Mickoo's American Modelling Empire

[mickoo]

The Sixth photo down on post 499 shows a point with 5 angled patterns to the sleepers is something I’ve never seen before , it’s is also a great picture of a JUMP FROG “ flange bearing frog” I don’t think we have them in Australia yet but give them time, I believe BNSF use them but only use them on sidings that don’t see continuous traffic and can only be used with Vehicles that have wheel / flanges that are capable of crossing jump frog points.
David.

You are indeed correct and I took several photos, it was the only one I've seen up close and remote enough to photograph safely.

Technically it's MRL trackage, but as of Feb 24th 2024 (I think that's the official change over date) it's now all BNSF.

 

[Lancastrian]

Are these jump frog type points trailing only, facing only or bi-directional ?

Mick, did you nick those Pandrol clips? Did you? Souvenirs in your luggage?

 

[mickoo]

Are these jump frog type points trailing only, facing only or bi-directional ?

Mick, did you nick those Pandrol clips? Did you? Souvenirs in your luggage?

They're bi directional as they're often into sidings, what goes in, invariably has to come out

No I didn't, got a few from work on the docks as they're pretty much the same type, I did bring a few rail spikes back one year, amazed they got through baggage to be honest.

 

[Big Train James]

There are also movable frog turnouts. I think they are often used on mainline higher speed crossovers, not sure where else they may be applied.

Frogs - Moveable Point Frogs (MPF) - voestalpine Railway Systems Nortrak

 

[Yorkshire Dave]

There are also movable frog turnouts. I think they are often used on mainline higher speed crossovers, not sure where else they may be applied.

These are pretty much standard on high speed lines in Europe.

 

[Yorkshire Dave]

They're bi directional as they're often into sidings, what goes in, invariably has to come out

In the last photo of the sequence I can't see how it can be bi-directional. A train leaving the siding heading towards you will be fine -you couldn't enter the siding from where you're standing as the train will derail.

 

[mickoo]

In the last photo of the sequence I can't see how it can be bi-directional. A train leaving the siding heading towards you will be fine -you couldn't enter the siding from where you're standing as the train will derail.

Trust me it can, I watched a MOW vehicle come up the hill and then back into this siding right in front of me.

What isn't so obvious (unless you know) is the the LH rail (curved closure rail) is actually higher than the main (straight closure rail) running rail, the same is on the RH (curved main line rail) rail and it has a hump in it to keep the axle flat and not tilted as it crosses the crossing.

As the axle rolls into the siding the rail rises up so that the rim of the LH wheel rolls across the top on the main running rail, behind the crossing is a sloped section to capture the rim and lower it back down so that the tyre then rolls on the rail head.

You can just see the raised curved closure rail more easily in the first photo, it's a real mind bender and I watched closely as the MOW vehicle crossed, such that the guy got out and asked what I was looking at, I pointed to the crossing and said "that", we don't have them in the UK so I didn't know how on earth it could work, he laughed and said they had them all over the place.

 

[timbowales]

Trust me it can, I watched a MOW vehicle come up the hill and then back into this siding right in front of me.

What isn't so obvious (unless you know) is the the LH rail (curved closure rail) is actually higher than the main (straight closure rail) running rail, the same is on the RH (curved main line rail) rail and it has a hump in it to keep the axle flat and not tilted as it crosses the crossing.

As the axle rolls into the siding the rail rises up so that the rim of the LH wheel rolls across the top on the main running rail, behind the crossing is a sloped section to capture the rim and lower it back down so that the tyre then rolls on the rail head.

You can just see the raised curved closure rail more easily in the first photo, it's a real mind bender and I watched closely as the MOW vehicle crossed, such that the guy got out and asked what I was looking at, I pointed to the crossing and said "that", we don't have them in the UK so I didn't know how on earth it could work, he laughed and said they had them all over the place.

Very interesting. I wonder how RSSB, ORR or HMRI would react to something like this being used in the more remote extremities of the UK rail network?
Tim T

 

[Genghis]

There are also movable frog turnouts. I think they are often used on mainline higher speed crossovers, not sure where else they may be applied.

Frogs - Moveable Point Frogs (MPF) - voestalpine Railway Systems Nortrak

These are pretty much standard on high speed lines in Europe.

Also used on some modern metros where noise is an issue.

 

[Yorkshire Dave]

What isn't so obvious (unless you know) is the the LH rail (curved closure rail) is actually higher than the main (straight closure rail) running rail, the same is on the RH (curved main line rail) rail and it has a hump in it to keep the axle flat and not tilted as it crosses the crossing.

As the axle rolls into the siding the rail rises up so that the rim of the LH wheel rolls across the top on the main running rail, behind the crossing is a sloped section to capture the rim and lower it back down so that the tyre then rolls on the rail head.

