This phrase is reputed to have been heard on the railway radio over a scanner.  I think I know what it means!

Before the days of radio, crews had to use hand signals to give movement instructions to the locomotive.  When I first came to Canada I was struck by the difference between British and Canadian practice. 

In Britain the hand signal was given in relation to the person giving the signal.  There were two signals, one for “Come towards the signaler” and another for “Go away from the signaler.”  This meant that when a movement was passing the signaler the hand signal had to be changed.

In Canada there are also two signals but they are made in relation to the locomotive. “Move forwards/go ahead,” and “Move backwards/back up.” In Canada, the one hand signal is used throughout the movement regardless of where the signaler is in relation to the locomotive.  This does lead to a slight complication in that the signaler must know which is the front and which is the back of the locomotive.  This is normally pretty evident, especially today, but in early diesel days many locomotives were set up to run long hood forward so the front might not have been so evident.  This is one of the reasons why many locomotives have an “F” on the frame at the front of the locomotive.

The Thurso and Nation Valley Railway had an additional complication.  Their road locomotives were all GE 70 tonners which were setup to run long hood forward.  The TNVR wanted to improve visibility for locomotive crews but would not go to the expense of changing over the control stands to make it easy for the engineer.  The standard procedure was for all TNVR trains to be run with the lead locomotive running backwards.  However, the crews made a rigid distinction about which was the front and which was the back of the locomotive.  Thus if a train was ready to leave you would hear the instruction “Back up (reculez)” which was the instruction to leave (i.e go ahead). 

This took a bit of getting used to and the TNVR was one of the few railways where “Go ahead and back up” really did mean something.