> In that area of the country, the ground freezes in winter, and digging becomes very difficult, which would make repairs that much more delayed and expensive.

> In that area of the country, the ground freezes in winter, and digging becomes very difficult, which would make repairs that much more delayed and expensive. Could underground lines be placed in tunnels large enough for repair crews to reach where they need to work by going through the tunnel? Well, I'm sure they could for runs that aren't too long, so perhaps the question should be over what distance is it economically and technically feasible to run underground lines in tunnels human accessible maintenance tunnels?