Stringing together UK Catenary help?

[JackClare1995]

Hello all

So I am toying with the idea of making a route with realistic UK catenary. I have a few screenshots here to show what I've done, and I'm asking if anyone can point out where any mistakes are in the way it's done...

The new wire enters, with the pre-existing wire alongside:





The new wire runs alongside the pre-existing wire between two pylons:



At the next pylon, the pre-existing wire begins to drop into a single wire at a termination point, passing between the two new wires:



The pre-existing wire ends at a termination point whilst the new wire continues in the normal push off, pull off, push off pattern:



Am I doing anything wrong? If so, can someone tell me exactly what I am doing wrong?

Jack

 

[JackClare1995]

I take it from the stunned silence that this is actually the correct way of putting up OHLE? :hehe:

 

[mezzoprezzo]

Some splines behave in strange ways.

I'm not familiar with the catenary you are using, but had a similar problem with a mainland European one. It worked well enough when stretching the spline out over a long distance, but didn't like having additional sections added to it. The newly connected section was out of line.

The remedy was to split the offending spline at the "bad" join and reverse it. All then connected perfectly.

The same problem can occur with some cliff splines and retaining walls.

What I now do, when adding additional sections of these "difficult" splines, is to lay the new piece separately on the baseboard and visually check which way it need to be connected. it's then a simple matter to pull the correct end across to make the join.

 

[stagecoach]

You would not pass wires through each other. New wire comes in from left, runs along side old wire. Old wire leaves to the right and new wire continues as single wire.

 

[JackClare1995]

Cheers for that, Mezzo! The catenary is the UK 25kv Mk1 range

@Stagecoach Is this also the case if there is a double track? It's very difficult to see it in some instances on mainlines, but on the tram route near me, where the new wire and old wire both terminate on the 'left' side of the track, how would the new one pass through the old one (or vice versa)?

Jack

 

[nexusdj]

There are some cases where the wires actually cross (slow speed diamond crossovers , slips etc.) with one going just over the top of the other with the action of the pantograph head to pick up on the incoming lower wire to allow it pass through the section .
Crewe north pre 1985 rebuild , check out the catenary wires at the top of the picture over the points : Here

In the case of the transfer between two tensioned wires runs on Mk1 catenary the newer collection wire comes in at a higher height than the existing collection wire to allow it to cross over above it (the double mast having one wire support higher than the other to facilitate this) . This new section then drops down to run level and parallel with the existing wire over 1 or more runs of supporting posts / gantries . The original contact wire then climbs up and away to it's tensioned terminating mast (this may pass through the new section to reach it's terminating mast) . This allows a continuous run for the pantograph head as it moves along .

I have not modelled this in it's full state , given that I wanted to keep the system fairly simple for users to set up . So Jack has set it up correctly for how I have modelled it .

 

[JackClare1995]

Hey Dave cheers for the reply!

So the existing wires (contact and upper*) pass in between the contact and upper wire of the new wire to reach the termination section on the 'left' side of the track?

Also, in that image at Crewe, is that two wires that cross each other or four wires that terminate? Edit: The only reason I ask is because I'd have thought that if they cross, one wire would be a few centimetres above the other so if a train were to take the right route, wouldn't the pantograph lose connection with the wire for a short amount of time which could cause arcing?

*I've no idea what the upper wire is called.

Jack

 

[nexusdj]

The top wire is the catenary wire , the bottom wire is the contact wire .

The photo : It's hard to say without seeing photo's of the rest of the OHLE set up in that area whether some of those wire's terminate or carry on . Given that you can see the platform end ramp in the bottom left hand corner then its possible that the cat wire in the middle of the picture (closest right hand side of signal) will have run alongside the cat wire it crosses in the station area to a termination point a few gantries back , as it's rare for them to run cat cables over platforms to remove any possibility of passengers getting electrocuted (umbrella's up etc.) .

As for the contact wires crossing , as the pantograph moves towards the point of the crossing it's head will start to make contact at it's far end with the other contact wire (Pan ends are shaped to assist with this) , This other contact wire will force the pantograph down and away from the higher wire until it looses contact with it , It will continue to run along the lower wire until this runs off the other end of the pantograph . These area's do usual create sparks as it's possible that the pantograph can loose contact momentarily whilst it's trying to raise up to the original height of its correct contact wire , especially if the train is drawing power for traction etc.

If you look at the picture closely you can see an additional wire connected to the lower contact wire which passes over the higher contact wire at the crossing point and locks down that contact wire , This prevents the pressure in the pantograph pushing that higher contact wire up too high on its approach which could result in the ends of the pantograph hooking over the lower contact wire and fetching the wires down !!

 

[JackClare1995]

Hey Dave

As for the station layout, I must say I travel through Crewe probably twice a month and I don't recognise the area on the photo at all apart from the signal box which is now part of the Crewe Heritage Centre where the Intercity APT is parked. I wonder if some of this track has now been lifted or re-aligned for the current carriage sidings.

Now that you mention about the pantograph shape it, I do know what you mean. They look somewhat like an elongated bow from a bow and arrow.

I did wonder what that additional wire was for actually, thanks for clearing that up!

I'll get on with building a route with OHLE, thanks again Dave!

Jack

 

[nexusdj]

The layout in the photo is the original steam age layout that Crewe had prior to 1985 when the layout was streamlined for higher speeds .

This is the signal box diagram from Crewe north Junction signal box (which is now part of the Heritage centre) this shows most of the pre 1985 track layout :

http://upload.wikimedia.org/wikipedia/en/9/98/Crewe_North_Junction_Track_Middle.JPG

The scissors crossover in my first picture showing the overhead catenary is on this diagram photo underneath the 2 lit red track circuit lights on the right hand side.
If you zoom in you can see the 195 signal number that matches the signal in the photo

 

[JackClare1995]

Oh yes, that's great! Wow, it looks so different! Seems like not all of the station is on that diagram. Almost unrecognisable :hehe: