Morgantown Lock Dewatering Reveals Severe Damage

The Waterways Journal
15 December 2014
By Jeff Hawk, Pittsburgh Engineer District

What lies beneath the water in the U.S. Army Corps of Engineers Pittsburgh District's aging navigation locks is sometimes difficult to fathom.

The $2.8-million maintenance dewatering of Morgantown Lock and Dam on the Monongahela River, October 17–November 19, revealed unexpected deterioration that lengthened the repair schedule and complicated the work needed to fix critical components. But skilled technicians and craftsmen from the Pittsburgh Repair Fleet and Pittsburgh Engineers Warehouse and Repair Station were up to the task.

Once they dewatered the chamber, crews found that the upper and lower sills providing a seal for the lock miter gates were in much worse condition than originally estimated. Severely cracked concrete and dislodged timbers required crews to completely replace the lower miter sill, stretching the work schedule an additional 12 days and adding $600,000 to the price tag.

Fixing the sills required installing an upstream needle dam and downstream poiree dam so that the existing miter gates could be removed and crews could work in the dry. Jack-hammering, concrete placements, custom fabrication to replace 50-year-old parts, and hard work ensued. Crews fixed the sills as well as gate anchorages, dam gate hoist gear boxes, and feeder electrical cables. New dam safety signs warning mariners of the approaching lock and dam were also installed.

When the repair party departed on November 19, its month-plus stay yielded a more tightly sealed chamber and a more reliable facility necessary to keep navigation moving on the upper Mon.

Members of the Upper Monongahela River Association and local government officials toured the site on two separate occasions during the dewatering to emphasize the importance of the facility to the community and the local economy.