Some Modelling 'How To' tips

Laying Peco Third Rail

Practical experience from Colin Duff

The following is my experience of laying 24 real feet of third rail on my 00 layout using Peco IL-120 conductor rail chairs, IL-1X code 60 rail section, and joiners SL-210X.

The IL-120 pack contains sprues providing approx 100 conductor rail chairs, plus "spacers". As the chairs are designed to give the correct conductor rail height when using code 75 running rails the spacers are provided to get the height correct for code 100 running rails. In use the spacers look like a packing shim, or a very overscale extra insulator.

I am using code 100 track, basically because I bought it in bulk before code 75 was widely available (purchase to laying elapsed time being about 5 years!) but also because I have some Hornby Dublo and Triang stock of sentimental value that I want to run every now and then. It was my original intention to fit the chairs onto code 100 track without the spacers to give extra clearance. At the last moment I changed my mind and fitted them - I am glad I did as it would never have looked right.


First design your 3rd rail layout according to prototype practice. There is a dearth of literature available on this, but after a lifetime of observing the SR 3rd rail, plus looking at pictures and taking notes whilst travelling (knowing I was going to model the 3rd rail eventually), I planned mine on general experience. Knowing that the 3rd rail is generally, but not always, laid on the outside except in stations, and that alternate sections are laid on alternate track sides, plus the length of a gap without conductor rail is kept as short as possible - basically I put myself in the position of a pick up shoe and then designed the layout so that my chances of being in contact with the third rail without being knocked off sideways were minimised. The back of the Peco pack also gives advice with which I do not entirely accord because it shows the conductor rail running straight alongside the straight side of a point. My prototype track notes suggest that this is only possible if the conductor rail is split lengthwise and overlapped (like an expansion joint in CWR) with the inside approach being ramped up. My modelling skills are not up to reproducing this so wherever possible I changed track sides through the point. There are a few places on my layout where I cheated and in reality a pick up shoe would be sideswiped off. At baseboard joints I was originally going to solder the third rail to a brass nail hammered into the baseboard end board then gap the rail, but I decided instead to represent a section gap at each baseboard end even if the section lengths are then unrealistically short. It does make the third rail layout look realistically "busy"!

Measure the length of a conductor rail run, cut the code 60 rail to length, lightly filing the rail-foot (I think that is what it is called) at each end to a slight point. It is easier to thread the chairs onto the rail if the end of the rail is slightly chamfered - I only realised this after a day and a half. Turn down the rail ends at about a sleepers gap length from each end. I did not find the need to pre-curve any rail except where I had no choice but to join two lengths of rail with a joiner on a curve. At one place (but only one place) my track radius goes down to 18 inches, but even then I did not have any difficulty fixing the conductor rail without pre-bending.

Drill 0.8mm holes (I used a Nº66 drill) in the end of approximately every 4th sleeper. I was going to make a drilling jig but in the end I did every hole by mk1 eyeball with no real problems. It is realistic to vary the chair spacing every now and then - towards the end of a rail section I would suggest inserting an extra chair, and on straight long runs I (purely accidentally) sometimes only had a chair every 5th sleeper (it does get very tedious laying this stuff!). I found that a slightly larger hole in the sleeper end was better than a slightly too small hole because the spigot attached to the chair is quite flexible and will bend rather than go into a slightly too small hole.

Cut as many chairs off the sprue as you are going to need for the length being laid, plus a few extra. Ditto spacers if you are using them. Thread the chairs onto the rail, placing them in approximate position. Thread on a few spares - it is easier to remove excess chairs at the end rather than thread on extras once laying has commenced. These small plastic parts do sometimes adopt projectile tendencies. At the end of two days I had a very sore blister on the end of the finger I used to press the chairs onto the rail.

