LIONEL FT A A BACK TO BACK RUNNING

If you want full control of direction, swapping the motor leads is probably the way to go.  I'm assuming these are electronic reverse boards and not mechanical E-units.

Like John says, just swap the motor leads (if they're conventional boards)

F3 and FT frames are different. A and B unit frames are different.

Thank you all for the replies.  For now, this is how I am running.....

Lead A unit is "locked" in forward.

Trailing A unit is unlocked.

Units are coupled back to back.

On start up, I apply very low power on and off as the trailing unit goes through the F N R process. 

Since the units are coupled back to back, they tug against each other until the trailing unit goes into R.

When trailing unit is in R, then both units travel in the same direction.   For station stops, I throttle way down, but do not cut power completely so the trailing unit does not go into the F N R sequence.   The Polar Express train is for X Mas only and 100% of the time it runs continuously forward.   Backing up the passenger train is not of interest to me, so for now, with no modifications of either unit, this allows me to run back to back.

Best regards, and wishes for a great holiday season,

Lackman