Hornby dublo 3 rail [childhood revisited]

[Ian R. Weeks]

Dear All,

               Whilst visiting Glasgow show this year ,I was entranced by the hd layout . After years of slowly,ever so slowly building stock for my proposed HR P4 layout. I was transported back to my childhood and the oval of HD with an n2 tank. I resolved to duplicate the fun again.I have slowly assembled the track and a couple of locos etc . I decided to build the last layout in a reproduction HD track plans book .All went well till switching the power on -both circuits[of track] live. Discovered the hard way that hand points are isolating and electric points constantly live. Is there a wiring way around this or should I bite the bullet and acquire electric points and switches. I should really attach the layout diagram but fear I will breach copyright.Any advice appreciated.

                               Kind regards Ian

 

[Player of trains]

I could be wrong but i think I've had the same issues as you when building double loops presuming you are using three rail track. Hornby used to make isolating tabs to put between he tongues of the centre rail all you need to do is use some paper or thin card slotted in between the tongues and that should solve the wiring issue.

Hope i was able to help PoT  

[sagaguy]

Electric points need a 3rail isolating rail & black D1 switch for true HD operation,However.if you havn`t got these,a small square of card between the tongues & a on/off toggle switch with the wire made into a loop & placed round the tongue of a rail in the isolated section will do the job.You do need a insulating tab between the points of the crossover.Also bear in mind that if you are using Gaugemaster hand held controllers for up & down circuits,they mut be fed from two separate 16v ac sources.

 

                          Ray.

[Il Grifone]

It's easy enough to convert isolating points to non isolating. Either solder a link underneath across the switch or link externally with the use of terminal and/or isolating rails. For a temporary connection, it's enough to wrap wire around the joining tongues at the end of the rails, ensuring it doesn't short to the base.

 

The metal base automatically forms a common return which is handy for returns of lighting etc., but it does mean that all supplies have to be independent to avoid shorts.

 

Is it this booklet, by any chance? (not that I have a copy - I had the original in the distant past.)

 

http://www.ebay.co.uk/itm/Hornby-DUBLO-3-RAIL-TRACK-PLANS-REPRO-BOOKLET-12-PAGES-USEFUL-INFO-LHP-HD252-/161487216380

 

EDIT. I forgot to mention that hand operated points can be found in isolating and non-isolating versions - the former being the earlier type.

[Ian R. Weeks]

Thanks chaps,I really appreciate the swift response.Iwill try and get time later today to a.check the hand operated points and ensure which version they are(did not realise that they came in two versions).b start the process of trial and error placing of the isolating tabs.I had followed the diagram for placing these but obviously this will depend on the version of the hand operated points I have. Oh and yes that is the plan book I have.Once again thank you for the help. Ian

P.S.Does the size the third rail tab give a clue as to which version the points are?

[Il Grifone]

From what I remember (it was a long time ago!), the Dublo diagrams included the locations for insulating tabs etc.

 

As a general rule, the non-isolating points (EDPL/EDPR) have narrow tongues and the isolating (ISPL/ISPR) wide. I wouldn't like to claim this as universal however - in fact the link below shows narrow tongued isolating points*. Pre-war manual points are all non-isolating and the manual ones have a sleeper base like the plain track and plain brass rail. The point lever and frog casting are often cracked due to zinc pest.

 

The tabs (made from proper transformer laminating material* turn up from time to time, but a piece of thin card makes an acceptable substitute, as has been stated above.

 

* I'm not sure what this actually is made from, but it's a grey coloured paper/card.

 

This might be helpful (details of electric point wiring)

 

http://www.modelrailforum.com/forums/index.php?showtopic=9097

 

and

 

http://www.modelrailforum.com/forums/index.php?showtopic=1435

 

(Sorry about the source!)

 

*It appears that the isolating points appeared in 1953 and the wide tongues in 1954.

[Ian R. Weeks]

Thanks chaps,I really appreciate the swift response.Iwill try and get time later today to a.check the hand operated points and ensure which version they are(did not realise that they came in two versions).b start the process of trial and error placing of the isolating tabs.I had followed the diagram for placing these but obviously this will depend on the version of the hand operated points I have. Oh and yes that is the plan book I have.Once again thank you for the help. Ian

P.S.Does the size the third rail tab give a clue as to which version the points are?

Thank you very much . the details in your attached post are really  surprising. I thought a 'Table Top railway ' would be a relaxing diversion,Oh how wrong I was. Now when I even mention recreating my first ever railway[ 3 rail o gauge br blue 0-4-0 tender loco 2 blood and custard coaches controller built by my father involving screwing out bulbs in series for speed control!]! Will some one send around the men with the jacket  that fastens at the back!!

[sagaguy]

Just found this pic on the web showing the difference in wiring,non isolating points on the far left & later production of isolating points to the right.

 

 

                          Ray.

[Il Grifone]

The switch appears crude, but, apart from physical damage - easily repaired, I've never had a switch fault.

 

2 rail points are not quite as reliable - they don't have a sliding contact - but as long as corrosion is kept at bay they are fine. Electronic switch cleaner should be used with caution, because some of them attack polystyrene.

[Wolseley]

From what I remember (it was a long time ago!), the Dublo diagrams included the locations for insulating tabs etc.

 

They are shown as black dots over the centre rail, as in this example:

[Wolseley]

Here's what the insulating tabs look like.  They are about 5/8" square and are made from a rather rigid but relatively thin piece of paper of some sort:

 

[Il Grifone]

AFAIK they are made of this stuff.

 

https://en.wikipedia.org/wiki/Electrical_insulation_paper

 

Ordinary paper or thin card is quite adequate for the low voltage Iinvolved in model railways, but if you want to do the job properly....