Spring Frog on turnout

That is where the question came from. Going straight is fine (frog closed). Entering from the diverging route should work fine too as long as the springs allow the frog to open and not lift the wheel. Taking the diverging route facing the frog is where I see a problem ...the springs would get a sharper force right on the tip of the frog.

Perhaps this particular spring frog was not designed for facing movements other than straight? Perhaps it is part of a passing siding where spring switches and frogs are at both ends and a train never needs to take the other path? Or a siding that is one direction only? There were a lot of railroads designed for current of traffic only before technology caught up and it was cheaper to run bi-directional lines than maintain additional tracks. Modern remote switches also help.

Spring switches are great for entering from a siding where you don't want to leave a man behind (or hire an extra man) to throw the switch back after entry. I watched a crew last night that was aided by a switch operator in a truck. The guy in the truck pulled up before the train ... waited for the train to pass and stop ... threw the switch and derail for the train then flagged a nearby crossing as the train backed up into an interchange siding. He drove to where the crew left the cars then came back as the light engines went back through the switch. The guy in the truck hung around long enough to close the switch and derail as the train reversed to go back to where they came from. A spring switch at that location would have allowed the crew to enter from the siding without throwing the switch. The derail would have had to been dealt with. At other locations on the line (places with spring switches or powered switches) there are power derails present.

My best guess for the photo was this was a single direction turnout entering the other track with no trains ever taking the diverging route facing the points.

justalurker66 wrote:That is where the question came from. Going straight is fine (frog closed). Entering from the diverging route should work fine too as long as the springs allow the frog to open and not lift the wheel. Taking the diverging route facing the frog is where I see a problem ...the springs would get a sharper force right on the tip of the frog.

Perhaps this particular spring frog was not designed for facing movements other than straight? Perhaps it is part of a passing siding where spring switches and frogs are at both ends and a train never needs to take the other path? Or a siding that is one direction only? There were a lot of railroads designed for current of traffic only before technology caught up and it was cheaper to run bi-directional lines than maintain additional tracks. Modern remote switches also help.

Spring switches are great for entering from a siding where you don't want to leave a man behind (or hire an extra man) to throw the switch back after entry. I watched a crew last night that was aided by a switch operator in a truck. The guy in the truck pulled up before the train ... waited for the train to pass and stop ... threw the switch and derail for the train then flagged a nearby crossing as the train backed up into an interchange siding. He drove to where the crew left the cars then came back as the light engines went back through the switch. The guy in the truck hung around long enough to close the switch and derail as the train reversed to go back to where they came from. A spring switch at that location would have allowed the crew to enter from the siding without throwing the switch. The derail would have had to been dealt with. At other locations on the line (places with spring switches or powered switches) there are power derails present.

My best guess for the photo was this was a single direction turnout entering the other track with no trains ever taking the diverging route facing the points.

I would assume that there would be a speed restriction over theses frogs??

scharnhorst wrote:I would assume that there would be a speed restriction over theses frogs??

I would assume that there was. Diverging routes through turnouts often have speed restrictions. Some engineering guru would set the speed that should be maximum going through the springs. It may not be much different than track speed if the turnout is designed for near track speed.

That is where the question came from. Going straight is fine (frog closed). Entering from the diverging route should work fine too as long as the springs allow the frog to open and not lift the wheel. Taking the diverging route facing the frog is where I see a problem ...the springs would get a sharper force right on the tip of the frog.

The point ( called the toe) of the frog does not move. It is located exactly where it would be on a conventional frog. The difference is in the rail part of the frog ( wing rail) that is an extension of the straight closure rail. Normally this rail is bolted solid as part of the frog, with a opening for the flangeway. In a spring frog, this rail is pushed against the frog toe by a spring. When a train takes the diverging path, the wheel nudges the wing rail away from the frog toe to create the flangeway. The guard rail on the opposite rail retrains the other wheel on the axle to keep the wheel from striking the point of the toe, just as it does for any turnout.

Sometimes very light equipment, such as a track speeder, isn't heavy enough to spring the wing rail out, so the wheel rides up and over the wing rail , held in gauge by the guard rail on the other side, and bumps back down after clearing the wing rail.

Of course the advantage of a spring frog is that it provides a smoother, quieter ride for the higher speed traffic on the main track.

I assume such a facing diverging move would have a extreme speed restriction?