SWITCHING PUZZLE
SOLUTION

Two trains travelling in opposite directions on a single track line reach a passing siding. The problem is that both trains are too long to fit on the siding. How do you get the two trains to pass each other? A move is any coupling/uncoupling of cars and any reversal of train direction.


1. The blue train leaves the rear part on the main and proceeds into the siding

2. The red train passes the blue on the main and couples to the part of the blue left on the main.

3.The blue train continues off the siding and in the clear for the red train to follow.

4. Red train pulls the part of blue to the main between the switches

5. Red drops the blue part on the main

6. Red uses the siding to go around the blue part and continues on it's way while the Blue backs into the back part of it's cars.

7. Blue continues on its way



Animation


2009 by Joseph D. Korman