Ravensclyffe

[pendlerail]

There is shuch a thing on the approach to Platform 1-3 at Liverpool lime street, but due to the complexity of the area I think there is 3 parallel wires on the approach

[Dagworth]

There is shuch a thing on the approach to Platform 1-3 at Liverpool lime street, but due to the complexity of the area I think there is 3 parallel wires on the approach

Thank you, that gives me some good hints for a photo search

[Titan]

No easy answer on this - in real life it depends on track geometry and each location would be different. The most likely would be three parallel wires leading up to the toe of the points, then the left hand wire would cross over the other two to become the wire for the right hand diverging track, and vice versa for the right hand wire. This would help ensure the staggers are correct for the curves leading away from the points (left stagger for right hand curve, right stagger for left hand curve)

 

Supporting it might be tricky, For a normal set of points you would have a twin cantilever, which of course only provides for supporting two wires. What would probably happen in this case is that one cantilever would support two catenaries, spaced between 230-380mm apart (in real life!)  and there would be a knuckle between the two respective contact wires to keep the contact without a registration arm registered.  You would usually find this type of points in a low speed area where the OLE is fixed equipment, so tying stuff together with knuckles and putting two catenaries on one cantilever does not cause problems with differential thermal expansion of different wires.

[Clive Mortimore]

Hi Andi

 

Is this for Ravenscliffe? Do you have a photo of its location on the layout with respect to the other OLE around it. The reason I ask could the registration arms be on a portal?

[Dagworth]

I'm coming to the conclusion that it's going to have to be a portal, I wanted to try to get away from portals over that section but I don't think it's going to be possible.

Although re-readng Titan's reply this is in the yard so yes it is low speed...

 

Andi

[Titan]

A picture is worth a thousand words!

 

Its a little crude due to being quickly done on paint, but a few points to note. It would be a single mast  of the heavy duty double channel type, with two cantilevers attached - pretty much the same as you would expect on any other points. However one cantilever supports two equipments. You can see that one catenary is placed above the top tube, the other below. This is to ensure different heights where they cross in span so that they do not rub.  In practice the wires would not all cross in the same place, usually because three way points are unlikely to be symmetrical, but even if they did then the designer may swap registrations around or alter staggers to ensure they did not. Its just the way my drawing turned out, which is far from scale anyway!  The blue and green wires would be lifted 'Out Of Running' on the support to the left, that is usually 230mm above the 'In Running' wires, which would normally be the red wire. They would then go out to anchor, although if in a station area they may continue out of running throughout the station and be anchored beyond the platform as you would not allow an anchor wire to cross above the platform and there is rarely room for an anchor mast between platforms.  The red wire is shown staggered to the right on the right hand side of the drawing, this is to ensure there is a load to keep the knuckle in tension, which otherwise might be at risk of collapse.

Edited May 16, 2014 by Titan

[Clive Mortimore]

Hi Ian

 

To add to your post would the point wires be anchored something like this. The blue wire on mast 3 is out of running.

 

[Titan]

That is one option, although the red wire on 3 ought to be a push off on a right stagger if anything to help maintain the knuckle on 2 in tension.

Edited May 16, 2014 by Titan

[jamie92208]

These photos of some OLE at Lancaster might help you.  Though the supporting structures are pure Midland 1907 the OLE had been altered when it was converted to 50Hz in 1955 and I think was used to develop the Mk1 OLE equipment.  One photo shows how a bay platform was wired and the other shows a 'knuckle' that was above a single slip.

 

 

Both Copyright R Jackson, used with permission.

 

There was a strecth of line about a mile towards Morecambe where there were seeral types of experimaental OLE erected as test beds for the forthcoming WCML.

 

 

 

Hope this is of some use.

