Western Railroad Discussion > Lightning or live power lines on a locomotive

I am curious as to the isolation of a locomotives cab occupants in the event a locomotive was struck by lightning or had live power lines upon the cab. I know the cab has a bunch of electricals but how are or are the cabs isolated from these threats. Cars have the rubber on the road and planes aren't grounded by virtue of being in the air. Locomotives are pretty hefty hunks of steel on top of steel wheels and steel rails. Just wondering cause I don't know.



Edited 1 time(s). Last edit at 11/26/24 05:59 by jdtravis.

I've always heard that the safest place you could be during an  electrical storm is inside a steel box that's sitting on the ground.  That pretty much describes a locomotive doesn't  it?

OTOH, you don't  want to be on top filling the sandboxes!  (Or, back in the day, on top of a boxcar passing signals or tying a handbrake.)

-LD

Edit:  Oh, and for live power lines:  climb down the ladder or stairway and jump, not step, to the ground.  Don't  step on a rail either.



Edited 2 time(s). Last edit at 11/26/24 06:52 by LarryDoyle.

A friend of mine who is an electrical engineer wrote a short piece for TRAINS around the turn of the century about this.  I don't recall the exact issue but maybe a search of the TRIANS archives will turn up the piece by Ed Larsen.  

Nick Tharalson,
Marion, IA

Locomotives, as other industerial equipment (electric fork lifts, etc) have a ground loop wire. An aoutmobile uses the car body as a ground.

A big Faraday cage I would assume. 

What about being on a train car? I understand the cab is pretty safe. But let's say the conductor is riding a shove, and the train gets struck by lightning? 

I under stand locomotive cabs are isolated from the rest of the body and you are generally safe in it.   But, if you try to get off while electricty is in contact you run the risk of making a "ground" and maybe being electrocuted.

In 1975 Southern Railway did static lightning tests on certain freight cars, particularly our then new "Autoguard" articulated auto racks.  They utilized my local to perform the tests.  I ran the cars up on wrestling mats under high tension transmission lines coming from a power plant.  One of our chief test engineers monitored the static lightning strikes.  At one point they wanted to test my engine GP38-2 5038.  After I ran the 5038 up on the wrestling mats, the test engineer told me to keep my feet on the fibreboard floor and not touch anything metal while testing.  The engine was struck, I was not affected, and the testing went well.  Several years later I was struck by regular lighting during a severe thunderstorm.  My crew crew had stopped work and were seated with me on our relatively new tall cab MP15 switcher.  I gave them the same instruction the test engineer gave me. We were struck by lightening, possibly from a bounce strike from and adjacent metal building that we were trying to deliver to.  It was scary but only the engine died.  Some of the breakers in the electrical cabinet were tripped.  After the storm passed, I was able to recrank the MP15.

The scariest lightning strikes I endured were not as engineer but as an officer humpmaster in our tallest yard tower (six stories and over seven stories tall counting the radio tower.  I went through about three strikes that not only killed the power and radio for a time, but also sent blue electrical fire through my large control desk.

Years ago on the CNW a train was stopped and lightning struck the lead engine. The crew said blue electric balls raced around the windshield a few times then shot out into the ditch. Both the lead and second engines stopped running and wouldn't restart, they said it smelled like an electrical fire in both engines. The crew was not injured at all but said it was pretty exciting!

Eons ago when I was a Conductor....we were going east in a magnificent electrical storm....we had a dash 8 in the lead....the first strike got bells to ringing...and the second strike shut the engine down and more bells ringing...we stopped and were able to get restarted...when we got to the away terminal I looked up on the roof.....a big patch of paint was missing, replaced by a sooty spot. I can't say my hair stood on end, but it's possible it did. 

I was westbound at Matfield Green, KS long ago, our lead unit and SD40-2 got struck in the cab area. We saw a bright flash, but not much of a boom, and the lead unit instantly died. When we ran out of the rain, I went back to get it started, but it wouldn't crank, that's when we noticed smoldering smoke coming out of the air cleaners, which were right behind the cab.

I ran over a big power line just out of the plant at 40mph. I survived by lifting my feet....

tomstp Wrote:
-------------------------------------------------------
> I under stand locomotive cabs are isolated from
> the rest of the body and you are generally safe in
> it.  

No. Only those SD70MAC units that had "Isolated Cabs" were built that way.


But, if you try to get off while
> electricty is in contact you run the risk of
> making a "ground" and maybe being electrocuted.

Don't think so.

Not that many years ago, lightning struck a GP60 on the Santa Fe. The entire computer/modular mother boards were totally destroyed. The crew was not hurt. 

HotWater Wrote:
-------------------------------------------------------
> tomstp Wrote:
> --------------------------------------------------
> -----
> > I under stand locomotive cabs are isolated from
> > the rest of the body and you are generally safe
> in
> > it.  
>
> No. Only those SD70MAC units that had "Isolated
> Cabs" were built that way.
>
>
> But, if you try to get off while
> > electricty is in contact you run the risk of
> > making a "ground" and maybe being electrocuted.
>
> Don't think so.
>

Yes think so.  You have to just jump farther then the arc distance of the voltage that has energised locomotive or vehicle you're in.
For something like a 3300 volt line that's about four feet.
Don't believe me, go look up safe approach distances for high voltage.  AT&T was very big on this, it's why we carried those 4' x 4' rubber blankets in the bucket of our tower trucks.
If the truck becomes energised you throw the blanket out the required distance and then you jump from the vehicle to the blanket.
The object being to not complete the path to ground while you're still within the safe approach distance. More then a few Telco and Power Co people have died because of this.


> Not that many years ago, lightning struck a GP60
> on the Santa Fe. The entire computer/modular
> mother boards were totally destroyed. The crew was
> not hurt.