in that the dispatcher directs the direction of traffic, so I can move out on the main knowing that opposing traffic is not a big concern.
On the other hand, if I am given permission to occupy a track, as in "Port Job 152 has authority to occupy west track 101 for a eastward movement between mp 2.2 and 3.7, then I know that I may encounter opposing traffic, outside the limits of the authority the dispatcher has given me.
Which is exactally why the dispatcher has given me limits I can work within, between the two mile post.
On occasion, the limits may overlap other train limits, but....the dispatcher will inform all crews of this, and adivise you work under GCOR rule 6.28, restricted speed.

When its a main, I can only go in the direction the dispatcher allows, on tracks, I can go where I want within the limits given.

And, it can get even more complicated than that, which is why you are required to repeat the dispatchers instruction back, correctly, so no one misses or fails to understand the instructions.
Down here, you get three trys at repeating it, then your out(as in out of service).


Ed[:D]

[espeefoamer]

There was an accident on the SP in 1973 that relates to this.It was in El Monte,CA. An eastbound train was in a siding waiting for a westbound .Maintainers had been working on the signals a few days earlier, and the signals had been wired wrong.The westbound signal showed a clear on the main,but the switch was actually lined for the siding.The westbound train went into the siding at 60 mph.The eastbound crew jumprd out in time, but the westbound crew never had a chance[:(].Your hypothetical situation could happen but it would require a miswired signal,and would be very very rare.

[Anonymous]

Ed,

I don't know if I would have made it on your RR. You should have heard me repeat dispatcher orders the first few times! I cringed when I heard that restrained sigh on the other side of the radio knowing the dispatcher was about ready to scream, but it finally clicked just like everything else you do after the first couple of times. [:D]

[edblysard]

Amazing, aint it?

And I am mean...when we have to deal with TD3, Spring terminal dispatcher, I often make the rookie on the crew repeat it back.

Not to be really mean, but to show them that they can do it.

They usually screw the pooch the first time, and if they vaopr lock, I do it for them, under my name..but so far, none of my rookies have messed up more than twice.

Because we are working in such a crowded area, there can be no goofs on the fact that both crew and dispatcher have a complete understanding of who is where, doing what.
Ed

[CliqueofOne]

Here is another switch story that happened at Hinton, Alberta, Canada on February 8, 1986. A westbound freight went past a red signal, through a switch and onto single track where it had a cornfield meet with an eastbound passenger. Many lives were lost and the outcome from the investigation forever changed the climate on Canadian railways.
Signal Mechanic. Signal Department. Canadian National Railways.

http://arbitrations.netfirms.com/croa/20/CR1677.html
http://archiver.rootsweb.com/th/read/CANADIAN-TRAIN-DISASTERS/2002-06/1024771593

[MP57313]

QUOTE: Originally posted by espeefoamer
Your hypothetical situation could happen but it would require a miswired signal,and would be very very rare.

Miswired signal also caused a freight train collision on ATSF in the late 80s (Pico Rivera), but I don't recall if a crossover was involved. Don't recall the fate of the crews; trackside buildings were destroyed by fire and never replaced.

[mudchicken]

Pico Rivera was not a crossover. CTC signal guarding entry into east end of yard (at the yard tower) and nearby Rosemead Ave were involved. Train standing on the main line and finishing the process of setting cars out was rear-ended by another heading to LA Hobart after a false clear indication.[:(][:(][:(]

[Anonymous]

Recently here in Portland, down at the docks, a longshoreman lined a switch with an SW unit parked over the points! When the engineer backed, one truck went straight, the other took the siding! By the time the engineer stopped, everything was ripped out. DOH!!!!!!

[Anonymous]

Run through switches are one of the most common man-failure incidents that occur in railroading.....the sin of the run through switch then gets compounded when the crew that ran through the switch then reverses their movement and derails several cars on the run through switch. Railroading 101.

[retsignalmtr]

as a former signal maintainer on the nycta i have worked on about 100 runthroughs of switches that have switch machines that are interlocked with the signals and all of them were caused by the train operator running a red signal. usually the only damage is bent operating rods which are about 1 1/4" thick. sometimes the throw bars or locking bars in the machines will also bend or break off. i have seen several where the train operator backed up thinking no one would find out but ended up derailing. there are many things that are checked by relays and other equipment before a signal will be allowed to clear for a route. false clears have been caused by relays that jam in the energized position but the most important relays have a checking feature that if they don't return to their resting position the route cannot be established again. misswirings are not common but they may happen although several employees are required to double check the work before the signals are placed back in service. the signal maintainers i worked with took their job seriously knowing that any accident that could take lives would be punished by jail time (criminally neglegent homicide).

[Puckdropper]

QUOTE:
Recently here in Portland, down at the docks, a longshoreman lined a switch with an SW unit parked over the points! When the engineer backed, one truck went straight, the other took the siding! By the time the engineer stopped, everything was ripped out. DOH!!!!!!

I've seen that happen on my model railroad before. By the time you realize it and stop, the car/locomotive has derailed. Sometimes our models are really good at imitating their prototype. :-)