@rsjb18, I only have real experience with smaller (i.e.pickups) type hy-rails as far as operating them goes, but the smaller ones don't have brakes on the hy-rail wheels themselves.
As the tonnage of the truck and payload increases, additional braking power is a good idea. The contact of wheels or tires to the rail is so small in perfect conditions that extra braking power would be effective, but my limited experience is my only guide.
My other concern with a dump-truck with a rotating dump body would be over-tipping sideways off the rail! Having experienced a derailment of a hy-rail in wet weather, I don't recommend it.
But I'm straying off the subject, so will close for now.
Don Francis
