By Joseph Stachler
The various control features on today's 3-rail locomotives are pretty amazing. It used to be that the most engines could do is change directions and have a whistle or horn. Now there are other features including electronic uncoupling anywhere on a layout without the need for a special track section and running at least two trains on the same track at the same time.
Actually, the potential for those modern operations has been around for decades. Lionel always knew this and illustrated how to implement those extra features in their Dealer Repair Manuals. Only locomotives without a whistle or horn could be upgraded to either have "teledyne" uncoupling or "Magic Electrol" reversing. The reason was because their whistle relay was used to perform those functions. Trying to implement teledyne uncoupling on an F-3 would mean every time you blew the horn, the locomotive would break away from the train. By the same token, a locomotive cannot have both teledyne uncoupling and Magic Electrol. You have to choose between the two.
The vast majority of Lionel trains run on Alternating Current, or AC power. The relay is an electromagnetic coil energized by Direct Current, or DC power. When DC power is injected into the track power, the relay coil draws a metal plate up to it which completes a circuit for things like a battery powered horn or track powered whistle. When the coil is no longer energized, gravity drops the metal plate back down. The whistle relays can be found for between $20 and $25.
This was a neat idea introduced in 1940 where two small steam switchers could be run on the same loop at the same time. One locomotive had the standard 3-position E-unit. So did the other except that instead of a cut in track power activating the E-unit, the DC whistle relay would when the whistle button on a transformer was pressed. This meant the reverse units of two separate locomotive could be activated separately.
Although trying to control two different E-units at the same time can put your hand/eye coordination to the test, there are some layouts instead of a simple loop where this feature can be better utilized. An example would be a loop of track with a single line running through it using crossover track sections. The two trains would run on their lines and one could be stopped allowing the other to proceed without interrupting it and vice versa. The Magic Electrol feature is a great way to give two operators the individual task of running their own locomotive.
This is the simplest upgrade for locomotives such as steam or diesel switchers that have the older coil couplers. These switchers include the 203 and 622 varieties. The line that is connected to the contact shoe is attached to the whistle relay as illustrated. It is important to insulate the relay from the locomotive body. You can leave the contact shoes functioning as well for operating versatility. The three switchers without the bell obviously have a lot more room to install the whistle relay. The re-issues of the 622-type switcher from Lionel Trains, Inc. in the early 90s can be upgraded using Lionel's current Electrocouplers Upgrade Kits made for Geeps. Just change out the couplers and connect them to the whistle relay.