O Gauge SR conductor rails and pots

[Pelham Street]

Am working on the Uckfield MRC,s new layout. What is recommended  for SR conductor rails in O gauge, and where can the pots be purchased? 

 

The conductor rails were laid on alternative sides of the track to help shoe wear. Were the ends opposite each other or was there an overlap? Any help appreciated as we are up against the usual Club layout deadline! 

[Tony Teague]

Although not yet shown on the website, I know that Mike Radford of Electrifying Trains (in which I have an interest) has a casting for the pots; if you call him during business hours (0208 440 5918), he will certainly send you a sample.

I believe that Peco do a suitable third rail.

 

Tony

 

Edited to remove erroneous reference to bullhead rail

Edited May 8, 2017 by Tony Teague

[bécasse]

 

I believe that Peco do a suitable bullhead rail.

 

 

 

Surely, Southern conductor rail was a fat, low profile flat bottom?

[Tony Teague]

You are right - I was talking through my ar$e - have edited original post!

[Pelham Street]

The conductor rail was flat bottomed. Hence the problem of locating any. Preferably nickle silver, brass will do. I thought that getting the rail would be easier than this! 

[jim.snowdon]

First, there are on the Southern two distinct common conductor rail sections, 106 lb/yd and 150 lb/yd, as illustrated below -

 

 

The 150 lb/yd came in in the 1960s, really with the Bournemouth electrification, and in its derived wide-head version as the 75 kg/m section, is the current standard for all new work. The differences between the original and wide head versions are, in modelling terms, miniscule and need not be worried about here. Conductor rail is very long lived in comparison to running rail and is generally not renewed at the same time as the track, with the result that there is still a lot of the older 106 lb/yd rail in main lilne service. Sections o fthe original 100 lb/yd rail can still be found, but are uncommon. Taking the details from your club website, 106 lb/yd rail would be appropriate for the late 1930's, bearing in mind that the Portsmouth electrification did not go live until mid-1937. Southampton did not get electrics until the Bournemouth scheme went live in 1967.

 

As far as conductor rail layout is concerned, early practice was to put the rail on the cess side of the track "where it could be better observed by the driver" - modern practice favours putting it in the six-foot, where it is away from the cess for safety reasons. Alternating the rail from side to side is not a necessity, as over the course of a return trip each side of the train will see a nominally equal proportion of conductor rail. In station and junction areas, the location of the rail is dictated by other considerations - it must be on the side farthest from the platform, and through S&C it is a case of wherever practicable to maintain as much continuity as practicable. It is normally gapped through points - continuous rail with side ramps is a non-preferred option (a) becasue of the operational limitations of side ramps and (b), for the simple reason that it is preferable to keep it out of the way of the S&T staff involved in the maintenance of the rodding and switch drives/detection.

 

Overlaps where the rail changes sides are not a requirement - even a two-car unit is long enough to cope with a short gap at the change point as the collector shoes on each end of the unit are electrically interconnected. Quite long overlaps were required at Track Paralleling Huts as their switchgear at that time was operated from the 750V traction supply, but as you appear to be modelling a terminal station, the nearest TPH would be way off scene.

 

Jim

[bécasse]

I would be inclined to look at Karlgarin code 125/7 rail. While it is still slightly taller and quite a bit thinner than the prototype scaled down, it is closer to the shape than anything else that I, personally, are aware of. Giving it a good thick coat of grubby dark grey paint and then cleaning the top with an abrasive track cleaner might be sufficient to make it look quite good.

[jim.snowdon]

I would be inclined to look at Karlgarin code 125/7 rail. While it is still slightly taller and quite a bit thinner than the prototype scaled down, it is closer to the shape than anything else that I, personally, are aware of. Giving it a good thick coat of grubby dark grey paint and then cleaning the top with an abrasive track cleaner might be sufficient to make it look quite good.

One thing I wouldn't do, unless you are actually going to use it as a real conductor rail, is clean the top surface. Real conductor rail doesn't develop a shiny surface in the same way as running rail does, being made out of a quite different steel alloy and subjected to sliding wear from the cast iron shoes. If anything, it ends up as more a dull gunmetal colour.

 

Jim

[steve fay]

Contact JLTRT they are now doing them.

[mike hughes]

Pete Clark does them as well

 

Michael

[keefer]

lots of 3rd rail info here: http://www.clag.org.uk/3rd-4th.html

[Revolution Mike]

A friend of mine has 3D printed some O gauge conductor rail - it might be worth searching on Shapeways.

