http://www.coachbuilt.com/bui/w/wayne/wayne2.htm
Interesting reading. Our school district had two Wayne bodied buses on Ih chassis.That article explained the ribbed siding. They were also galvanized. Pita, due to paint chipping. Ever try to touch up school bus yellow? A million different shades after in weather two or three years. Had to constantly mix and blend colors to get a satisfactory touch up blend.
The school district purchased 6 Ward bodied buses due to low bid. The lights were a night mare. Constantly fiddling with the comb. brake and tail light units due to the cheapness. Thin curved ss metal pieces held bulbs and vibration would constantly cause contact issues. Looking back, We should have just installed quality units, but school districts are tight with funds to upgrade their buses. We liked the Thomas bodies the best of the three. Well made at the time.
I saw that rather long bus pulled by a semi tractor. Look longer that 60'. Would imagine that it was for off highway use only like a large plant or military base.
Be sure to visit the root part of the site there are a lot more interesting stories of builders and plenty of vintage eye candy.
I liked Blue Bird bodies because of the head room.
Jim
Last year I was there they spent big bucks and purchased three Bluebird 84 passenger flat nose with 555 cummins v8s. Those things worked well and the bodies were even nicer than Thomas's. 72 passenger buses got 5 1/2 to 6 mpg. The bluebirds got 9.