Lightweight manhole covers boost productivity, enhance safety
Mulberry Cogeneration
Owned by Northern Star Generation Operated by CAMS
115-MW, dual-fuel, 1 × 1 combined-cycle cogeneration facility located in Bartow, Fla
Plant manager: Allen Czerkiewicz
Mulberry operators were required to open manholes in the water treatment area with covers that were very large and weighed around 250 pounds. This practice raised a safety concern as there was no easy way to maneuver the covers. To open a manhole, it would take several employees and crowbars and there was a risk of injury to hands and backs.
The Mulberry team was tasked with finding a better way to remove the heavy covers safely with one operator and with no risk of injury from the cover itself. Staff looked at several possible solutions. A manhole cover-lifter was purchased but it did not work for Mulberry, requiring participation by several employees in its operation and the possibility of hand injuries.
The plant settled on the fabrication and installation of aluminum covers, light enough to be handled by one person and rated to support a personnel load (Fig 1). Because they are not yet rated for vehicle loads, covers have not been replaced in areas with vehicular traffic.
The new aluminum manhole covers are working well. Personnel can remove them safely with no risk of a hand or back injury from heavy lifting. A secondary benefit of this upgrade is that it greatly reduces the time that personnel spend opening the covers now that they are not heavy and awkward. Covers now can be removed safely by one employee rather than requiring two or three.
