Sn30 model railroads, 30 inch gauge railroads, were famous for industrial commodities hauling, mostly operated locally with some passenger service offered. There are many different one of a kind car types which makes modeling the 30 inch gauge layouts unique. Go to Big Indoor Trains, this site has a lot of info on 30" gauge railroads, it's a real good read! Sn30 equates to Sn2.5, as an "either or" expression of types

Modeling the (wide track version) Sn30 utilizes certain Sn3 locomotives/rolling stock modifiable to compliment Sn30s 1/64th scale. Sn30's (wide track version) track is the On2 type, gauge .500 or 12.7mm. On2 track is approximately 6% too wide to be correct for a 1/64 modeling scale of a 30" narrow gauge railroad. The correct gauge is .469 or 11.9mm. On2 track being close in gauge and readily available is considered to be an acceptable standard when modeling to the (wide track version) of Sn30. On2 track is available in rail codes of .040, .055, .070 and .083.