A Texas general contractor had to place 92 precast concrete girders on top of a large wastewater treatment plant. The 240-foot width of the tank was to be spanned by 46 pairs of 110- or 120-foot girders that weighed about 50 tons each. Unfortunately, his crane couldn't reach far enough to do the job. Using experience gained on highway bridge projects, he decided to roll the beams into place using high-strength rollers.