@mike g. Great question. I just had the camera discussion with my son. I think a webcam might make the most sense, but we will investigate. I have a battery powered cheapie GoPro knockoff which will stream to a phone - quality is marginal and signal can be choppy when transmitting from a moving train. The cab views on TPRR were taken with the camera. They were saved to a minicard and not saved streamed images. Details on the camera are there.
I have a total clearance of 8 inches - so a little over 4 inches from the top of the cars to the ceiling. I can see in from both directions so I do not anticipate a major issue. Total width is 30 inches and with clear access from both sides its basically 15 inches. Its also the reason I trimmed off the vertical portion of my L-girders to be able to see into the yard. I have to add a central support column to stabilize the upper level. Yours is a little more limited in access - I would consider having enough room to get a hand in to address a derailment or other mishap. I would just leave an open access space from below. No fun crawling around under the layout, but way better to have some access than none.
The images show how much access I have. Note, I really trimmed out the L-Girders, the one remaining shows how much they reduced clearance when in place. Each track is isolated, so you can see the wires inserted into the track to provide neutral and hot. (The Ross turnouts did not have the inside electrically rails connected, so a jumper from outer to inner rails provides the neutral connection.) I'll eventually put a switch on each power supply to turn off as needed. I see no point in keeping passenger cars lit on the track when not in use.
