technique – Two Trains, One Monitor

Two trains are heading in direction of one another on a monitor. One prepare is blue, the opposite is inexperienced. Every prepare has a locomotive hauling 9 wagons.

Every locomotive is 10 meters lengthy, and every wagon can also be 10 meters lengthy.

Between the trains, there’s a small space with a parallel 40 meters monitor accessible by way of switches. The tracks between the switches can subsequently accommodate 4 wagons, or one locomotive and three wagons, or two locomotives and two wagons.

One thing like this (B=Blue, G=Inexperienced, W=Wagon, L=Locomotive):

INITIAL SETUP
                                          /------------
--------BW-BW-BW-BW-BW-BW-BW-BW-BW-BL----<              >----GL-GW-GW-GW-GW-GW-GW-GW-GW-GW-------
                                          ------------/

Locomotives can haul (pull) and shove (push) different rail autos (i.e. wagons and/or the opposite locomotive), in each instructions. Rail autos might be hooked up and indifferent. For instance, one might detach the final 5 wagons, and let a locomotive solely haul 4 wagons.

The aim is to get the trains previous one another, with every locomotive hauling its unique 9 wagons (not essentially within the unique order for the wagons, however the locomotive needs to be on the entrance of the prepare):

THE GOAL
                                          /------------
------GL-GW-GW-GW-GW-GW-GW-GW-GW-GW------<              >----BW-BW-BW-BW-BW-BW-BW-BW-BW-BL-------
                                          ------------/

Connect and detach rail autos and make use of the 40 meters parallel monitor to attain this.

For instance, one might begin with the unique setup (that is simply to display some attainable actions, not the precise resolution):

INITIAL SETUP
                                          /------------
--------BW-BW-BW-BW-BW-BW-BW-BW-BW-BL----<              >----GL-GW-GW-GW-GW-GW-GW-GW-GW-GW-------
                                          ------------/

Then detach the third wagon from the inexperienced prepare and produce the inexperienced locomotive and its first two wagon on a monitor between the switches:

STEP 1
                                          /--GL-GW-GW--
--------BW-BW-BW-BW-BW-BW-BW-BW-BW-BL----<              >-------------GW-GW-GW-GW-GW-GW-GW-------
                                          ------------/

Then detach the final blue wagon and take the blue locomotive and its first eight wagons to the opposite facet, doubtlessly shoving the inexperienced wagons alongside:

STEP 2
                /--GL-GW-GW--
--------BW-----<              >------------BW-BW-BW-BW-BW-BW-BW-BW-BL-GW-GW-GW-GW-GW-GW-GW-------
                ------------/

Then detach the final wagon linked to the inexperienced locomotive and go away it on the facet monitor, whereas the inexperienced locomotive is transferring ahead, shoving the blue wagon:

STEP 3
                /--------GW--
---BW-GL-GW----<              >------------BW-BW-BW-BW-BW-BW-BW-BW-BL-GW-GW-GW-GW-GW-GW-GW-------
                ------------/

Then connect the inexperienced wagon to the blue locomotive and transfer the blue locomotive backwards, on the decrease monitor, and on to the opposite facet, and cease someplace:

STEP 4
                               /--------GW--
---BW-GL-GW-BW-BW-BW-BW-BW-BW-<              >-GW-GW-GW-GW-GW-GW-------
                               -BW-BW-BL-GW-/

And so forth.

Connect, detach, haul, shove, use the parallel tracks to get the trains previous one another.

Supply: that is from the sport Puzzillion, although I consider I noticed this puzzle someplace else a few years in the past, however I can not discover it anyplace else now.