Shay16

The Shay's rear driveshaft and the gears on the rear axels. Every axle on the Shay and it's tender is powered by direct gear drive. Note that the gears are square cut; helical cut gears which would have been much more efficient and smooth running were not invented until years later. The driveshaft's universal joint, which allows the rear set of axels to negotiate curves, is at extreme lower right.