Good safety system, Vance thought. He could feel them now, beneath the
explosive--electronic sensors on the tracks, a thin line of parallel
wires held by insulators, had detected his tampering and halted the
gantry.
Wait a minute, he suddenly thought, maybe I don't have to blow the
track after all. Why not just short-circuit these wires and let the
thing's own safety system shut it down? They may not figure out for
hours what the problem is.
With a grin he began going along the track, feeling his way through the
dark as he twisted the parallel safety tripwires together every few
feet, making certain they shorted.