Swing nose frogs nothing new(?)

With regards to the LIRR conversion of their permanent crossover frogs to the swing nose frogs, I came across this Old Saybrook, CT photo of an early switching frog dating back to 1909. I'm sure it was manually controlled, but it looks like the concept is not a current one. Can anyone comment on this?

You are correct. Swing-nose frogs are not new in railroading. They are a long-standing feature of high-speed turnouts.

What moved the frog in 1909? For that era I would expect to see rods, bell cranks, and other hardware typical of the period (probably not switch machines at that time). I have read, and seen photos, of turnouts in which the wheels of a diverging movement ride up on the wheel flanges -- very slowly -- over the rail of the main track to smooth the through movements, which would occur many times oftener than the diverging ones. Was that done that far back?













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frankie wrote: ↑Fri Jan 26, 2024 3:03 pm With regards to the LIRR conversion of their permanent crossover frogs to the swing nose frogs, I came across this Old Saybrook, CT photo of an early switching frog dating back to 1909. I'm sure it was manually controlled, but it looks like the concept is not a current one. Can anyone comment on this? frog.jpg

Spring frogs (as we call them in Virginia) are operated by the wheels of the train. The portion on the left side of the frog is held tight by springs which are the two protrusions on the left side of the frog. When there is a diverging movement, the wheels force the track on the lower left of the frog to move over and create a gap which makes it act like a regular frog. After the wheels go by, the springs slam the rails back to allow a seamless mainline move. It is vital that the guard rail on the left rail be properly gauged and securely anchored to stop the wheels from hitting the point of the frog and causing a derailment.

I can see how that would work in a trailing movement from the diverging track to the main track, but in the opposite direction would the weight on the rail have to move the frog before the wheel reaches it rather than have the frog linked to the movement of the switchpoints? It seems like it would require a very delicate adjustment.

Actually, spring frog sounds like the right name for it since it works on the same principle as a spring switch.