That's a fucking rough way to make a living. hoozah is right - you need safety and materials credentials before they'll even look at you, since on those kinds of jobs you're a danger to everybody and not just yourself. If you're serious, look at mining first. The pay's not as good unless you wind up in bumfuck nowhere, but the work's generally safer and there's a lower barrier to entry.
11/19/12 at 7:00pm