The link below will take you to an online history of the 2 ft. SAR railways.
https://sites.google.com/site/soulorailway/home/system-3-1/joubertina-avontuur (https://sites.google.com/site/soulorailway/home/system-3-1/joubertina-avontuur)
The famous NG-16 Garratts ran there. These were the largest 2 ft. gauge locomotives ever built and had almost the same tractive effort as a Rio Grande K-27.
The next largest/most powerful locomotives used on this line were NG-15's which could hit 40 mph! These were/are 2-8-2s and that were designed to take really tight curves - the lead driver was tied to the pony truck. These were essentially 4-6-2's with the first wheel of the pony truck being powered.
These could be "Americanized" or serve as the source for unlimited bashes into 2-8-2s in On30!
Just a thought. Neat locomotive.
They are great looking locos. There are a few of them preserved in the UK: this one isn't far off being operational. http://www.whrsoc.org.uk/WHRProject/ng15.htm
There is an operational NG-16 Garrett on a private estate railroad in Texas.
4 of these locomotives NG 16s run not far from my home here in Wales.
On the Ffestiniog & Welsh Highland Railway
check out www.festrail.co.uk and enter locomotives in the search box