The model railroading community has longed for years for a realistic way for “road crews” to operate dual-control power switches. Most typically, such switches are located at the end of passing sidings within CTC territory. Normally, these switches are under direct control of the dispatcher. However, when the switch must be thrown back and forth multiple times, as in switching, it can be beneficial for the dispatcher to authorize the local crew to take control of the power switch. Steps involved are:
- Local crew requests, from the dispatcher, permission to place Switch “XYZ” in hand
- Dispatcher grants authority for local crew to place Switch “XYZ” in hand, typically for a defined time period
- Local crew inserts switch key to unlock padlock(s) securing the Selector and Hand Throw Levers mounted on switch motor
- Once local crew has switch unpadlocked move Selector Lever from “motor” to “hand” position which disengages the drive motor
- Local crew now free to throw the Hand Throw Lever, and the associatged switch points, between “normal” and “reverse” as required to carry out the required switching movements.
Once switching complete, local crew lines switch to normal, places Selector Lever in “Motor” position, locks the padlock(s) and removes switch key and then informs the dispatcher that work is compelete and Selector Lever back in “motor”. Once back “in Motor”, CTC system restores switch points to alignment prior to local crew taking control.
The Jam Solutions “dual-contol power-switch mechanization kit” makes the above possible by supplying three custom machined brass pieces: Locking Bar, Pivot Pin and Switch Key. The larger figure illustrates the installation of the brass locking bar and the pivot-pin (located under the screw and washer) in a typical fascia panel as used on the Sunset Valley Oregon System to enable the local road crews to take control of the two dual-control power switches at the crossover at Dillard Oregon.
Several additional smaller toggles, not part of the Jam Solutions product line, enable local crews to align electrically locked hand operated switches to spurs emanating from the main track and hand operated switches with a circuit controller emanating from sidings.
The figure below shows the comparison between a prototype switch key and the switch key provided by Jam Solutions, with an added 3/4-inch diameter brass disk.
Looking at the left end of the panel above, the dual-control power switches for the crossover are unlocked by the road crew inserting their switch key into the padlock, simulated by a standard 1/8-inch phone jack. Once unlocked, the Selector Lever, a standard size toggle, is moved from “motor” to “hand” position.
It is important to note that it is only when the switch is unlocked, i.e. switch key inserted in the padlock and the Selector Lever is in “hand” that the Hand Throw Lever is activated thereby enabling the local crew to line the switch between normal and reverse.
Another important feature of the Jam Solutions mechanization is that the locking bar secures the switch key so that the switch cannot be locked up, i.e. the switch key removed, until the Selector Level is returned to the “motor” position.