signalman

noun3

1. •
   Somebody employed to operate the signals and points of a railway.

   • With extra traffic, numerous boat trains to and from Southampton Docks, and working of empty stock, his job, like that of most signalmen, is no sinecure. — 1954
2. •
   A member of the armed forces responsible for signalling.
3. •
   Somebody employed to direct rigging or crane operations by providing a different point of view.