As for the “Big Railway”, this topic includes track laying as well as the trackbed (formation) and the bridges and structures and, indeed, the whole of the landscape through which the railway is built. However, baseboard construction also comes under this heading for the indoor modeller.
One of the biggest choices to make when planning a garden railway is the height of the railway. Building the trackwork at or near the level of the surrounding ground allows landscaping to blend the railway into the scenery and to give a more realistic appearance. On the other hand, building the trackwork on a shelf four feet or so above ground level makes it easier to watch the trains go by, but there seems very little chance of blending the railway into the garden and, if any stock derails, it has a long way to fall! Navigating around the railway on foot is another consideration. Building at or near ground level makes stepping over easier, putting it on a high shelf suggests lifting sections or having to duck under ... and none of us are getting any younger!
It seems to me that a high level layout is principally about running trains, whilst a low level layout is more about creating an image in context. Whatever height I settle on, I have to consider the levels within the shed where the main station, fiddle yards, storage sidings, etc, will be accommodated.
I shall be working out the details of my choices as time and other distractions permit. I have a bungalow in Lincolnshire with a 50 foot (15 metre) long garden and with a roof-space about 35 feet by 17 feet, although this is not uncluttered, so I am spoilt for choice!
The track standards I will be able to adopt will be dependent upon the wheel standards I decide to use. I have a substantial fleet of Hornby Dublo wagons and coaches with their original wheelsets and this will define my starting point.
I’m quite attracted to 00-SF which is designed to allow commercial ready-to-run stock with standard wheels to be run straight out of the box with finescale (1.0mm wide) flangeways. The flangeway gaps in S&C is where the improvement in appreances really stands out. However, since the wheels of my original Hornby Dublo stock have a back-to-back dimension of 14.0mm, I fear they will not run on track made to this standard. If I have to re-wheel my stock, then I might as well go to EM, OO has little else going for it, especially in the garden!
Most of the trackwork will represent bullhead on timber sleepers but I will have one length of concrete sleepered track representing an early installation of flat bottom CWR on the main line. I will be setting out all curves with transitions to smooth the entry and exit of my trains and the curves will be canted (banked or superelevated).
The setting out of transitions and the application of cant can be quite complex on the big railway but some considerable simplification can be made for a model. The maximum cant is 6 inches for the big railway which is 2mm at 4mm to the foot. However, cant is measured over the centres of the rails which is 5 feet, or 20mm, so the corresponding cant on OO would be 1.75mm. The normal rules for calculating cant and cant deficiency don’t apply for a model and a cant of less than 1mm will not be noticeable, so a value of 1mm to 1.5mm would be about right for most curves. The important thing to take from the prototype is the rate of change of cant because this translates as twist and creates a potential for derailment. The normal design limit for the big railway is 1 in 400, 1.5mm at 1 in 400 gives a transition length of 600mm which will probably look about right. Interestingly, Templot’s default transition length is 2 chains or 528mm at 4mm to the foot, which gives a cant gradient of 1 in 352. I think some experimentation is called for!
It’s worth remembering that, for a double track railway in the 1960s, all four rails on a curve often remain coplanar. The railway today economises on ballast by canting each track independently so there will be a step down in the six-foot. For a four-track railway, pairs of tracks would be coplanar, with a step down in the ten-foot space. This makes canting easier on the model if the roadbed or sub-base is canted, rather than trying to shim the high rail.
For my turnouts, I am considering different options for outside and inside, they will be adjusted to suit my corrected six-foot dimensions. Whichever I go for, I won’t be using turnouts with hinged switch blades in prime spots indoors because I can’t abide the look of them, totally unprototypical! Viewing distances in the garden would help to disguise the hinges if I use them there.
Following a recommendation, I bought a couple of books written by Iain Rice: A Pragmatic Guide To Building, Wiring and Laying PCB Track and An Approach to Building Finescale Track in 4mm. In these books, he takes a fresh view of what the modeller is trying to do, what can be done and the implications of the different standards that can be adopted. I reckon I may well be building my own S&C and, to help me with this, I have splashed out on a copy of the Templot software for track planning and plotting construction templates. It is quite unlike any other track planning software (it’s designed for plotting templates) and there’s a steep learning curve. However, after a few hours experimentation over two or three evenings, I suddenly found that I was producing something useful.
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