Army Porter 0-6-0 question

I'm wondering if anyone knows the story behind the 36" gauge Porter 0-6-0's that were built in 1918 for the US Government? Montezuma Lumber used one as a sawmill boiler in Colorado, the Army and then the Navy used one to switch at Honolulu and several were stored at Morse Brothers in Denver into the 1930's. Builder info shows them built for "Forestry Service in France". One may have ended up in Madagascar. As the 36"/914mm gauge is pretty rare in Europe, I wonder if the order for these engines was just a military screw up or was there a real purpose for them? Also, how many in all were built?