Static points, has anybody created a working set?

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philipy
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Re: Static points, has anybody created a working set?

Post by philipy » Thu Aug 05, 2021 9:41 pm

I know this isn't what you want to hear, but this is how it is done in the real world - about 5-55 is the clincher.
https://www.youtube.com/watch?v=jNNtqtYVHWU
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Melbournesparks
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Re: Static points, has anybody created a working set?

Post by Melbournesparks » Fri Aug 06, 2021 12:44 am

So it is important to note that while completely static points do exist in 1:1 scale, they are exceedingly rare and as far as I know not used on any currently operating electric tramway.

The vast majority of points on modern systems use a pair of moving blades just the same as heavy rail points. As you point out they are indeed a maintenance item and the flangeways and slots in the road the point blades move in do have to be kept clear of debris. The reason why you usually can't see any point lever or similar by the side of the road is that the point mechanism (either manual or power operated) is completely under the road surface.

If the points are manually operated, they're changed by a "points bar", basically a short crowbar you stick in a slot between the rails, and in the flangeway to lever the points across. A spring or weight holds the points in position one way or the other.

Image

Here in Melbourne a tramway staff member changes a set of points with the points bar. As you can see this is an infrequently used set of points, so they have had to use the points bar to scrape some dirt out of the flangeway to allow the blades to move.

Like mentioned above points can have either one or two blades. Single bladed points were very common on old systems because of their simplicity, but modern systems almost exclusively use double bladed designs like in heavy rail. Part of the reason for this is that for a single bladed set of points the wheels have to roll over an extra gap in the rail, with resulting extra noise and vibration.

Image

Here is a single bladed set of points still remaining on the Melbourne tram network, though they are becoming rare now. The moving blade is on the right (set for the diverging direction) and the static part is on the left. The metal plates in the roadway cover the spring mechanism that holds the blade over. The spring also allows the blade to spring back if pushed aside by a tram in the trailing direction, which is how the vast majority of points work in places where the tram always takes the same route in the facing direction.

The advantages of single bladed points also apply in modelling, here is a representative example on my tramway.

Image

The blade is on the left, set for the diverging direction. Only needing to clean out one blade is a big advantage for running outside.
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DafyddElvy
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Re: Static points, has anybody created a working set?

Post by DafyddElvy » Mon Jun 26, 2023 6:12 pm

11thHour wrote: Tue Jun 29, 2021 2:20 pm 1E648061-BCBB-42CC-82A4-783252E3E0F6.jpeg
Can anyone advise where this stub point turnout is please, thanks?

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Re: Static points, has anybody created a working set?

Post by dudeface » Wed Nov 15, 2023 8:53 pm

spaeker wrote: Thu Aug 05, 2021 8:08 pm

I did make my own system added a moving flexible joint ( just one). Worked fine but this cannot be the real world solution ?
google earth doesnt come anywhere near close enough to see.
ciao spaeker
Spaeker I believe what you're talking about is called a stub switch/ stub points
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Re: Static points, has anybody created a working set?

Post by Melbournesparks » Sat Nov 18, 2023 11:54 pm

DafyddElvy wrote: Mon Jun 26, 2023 6:12 pm
11thHour wrote: Tue Jun 29, 2021 2:20 pm 1E648061-BCBB-42CC-82A4-783252E3E0F6.jpeg
Can anyone advise where this stub point turnout is please, thanks?

David
Wee Georgie Wood railway in Tullah, Tasmania. 2' gauge. I believe they're ex mining tramway somewhere, probably Mt Lyell?
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Re: Static points, has anybody created a working set?

Post by Scrat » Mon Nov 20, 2023 12:15 pm

These stub points cannot be trailed.
A friend has two of that type on his 5" gauge layout.
Another driver wanted to pass from the siding onto the main line.
Was going fast and did not check the track (and point positions) ahead.
One point was in the wrong position and she and her loco ploughed into the ballast.
No damage to the loco...but to her pride.

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