Freelance 2014-2

[faraway]

But why not simply have a full electrical interlock -- microswitch on one or both hatches connected to a relay. Microswitch not closed due to hatch being open at any time, relay unlatches and cuts off power to the whole layout. One evening job, wouldn't it be? What you're saying is that no matter what you do on, near, past, or whatever, one of the hatches, you don't have effective protection. That would be a separate issue from what you did in any corner.

Sorry, I did not explain it correctly.
The hatch and the connecting tracks are protected by a switch. No engine can run on the hatch if it is open. That is fine for trains running over the hatch.
The situation changes if I use the tracks on the hatch while switching. I may stop an engine on the hatch, do something else, and forget the engine on the hatch when my wife calls me. I grab the hatch to get out of the room, lift is quickly and the engine becomes an airplane.
To protect that situation the hatch should be mechanically locked when the track on the hatch is occupied.
Anyhow, the hatch and the door is normally all time open and I leave and enter the room frequently. A closed hatch is very inconvenient. I close it only if a train runs at the east side for less than a minute.