Norfolk Naval Shipyard (NNSY) has started the renovation of Dry Dock 4 with an investment of $200m.

The Dry Dock 4 renovation project will support submarine overhaul requirements and the needs of the navy’s future Ohio, Virginia and Columbia-class vessels.

The renovation is an initiative of Naval Sea Systems Command’s (NAVSEA) Shipyard Infrastructure Optimization Program (SIOP).

Under the 20-year SIOP, the four US public shipyards will be refurbished with modern equipment.

The programme is valued at $21bn and will enhance the workflow and upgrade the facilities available at the dock.

Assistant secretary of research, development, and acquisition James Geurts said: “Today’s ground-breaking will ensure this historic dry dock will continue to serve the navy and nation for the future navy, just as it has done for the last 100 years.”

The renovation programme will see the replacement of concrete, the dry dock caisson, pump well refurbishment, and mechanical and electrical equipment overhaul.

Buildings 261 and 1539 will be refurbished with interior enhancements, new roofing, and other upgrades.

The renovation of these buildings will be performed under a two-and-a-half-year contract valued at $26m.

Furthermore, the dock’s Stiff Leg Derrick Crane is no longer operational and will be demolished.

NAVSEA commander vice-admiral Tom Moore said: “It was designed and laid out to build ships powered by the wind and coal. SIOP is our opportunity to rethink the infrastructure of our shipyards to improve workflow, modernise our capital equipment, and execute the dry dock modernisation needed to maintain our current and future navy.

“As the only public shipyard on the east coast able to dry dock an aircraft carrier, and given your co-location with the largest fleet concentration in the navy, we are dedicated to delivering a 21st-century shipyard to support our amazing women and men who keep our ships in the fight.”