How big a loop of track do I need to reasonably run live steam?

[DCooper]

I have always wanted to have a small live steam locomotive but never had the time, money or space to splash out for one. I have contented /enjoyed myself with small indoor layouts either on DC or lately RC/battery power. But given that in a very few years I will be retiring and have a little money saved up thoughts go to maybe lashing out and actually trying my hand. The catch is I need to do the planning right as I get maybe one shot at this.

Parallel to this is that I have been working the last few years in our garden and enjoying the work enormously. This has freed up some small spots that could be used as right of way. I have several potential areas I 'could' put an elevated loop of track on but they all have a slope and their own unique strengths and drawbacks. Without knowing how big a loop I need I can't really do any planning. I do say loop as I have done enough modelling now to know that I like to just watch the trains run and working the train isn't of much interest for me. I have tried out a simple round loop of small radius 45mm gauge LGB track with my present RC/battery powered locomotive and stock but I can see from that testing I would need considerably more space to run live steam.

Any guidance as to what a working minimum length of track run I would need to run a very small live steam locomotive? Ideally I would like to use the small radius curves I have but is that practical? Is there somewhere I should be looking for this kind of information. Much of what I've read is geared for folks that have more resources than I can put to this project.

Any thoughts or guidance you can offer would be greatly appreciated.

Thanks

Dan

[LNR]

Hi Dan,
An often quoted rule for small 0-4-0 live steam locos is 36inch minimum radius. Therefore the smallest ideal loop would be a 6foot Diameter circle. Any straight sections you would want to add on any of the four sides of that circle would make it correspondingly bigger. Level track is always easier to run on, although personally I like driving my locos manually and grades add that extra interest.
A right of way about 6" wide can lead you from one circle to another area and of course the possibilities then are endless.
Good luck.
Grant.

[Preseli Chris]

Edited as I realised its about 45mm not 32mm !

[Preseli Chris]

Hi Dan.
I presume you are looking at sm45 track gauge. In sm32 gauge the bare minimum radius which I would use is 4ft thus requiring the use of flexi track . So factoring in 45mm track I would use a minimum 5ft radius curve , this would future proof running any larger locos and rolling stock. What steam loco are you thinking of acquiring? I ask this as the manufacturer usually recommends a minimum radius that their engines can run on.

Chris

[Durley]

I’m running live steam on minimum 2ft radius Peco G45 curves. Works fine for a small loco like my Roundhouse Katie and 4 wheeled wagons/coaches. So I’d say anything from a 4ft diameter circle upwards works! I had been using LGB R1 points which match the Peco curves but the loco tends to derail if going through as a facing point, in the trailing direction it is fine. If you can squeeze in larger curves, that would look better and obviously allow more freedom on stock that could be run.