I really think S Scale is ideal for modeling narrow gauge. HO Scale narrow gauge is a little too small, O Scale narrow gauge takes up a little too much space, but S Scale narrow gauge is just right – and it gives you more and better choices. With HO, your choices are HOn30 (HO models on N Scale track) or HOn3. With O Scale, the choices are On30 and On3. S Scale gives you Sn2, Sn3, and Sn42.
Sn2 has a good selection of motive power as long as you like Forneys. Train and Trooper made quite a few different versions and they show up surprisingly often on eBay for around $250 – not a bad price for a nicely detailed brass locomotive. Brass passenger cars are also available once in awhile. The main problem with Sn2 is the availability of freight trucks – you can scratch build rolling stock all day long, but if you don’t have an easy way to put them on the rails you’re kind of stuck. If I was going to model a 2 foot gauge railroad I’d probably do it in HOn30 instead of S Scale.
Sn3 is awesome if you’re modeling a specific prototype – in fact P-B-L’s Southern Pacific locomotives are what got me into S Scale. No matter what prototype you want to model, chances are best that you’ll find locomotives and rolling stock in S Scale. P-B-L is the king of the hill, with lots of very nice brass locomotives imported over the years as well as rolling stock kits for various Colorado roads and my beloved SP narrow gauge. Older brass imports show up fairly often on eBay for good prices, and if you like to build, Railmaster Hobbies has lots of Sn3 locomotive kits. The problem with Sn3 is cost… a Railmaster locomotive kit is around $500, and if you want brass the price starts there and goes up to $1500 or more for a single locomotive. If you’re modeling a specific prototype the cost is worth it, but if you’re on a budget and don’t mind freelancing there’s a better (cheaper) alternative…
Which of course is Sn42 – S Scale narrow gauge running on HO Scale track, which scales to 42″ gauge. Instead of expensive brass locomotives, you can run modified HO Scale locomotives. In fact, the Tyco old time 4-6-0 is perfectly scaled for S so you don’t have to do anything to it besides paint. Other good candidates for Sn42 steam power are the MDC 2-6-0 and 2-8-0 locomotives, and HO scale diesel critters are perfect for more “modern” motive power. Some of the Athearn switchers can also be kitbashed into Sn42 pretty easily. For rolling stock you just use Sn3 kits with HO Scale trucks, and Titchy Train Group makes an HO Scale ore car that is perfect for an Sn42 mining layout. The picture shows a Tyco 4-6-0 that I just scored off of eBay. It’s just about a perfect match for Southern Pacific Narrow Gauge locomotives 12 and 13 – in fact it’s so close I’d almost consider narrowing the drivers to true 3 foot gauge and running it on my Slim Princess layout. But I need an Sn42 steamer to go with my Sn42 critters, so I’ll just paint it and run it.