Picture of the conductor rail on Colin Duff's previous layout

Insert the spigot of the first chair into the first hole. I used a jeweller's screwdriver or the end of a knife to manoeuvre the chairs into position. Then pressing down lightly on the rail at that position to keep it in place (I could not find any plastic solvent to bond this stuff) manoeuvre the next chair into final position and place it in the next hole. Go along the length of the rail progressively. On short lengths, particularly on curves, there is a tendency for the whole thing to come unfixed before you get to the end of the run unless you can find some way of holding the already fixed part of the conductor rail in place. Parts fly everywhere - start again!

If using the spacers, I suggest positioning the spacers between the sleepers at the sides of the running rails in advance of the holes. At this point it all begins to look like real life track laying is in progress First manoeuvre the spigot over the spacer, lifting the spacer onto the spigot with the blade. Then holding the spacer on the spigot with the blade manoeuvre the assembly over the hole and pop it in quickly.

To finish off I soldered thick layout wire to conductor rail sections, threading it under the track where appropriate, etc, to reproduce the power feeders which will eventually disappear into the trunking I have yet to model.

I then ran my Hornby Networker. I do not know how accurate the positioning and dimensions of the shoe beam on this model are, but the shoe ran a microscopic distance above the conductor rail head and tracked the position of the conductor rail exactly. Did I feel good about it - you bet! Subsequently I have found that the pick up shoes on my Ian Kirk 2Bil plus Hornby Class 92 and Eurostar models all track the third rail laid this way well. The Lima Class 73 needs its shoes filing down as they are set too low and lift the model off the track slightly. Unfortunately the bogies on Golden Arrow Productions' Class 71 model are made to exact 4mm scale so do not track third rail laid on 16.5mm gauge track - in fact the shoe beams foul it so badly that the model will not run.

In all it took me about 16 hours painstaking but tedious work to lay 24 feet of conductor rail. The good thing is that you get quicker as you go along and perfect the technique.

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Modelling 4mm Scale Conductor Rail

Practical experience from Colin Duff

Image of 4mm scale conductor rail

In this section we review some of the products available to assist with representing the 3rd rail on a 4mm scale layout and provide some advice.

An element of compromise is usually necessary when modelling, particularly in smaller scales, so before we take a look at the products we raise a few issues about which we think you need to be aware:

Height and Location of the Conductor Rail

If you are adventurous and intending to have a fully working conductor rail system then accurate alignment both vertically and horizontally will be vital, but even if not, the pick-up beams and shoes on the rolling stock will need careful adjustment to prevent snagging on the conductor rail. For instance, the writer found that when using Peco Individulay components on Peco Streamline code 100 track with the conductor rail at scale height the pick up shoes on Lima Class 73 locomotives were rewardingly accurately aligned horizontally with the conductor rail, but the pickup shoes contacting the conductor rail lifted the locomotive fractionally off the track so they would not run. It may be necessary to compromise and lower the conductor rail fractionally.

Narrow Gauge Considerations

Obviously OO gauge track is less than true scale width, and to a lesser extent so is EM gauge track. There will be a problem if rolling stock is fitted with accurate scale width bogies but running on OO gauge track because the pick-up beam/shoes fixed to such bogies will not align with the conductor rail, actually tracking outside the conductor rail. Not only does this look odd, but the beam/shoes might snag on the conductor rail, especially on tight curves and pointwork. Most ready to run stock intended for OO gauge makes a compromise with the width of its bogies, and, for instance, this is not a problem with Lima Class 73 locomotives nor Hornby Networkers. However, the bogies on Golden Arrow Productions Class 71 locomotives appear to be accurate scale width, which is ironic as these models were advertised as only made for OO gauge.

Strength/Resilience versus Accuracy and Looks

4mm scale conductor rail supports are rather small and thus prone to be delicate both to install and maintain. Fixing of the supports to sleeper ends and fixing of the conductor rail to the chairs may be weak and thus prone to damage by derailments and during track cleaning. So a compromise, trading slightly over scale components for strength might be worth considering or even sacrificing realistic looks all together by adopting a strong fixing method by not using scale supports.

Scratch Building

For strength and resilience at the cost of looks, fixing appropriately sized domed brass screws or brass tacks to sleeper ends and soldering the conductor rail to these is a consideration. Some modellers have even been known simply to glue the conductor rail to sleeper ends. These are likely to be the cheapest options!

