wye junctions

[melmerby]

7 hours ago, Andy Reichert said:

 

You mean one of these?

 

I haven't wired this one myself yet. I think you can simplify it by picking the straight through top/bottom pair of double junctions as one circuit and just put reversers on the LH double junction section. You'll  have to decide up front if you want to allow multiple practical routes to operate simultaneously, because that will mean that you have to separate the DCC wiring for each half of the double track. Then treat them as two separate single track triangles split up in top/bottom and LH turnouts as above. I'll have to photograph the undersides in the next day or so and post those.  I've wired every frog separately, so I've hopefully allowed for every possible situation.

 

Andy

 

You need a form of interlocking (mechanical or electrical) to stop conflicts being set, of which there are several with a triangular junction.

There is a maximum of three routes that can be set simultaneously, (the three outer tracks only) any others are conflicts.

Once you have sorted  that the wiring should become a little easier.

[Andy Reichert]

4 hours ago, melmerby said:

You need a form of interlocking (mechanical or electrical) to stop conflicts being set, of which there are several with a triangular junction.

There is a maximum of three routes that can be set simultaneously, (the three outer tracks only) any others are conflicts.

Once you have sorted  that the wiring should become a little easier.

 

I was wrong in my too quick to post statement. There are a lot of constraints, especially around the crossing frog polarities. In the street running case, there is also the traffic lights logic to consider. That's why I'm going to be using small (fortunately also cheap) embedded computers for controlling the complicated junctions. I think If all 3 outer routes run simultaneously, then the break already shown between the straight sections is also needed. 

 

Of course, I also have to live that long.

 

Andy

 

PS do you want to see the Grand Union?

[St Enodoc]

11 hours ago, Andy Reichert said:

PS do you want to see the Grand Union?

Yes please.

[Andy Reichert]

 

Here is the roadway base for the GU without the rail fitted.  The front half has the full width street and pavement, the rear half just the track base.

 

 

This is a close up of the rail installed in the centre crossings. The underside is below

 

 

This shows the connections to the various powered frogs and running rails. The centre wiring (16 90 deg frogs) was so complicated with wires crossing that I made up a PCB to keep the wiring flat and make it easy and reliable.

 

 

And finally, here is the base being test fitted into a future city block layout

 

Andy

 

I guess I should put this into a separate topic. But I'm not sure which part of the forum would be most appropriate?

 

 

 

 

[melmerby]

18 minutes ago, Andy Reichert said:

I guess I should put this into a separate topic. But I'm not sure which part of the forum would be most appropriate?

 

 

If it's a road tramway, in the tramway modelling section of the forum:

https://www.rmweb.co.uk/community/index.php?/forum/142-trams-tramway-modelling/

 

 

Quite a few European tramways have/had "Grand Unions" but a railway equivalent is hard to find.

The Chicago "L" has a threequarter one.

There is another track, just off the bottom of the screen

 

Edited December 3, 2019 by melmerby
better picture

[Mike Buckner]

Just west of Bristol Parkway is a 4-way Wye, where you can get from any point of the compass (North / East / South / West) to any other point:

 

https://www.google.co.uk/maps/@51.5155291,-2.5583017,1231m/data=!3m1!1e3

 

Stewart's Lane has a Wye suitable for turning, which probably gets used on specials from time to time.

 

Selhurst Depot contains the makings of a Wye.

[melmerby]

27 minutes ago, Mike Buckner said:

Just west of Bristol Parkway is a 4-way Wye, where you can get from any point of the compass (North / East / South / West) to any other point:

 

https://www.google.co.uk/maps/@51.5155291,-2.5583017,1231m/data=!3m1!1e3

 

Stewart's Lane has a Wye suitable for turning, which probably gets used on specials from time to time.

 

Selhurst Depot contains the makings of a Wye.

It's not a Grand Union though, it doesn't have double track on all the cord lines.

[simon b]

There used to be a wye junction at Denham with the branch from Uxbridge, there is another just outside Cannon street station.

 

[The Stationmaster]

16 hours ago, melmerby said:

It's not a Grand Union though, it doesn't have double track on all the cord lines.

And it is also 1 (one) mile across on both axes so you need a very large layout room to take it..