I would imagine it goes like this:
A-------------------B
\ /
\ /
\ /
\____C___/
|
|
|
D
Train starts at A (and I didn't feel like trying to ascii draw that whole dang triangle).
Train unhooks the back of the car that it wants to swap positions with.
Train pulls the string of cars past C, then backs into D. At this point it can disconnect the car that it wants to change position of.
Pull back out towards B until all cars are back on track between C and B.
Train then backs back up to A and reconnects all the other cars that were behind the car it wanted to move.
If the train wants to insert the car somewhere into its lineup, it simply disconnects the rear of the car that it wants to use at the insertion point.
Train then goes past C and backs up to D, connecting the unhooked car into its new position.
Train now pulls back up towards B, and then backs back to A, connecting to the rest of the row of cars left behind.
Repeat until cars are in the order that the train needs to be in.
A-------------------B
\ /
\ /
\ /
\____C___/
|
|
|
D
Train starts at A (and I didn't feel like trying to ascii draw that whole dang triangle).
Train unhooks the back of the car that it wants to swap positions with.
Train pulls the string of cars past C, then backs into D. At this point it can disconnect the car that it wants to change position of.
Pull back out towards B until all cars are back on track between C and B.
Train then backs back up to A and reconnects all the other cars that were behind the car it wanted to move.
If the train wants to insert the car somewhere into its lineup, it simply disconnects the rear of the car that it wants to use at the insertion point.
Train then goes past C and backs up to D, connecting the unhooked car into its new position.
Train now pulls back up towards B, and then backs back to A, connecting to the rest of the row of cars left behind.
Repeat until cars are in the order that the train needs to be in.