5,600 pylons were drilled in place to support 5,600 sleepers and 4,200 prefabricated L-shaped track pieces, sited at 12-metre (40-ft) intervals. The width of both tracks, sitting on the sleepers, is 6.2 metres (20 ft).[4][5] The O-Bahn's concrete tracks were narrower and lighter than those of the initially proposed light rail development, and put less stress on the land. The concrete components were precast and then laid onto piers.[3]