Is this switch seen on railroads ?

3rdrail wrote:Does anybody else have any unusual photos of unique switches that they would like to share ?

Paul - While it's probably not unusual, this pair of self-guarding frogs in the photo below are the only ones I've ever stumbled across. ...FB

Amtrak has installed some "spring frogs" at some hand throw or slow speed interlocked switches on the Northeast Corridor. Somehow, I have no idea how, the frog slides over from being lined for the Main, and let the wheels slide over it. Its very weird looking when you are going over it. The first time I stopped and thought................

...........uhhhhhhhhhhhh..........

But then I remember reading about them in the paperwork, and a light bulb went off

I am surprised no one has mentioned moveable frogs. These are used on high speed turnouts. The points move, and the frog moves, presenting a continuous rail to the high speed wheels. Union Pacific uses them and I saw the first ones in the Pomona, CA area.

FarmallBob wrote:

3rdrail wrote:Does anybody else have any unusual photos of unique switches that they would like to share ?

Paul - While it's probably not unusual, this pair of self-guarding frogs in the photo below are the only ones I've ever stumbled across. ...FB

Interesting frogs there, Bob. I have a feeling that the guards on them are more cosmetic than anything else, though. If you look at the opposite rail, there's no restraining rails or guards at all, and the ones on the frogs don't look like they would keep a model train on track ! The frogs manufacturer probably had a little extra manganese in the mold and thought of a good way to apply it - and advertise it as a "safety frog" !

Most every chemical plant in Houston that I've switched at has those type of self guarding frogs. They're actually pretty beefy, that picture doesn't do them justice. That raised part actually comes up a couple of inches, which at 5 mph or slower - is plenty.

Britt

I'm sure that you know better than I, but it would seem that one that wasn't used frequently (as in this photo) because of it's rusty, gritty surface, would give good climbing friction to a naughty tread that wanted to make the great escape - no ? Another interesting thing about this setup is that it looks like they have installed a kink in the opposing rail just opposite the frog, as well, to jolt the wheels over in the direction of the frog. At first, I thought that it was just a fluke, but then I noticed the same phenomenon on the second switch as well.

3rdrail wrote: Interesting frogs there, Bob. I have a feeling that the guards on them are more cosmetic than anything else, though. If you look at the opposite rail, there's no restraining rails or guards at all, and the ones on the frogs don't look like they would keep a model train on track !

3rdrail - "Upon further review" the guard ribs cast into this frog are more than just cosmetic! They are about 1-1/2" thick in both dimensions (width/height).

Presuming the frog is cast of manganese steel it would require an enormous amount of force to bend/break off a guard rib.

Further, wear marks on the inner faces of both ribs indicate they frequently do their job guiding/aligning wheels as they roll thru the frog.

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Below is better look at the self-guarding frog from various angles. A couple observations:

- The main casting is huge! End to end it's about 12' long. Including the cast wedge piece between the rails on the trailing point end, the entire frog assembly is nearly 14 feet long. Width is a bit over 2 ft at the facing point "inlet".

- The rail bolted to the frog are 136 lb. However subsequent rail beyond the switch is 105-110 lb. (BTW many of the rails beyond are dated 1905 - 1907 - really old stuff!) ...FB

General view of the entire switch:


Frog - facing point view:


Frog - trailing point view:


Detail view - facing point:

Self-guarding frogs (such as these depicted) are not rare -- they are pretty much standard configuration for yard turnouts. As for the opposite rail, when there is a self-guarding frog, there is no need for a guard over there.

Plain and simple -- it works very well in low speed operations.

I'm a believer ! Those low angle shots convinced me.

I'll try to post pics of Spring Frogs, Moveable Point frogs, and Double Slip Switches used on the NEC. If I can't get them, I'll scan the ages from Amtrak Employee Timetable.

Excellent photos. Really explain what we are talking about.

A shot of moveable frogs would be interesting. Such switches are designed for speeds in excess of 125 mph.

The old Boston El used to have a few frogs that only had flangeways on the straight and not on the curve. One of these, I recall, existed right out of Forest Hills Station, and had originally been set up as a diversion from the main into what was a rapid transit storage yard in what became the Arborway. With an opposing rail restraining rail to keep the axle under control, the flange would literally climb over the unbroken frog's rail head at slow speed. They were used on switches which were seldom, if ever used. I wished that I had taken a picture of that as I've never seen another like it.

Regarding the above post - little did I realize that I had a photo of this switch all along. I was doing an unrelated post on Boston's Main Line tonight and found it. Anyway, here it is. (both sides) The linear rails are uncut at the frog. The diverging rails are set up so that the flangeway climbs up on a ramp, over the linear rail, and then down another ramp, with a restraining rail keeping the opposite wheel/axle in line. These turnouts were used at an old abandoned ramp that used to lower elevated cars to a street level yard (Shea Yard in Forest Hills). They cut the ramp out and rarely used the crossover, so for the sake of maintenance and smooth running, installed these "flangeless frogs" for the diverging rails.
http://naphotos.nerail.org/showpic/?200 ... y&BOOL=ANY

3rdrail,
Although i dont know anything of the switch you mention the pictures reminded me of a sprung-spring? switch that is used on a trolley museum in conneticut. the switch was set up so an outgoing trolley would come to the switch, take the right side of the switch and await the inbound trolley.

when the inbound went past the outbound trolley could continue on its way

newyorkcentral wrote:3rdrail,
Although i dont know anything of the switch you mention the pictures reminded me of a sprung-spring? switch that is used on a trolley museum in conneticut. the switch was set up so an outgoing trolley would come to the switch, take the right side of the switch and await the inbound trolley.

when the inbound went past the outbound trolley could continue on its way

Like this (minus the slot) ? :

http://naphotos.nerail.org/showpic/?pho ... ullman0517