Perhaps this was because I had just made a simple bend with a pair of flat parallel faced pliers.
What sort of bend should the flare be? Should it be a knuckle bend?
It would be quite useful (for me anyway) if Templot could put a mark on the check rail where the bend should be.
@Steve_Cornford
Hi Steve,
It's not possible to answer a question like that without specifying a prototype -- check rails vary a lot.
And even then it can't be answered because the model flangeway gaps are different. Even P4 flangeways are over scale.
However, assuming you mean the original REA bullhead designs (now a century old), and exact-scale flangeways:
1. The flare is not a fixed bend. It is a curve with a radius of 33ft-6in. That's a radius of 134mm or 5.1/4" in 4mm scale.
2a. On some drawings a simple curve starts 3ft-1.5in from the end of the rail and curves outwards to a gap of 3.5" at the end of the check rail, from a flangeway gap of 1.75" at the start.
2b. On other drawings the 33ft-6in radius fits between the edges of the end two check chairs, with a straight end on the check rail at 1:18 from the running line, again to an end opening of 3.5". That puts the centre of the bend central between those chairs at 33" from the end of the check rail. It means the flangeway at the centre of the end check chair is 2.5", angled at 1:18.
3. Special angled end check chairs are made which fit at 18" from the end of the check rail (to the chair centre), to match the flared end. Left and right-hand angled versions are made.
4. For a typical 5-chair check rail, that means an overall check rail length of 13ft.
Nowadays check-rail flares tend to be a simple bend, starting typically about 3ft from the end, which is what Templot draws by default. Here is how that compares with the REA design:
n.b. that's the wrong chairing of course -- not done yet.
A is where Templot puts a simple bend, 3ft from the end of the check rail, and the green fill shows the result.
B is central between the chairs as per REA, and the red lines show where a 33ft-6in curve centred on B would run. The model rail is 36 thou wide, so you can see that the discrepancy is only a couple of thou.
All of which is largely meaningless because very few modellers use exact scale flangeways. Even P4 uses a flangeway which is 15% over scale.
You can customize the flare to whatever length and opening you want for model use by clicking the
real > adjust check rails... menu item. You can also change from a "bent" flare to a flare angle machined into the rail, as on most heavy-rail flat-bottom. See:
https://85a.uk/templot/companion/check_and_wing_rails.php
I will look at adding a mark on the template for the flare length, but it's easy to remember 3ft from the end = 12mm in 4mm/ft scale. Check rails are always vertical, not inclined, so there would be no difficulty in making it a sharp bend, as drawn by Templot. But in practice it is usually a more gentle radiused bend -- as is typically made by holding the rail in pliers and bending the end with fingers, and thus making a closer match to the red line.
I shall need to give all this some thought when it comes to doing the end check chairs for Plug Track. Looking at those wrong chairs above, don't hold your breath.
As an example of the differences over the years, here are some pre-grouping check rails and interlaced turnout timbering on the NER at Hessle. The short bent end is sharply angled and beyond the chairs -- very similar to countless model railway check rails:
Thanks to Mick Nicholson for this pic.
Such check rail ends can be easily set up at
real > adjust check rails... menu item.
cheers,
Martin.