Rounding a sweeping curve in Red Rock Canyon is the "Fast Mail" powered with F7 A-B-A units. The "B" unit holds a battery pack to power the head and rear marker lights. Sound comes from a MRC sound and power pack that is routed to speakers from relay contacts in the Twin "T" block detectors. This old system allows the "sound" to move with the train over the layout. Ballast is #1032 HO Fine Black Cinder along the roadbed edge with #1352 HO Fine Silverton Gray around the ties on hand laid code 83 rail.
Our Fast Mail runs with two RPO'S with the streamlined car in transfer and the heavy weight operational. Their both fitted with operating catching arms and lights. The battery pack is in the heavy weight car and powers the streamlined car through gold connectors. I use AA rechargeable batteries and control the power with a sub miniature toggle mounted through the car floor. You can barely see the toggle lever under the car below the large door. Needle nose pliers work for flipping the switch while the car is on the rails. Dimmer 3 volt bulbs will light the other mail storage cars as work crews need some light to pass through the train getting to the last baggage dorm car in the train.
The fastest way for V.I.P.'s to get from Los Angels to Chicago is via the "Fast Mail" as it only stops for fuel and crew changes. Such is the case with the "Railroad Model Craftsman" modified coach car and the transfer of an empty "Chair Car" needed at the other end of the line.