Dublo Three Rail Layout

[Wolseley]

Back in 2016, I started a thread about Dublo three rail track plans and mentioned that I was looking at constructing a layout: https://www.newrailwaymodellers.co.uk/F ... 88#p612488

For the time being all I am doing is assembling some track on the dining room table for when our grandson comes over. He's only 16 months old, so something fairly simple will interest him for some time yet. I settled on plan number 4 for now, partly because it fits nicely on the table and partly because it's the sort of plan that I currently have more than enough track for at the moment. If you are prepared to do some non-prototypical reversing from time to time, it offers a few more operational opportunities than I thought at first. Small beginnings I know but, given a bit more time, hopefully something bigger, better and more permanent will arise. I have started accumulating locomotives and a bit of rolling stock for when that eventuates.

Dublo 1.jpg

Dublo 2.jpg

I thought I had better follow that up with an update as to where I am at now. The trackwork and virtually all the electrical work has been done, together with some scenery. Here are a few recent photos of the layout:

And to finish it off, here are a couple of retro style black and white shots - taken with a 1936 Leica IIIa with a close-up attachment:

[Wolseley]

The baseboard is in three sections, joined by coach bolts with metal dowels. The boards are connected electrically using plug-in terminal strips but for ease of wiring, the switches are on the boards that they control. I still have to add identification numbers or letters to the switches and do a diagram for each board which will help, as it's a bit difficult to remember which switch does what.

[Dublo]

Looking very nice Wolseley, it is amazing what difference the scenery makes to a HD layout. There are very few of us out here that are doing this. Looking forward to seeing more.

[Wolseley]

And, just to show there are some other items besides Hornby Dublo, here's a Trix Twin Pullman psed outside the station. The Trix steamroller wheels have been replaced with Dublo ones.

And a small selection of my collection of Duchesses (taken before scenic work commenced).

[Mountain]

Wow! You know the only alteration I would be tempted to do is to see if I could open up an old Hornby Dublo controller and put a modern cased controller inside it so it looks like the old controllers but inside it isn't. (Can this be done?)
It will complete the 3 rail look!
I have loads of HD 3 rail I don't really know what to do with at the moment, as I have no room.

[Wolseley]

Can this be done?

It probably can, but they take up more room on the board than a modern controller does and, as space is at a premium on my layout, I won't be trying. It would be interesting to know if anyone has done it though.

[GeraldH]

Excellent work! Looking forward to seeing more photos.

[Wolseley]

The latest addition to the fleet is a GEM Cardean on a Tri-ang B12 chassis, which I converted to three rail using a Marklin skate. Whoever painted it was a bit heavy handed with the lining but, as it looks presentable from a normal viewing distance, I'm not in a hurry to repaint it.

[Bufferstop]

Trying to judge their colour, are those the original design of point switches with the sprung contact that gave just one pulse? They were much sought after in the late 50's as they were just about foolproof whereas the later simplified design pulsed both coils as it was moved, and worse could be held on either deliberately or by something pushing on the lever. Warnings were given in the "Meccano Magazine" about the dangers of leaving tools etc in the vicinity of the newer switches after one or two cases of burnt out point motors.

[Wolseley]

Trying to judge their colour, are those the original design of point switches with the sprung contact that gave just one pulse? They were much sought after in the late 50's as they were just about foolproof whereas the later simplified design pulsed both coils as it was moved, and worse could be held on either deliberately or by something pushing on the lever. Warnings were given in the "Meccano Magazine" about the dangers of leaving tools etc in the vicinity of the newer switches after one or two cases of burnt out point motors.

I could be wrong, as my understanding of things electrical is not the best (to say it was stretched to its limit in constructing and wiring this layout would be pretty close to the mark) but I always thought that the basic design of the switches that operated the points and semaphore signals was more or less unchanged from the beginning right up to the end of Dublo. The warning with these switches, as far as I am aware, was to move them with a steady movement, neither too fast, which may not operate them properly, or too slowly, which could burn out the coils.

The only switches I know of that are a different colour from the red/brown D1 switches were the black isolating switches, and the green switches, for use with the colour light signals.

Most of my D1 switches that I bought boxed (about half of the ones you see in the photo) were early ones in dark blue boxes, but three were late ones in red and white striped boxes. There were no noticeable differences between them, other than the length of the "feet".

[Wolseley]

On another note, the Cardean is now running beautifully, if a bit fast (typical Tri-ang).

Initially I was finding it was sometimes, but not always, drawing almost 1 amp when starting and, when it did this, it would run for a short while very slowly and then either grind to a halt or suddenly pick up speed to an alarming extent. On the other hand, it would run perfectly in reverse.

I tried dismantling, cleaning and lubricating everything and checking for any binding of motion, wheels or gears, but no luck. As I had a couple of spare X04 motors, I swapped the existing motor for one of my spares, and the problem disappeared. It now performs better than I expected both forwards and backwards at speeds varying from a crawl to something that looks like it's two or three times as fast as Mallard was able to do.

[pete12345]

I like to see the old stuff taken seriously, and as Dublo mentioned, a bit of good scenery makes all the difference. Converting the Triang chassis to 3-rail strikes me as just what would have been done back then too. Purists (and collectors who like to hide things away, never use them and make money out of them later) might not approve, but to me it's like modifying a classic car with period parts.

[Bigmet]

...Initially I was finding it was sometimes, but not always, drawing almost 1 amp when starting and, when it did this, it would run for a short while very slowly and then either grind to a halt or suddenly pick up speed to an alarming extent. On the other hand, it would run perfectly in reverse...

That's a sure diagnostic for friction due to excessive wear somewhere in the drive mechanism (it has been preferentially operated going forward naturally enough, regular thing with steam tender locos that have had a lot of use).

Since a replacement motor 'fixed it', the most likely wear damage is to the thrust bearing in the motor, which for forward direction on the old B12 mechanism is the rear bearing, by the magnet. Is it 'dry'? Try a dot of light oil and see if it improves. If that does nothing then a competent service agent can sort it out, and you will have a good motor; as it must be electrically sound to run well in the reverse direction, when the rear bearing is unloaded and thus not creating any great friction.

[Wolseley]

That's a sure diagnostic for friction due to excessive wear somewhere in the drive mechanism (it has been preferentially operated going forward naturally enough, regular thing with steam tender locos that have had a lot of use).

Since a replacement motor 'fixed it', the most likely wear damage is to the thrust bearing in the motor, which for forward direction on the old B12 mechanism is the rear bearing, by the magnet. Is it 'dry'? Try a dot of light oil and see if it improves. If that does nothing then a competent service agent can sort it out, and you will have a good motor; as it must be electrically sound to run well in the reverse direction, when the rear bearing is unloaded and thus not creating any great friction.

I did try oiling it (Labelle 102 gear lubricant is what I used), gave it a couple of days to soak in and then gave it a couple more drops. It didn't make any difference.

Thanks for pointing out the most likely cause - I'm not intending to do anything with the motor at the moment, but I could find a use for it later on. It's going to live in my spares box for now but it might, once fixed, come in handy later.

[Wolseley]

Converting the Triang chassis to 3-rail strikes me as just what would have been done back then too. Purists (and collectors who like to hide things away, never use them and make money out of them later) might not approve, but to me it's like modifying a classic car with period parts.

Hatton's full page advertisements in the Railway Modeller in the early to mid 1960s regularly advertised Tri-ang locos converted to run on three rail Dublo track. Here's an excerpt from the January 1964 issue: