The main lock chamber of Mel Price Locks and Dam, Upper Mississippi River Mile 200.8, reopened March 31 after a 90-day planned closure to allow contractors to demolish and replace an overlook building. The work was Phase II of a three-phase plan to replace the main chamber’s lift gates. Phase III, the replacement of the lift gates, will take place in the winter of 2025 and will require another closure.
The first vessel through was the mv. Robert B, operated by Ingram Barge Company. There were 15 vessels in the queue, according to Andy Schimpf, operations manager at the St. Louis Engineer District, although during the closure the queue reached into the upper 30s.
Phase I of the project, a $7.7 million contract, was awarded to G&G Steel of Russellville, Ala., which has been fabricating the lift gates off-site. Schimpf said they should be completed by summer of this year.
Phase II was the demolition of the overlook and the construction of a new one that does not hinder access to the lift gates.
The overlooks, located on the upstream end of the main lock on both sides of the lock chamber, are reinforced concrete buildings supported by reinforced concrete columns that house the lock’s primary control operations and an office, break room and visitor area.
Under the $9.9 million contract, the contractors, Alberici Constructors of St. Louis demolished parts of the structure and removed and relocated concrete columns, beams, slabs and walls. “There were times when we did worry whether we were going to make the timeline,” said Schimpf, but in the end the timeline held.
Located 14.5 feet above the top of the lock wall, the overlook buildings sit directly above expensive lift gate machinery which had to remain in place and be protected for the project’s duration. These challenging site access restrictions required Alberici crews to work primarily from barge-based floating plants on either site of the lock chamber. An Alberici-designed temporary shoring system was used to provide structural support during demolition as much of the building’s reinforcing steel will also be left in place and reused during reconstruction.
Alberici’s scope of work also included building fit-out and renovations of the low voltage electrical and HVAC systems, as well as modifications and upgrades to the medium voltage power distribution equipment to provide temporary power to the project while power distribution equipment is down.
Phase III will require another closure in the winter of 2025 to install the lift gates, along with concrete work and the raising of the sill. It will be the first replacement of lift gates since the lock and dam opened in 1989.
Caption for top photo: Phase II of the Mel Price Lock project involved demolition and reconstruction of a lock overlook building. (Photo courtesy of Alberici Constructors)