I recently came across a small book while browsing my LHS. titled Fortress Railroads. Intrigued because of the unusualness and my interest in military history, I checked it out. The book was about the Russian coastal defense fortresses which were quite large and which each had it's own small gauge railroay to move men, supplies and ammunition. The gauge was two-feet, and each fortress had full facilities, including a roundhouse, shops, coal bunkers, and all the rest. They seem to have had several locos and quite a bit of rolling stock at each one, understandable when considering that the average caliber of shore guns was 12 inches, requiring a lot of haulage capacity, and they also served to move the gun crews around as well. It seemed like something that would make an unusual modelling project, our perhaps a diorama type of thing with a lot of switching.