Switch Frogs

Can anyone explain to me the workings of the current tuning fork style frogs? It looks like they double as switches. What is the purpose of them and will they eventually replace all the traditional frogs on the system.

That is a Movable Point Frog. Movable point frogs are power operated and must be
properly lined for straight and diverging movements. They enhance ride quality and allow trains to move over them at higher rates of speed.

Yes, note the switch (frog?) motors to the right.
Moveable frog point means no more chance of picking the point and derailing and also the elimination of the guide rails.
"The best part is no part"
Elon Musk

regards,
vince

The other unusual items are the movable crossing points. There was one at Mineola until the third track project eliminated the crossing. Also many double slip switches at Jamaica use them as well. Here is how Mineola looked: And here is a slip switch at Jamaica: They add complexity but minimize derailment possibilities.

Both images from Steve Lynch's trains are fun website

Thanks for the education fellas! This makes a lot of sense. I've been researching this along with watching different youtube clips of different rail line including Chicago's Metra who uses these switches quite extensively. I'm surprised this is a fairly recent development. One wonders if the subway system will eventually adopt them?

One more question: Can I assume that these movable point frogs operate in unison with the regular switch?

frankie wrote: ↑Sat Jan 21, 2023 11:26 pm One more question: Can I assume that these movable point frogs operate in unison with the regular switch?

They do. Typically a switch with a movable frog has multiple motors (the ones Brightline is installing have 5 motors per switch-1 for the frog and 4 for the points), which means more points of failure and more to inspect and maintain, so they are only likely to be introduced when speed through the switch matters. I don’t know at what track speed installing a movable frog has a positive ROI over a fixed frog.

Can one assume the railfans with a tripod, standing on the main line are idiots?

frankie wrote: ↑Sat Jan 21, 2023 11:21 pmI'm surprised this is a fairly recent development. One wonders if the subway system will eventually adopt them?

My understanding is that movable frogs have been used for almost 100 years at high traffic crossovers like the Metra crossing of the UP/CNW and the MILW two miles west of downtown Chicago, so they're not what I'd call a recent development. What's relatively new is their deployment on freight rail lines in high speed crossovers.

RGlueck wrote: ↑Sun Jan 22, 2023 11:23 am Can one assume the railfans with a tripod, standing on the main line are idiots?

Yes, I agree with that assumption. A symptom of foamer dementia. Violates the safety principle to expect a train on any track at any time.

jhdeasy wrote: ↑Sat Jan 28, 2023 9:29 am

RGlueck wrote: ↑Sun Jan 22, 2023 11:23 am Can one assume the railfans with a tripod, standing on the main line are idiots?

Yes, I agree with that assumption. A symptom of foamer dementia. Violates the safety principle to expect a train on any track at any time.

RG and JHD - From looking carefully at that Nassau photograph from May 17, 1979 by Steve Rothaug
This looks to me as two LIRR employees standing on the track at Nassau Interlocking at Main Street Mineola -
the one on the left looks to be holding a broom or other long tool watching the arriving train from OB led by
ALCO FA2 606 (retired after Huntington wreck in August 1988) westbound to Jamaica...

Back then safety vests were not yet a requirement and more importantly a clueless foamer would not be able
to go onto tracks let alone take any pictures at Nassau Interlocking from that exact location without getting
the full negative wrath from the Towerman or another staffer at Nassau by getting yelled at - or being called
in to the LIRR Police (or Nassau County PD) by them or other LIRR employees at that very visible spot...

On the original subject - The switches at Nassau Interlocking then needed to be continuously maintained W/
the sheer amount of daily train traffic - they took a constant beating - and making this just more interesting
is how the Main Street crossing pavement was placed there making it somewhat easy to look at just how
intricate that Nassau used to be in the days before the Third Track Project changes...MACTRAXX

I thought it was a broom.

Could be a thing they use to apply Graphite. Graphite is a black sticky liquid used for lubricating the switches and switch mechanisms and part of the Maintainer's job is to go out periodically and swab the stuff in. Using radio or shouts/curses/whistling they would have the operator throw the switches to allow them to do it and they're waiting for that Bay to clear in order to finish up. That pic was taken from the second floor of Nassau Tower by either another Maintainer or an Operator.

* edit: If they are RR employees, they could be a little too well dressed for Signal, LOL. Nassau was a hotbed for both railfans and crazy ladies in HUGE SUVs fouling the crossing trying to get a good spot at Foxes. Looking out the window could be both fraught with pleasure and pain

Employees or not, they're in a precarious position.
Another thought, have you noticed you hear almost nothing about switch toads? Frogs, frogs, frogs! Tell me this isn't blatant racism!

The two rail ends that correspond to the two prongs of a tuning fork are sometimes called wing rails while "frog" refers only to the pointed tongue in between. Short portions of the rails leaving the tongue going further into the background are called frog rails. A simple moveable frog is pivoted where the frog rails begin and the pointed tongue tip just wags back and forth between the wing rails.

For the example presented by the OP, the entire tongue slides laterally between the wing rails, and the frog rails are pivoted a little further back so the frog area seems to morph as the switch is thrown. This makes an uninterrupted rail for the wheels for the direction of travel set by the (entire) switch. To accomplish this two switch rods and usually two switch motors are needed. (Yet anotherl switch motor off of the picture foreground moves the switch points.)

Given perspective and the camera angle, it is a little difficult to visualize that in the foreground the left two rails (stock and closure) converge and the right two rails (closure and stock) converge at the two respective switch points.

Gaps in the rail at the frog are larger for shallower angle switches so use of movable frogs is more significant.