I think that you have to ask to the crane guy about the solution too, because he's the one who will work there and he want to work safe too (you could be amazed about the solutions he would give you). But you still have the last word.
Putting a "building" between the work area and the "spark"...
I dont know why he is asking for advice, he have it very clear but he is afraid of the decission he want to do.
Quit but before of that, you should find another job. thats all.
First of all it would be interesting to know why its not possible to turn off both side o railway (service, traffic, electrical reasons or just foolishness)
How many piles are you going to do? maybe doing the job at night while the rail service its closed or almost, would be the solution...