Peteski: Those are spring-closed frogs. They lasted at least into the late 1970s, as there were several just south (timetable west) of the Pasco depot in Washington. The idea is that the frog stays closed on the branch side, giving a smother ride for mainline wheels. When a cars takes the branch, the flanges force the frog open. They were used where almost all of the traffic went one way, as there was quite a bit of wear on the closed side when flanges rubbed against it. In spite of the cylinder being on both sides, it was strictly a one-way spring. The other side apparently protected an extended alignment rod or something similar.
The odd thing here is that both frogs on the crossover are sprung, but they're not both sprung for the same route. The one on the right is set for traffic going straight through, and the one on the left is set for the crossover. That's a little weird, unless the left track isn't used much. It doesn't look very well maintained.
