There is a Fordson locomotive (maybe about 18" to 24" gauge) on display at the the
Heidrick Ag History Center in Woodland, Calfiornia.
I posted a photo of the device on this forum about 18 months ago.
Here is a link to the post.
I also found some pictures on a discussion page on the
MODEL RAILROADER magazine web-site.
From the museum's collection discription page:
Quote
Fordson-Towner Locomotor 1924
This Towner attachment pulled three to four ore cars in mines around Placerville. CA. This attachment sold for $750. H. F. Towner was better known for his tillage tool business.
This was known as an Armstead Snow-motor. Hauling capacity was said to be five tons. Each drum receives power from a separate clutch which, depending on the position of the steering gear, engages and disengages. It can also traverse bare ground. This machine hauled mail from Truckee to North Lake Tahoe.
Brian Norden