Overhead wire layouts

[danny]

Electric current passing through something is only going to affect paint on the surface if it gets hot. Hopefully we're talking about much lower currents than that!

It might be easier to common the overhead. My reasoning is that it's fairly easy to put insulated rail joiners in track but much less so in the overhead wiring. (The previous discussion about robustness also applies here.) If there's an issue with poor conductivity of the masts, then putting the feed through several of them will improve the situation. (Think of them as resistors in parallel.)

As I said before, this ios all very theoretical for me - I've never built model OHLE. I hope it's helping anyway.

Ian

I can't see why I wouldn't common the track (at one polarity) and the overhead (at the other polarity). No isolating sections because I will only shunt with one loco at a time, and unlike 2-rail you don't have to have things like isolating sections and switchable frogs for points as both rails are the same polarity. If I did want isolating sections though, these would be achieved by insulated fishplates, simply because it's easier and the appropriate fishplates already exist.

[danny]

Back a good many years ago, I built several HO American trolley (tram) layouts with overhead wire--simple suspension, not catenary.  It's standard procedure to use the masts (poles over here) for power feed, and it doesn't cause any problems.  The small gauge wire used for contact wire does have relatively high resistance, especially if it's nickle silver, so fairly closely spaced feeders are desirable.  Whether to gap the trolley wire or the rail for sections was a hotly debated topic.  I usually gapped the rails for the reasons Ian suggested, but either one will work and neither one is right in an absolute sense. In the early 2000s there was an article in the 009 News about the Isle of Dhoon Railway, which used overhead wire; you may want to look it up.

Paul

I looked up Isle of Dhoon but I can't work out if the overhead is live or just cosmetic as there appear to be steam and diesel locos running as well, although I suppose it could be dual-wired for wire or rail, with return through the remaining rail.

[Graeme Dunbar]

...  although I suppose it could be dual-wired for wire or rail, with return through the remaining rail.

I understand that is an established way of controlling two trams or other overhead wired layouts - or a variant, with one of the conductors being common.

[danny]

...  although I suppose it could be dual-wired for wire or rail, with return through the remaining rail.

I understand that is an established way of controlling two trams or other overhead wired layouts - or a variant, with one of the conductors being common.

It is, but I'm not sure if that's the system Dhoon uses.

[Paul Alliet]

The overhead duplicates the common return (009 News, June 2006, page 20).  The electric locomotives actually run two-rail, with an additional common connection via the overhead.

Paul

[danny]

The overhead duplicates the common return (009 News, June 2006, page 20).  The electric locomotives actually run two-rail, with an additional common connection via the overhead.

Paul

Ah, that makes sense. So not quite the same system that I intend to use, which is power through the wire with return through both rails - this therefore won't be able to be used by locos that aren't fitted with pantographs but that's not a problem for me.

[Pete Williams]

 Re-Tram track (grooved rail)
search the internet, I think a 00 version is made in america, but no UK stockest.
the most realistic girder type was made by Richard Ore, but production ceased a while ago plus a specialised rail bender was reqired.

[Ian McAulay]

I too have tried and failed to find tram-style rail. Electric Avenue in the USA do grooved rail for HO, but it's very expensive (more so when you include impost costs) and it's intended for Proto87, so probably far too fine flange standards even for modern 009.

However, embedded track doesn't necessarily have to have tramway track or even continuous checkrails. Here's an example from the once-extensive network around Leith docks (Edinburgh).

[Ian McAulay]

And another angle. Note that the granite setts are lined up parallel to the rails where they define the edge of the flangeway but transverse in between, including where they abut the actual checkrails on turnouts.

I have no idea what serves as sleepers under this lot, or what the rail profile is, or what the rail fastenings are.