Lineman

Tom is a defensive lineman.

Tom is an offensive lineman.

In the event of a failure, by the operation of a switch signalmen at the panel boxes can set up flashing white lights on certain signalling apparatus cases spaced at approximately half-mile intervals alongside the line, in order to call the lineman. The lineman can communicate with the signalman by plugging in a hand telephone at any one of these points.

[…]or even, daring, spent the night up some pole in a lineman's tent like caterpillars, swung among a web of telephone wires, living in the very copper rigging and secular miracle of communication, untroubled by the dumb voltages flickering their miles, the night long, in the thousands of unheard messages.