By MICHAEL BATES

What cargo awaits
  the train shunted
    into this kind of siding
      in the middle of the night?
A lone locomotive
  coupled with odd
    numbered cars
      chugs ahead.
Clear signals keep it on track,
  right from wrong
    seen as red or green.

The master in charge of the yard
  works long, late hours
    making haul choices.
Loading starts at whistle stop,
  ends in time
    for the likes of dawn.
On his darkest watch,
  no train can come
    and go, empty.