River traffic at Lock and Dam No. 4 in Natrona is closed for two months for maintenance.
Crews are draining the lock chamber to repair the valves and gate sill, according to Ian McKelvey, a supervisory operations specialist with the U.S. Army Corps of Engineers Pittsburgh District.
McKelvey said the district coordinated the maintenance schedule with industry and Port of Pittsburgh Commission partners to minimize river traffic disruption.
Originally planned for September to November, the project was delayed by nearly a month to allow a major commercial vessel to complete its shipment before work began, McKelvey said.
Work at the lock started Monday and is expected to last through Dec. 18.
It appears the delay was to allow for the river transport portion of the ongoing superload shipments from Armstrong Terminal in Gilpin to Homer City. The lock’s closure will not affect the ground transport portion of that project, according to terminal manager Mike Carr.
The superloads consist of heavy equipment meant to be transported by a giant, specialized truck to a power plant and data center project in Homer City. The equipment has been arriving at the dock by barge in waves. The first wave of equipment is complete and stored on site, Carr said.
The next set of truck transports will take place through the rest of October and into November, according to a release from PennDOT.
“The second wave (of barge transports) is scheduled for mid-December,
after the lock work is complete,” Carr said.
Edwards Moving and Rigging, the company leading the project, planned for the first set of barge shipments to be complete and to operate truck transports while the lock work is completed, Carr said. The third portion of barge transports is tentatively scheduled for sometime in January as long as weather and river conditions allow, Carr said.
Lock and Dam No. 4 is among eight major river facilities on the Allegheny. There’s a single 56-by-360-foot lock chamber and a fixed-crest dam that maintains a minimum river depth of 9 feet for commercial traffic.
The lock and dam was last closed in December. Maintenance is needed to preserve structural integrity and improve safety.
In 2019, a major dredging project took place downstream of the lock after sediment buildup reduced the water depth to about 7 feet.
A West Virginia company was paid about $165,000 to remove about 2,000 cubic yards of material from the site.
In 2020, new pipes were installed to divert drainage that caused sinkholes on the grounds of the Natrona site.
McKelvey said routine work reduces the risk of extensive or unplanned closures.
Staff writer Haley Daugherty contributed to this report.