3rd and 4th rail track

[John Branch]

As my own modelling interests largely lie in the London Underground arena, I have tried several times to make a stab at creating 4rail track to enhance the visual accuracy of my line.  I have no desire to use either of the extra rails to carry traction or control signals, but the opportunities presented by such an arrangement would be interesting.

I have found a lot of information on the interweb about the track standards, chair design, rail  weight, and many other features.  It does become very complex.  I am only immediately interested in straight, uninterrupted track, and to this end I have had a gauge made that positions the 4 rails relative to each other.  But how to support the rail?  Chairs, of course, but are these to be scale models of a selected type, or representations only?  How to fix them in a weather-proof way?

I have seen many pictures of models of G3 Southern electric stock in the newsletter, and surely their owners must have pondered the problem.  If anyone has come up with a source of supply or method of reproducing 3 or 4 rail track, please share it with the rest of us.

Thanks in advance

John

[IanT]

I imagine the chairs could be 3D printed in ABS John - and then added to CB's standard G3 track using solvent - possibly into pre-drilled holes. You'd need a UV resistant filament if you can find one.

I don't know what the exact scale size of the (150lbs?) flat bottom conductor rails required is but possibly a flat bottomed rail section from another scale/gauge (e.g. 16mm) might be suitable.

Regards,

IanT

[Doddy]

I have several original London Transport and British Railways (SR) insulator pots for 3D scanning. My idea was to have the CAD file modified with a screw fixing underneath them, which would enable a hole to be drilled into the sleeper and then the insulator pot inserted and bolted from behind. Brass rails would then be soldered onto the insulator pot.

Unfortunately, ill health stopped all work and I never got around to selecting an appropriate flat-bottomed rail for use as the conductor rails, nor obtaining the London Transport and British Railways insulating mounting pads to complete the three types of insulator assemblies.

[John Candy]

On the matter of LPTB/LTE insulators, as a youngster (in the 1950's and 60's) frequently riding the Northern Line (ex-C&SLR section from Morden to the City) I recall the 4th (centre) rail (certainly in stations with the suicide/safety pit) having a cubic insulator with elongated elevation standing vertically. I think (but memory may be failing) that the outer rail also had cubic insulators.
Anyone know when those were discontinued (more recent photos show the circular types)? Were they unique to the Northern/C&SLR stations and to the sub-surface sections?

Regards,
John.

P.S. Having reflected upon above, I recall from pictures I have seen in past that the abandoned (before Great War) second platform at Aldwych/Strand (GNP&B/Piccadilly Line) still has the type of insulator I remember on the Northern Line but without the suicide pit.

[Doddy]

"On the matter of LPTB/LTE insulators, as a youngster (in the 1950's and 60's) frequently riding the Northern Line (ex-C&SLR section from Morden to the City) I recall the 4th (centre) rail (certainly in stations with the suicide/safety pit) having a cubic insulator with elongated elevation standing vertically. I think (but memory may be failing) that the outer rail also had cubic insulators."

Yup! as below . . .



I do not know the dates involved, but the ground level metal support plates are being swapped out for adjustable height plastic versions when under repair/maintenance.

[John Candy]

The type of insulator I remember were very different to those.
 I left Morden in 1969 for Sussex and the type in the above photos is the later/replacement type which I saw on other tube lines and which appear in later photos of Northern Line stations.

I have looked again and below is blow-up of section of photo I have found of Colliers Wood (next stop south from Tooting Broadway) taken in 1950s.
My memory is that that rectangular insulators were white ceramic but not shiny/glazed like the circular types.



Regards,
John.

[Doddy]

Hi John,

There is an obsolete rectangular design of ceramic insulator, as described below.

 

[John Candy]

This ia a better image showing the type I remember.

It is a Northern Line train at Euston,not dated but pre-1938, since it is a UER "standard stock" train and post-1924 when the C&SLR was completely rebuilt with "normal" diameter tunnels to accommodate the larger stock.

Regards,
John.