Modelling a French village scene.

[ianp]

I am planning to build a micro layout, modelling a French village scene, in HOm (12mm) gauge. The track will be a simple circle. So, what is the shortest radius I can sensibly expect to achieve using commercially available HOm track from manufacturers such as PECO, Tillig and BEMO? My guess is a radius of about 12 inches. Does anyone know better?

Edited October 28, 2021 by ianp

[Nearholmer]

There are bound to be two answers:

 

- one that revolves around how tightly you can curve the track, and by cutting out the web of the plastic sleepering you can probably get below 12" radius without either using a rail bender or popping the rail fastenings, but will have trouble keeing a uniform curve and avoiding gauge tightening; and,

 

- another that revolves around what you can get to run reliably round any unusually tight radius, which will depend on the fixed wheelbase.

 

Can you buy horribly tight radius TT "set track"? Using the rail from that, soldered to copperclad sleepers would probably be a safer bet for uniformity of tight curvature.

[Gordonwis]

BEMO min radius recommended is 330mm. That's the radius of the old BEMO 'settrack' . I think it's a good choice for a FRench scene as it is quite 'basic' in appearance. I recommend using that if you don't want the hassle of getting an even curve with PECO HOm flexi track.

[Pacific231G]

Coming late to this Ian so you've probably already built it but the old Tri-ang TT-3 type B track came with radii of 12" (30.5cms) and 10 3/16 (25.9 cms): the point radius was 12". I know someone who's built a French metre gauge layout using Tri-ang TT-3 material (once a popular option for 00n3)  but Tri-ang stock had wider tyres than more modern metre gauge and the standard 0-6-0 chassis had a flangeless centre driver.

You'd probably get typically short wheelbase metre gauge stock around an evenly laid 12" curve but Bemo's 330mm would be more comfortable if yuo can still get it. Tillig do offer a 12mm gauge setrack with a radius of 310mm but it has an integral plastic (ballasted) base and is TT rather than H0m.

As an aside, I know that with H0e on 9mm gauge track  I found anything less than 9 inches to be problematic for my Lilliput 0-6-2s (though Eggerbahn/Jouef used about a 6 inch radius for their Decauville inspired models but with 0-4-0 chassis) It therefore depends a bit on what you intend to run on it.

 

As a rule I reckon that the radius in inches probably shouldn't be less than the gauge in mm. or , more mathematically, not less than 25-26  times the gauge. Curiously, that's about the same as Decauville's own minimum radius for loco haulage for all but their very smallest loco though for their six coupled locos that ratio went up to 4`1.