 

Jamie

Edited May 16, 2014 by jamie92208

[Dagworth]

Thank you guys so much, I knew the answer would be among the members here

 

A

[pendlerail]

Having just been through the 3 way point at lime street, I can say that the 3 wires run parallel up to the point then split without crossing eachother in this location

[Titan]

And that's the thing, each arrangement in real life is designed to suit the specific location, taking account line speed, traffic direction, track geometry etc. So what might be suitable in one location might not work in another. The principle reason why wires cross at points is to avoid pantograph hookover, a cross contact bar ties the two contact wires together so that as the pantograph lifts one wire, the other is also lifted to match.  This is more important at high speed where trains can run in either direction on each wire. At low speeds where the wire does not lift so much it is not so much of a problem, although it would still be normal practice to cross the wires if possible. As an aside, modern high speed crossovers don't cross the wires, but they usually have something like 'cross droppers' that connect the catenary of one wire to the contact of the other, so that when the catenary lifts it tends to lift the other contact wire also. Needs much more accurate setting up to get it to work, but the end result is a softer ride for the pan. That won't be applicable to a three way though!

[Dagworth]

In answer to Clive's earlier comment this is the board in question.

 

The electrified lines are the two concrete sleepered tracks, the one above and the three below coming into the three-way from the left hand side of the board. On the right hand side only the main lines and the line at the bottom will be wired, the two other roads feed in to the NCB and will not be wired, the bottom road is a shunt neck. i was going to wire the lower NCB road but have now changed my mind so one of the wires from the reception roads will now need to terminate on this board.

The board to the left of this one as viewed here has a portal virtually on the edge of the board carrying wires for all six wired roads.

 

Andi

[TheSignalEngineer]

The ends of Bescot Yard may well be worth a look. There was some pretty complex knitting there, some of which still exists.

[Clive Mortimore]

Hi Andi

 

wot bout this matie ?

 

To terminate the blue wire it will need to be fixed to a heavy portal, the type used for overlaps. An alternative is to terminate it on the upright of a standard portal which means it will need to cross over the red wire on the first span so it can get to outer post. The same portal (either design) would be an advantage for the registration of the mainline wires and that of the crossover from the outer track to the outer mainline line. 

 

 

I await Ian's thoughts. 

 

Another thought is regarding the sidings, would they have isolating swtiches, are you intending to have them?

 

 

[jamie92208]

If you do  follow Clive's suggestion above here's a photo of a reinforced gantry that acted as a terminator at Lancaster.  The cross beams were 3" by 5" by 1/2" angle iron with 2" by 2" stiffenners.

Copyright Rev R Jackson, used with permission.

 

Jamie

[Dagworth]

That's pretty close to my plans Clive, except that the blue wire will go to the siding covered by the 'out of running' label. The red wire continues over the crossover from Up to Down main on the next board beyond this and then to a terminating mast. Oh and I don't need the portal over the three sidings on this board, just a pull off wire for the siding nearest the main, the other two are straight enough and short enough runs from the portal on the previous board to the point cantilever set.

 

The switching for the sidings is at the other end so this end only needs a section insulator in the wire between the yard and the main.

 

Andi

Edited May 24, 2014 by Dagworth

[Dagworth]

Does anyone have a decent close-up of this tunnel portal at Crewe that they'd be willing to share please?

 

Andi

[Phil Bullock]

Andi

 

Does this one help?

 

http://www.flickr.com/photos/r-t-c/8371993162#

 

From Tim Young's Flikr photos

 

Kind regards

 

Phil

[Dagworth]

Thanks Phil, that's excellent

 

Andi

[Phil Bullock]

Welcome!

 

P

 

[Taigatrommel]

http://www.crewearchive.com/2011/08/liverpool-independent-goods-tunnel.html

[Dagworth]

So with inspiration provided by Crewe avoiding lines as per Rich's link above and Phil's link to this https://www.flickr.com/photos/r-t-c/8371993162 in the other topic here is the results of today's work. Gone from this

to this

and Ravensclyffe has a new tunnel mouth

Painting will continue later, then more overhead...

[Guest bri.s]

I've followed your progress for a while but not posted for along time , but awesome modelling I love the idea of the avoiding lines.

Great layout .

 

Brian

[Dagworth]

And with a bit more paint it starts to look the part. Lots of weathering to do yet though. Not bad for an afternoon's work I don't think.

 

Also this evening I've built the big parts of three OLE portals, they just need legs and suspension equipment added now

 

Andi