An occasional maintenance task on my railroad is repair or replacement of a switch machine linkage. This could follow a period of intense use such as the recent Western Oregon Operations (WOOPS) event or just “normal” wear and tear. I use two types of switch machines: Circuitron Tortoise powered machines for mainline switches or Blue Point manual switch machines for secondary trackage. The Circuitron Tortoises rarely cause a problem, but the manual throws with the Blue Points do need repair.
I connect the throw bar of the Blue Point machine using threaded rod with a knob in the layout facia and by threading the rod through a screw eye on the Blue Point throw bar. That screw eye connection can be broken if the operator either twists the knob or slams the linkage. Such failures affected two machines in my Eugene Yard and Depot area in the past couple of months. While one will be replaced by a Circuitron Tortoise powered machine due to its long linkage (more than 24-inches of threaded rod under the layout), the other one was on a very short linkage.
Layout fascia knobs controlling manual switch machines. The knob labelled for L (ladder) and scale track needed replacement.
When I investigated the two Blue Point machines, I found each had a broken switch machine throw bar. Both broke around the hole for the screw eye. Note, I do not expand the size of this hole beyond the manufactured hole. The screw eye simply screws in. Fortunately, I discovered the two machines had broken connections on opposite sides of their respective machines. That allowed me to repurpose the machine with the long throw to serve for the short throw needed for the ladder to scale track switch.
Broken switch machine throw bar with remaining linkage still attached to the threaded rod.
When I installed the repurposed switch machine, I found the old linkage could be reused. I had nuts on both sides of the screw eye, but I had not applied CA glue (aka, “super glue”) to that assembly as I have in a number of other cases. I use glue to resist the knob turning tendency some operators have. I have since shifted to using school glue to fix the nut and screw eye assembly on the theory that the glue provides reasonable resistance to turning the threads but might still be disassembled if the joint is soaked in water.
Replaced/repurposed switch machine installation for the ladder-scale track switch.
I remain concerned that I experience these failures. I am getting very tired of having to crawl under the layout to install a replacement.
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