It's definitely 3/4" = 12" scale, or to put it another way, 1/16 scale.
Interesting that in the UK, locomotives etc. are much more usually referred to by their gauge, rather than scale. In this case, the loco is 3 1/2" gauge.
David
3/4 inch scale Challenger
Re: 3/4 inch scale Challenger
I've cut this bit of wood three times now, and it's still too small!