Train Nystagmus

[Anonymous]

QUOTE: Originally posted by CopCarSS

I thought Nystagmus was the guy that predicted the BNSF merger 400 years ago.[:p]

Oohhh, good!!!! Here I though I was the only one that thought that!![:p]

[zardoz]

QUOTE: Originally posted by CShaveRR
We used to have a yard at 40th Street where the tracks were much closer together, and yes, it was hard to walk between these tracks, even in my skinnier days. The yard's no longer there, thankfully.

Carl,
Wasn' that yard a pain to work in? Incredibly dangerous to ride a cut of cars in, especially at night.

And on top of that, there was the local wildlfe to contend with....


And Ed is spot-on about the effect of standing between the moving cars on adjacent tracks. When I hired out, one of the things they emphasized was what to do when in that situation: Immediately sit of lay down where you were (much preferable to falling over).

[Anonymous]

There was a PBS special on railroading a while back that mentioned (and showed) this phenomenon of yard crews standing between two cuts of cars moving in opposite directions and getting disoriented, although I don't think they used the clinical term "nystagmus". I can't remember the name of the program (?), but if I remember correctly it had TRAINS mag backing.

Somwhat off topic, anyone remember the movie "Top Secret"? There was one brief shot that spoofed this phenomenon.

[edblysard]

Or how about busted banding on flat cars full of pipe...give you a haircut and a shave all at once!
Ed

[coborn35]

Most of the tracks I work with have enough clearance for me to get between two trains safely but watch out for guardrails on cars sticking out! OUCH!

[jeaton]

QUOTE: Originally posted by jeaton

Gates-Do you actually think any T&E crew members would know a nystagmus if they saw one? I thought they went extinct in the Jurrasic Era.
[:-^][:-^]

OK, My bad.

Jay

[Anonymous]

I believe that it also refers to the tendency of a loco, or car, to hunt from side to side on the tracks. Yard switchers, with no leading truck, tended to be bad for this at any higher speed. You can even see it on models. Watch a 0-4-0 going down the track. It will look like it is wobbling. It's almost bouncing back and forth between the rails.
It's caused by the tendency of the wheels, due to the tires being machined at an angle, to always try to center the wheels on the track. Four wheel locos, and trucks, can be very bad about doing this.

CShaveRR,
That drowsy feeling is vertigo. Airplane pilots are taught, when you fly single engine prop planes, when on final approach, especially into the sun, never let the engine idle for any period of time. Always blip the throttle occasionally to break up the pulse. It can cause vertigo, and eventually lead to unconsiousness.
My instructor told the story , when I was taking flying lessons, of a pilot that landed just fine, and rolled to a stop at the end of the runway. The tower couldn't raise him on the radio. A truck was sent out to the plane, and they found him unconsionus over the wheel.
Any steady pulse, especially if it is a light pulse, can cause it.

[selector]

Nystagmus is a symptom associated with a break in meaning between the vistibular system and the visual cortex. Essentially, it is the same phenomenon that one gets after spinning around several times. The fluid in the inner ear continues to swirl after you stop spinning, so your brain continues to tell the eyes to do their sweep in order to see well while spinning...which you have stopped doing. Accordingly, your eyes transmit a sweeping image that should not be there, and you eyes flicker from side to side in order to achieve that. The brain has been fooled. In train nystagmus, the opposite is true, althought the same mechanisms are involved. You watch a train go by by sweeping onto cars, then another, and then another, creating the impression that you are spinning. Similarly, the crew on a moving train will attempt to sweep their eyes to get a comfortable view of things being passed, and they get the same effect when they turn their gazes back to the stationary world of the cab. This is a precursor to motion sickness, and if you have never experienced it, consider yourselves fortunate indeed.

[jchnhtfd]

Ed's discussion of what happens to your eyes in yards is right on -- and shows up the problem and why it is a safety issue. You can wind up flat on your tush in the snow just by standing really near a train going by and watching it, even if it is relatively slow. I know. Been there, done that. It's fine if you fall away from the train; not so good if you fall towards it.

[espeefoamer]

If I stand in the last car of a train and look out the rear at the tracks,when the train stops at a station,it looks like the train is going backwards for the first few seconds.

