I have run trains all my life, so this question is a bit embarassing. Having not owned a Lionel etc. I have always wondered...what the heck is that third rail for? Is it a ground? Thanks guys.... John
John, I'm speaking from over 50 years ago, but in those days the third (center) rail was the power rail. Lionel (and Marx) had slider power contacts on the engines that rode on the center rail. The two outside rails were ground. It may have changed since, but I doubt it, seeing those old Lionel transformers on some modern O gauge layouts. :teeth: I can remember my old Marx 999, I ran it so much that there was a hole in the copper pickup. They were spring loaded as I recall, so even worn through they made contact.
Lionel used a roller contact. Mine were all run so much, the rollers ended up with grooves. Loved running trains with lights in the room turned off. Buildings lit up, street lights, headlight, and sparks aplenty from the pickup. Boxcab E50
So I assume the contact was constant, thus there was reliability and thus the reason the three rail is still around? John
Yes, the contact has to be constant. Three rail trains run on AC. The two outside rails are considered "common" (neutral, ground) and the inside rail is considered "hot". When Lionel trains were first made in the early 1900's, insulating the wheels for two rail would of added to production costs. Lionel never switched to two rail because people wanted the trains currently being marketed to work with the trains they bought previously. This tradition carried on from the early 1900's until today. Three rail track systems are easier to wire and signal for automatic block control. You don't need reverse toggles for reverse loops. One of the outside rails can be insulated for a short distance and act as a sensor where the wheels close the circuit between two outside rails. This insulated rail is known as a control rail. Lionel uses control rails in their famous non-derailing switches where if you enter the curved leg of a switch and the switch points are set straight, the control rail on the curve leg activates the switch motor, setting the points to the curve position preventing a derailment. Control rails are also used to activate grade crossings and relays that control block signals and shut off the block of track behind the train for multi train operation.
Two rail tinplate track did come into existance. In "S" gauge. When A.C. Gilbert did their American Flyer line of trains. They weren't bad at all. Some beautiful stuff. But it never quite caught up the Lionel in popularity. And there were some quirks. Such as a special device for reversing, loops, so there'd be no short circuit. I can't think of it's name. But I had them. Boxcab E50
