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Discussion Starter · #1 ·
Hi, My name is John Piper and I am a new member, so "Hello" everybody.
I am about to start building a fully working model of a steam locomotive, possibly a 'Britania Class', and would like some advise please.
I have bought some locomotive and tender wheels which will determine the scale of the model, but a I am usure of what this scale would be. The diameter of the driving wheels is 120mm ( 4 inches ) and I think that a 'Three and a half inch' scale would be the correct size. However, I am also unsure what this means. Is it the width of the track or what ?
Apart from the wheels, everthing else will be scratch built. I also will build a full set of carriages and intend to run this set ( and any others that I will have time to build ) in a garden layout.
'Whoopy Do', you might say, ' And where will you get the time'?
Well, I am now retired from the everyday grind, I moved to France last year, and I intend to start on my affore mentioned lifelong ambition forthwith. I suspect, like many others reading this that I am not the only one that has started many such projects, and failed to complete them for various reasons, so am exited at the prospect of completing at least the construction of the engine.
At my age, ( the Oh comes just after the Six ) I can remember the final years of the 'Steam Age' regarding railways, and spent many a happy Saturday as a child at Scarborough Central Station watching the tourist excursion trains coming and going,from West Yorkshire towns, being hauled , in that particular era, by steam locomotives that would normally have hauled trains on more prostigious routes, most of which were in 'Weathered ' condition. Happy days, which I hope I can re create in part at least with my proposed venture. JP.
 

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Dear John,
Welcome to the forum and best wishes with your plans to build a live steam loco. You'll see that there is a section of the forum devoted to the larger scales, garden railways and live steam; it could be worth your while taking a look at some of the posts in that section.

Your driving wheels are 120mm? I query this because 4inches=100mm (1inch=25.4mm to within 0.1%)
The prototype Britannias had driving wheels 6ft 2in in diameter. So to a close approximation your 120mm wheels give a scale of 20mm to the ft. The nearest accepted scale to this is three-quarters of an inch to 1 foot. This is associated with a gauge of 3.5 inches as you thought. (The gauge is the distance between the inside faces of the rails, by the way.)

There have been a number of plans published of this loco at that scale over the years. I can remember 'Practical Mechanics' having a series on building a Britannia soon after they came out in the early 1950s. 'Britannia' herself is preserved at 'The Railway Age' at Crewe.

There are a number of books on building live steam locos - look out for titles by Martin Evens and 'LBSC', although the latter have been published for some time now. Current practice can be found in the 'Model Engineer' and one or two other monthly journals.

You will usually need access to some machine tools. If you don't have a lathe or a vertical drill of your own you will need such items and learn how to use them correctly. Again there are plenty of books available on workshop practices - look at www.camdenmin.co.uk - click on this link and it will take you to the website of Camden Minature Steam Services who publish a wide range of books that should be of interest.

If you were still in the UK I'd urge you to join your local model engineering society where you would receive much help - but I don't know if the French go in for such societies; a bit of internet searching might help.

Hope the above is of help,
Regards,
John webb
 

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Discussion Starter · #3 ·
Hi John Webb,
Thanks for your reply. Firstly, the diameter of the driving wheels is 120mm, and it was my misprint regarding the 4inch bit ( it should have been 4 5/8 inches ). I take on board your advice regarding working drawings, however, I plan to compile my own drawings using data on the locomotive that I already have. Regarding the actual construction, I am fortunate to have the machinery and the skills, due to my (former) job as an engineer . It was really the scale part that I was unsure of, but you have now kindly resolved that for me. Perhaps you could assist me further by advising me as to where I can obtain the track for this particular guage.
Kind regards,JP
 

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Glad to have been of help.

Many owners and Model Engineering clubs don't bother with scale track at this gauge - they tend to use 1" by 0.25" mild steel strip or even angle to form a robust and solid track. Bolts running through tubular spacers hold the 'rails' together at the right spacing. At 3.5 inch gauge you are in the realms of passenger haulage so a raised track taking passenger-carrying cars is very popular. Martin Evan's book "Outdoor Model Railways", published in 1970 by Model and Allied Publications gives considerable detail on various forms of track. It's probably out of print but again adverts in current issues of the "Model Engineer" or the website in my previous post may lead you either to reprints or to modern books on the subject. Adverts should also steer you towards suppliers of materials etc.

I very nearly bought a partly completed 3.5 inch loco off the father of a friend of mine at school in the early 1960s, but the price asked was too high at the time. I did look again at this type of modelling several years ago when I was contemplating returning to railway modelling. Althought I live only a couple of miles from an excellent club track, in the end I went for the Hornby 00 gauge live steamer as this didn't involve the investment in machine tools I would have needed to make. It can also be run indoors all year round.

Regards,
John
 

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Discussion Starter · #5 ·
Hi John, Thanks for the advise regarding the track. As it happens, this type of inovation, using propriety items and materials, is exactly what I do in making my models. Some of the pleasure and satisfaction I derive from modelmaking is that I use many standard items that were designed for something else and utilise them for the particular model that I happen to be building. For instance, there is a small stainless steel doorstop that I have adapted to make a steam valve for my 'Britannia' class Loco'. This fits perfectly into a standard piece of brass tube, which is in turn encased in a standard piece of metal tube for added strength, and works like a dream. Both items have been precision built by others, so it saves me the trouble. Sounds odd possibly to the normal railway modeller, but I was never one for convention. Another break from convention regards the matter that you mentioned, that the 3 1/2 inch guage enters the realm of the 'Ride on' type of garden railway. My intention is to create a sytem that is totally remote controlled from the driving of the engine, to the workings of the signals, level crossings etc. A bit ambitious you might say, well, it will give me something to do in my dotage and keep me off the street corners.
Kind regards, JP
 

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Sounds fun! Most 3.5inch locos are designed with coal-firing in mind from the driver/fireman seated behind it. Will you go for gas to give you the remote-control facility? I'll apologise now if I'm telling you something you're already aware of, but do bear in mind that, like the prototype, models of this size need careful warming-up to avoid undue stresses and strains in the boiler which can cause weeping tubes etc..

Regards,
John
 

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Discussion Starter · #7 ·
I am toying with the idea of some sort of 'Drip feed' oil sytem, or a worm conveyor similar to those used on American steam locomotives to feed the furnace. These will be worked by the movement of the locomotive and will not need remote controls. I will decide what will fit the best once the main body of the locomotive is constructed. My intention regarding the remote controls themselves is to make the actions multi functional ie. combining throttle lever and brake on a slotted rod system so that when the brake is released, then the throttle is engaged, and visa versa for stopping. The only other remote control that I should need is for the reversing lever. Should be interesting.
Kind regards JP
 
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