OO vs HO

[Arthur123]

 My son wants to start a new layout using Thomas and Friends HO by Bachman but is interested in some other accessory trains by Hornby which is OO scale . Are they interchangeable ?
Thanks...

[the Bach-man]

Dear Arthur,
They are. The Hornby trains are actually scale models in OO to which they have applied faces. Our characters are proportioned more like the TV models, which are, in fact, caricatures, but they look fine with OO buildings. By the way, check out the Bachmann UK Scenecraft models- they look great, and are available from:
models11.com
in the US.
Have fun!
the Bach-man

[wjstix]

A little background - HO ("Half O") scale was developed in the 20's, first I believe in Germany with Marklin. A problem came up for the English modellers, since most British locomotives were relatively smaller than their European or US counterparts, so an HO scale (3.5mm = 1 foot) model of a typical UK engine was too small to fit the smallest available motor inside. So they increased the linear scale to 4 mm = 1 foot and ran it on the same track, calling it "OO scale".

So OO trains and HO trains run on the same track. Since British engines are about 1/8th smaller than a similar US engine, they don't look that different in size when next to each other. I'm not sure (Bach-man??) but I think the Thomas and Friends Bachmann pieces are really OO scale??

BTW the models in the TV episodes are I believe modified Marklin No. 1 gauge trains, 1:32 scale - using the same track as "G" gauge models.