"Turtle" couplers?

[OldProf]

Recently, I noticed something odd about the couplers on the "silver" tank cars that come with the Marias Pass route. It's a "now you see it ... now you don't" phenomenon that I'm calling "turtle" couplers. Here's a screen shot of this coupler in its shell:



When the engine's coupler reaches the point at which a couple should occur, this "turtle" coupler shoots out of its shell! I didn't bother to take a screen shot of this, since it's then just a pair of couplers. This does not happen with any of the other pieces of rolling stock included with the route.