HV under Railroad Tracks

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Chris_Goheen

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I'm working on running a 12470V line around to a new substation. I need to cross underneath some railroad tracks and I'm trying to find out how deep I need to be before I bore under the tracks. I am running sheilded wire in rigid pipe. My company owns the tracks, but I can't seem to find any specs on this. I was figuring on using the 300.50 table and going with the under roadway catagory. Can anyone tell me what this should be?

Thanks,
Chris
 
Private RR

Private RR

If your company must comply with NEC, then it looks like Table 300.50 applies. The large RR have detailed specs and often require 8' or more of cover. Also, it is POCOs who ususally deal with this and the NESC applies, not NEC. NESC 320 says that 50" cover is needed.
 
T300.5 is limited to 600v or LESS.

When I worked for a RR in the 80's, we ran 480v under the tracks at a minimum of 3'.

NESC might be the standard to investigate.
 
The depth below the track is set by the owner ot the tracks, not as an electrical issue but as a disturbance of the soil issue. I work with a Class A RR and they require anywhere from 5' to 8' depending on the amount and size of the rr traffic. A rigid sleeve is also required. Just stand near a fully loaded train as it is moving and observe the ground movement below individual ties. A soil disturbance below a tie will eventually cause a derailment.

Fred Bender
 
cowboyjwc said:
I don't know much about RR, but I don't think that 300.5 would be strict enough. A car weighs a whole lot less than a train.
Click to expand...
Forgetting the fact this is RR, T300.5 simply does not apply:

Chris_Goheen said:
I'm working on running a 12470V line
Click to expand...
T300.5 is for 600v and LESS.



One MUST consider the track bed....every once in awhile...the track leveling crew will show up with all their bizarre tools of the trade ~ tampers in particular.
016090.jpg

wrm_ballast_tamper.jpg


This monstrosity has some claws that actually drive down below the ballast (the rocks tracks are typically laid on), then GRIP the tie, then begin SHAKING THE LIFE OUT OF IT...to compact the ballast beneath to provide a sturdy bed for the tracks to lie on.

This is NOT a T300.5 enviroment by any stretch of the imagination....even below 600v....we are talking 12.5kV here...with TONS of moving stock riding above it.

The NEC is not the answer for this installation.
 
I did a crossing once where we had a steel sleeve jacked under the tracks. GRC and cable was placed in the sleeve and the voids of the sleeve were pressure grouted. Same voltage- 12470. The pipe was more than eight feet below grade but I can't remember how much. RR was a royal PIA to work with.
 
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