Has anyone seen, or even built, one of these?
It is a switch diamond. It uses movable rails where the crossing angle is too shallow for the passive trackwork of a regular crossing diamond.
Mark
I love items like this, Mark. I would bet that it is on Chuck’s and Tim’s to-do lists, or that they have already done something like it.
Am I right, fellas? This just begs for handlaying abilities.
Here’s a bigger view of the trackwork:
Don Z.
Thanks, Don. That is much bettah!
Mark
Looks like a crazy crossing diamond to me. May be they have a special car that uses both tracks at the same time. Other then that it just seems odd to me.
I did however note the old wood cross ties and the new concrete cross ties.
The crossing is at a junction. So, it is designed for whole trains to cross like a normal diamond.
Mark
Prototype railroads use this design to reduce wheel-rail pounding as well as for assured tracking on a typical shallow-angle crossing. They also use closed-frog turnouts for the same reason.
Most model railroad crossings are sharp enough that the obtuse-angle frogs are skewed sufficiently that both wheels on an axle won’t encounter both frogs at the same time. The ones I’ll be building at the down end of the Tomikawa complex will be #5s, and will do fine with fixed frogs, thank you.
An extreme opposite design (seen in Fukuoka-ken in the late 1950s) consisted of two kinked stock rails and two LONG switch points, pivoted about where the acute angle frogs would normally be. The result was a kinked double slip (!) used by four wheeled mine tram cars, one at a time. Motive power? Doubleheaded 0-5-0s, with a hardhat miner attached.
I don’t intend to model anything like the photo, but just might model that mine cart trackage.
Chuck (modeling Central Japan in September, 1964)
Where is that Mark?
The track in the photo is located somewhere in the UK.
Don Z.
That is interesting. Also, why do most of those ties look like they bow down in the middle??[%-)]
I noticed that also. It looks like concrete ties, the darker ones are wood ties?
Yes the light colored ones that look like they are “bowed” are concrete ties and the darker ones on the swithc/diamond are wood.
This is common practice on concrete main lines to have the area around the switch be wood since most switches are custom and made to fit. Since they are not standard size it would be too expensive to have them design and build a custom set of concrete ties for each switch or diamond.
Chris
Lancaster, CA
Don I saw that particular track on ebay a few months back. I copied the pic so I could look at it again and maybe piece one together. The ebay one was on a wooden roadbed. Can’t remember who made it but I believe it was no longer made.
If I remember I will post a pic of the ebay one
mike
I think the bowed shape of the concrete tie makes it stronger for it’s weight. And it may also get it deeper in the ballast, besides.
OK, so they really are bowed. It’s not just an illusion. Wonder if the Atlas concrete tie flex track is like that?[:-^]
The Atlas code 83 on concrete ties has a definite ramp down from the rail support pads to the lower (smaller cross-section) middle section of each tie. This is in line with some prototype practice. (The tie bottom is flat, not ramped up from below like the prototype.)
Other prototype concrete ties were tapered both vertically and horizontally - the tie was ‘wasp-waisted.’ An early design had concrete rail support pads connected by a steel bar about 1" by 3". I haven’t seen any commercial products that match those looks - possibly because I haven’t been looking for them.
Chuck (modeling Central Japan in September, 1964 - with concrete ties)