Cianbro’s team of construction professionals at the company’s facility at Ricker’s Wharf in Portland has been diligently working on the 5,000-ton concrete entrance structure for the Superflood Basin Project for the past year and a half. On Sunday, June 20, the team watched with pride as the barge carrying the structure and accompanying tugboats headed seaward down the Fore River and into Casco Bay, destined for its new home at Portsmouth Naval Shipyard.

Portsmouth Naval Shipyard, located in Kittery, Maine, is the U.S. Navy’s oldest continuously operating naval shipyard. Established during the administration of President John Adams, the shipyard has a storied history; building and servicing ships, housing prisoners of war, and even serving as the backdrop for an International Peace Treaty negotiation. For the last 100 years, Portsmouth Naval Shipyard has specialized in refurbishing and servicing the submarine fleet. Awarded to Cianbro in December 2019, the P-310 Superflood Project was the first phase of one of the largest infrastructure projects the Navy has undertaken at Portsmouth Naval Shipyard.

The precast concrete entrance to Portsmouth Naval Shipyard’s new Superflood Basin arrived at the shipyard by barge Monday, June 21.

Conventional construction of the basin entrance was not feasible as it could impact the availability of the shipyard’s Dry Dock #1, which remains in service during construction to support the submarine maintenance schedules at the shipyard. To overcome this challenge, the entrance structure was precast offsite and was floated into position and lowered onto a prepared foundation. The U-shaped precast structure includes two caisson seats to provide positioning options. It measures 110-ft long, 67-ft wide, by 60-ft tall and weighs approximately 5,000 tons.  

“This is a remarkable feat, and our team has truly risen to the challenge on one of the most technically complex projects our company has tackled,” said Andi Vigue, President & CEO of The Cianbro Companies. “The Superflood Project is a perfect example of the dedication and commitment of our team working to deliver quality outcomes; safely and on time.  We’re all very proud of their work, and now the construction team and others have the opportunity to celebrate all of that hard work, watching as the concrete entrance structure makes its way down the Fore River to its final destination.”  

The Superflood Basin directly supports the Navy’s Shipyard Infrastructure Optimization Program (SIOP), a multi-year, multi-billion dollar undertaking for refurbishing the nation’s four public shipyards with modernized equipment, improved workflow and upgraded dry docks and facilities designed to improve the efficiency of the naval shipyards to better execute maintenance and modernization of ships and submarines to provide the Navy the nation needs.

“As in any good organization, the foundation of our success is our people, but our crown jewels are our dry docks,” said Shipyard Commander, Capt. Daniel Ettlich. “The arrival of the entrance structure gets us one step closer to operating independent of the Piscataqua River tides and optimizes our dry dock operations for years of safe and efficient use in continuing to deliver submarine readiness to the Fleet.”

Cianbro recognizes and appreciates the importance of Portsmouth Naval Shipyard to the defense of our country. Cianbro values the partnering relationship with The Naval Facilities Engineering Systems Command as the company focuses on successfully completing the P-310 project and those future projects yet to come at Portsmouth Naval Shipyard.

‍