3 1/2 gauge Radii

I would like to build a small line in my garden, but need to know the min radius that a 3 1/2 inch gauge 2-6-2 tank engine would require! Would it run around a 12ft radius or is that to tight for this loco?

 

What is the fixed wheel base Ie distancew between leading and trailing drivers

 

Wheelbase length multiplied by 25 should give you a rough idea of the curves it will take.

 

Hmm... ...

Well, a Tinkerbell (7.25" gauge, 0-4-2T) normally has a 17" fixed wheelbase, which gives 425, which divided by 12 (12 inches to a foot) gives a radius of 35.416r feet (say 35' 6" for sake of argument). Now while I don't doubt the theory for ideal minimum radius - I know little about the theory of locomotive design, our two happily go round 25ft radius curves, given the standard 1/8" gauge widening.

I do know of a Tinkerbell that had the wheelbase shortened to 14" and was put round 12ft radius curves... ... :smt104

So if celticboy's 3.5" 2-6-2T has a fixed wheelbase of - say - 12", the minimum radius for the fixed wheelbase alone would be 25 feet?? Celticboy hasn't mentioned which design he is on about using (there are several), but I would personally hazard a guess that 10' would be fine, depending on the amount of play on the pony trucks... ...

Cheers,

Dom

 

Thanks for your advice, alot of help. It looks like my minimum radius of 12' could be workable.

Thanks