US Navy’s Norfolk Naval Shipyard (NNSY) has broken ground on a project to renovate the Dry Dock 4 located in Virginia, US.

Estimated to cost $200m, the renovation project could take up to three years and is claimed to be NNSY’s biggest initiative yet in realising Naval Sea Systems Command’s (NAVSEA) Shipyard Infrastructure Optimization Program (SIOP).

SIOP is $21bn programme to completely refurbish the country’s four public shipyards by modernising equipment, improving workflow and upgrading dry docks and facilities.

Dry Dock 4’s renovation is expected to meet the Navy’s needs to overhaul submarines in this decade and in the coming decades, supporting Ohio, Virginia and Columbia-class boats.

Navy Research, Development and Acquisition Assistant Secretary James Geurts said “Today’s groundbreaking 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 Navy continues to invest heavily in our naval shipyard workforce and supporting infrastructure to ensure we can continue to support the world’s finest naval force now and into the future.”

First opened in 1919, Dry Dock 4 is nearly 1,012ft long, 144ft wide and 40ft deep and is claimed to be one of the largest concrete structures in the world upon completion.

Over the years, the dock was used by notable ships including USS Langley (CV-1), USS Texas (BB-35), USS Arizona (BB-39) and the British aircraft carrier HMS Illustrious.

During the renovation, two-and-a-half feet of concrete will be replaced with dry dock’s floor, along with two feet from the sidewalls. In addition to replacing the dry dock caisson, the pump well will be completely restored while all mechanical and electrical equipment are also upgraded.

The overhaul will be completed with nearly 2,300 linear feet of mechanical and electrical services in the dock area being replaced.

Furthermore, NNSY will renovate the adjacent Buildings 261 and 1539, which act as the storage area and repair shop and their surrounding area.

A separate $26m renovation project, which is expected to take two-and-a-half years to complete, will offer new roofing, interior enhancements and other upgrades.


Image: Officials of the US Navy and NNSY at the ground breaking ceremony. (Credit: United States Navy).