Telegraph (engine order)

An engine-order telegraph is the device that relays the propulsion-speed order from the bridge to the engine room or, on a modern ship, to the engine control system. The classic handle-and-dial instrument set bridge and engine-room pointers to matched positions (Dead Slow, Slow, Half, Full Ahead or Astern, Stop), and the engineer acknowledged by repeating the order on the reply telegraph. On bridge-controlled ships the telegraph is a console lever feeding the remote-control governor directly, with the engine logged in a movement recorder. It remains a bridge-to-machinery command and acknowledgment link, separate from the actual speed governor that executes the order.