Having helped my father with his layout, 2000 to present, I have a fair bit of experience with the Gargraves switch in the lower right of this photo. This is an older type, and will probably be the cheapest to acquire. I would say that they are adequate in low-speed situations, maybe in high-speed applications, if the diverging route is not used at speed. Even at low speed, a scale Hudson or Mike taking the diverging route on one of these is a sight to behold, and not in a good way.
If you use these, prepare to deal with the following problems:
- Guardrails cause derailments, because they are too short, or too far from the running rail, or because they break off. We have replaced them with Ross guardrails, or ones homemade from wood.
- Arcing when the roller pickup crosses over the running rail of the diverging route (when going straight through) or the straight route (when diverging). These rails are not insulated on these switches. If this is not corrected, it can eventually cause pitting in the center rail 'plate'. You can use nail polish on the rails where the roller passes over; it will need to be reapplied periodically.
- Center rail 'plate' (between the points) is installed slightly off center. The side of the plate touches the inside surface of the wheels on certain equipment (especially prewar), causing shorts. Again, nail polish can be used as an insulator.
- Points flex under heavy trains and touch the bottom of the center rail plate, causing a short. Make sure there are pins in the ends of the running rails to support the points. You may still have to do a little bending.
- Center rail plate goes dead. The narrow end is pressed onto the center rail, and it relies on this for continuity. Solder in a wire jumper.
- Two piece frog leaves a small gap between the flangeway and the running rail. On postwar equipment, the flange can fall into this gap and cause a derailment. Fill the gap with epoxy and file smooth.
As much trouble as these have been, if we were to do it over again, we would still use them, at least in the yard, where the turnouts really add up. But I would keep them off the mainline if I could.
I should add that the newer Gargraves switches (easily spotted because they have silver-colored points, whether stamped or cast) have been pretty much trouble-free, though I would still take Ross over them if I had my druthers.