You can just see the raised curved closure rail more easily in the first photo, it's a real mind bender and I watched closely as the MOW vehicle crossed, such that the guy got out and asked what I was looking at, I pointed to the crossing and said "that", we don't have them in the UK so I didn't know how on earth it could work, he laughed and said they had them all over the place.

Ah, makes sense now. Shame you didn't lay down to take a pic at rail eye level so to speak .

 

[Yorkshire Dave]

Also used on some modern metros where noise is an issue.

Mind you, moveable/floating frogs are nothing new - weren't they used in old tram tracks?

 

[Rob R]

They're bi directional as they're often into sidings, what goes in, invariably has to come out

Two nations divided by a common language.......
Is it a "siding" or a "spur" (US speak) or a "loop" or a "siding" (UK speak)?

 

[mickoo]

Two nations divided by a common language.......
Is it a "siding" or a "spur" (US speak) or a "loop" or a "siding" (UK speak)?

It's a siding and so are loops, as far as I know there are only two, main and siding (which can also be a loop).

I think spurs (roundhouses) are called stubs?

 

[Big Train James]

Interesting regarding the colour as I found the opposite, whilst I didn't examine all their track, the few snap shots I did see were mostly uniform grey. These have a slight mix with something lighter and more brown in colour, but only a trace.

Any leftover pink ballast is quite likely then a legacy thing. It all just depends where BNSF quarries their ballast now as to what you saw on your trip.

When I was looking things up last night, I did see a reference to Santa Fe having a mauve colored ballast in the area you have visited.

 

[mickoo]

Any leftover pink ballast is quite likely then a legacy thing. It all just depends where BNSF quarries their ballast now as to what you saw on your trip.

When I was looking things up last night, I did see a reference to Santa Fe having a mauve colored ballast in the area you have visited.

Agreed, though you'd think even BNSF would choose a local quarry for ballast. Pink ballast is typically pink granite which by all accounts is the best binding aggregate you can have for railroads.

The pink ballast at Helena and Cajon was fresh so it's definitely still in use; mauve, I think I've seen some of that but cannot recall where, possibly on Transcon 2.

 

[76043]

Wow! "That's brave" as Sir Humphrey would have said. It looks like the wheel jumps over the rail, hence the term jump frog? I can't quite believe what I think I am seeing even if it does actually work.
Tony

 

[mickoo]

Wow! "That's brave" as Sir Humphrey would have said. It looks like the wheel jumps over the rail, hence the term jump frog? I can't quite believe what I think I am seeing even if it does actually work.
Tony

It doesn't jump as such, it's lifted by the curved closure rail and then set down so the rim is on the straight running rail for a short distance and then it's let down by a ramp for the rim on the other side......if we're taking the diverging path. If we take the converging then the rim is lifted first onto the rail head and then hits the raised curved closure rail to be lowered back down again.

It clearly works and not just for light weight stock, it can be used by Main line locos which in the US can reach close to 200t or roughly 33t per axle for the real heavies, though I'm sure I've seen 35t axle loads somewhere on specially weighted engines for coal drags etc; the jump frog is smoother than you might imagine.

You just have to do it reasonably slowly

This video is quite good although the engine stopped short, not sure why as I thought they could pass over but it might be that's where he had to spot cars anyway.

Here's a less clear one, but these are SD60's and they're no light weight (167t) and I'm surprised how rapid they're running over it, faster than I've seen before.

 

[David Waite]

Hi Mick thank you for the photos and videos such clear shots.
I have noticed the Japanese railway use jump frogs on many of their main city lines to gain access to and from refuge sidings ect, there also seems to be various designs of jump frog points and known by different names,
Flange Bearing Frogs, High Lift Frogs , or OWLS ( One-Way Low Speed ) on diamonds, I believe all have a maximum of 10MPH speed limit, I read somewhere a while ago that the angle of a grade track crossing diamond for a jump frog design, must be less than 90 degrees as both flanges cannot be jumped at the same time but things might have changed since I read that. To me having a fully loaded wagon or loco riding along on its flanges even for a short distance just doesn’t seem right but it works so it’s the future.
David.

 

[simond]

to me having a fully loaded wagon or loco riding along on its flanges even for a short distance just doesn’t seem right but it works

I've seen people do it with Peco to stop the infamous "wheel drop" in 0F

 

[Brian McKenzie]

To me having a fully loaded wagon or loco riding along on its flanges even for a short distance just doesn’t seem right but it works so it’s the future.
David.

Wheel profile is slightly different in North America, than we are used to seeing elsewhere. Flanges are marginally shallower, but wider.