A puzzeltask

[Kernelpanic]

The solution, below the graphic:

First the locomotive B (goods wagon) pushes onto the end track. Then the locomotive C (container wagon) couples to B.
Then the locomotive pulls them both back and pushes them onto track A.
Then the locomotive takes C and pushes it onto the terminal track.
Then the locomotive backs up, gets B, and pushes it to C (where the boxwagon was).
Now the locomotive drives over A, and then pulls B to its position.
Then the locomotive reverses to position A, just as it was before. See pictures.

A combination of L-Co-G (Leonidas) cannot exist. And the locomotive cannot be between the two wagons. In both cases there is no solution.
And if bplus thinks there is a parallel to the Hanoi Towers, ok, I don't see any parallel.

Here is the original in German:
Gegeben ist eine dreieckige Gleisanlage mit drei Weichen. (Bild 36) Der Abschnitt a ist ein kurzes totes Ende mit einem Prellblock. Die Abschnitte c und b sind kurze Strecken zwischen den Weichen, deren Länge gerade je einen Wagen aufnehmen kann.
 
Die Strecke D ist eine lange Strecke mit offenen Enden. Auf dem Abschnitt B steht ein Güterwagen, und auf dem Abschnitt C ein Behälterwagen; auf dem Abschnitt D steht eine Lokomotive mit Tender. Der Abschnitt A der durch den Prellbock begrenzt ist, ist so kurz, daß er zwar die Länge des Güterwagens oder des Behälterwagens aufnehmen kann, jedoch nicht die Lokomotive mit Tender.
Während also jeder der Wagen vom Abschnitt B oder C über die tote kurze Strecke A  allein auf die andere Seite umrangiert werden kann, ist dies für die Lokomotive wegen ihrer Länge nicht möglich.
 
Ein Lokomotivführer hat nun die Aufgabe, die Position der beiden Wagen durch einen Rangiervorgang zu vertauschen, so daß nach Beendigung des Rangierprozesses der Behälterwagen auf dem Gleisabschnitt B und der Güterwagen  auf dem Gleisabschnitt C steht. Die Lokomotive endet wieder auf dem Abschnitt D (Bild 37).
 
Wie ist der Rangiervorgang um dies zu bewerkstelligen?

The Solution:



PS: I get still a crisis with the letters!    The graphic says it all!

[SMcNeill]

Two trains??   Never would've guessed that, as mine was a 1-train solution!  O_o!

[bplus]

How the heck does car C get between A and B between the 2nd and 3rd step?

(I am assuming the diagrams are 1, 2, 3, 4 steps left to right then down eg step 3 is under step 1 as usually labeled like that. Going from the top left to the one below is not possible.)

BTW, A must be the locomotive because it moves first. There better only be one locomotive in this puzzle! or 

[Kernelpanic]

Where my Lord, are there two locomotives? - I need to get that out of my head now. 

[bplus]

How the heck does car C get between A and B between the 2nd and 3rd step?

[KingLeonidas]

Alright Kernel, I see you dont like my solution but have yet to point out what actually went wrong. Here is a visualization of every step. Be as specific as you can in your rebuttal.

https://paste.pics/fc07516df89a1f56dfdccd2e77d85301

For completeness, the instructions again:

L = locomotive, starts at D
G = goods, starts at B
Co = container, starts at C

1) Move L back toward the viewer.
2) Drive L forward (left at bottom switch) and hook to G.
3) Bring G-L back to the viewer again to pass the bottom switch.
4) Drive G-L forward (right at bottom switch) and leave G somewhere along rail D.
5) While on rail D, push Co into the bumper slot A.
6) Drive L (nakedly) through C, onto D, and then reverse to drive toward the viewer, switching appropriately.
7) With L on the viewer's rail, drive forward and hook to Co.
8) Move Co-L backward toward the viewer.
9) Move Co-L forward, taking a right through the bottom switch, and colliding Co with G.
*) At this stage, rail D should have the configuration L-Co-G.
10) Pull everything back toward the viewer.
*) Now, the viewer's rail should have the configuration L-Co-G (bottom to top).
11) Push the train upward, taking a left at the bottom switch.
12) Going all the way up/left, we now have G parked in bumper slot A, and Co parked at B (never to move again).
13) Unhook all cars from one another, and drive L back to the viewer.
14) Drive L forward and take a right at the first switch. This puts L on rail D.
15) Back up past C to hook to G, and drag G forward a little to park it.
16) Unhook from G and we're done. L can move freely along D and the incoming arc.

Note: this list can be made shorter but I was shooting for nine moments when the actual switches are operated going upstream, a tangent we haven't even touched yet.

[PhilOfPerth]

Alright Kernel, I see you dont like my solution but have yet to point out what actually went wrong. Here is a visualization of every step. Be as specific as you can in your rebuttal.

https://paste.pics/fc07516df89a1f56dfdccd2e77d85301

For completeness, the instructions again:

L = locomotive, starts at D
G = goods, starts at B
Co = container, starts at C

1) Move L back toward the viewer.
2) Drive L forward (left at bottom switch) and hook to G.
3) Bring G-L back to the viewer again to pass the bottom switch.
4) Drive G-L forward (right at bottom switch) and leave G somewhere along rail D.
5) While on rail D, push Co into the bumper slot A.
6) Drive L (nakedly) through C, onto D, and then reverse to drive toward the viewer, switching appropriately.
7) With L on the viewer's rail, drive forward and hook to Co.
8) Move Co-L backward toward the viewer.
9) Move Co-L forward, taking a right through the bottom switch, and colliding Co with G.
*) At this stage, rail D should have the configuration L-Co-G.
10) Pull everything back toward the viewer.
*) Now, the viewer's rail should have the configuration L-Co-G (bottom to top).
11) Push the train upward, taking a left at the bottom switch.
12) Going all the way up/left, we now have G parked in bumper slot A, and Co parked at B (never to move again).
13) Unhook all cars from one another, and drive L back to the viewer.
14) Drive L forward and take a right at the first switch. This puts L on rail D.
15) Back up past C to hook to G, and drag G forward a little to park it.
16) Unhook from G and we're done. L can move freely along D and the incoming arc.

Note: this list can be made shorter but I was shooting for nine moments when the actual switches are operated going upstream, a tangent we haven't even touched yet.

@Kernel: As Pontius Pilate once said, "I find no fault in him"!
I followed the steps above, and ended up with the two transposed, as required.
Well done Leonidas... Long live the King!