"Moving manholes because of new curb lines can cost up to 50,000 dollars each," says James Pitts, an engineer for Ohio Bell. To eliminate this costly and time-consuming work, Pitts and co-worker Richard Taus designed an innovative device that allows new curb lines to be placed right over existing manholes. The device is a movable steel curb attached to a cast-in-place frame. Utility workers can easily remove the curb to gain access to the manhole and then replace it when their work is done. Cost of the curb, including installation, is about 2,000 dollars. That's 25 times less than the cost of relocating a manhole.

Instead of taking days to relocate existing manholes, workers can install the movable curb in less than a day. Workers remove the manhole frame and excavate around the exposed hole. Masons then lay brick around the manhole until they form a base tall enough to hold the frame level with the street. Workers fit the curb unit into a 48-inch gap left in the new curb line and embed it in concrete to secure it in place. Then forms are erected and reinforcing wire is laid around the frame. After pouring and finishing the concrete, workers install the cover plate.