[edblysard]

Gates...
Don’t have the actual true figure, Mudchicken will have it, but on a practical example, if I stand in-between to trains on adjacent track inside our yard, I can hold my arms out straight, and just brush each car with my finger tips.

Remember, space is expensive, and on the older yards, designed when cars were shorter length wise, curves and track spacing were kept sharp and narrow.

It is not too bad when we have to walk in-between and one of the cuts is standing still, while the other is moving, which we have to do when getting tracks together...but both at the same time can play tricks on your eyes and balance.

If you e-mail me at
[e-mail]
With a private e-mail address that I can send a photo to, I will send you one that show how close the tracks are in North Yard, where I work.

Ed

[CShaveRR]

Even in our antiquated yard, it's possible not only to walk between tracks, but to get far enough away from the equipment to be seen by the engineer trying to read your hand signals. What I don't recommend is pushing a bicycle along while trying to negotiate between two occupied tracks. I've done it, but only with the knowledge of the crews who might be moving one of them, and for no more than the five or so car-lengths I needed to get out of there! I've also had my bike between two tracks not quite that close to each other, with both trains in motion in opposing directions, much like Ed described. I just stopped, held on, and looked at the ground.

We used to have a yard at 40th Street where the tracks were much closer together, and yes, it was hard to walk between these tracks, even in my skinnier days. The yard's no longer there, thankfully.

[CShaveRR]

I've been where Ed's been.

I am made drowsy by motion and steady noises in the locomotive cab, especially if we're struggling hard and making very slow progress (typical of transfer runs). As much as I'd like to take a job like that (just a little while, for variety), I don't dare.

[Anonymous]

QUOTE: Originally posted by edblysard


when standing between two trains, moving in opposite direction at walking speed...ended up having to sit down between the tracks with my head down till one of the trains got past...really screwed up my balance for a few hours.

Ed

That even sounds dizzying...The article I was reading was specific to this condition being a factor in EMD's decision to stop making "end cab" design locomotives for high speed applications.

I guess one of the intentional aspects of the "bulldog" nose design was to block the engineers view of cross ties slipping under a fast moving loco, a phenomenon that was often experienced by engineers on the Burlington Zyphers, as well as some of the other "box cab" electrics...

Just because you brought it up, Even though I'm going off topic by asking, customarily, how much clearance is left between opposing freights on adjacent tracks? I would have thought "too little" for a person to safely walk between...but I guess that is wrong?

[edblysard]

I would hazard a guess that any adult with an active case would not make it past the pre employment physical.
As an acquired illness later, most folks have no idea they suffer from it, unless someone points it out.
From what I have read on it, the brain is quite capable of compensating for the rapid eye movement, and the objects the affected are seeing appear stationary, so unless they looked in a mirror when an attack happened…

The same basic symptoms can also be caused by fatigue, and aggravated by watching a train move past you...the rapid eye movement needed to check reporting marks against a list can, and does often cause it, but more common is vertigo.

That I have suffered, when standing between two trains, moving in opposite direction at walking speed...ended up having to sit down between the tracks with my head down till one of the trains got past...really screwed up my balance for a few hours.

Ed

[jeaton]

On the other hand, if you mean dozing off, you may not get any one currently in T&E service to own up.

[CopCarSS]

I thought Nystagmus was the guy that predicted the BNSF merger 400 years ago.[:p]

[vsmith]

It has more to do with being a symtom of MS

www.mult-sclerosis.org/nystagmus.html

Rapid eye movement from side to side in the horizontal plane, its a sign of MS and it only resembles the effect of looking out the window at passing telephone poles. this is for MS sufferers.

Found another source

www.genesishealth.com/micromedex/detaileddisease/00058730.aspx?style=po

the type your describing seems to be an involuntary reaction to rapidly re-occuring stimuli. I have seen video of this , a very little kid getting off a very fast spinning turntable in a city park, and there eyes are going side to side like this. but its only temporary. like a knee jerk reaction.

Nope never seen it on a train passenger. Cant say for crews.

[jeaton]

Gates-Do you actually think any T&E crew members would know a nystagmus if they saw one? I thought they went extinct in the Jurrasic Era.
[:-^][:-^]

[Anonymous]

I was reading today about a phenomenon known as 'train nystagmus' and was wondering if any of you actual road crew types have ever experianced this, either personally or in direct witness of somone else who has.