Re: hy-rail--uh, uh!

Said to say, but hy-rail trucks just really aren't practical on the narrow-gauge. Here's the math: Hy-rail vehicles use the vehicle's tires to propel the vehicle down the track; the steel wheels guide only. The average full-size truck has about a 65" track. This is narrowed by using special wheels to about 56"-60" (standard-gauge is 56 1/2") to fit. So, to make it work for narrow-gauge, the vehicle's track would have to be narrowed to 36", just more than HALF the vehicle's original track. I wouldn't want to drive that down the highway!
The D&S inherited a "hy-rail" Pettibone front loader from the D&RGW. For that arrangement, the loader's wheels drove a metal "friction wheel" which in turn drove the steel "hy-rail" wheels. This works OK for a front loader, where the weight of the vehicle and the "hy-rail" componients is not a big consideration, but it wouldn't work for a truck. By the way, just the "standard-gauge" hy-rail components for a pickup add about 1,000 pounds to the vehicle weight.
What would be about the right size for a narrow-gauge hy-rail? An ATV.