The main trick with Spring Switches in smaller gauges is the light weight of the train.
The spring has to be strong enough to more the point rails, yet weak enough to not derail the engine or cars.
Electric non-derailing switches are a lot safer on the rolling stock.
In the 1970's the children's park in Oakland had a "jolly Trolley" train that had return loops with sprung switches.
My younger brother was the Engineer/motorman on this one crewman train, a second worker acted as ticket seller & station agent.
The Spring Switches worked well with the 500 pound plus weight of the cars, unless jammed with rocks and sticks.
Because the switches were outside the park fence, they had to be checked every day for damage by "kids".
The track was later moved inside the fence, for that reason and more.
