My first N-scale layout was the Deep Rock Railroad. My goals were to concentrate as much railroading as possible in a 5' x 8' island layout in the center of a room, and then to build a centralized, dual-cab control panel that performed all functions. This panel would be ultra-concentrated, with 21 block toggles, 23 turnout toggles, 46 turnout position indicator lamps, 4 uncoupler pushbuttons, 4 direction controls, a main power switch and layout lighting power switch all in a 1' x 2' control area. There are more pictures of this layout here.
The layout is a fictitious 1950s short line railroad with a triple folded loop mainline supported by a hidden staging area. All this is diagrammed on the front of the control panel with the help of Dymo tapes. The layout has three levels: 44", 47" and 50" and all but the staging area is open benchwork. It has cork roadbed glued onto ˝" plywood subroadbed, a minimum radius of 9", no grades, and Atlas nickel-silver track. It uses Walthers scenes on removable backdrops. The water is EnviroTex. The upper level is a loop-to-loop passenger service with two reversing loops—this constituted the only reason my control panel needed auxiliary (reversing loops) direction controls for each cab. The middle level has only trolley track. The lower level is the mainline, sidings and staging area.
I used four electromagnetic uncouplers and I do delayed action uncoupling in most switching operations. The trolley has its own set of controls—wait until you read about how I made them. There are four Circuitron Opto-Sensors run by a DT-4, and a Snapper (Circuitron's capacitor discharge unit) because I have Peco switch machines run by 19-volt AC (at 1 amp) current that didn't always give these switch machines a positive snap until the Snapper was added.
Centralized Control on the Deep Rock Railroad