Whitemetal Supports/Chairs

It is believed whitemetal casting of supports/chairs are either available or have been in the past, however I have been unable to locate any to appraise them.

Peco Individulay

Image of two sprues worth of Peco Individulay IL-120 chairsPeco Individulay IL-120 supports/chairs and IL-1X code 60 rail have been available for many years. The supports/chairs are injection moulded in a slippery engineering plastic which makes them next to impossible to bond to anything. They are also small and delicate items, prone to damage during installation and use. Packing washers are on the sprues to raise the supports/chairs to scale height when using code 100 track.

No jig is available for drilling mounting holes accurately into the sleeper ends.

For a full account of using these components, please read the article above.

Scalefour Society/Exactoscale

Image of Scalefour Society supports and chairs The Scalefour Society has commissioned Exactoscale to produce accurate scale conductor rail supports said to be made of etched brass (but looks like etched Nickel Silver to me) and injection moulded plastic to go with its scale correct section 150 lb/yard conductor rail. These supports can, according to construction, be used to represent outer third rail and lower centre 4th rail for London Underground tracks and low supports for Southern third rail. Each packet provides between 60-70 supports, depending upon type being modelled. This is equivalent to at least 2.3 metres of plain 3rd rail track. End ramps, as nickel-silver castings, for Underground tracks are also available. These components are only available via mail order to Scalefour Society members, however non members can buy them at Scalefour Society exhibitions.

These parts have been available since September 2005.

Whilst these are undoubtedly the most realistic looking and accurate scale representations, every single support/chair you will need has first to be assembled from three parts - base, top (both plastic) and chair (metal). The parts are small so good manual dexterity and excellent eyesight, or assistance from magnification, are required. Construction of a jig to bend the chairs to the correct position is recommended. As bases and tops for both inside and outside supports for London Underground and for Southern Electric 3rd rail are supplied on each sprue, if you are only modelling the Southern there will be more parts left over than used. The parts are identified on the sprue but these markings are very light and I had difficulty seeing them. No jig is available for drilling mounting holes accurately into the sleeper ends. The spigot to fix the base to the sleeper end is very short, thus the result will be delicate, however unlike Peco Individulay the supports/chairs can first be fixed to the sleepers and the the conductor rail then laid onto the chairs.

C&L Finescale

Image of C&L jig and 3rd rail chairs Recently introduced, C&L Finescale produce a number of components for 3rd and 4th conductor rails, including alignment jigs and side protection boards. For further details from their website, please click here.

Unlike with the Scalefour Society components, with C&L Finescale Southern Electric 3rd rail and London Underground 3rd & 4th rail parts are available as separate packs. Reviewed here are only items relevant to the Southern Electric System.

Image of C&L protection boards and brackets Above left can be seen the jigs for aligning supports/chairs and side protection boards, plus lost wax brass supports/chairs. The supports/chairs are robust, maybe a tad over scale, and the feed provides a spigot that can be cut to length, potentially for fixing though the sleeper to the baseboard. So a firm fixing is assured, however the diameter of the spigot is roughly two thirds the width of an HO scale sleeper, i.e. Peco Streamline/Setrack, indeed most ready to run OO gauge track, so care needs to be taken when drilling to avoid splitting the sleeper. The conductor rail is fixed to the chairs after the supports/chairs have been installed, either by glue or solder. Currently the cost of supports/chairs works out at about £2.25 per foot.

Left can be seen side protection boards and brackets, the latter requiring spiking to sleepers.

Hopefully you have found this page to be of use. It is down to the modeller to decide what will work best for his requirements.

For advice on prototypical use of 3rd and 4th conductor rails, you are advised to view Russ Elliot's authoritative and highly useful page of Third & Fourth Rail dimensions and settings.

This article is reproduced from the Southern Electric Group's pages with the kind permission of its author, Colin Duff.

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This page was last updated 1 March 2009

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