3″ aluminum I-beam crossmembers on 12″ center line full length, 28″ center line over tires
3″ steel I-beam crossmembers on 16″ center line full length; rearmost 3 crossmembers on 12″ center line
3″ steel I-beam crossmembers on 12″ center line full length, 28″ center line over tires
3″ steel I-beam crossmembers on 12″ center line full length
3″ aluminum I-beam crossmembers on 16″ center line full length; (9) 4″ tapered aluminum crossbars on 8″ center lines
3″ steel I-beam crossmembers on 16″ center line full length