[bécasse]

One thing I wouldn't do, unless you are actually going to use it as a real conductor rail, is clean the top surface. Real conductor rail doesn't develop a shiny surface in the same way as running rail does, being made out of a quite different steel alloy and subjected to sliding wear from the cast iron shoes. If anything, it ends up as more a dull gunmetal colour.

 

 

Jim is quite right, of course, but I forget to add mention of need to chemically blacken the top surface after cleaning it of paint. Nickel silver can be tricky to blacken, but I have found that Birchwood Casey's Aluminium Black works OK and produces a surface appearance very close to the prototype appearance of the top of a conductor rail. To reiterate, the process of painting the rail was to make the model rail seem thicker, like the prototype conductor rail, rather than just colour it, although, in practice, the sides of the real rails (at least, ones that have been in place for any great time, as most are) are generally well coated with a blackish muck.

[Pelham Street]

Thanks for your help. The colour was a problem, but chemical blackening would seem to be the answer.

[steve fay]

Just like the real things option,

[Judge Dread]

Just like the real things option, IMG_1566.JPG

I would make two very trivial observations here, firstly the insulator pot shown here (and wonderful it is) shows no provision for the rail to be secured and that because it's not. The rail just sits on the pot and the shoulders are there just to stop it being pushed off. Secondly the tradition of painting third rail ends (and check rail ends) white lingered on for many years and still might be being done now.

Incidentally, it makes me smile when I see  the end of the third rail bent down so much as to touch the ground. As the system works on a earth return set-up, need I say more?

Edited May 26, 2017 by Judge Dread

[jim.snowdon]

I would make two very trivial observations here, firstly the insulator pot shown here (and wonderful it is) shows no provision for the rail to be secured and that because it's not. The rail just sits on the pot and the shoulders are there just to stop it being pushed off. Secondly the tradition of painting third rail ends (and check rail ends) white lingered on for many years and still might be being done now.

Correct, although they might have had the wit to include the heads of the other two coachscrews that are used to secure it to the sleeper. Strictly, there are various heights of insulator depending on whether the track is 95lb bullhead or 113lb flatbottom and for 106lb or 150lb conductor rail, and for timber or concrete sleepers, but that can probably be overlooked. What should not be overlooked are the short insulators that go under the foot of bent rail ramps.

 

And ramp ends are still being painted white even these days for much the same reason as was done in the past, but not universally. The practice is more prevalent in complex areas than it is out in the middle of the countryside.

 

Jim

[Trog]

I would make two very trivial observations here, firstly the insulator pot shown here (and wonderful it is) shows no provision for the rail to be secured and that because it's not. The rail just sits on the pot and the shoulders are there just to stop it being pushed off.

 

Although there should be rail anchors either side of a number of pots in the middle of each con rail, to prevent the whole rail moving longitudinally.  The rail anchors are only fitted in the middle of the rail and longer rails have more than short rails so that as the temperature changes the rail can shrink and expand about its centre point thus relieving thermal stress. These days ring shaped clips like those modeled above are used on all pots, but in the past pots not required to be fitted with rail anchors would only have two C shaped single clips.

 

Also note that LT con rail practice differs in detail from that of the SR and ex LNWR North London Electric systems.

Edited May 30, 2017 by Trog

[NSE DAZ]

Hi all sorry to drag this up from the depths!! But is there anyone that produces the third rail pots? Peter Clark is out of stock but I am sure that I saw some 3D printed ones knocking about?

 

Stay Safe!

 

Darren NSE DAZ

[jim.snowdon]

On 30/05/2017 at 22:45, Trog said:

 

Although there should be rail anchors either side of a number of pots in the middle of each con rail, to prevent the whole rail moving longitudinally.  The rail anchors are only fitted in the middle of the rail and longer rails have more than short rails so that as the temperature changes the rail can shrink and expand about its centre point thus relieving thermal stress. These days ring shaped clips like those modeled above are used on all pots, but in the past pots not required to be fitted with rail anchors would only have two C shaped single clips.

 

Also note that LT con rail practice differs in detail from that of the SR and ex LNWR North London Electric systems.

These days, ceramic insulators are rarely used for new work or replacements, having been replaced by polymeric insulators that include a bolting flange on the foot so that the insulator is fixed directly to the sleeper.

 

True, there are detail differences between LT, LNW and SR practices, but they really are in the fine details, such as anchoring, cable attachment methods and ramp ends. The ex-LNW lines used an odd 105lb/yd conductor rail section, but in a model you would be hard pressed to spot the difference from 106lb/yd.

 

~Jim