Access Hatch Afterthought

We decided to add an access hatch to reach inside the mountain in the case of a derailment. It came as an afterthought upon finishing the task of repairing a broken solder joint on the center rail "inside" the mountain. I simply chose the center for the location. The photos show plugged and unplugged access. The piece is designed so that gravity holds it plugged into place with out the need for hinges. I will add more rock details to hide the visibility of the hatch.