Marine Infrastructure

Dry Dock 4 retrofit adds resilience within a maintenance window

Published 28 August 2026 Publisher IMWO Region Americas Confidence Confirmed
Seismic anchor heads along the concrete wall inside Puget Sound Naval Shipyard's Dry Dock 4, photographed after the initial retrofit work in May 2026

Jeb Fach / U.S. Navy via DVIDS, public domain. Dry Dock 4 photographed 19 May 2026 after initial work, before the expanded-scope completion milestone; resized. U.S. military imagery does not imply endorsement.

The US Navy has marked completion of Dry Dock 4's seismic retrofit at Puget Sound Naval Shipyard. An early finish on the original scope created room for additional waterfront reinforcement before the next scheduled maintenance availability. The wider contract value reflects that added scope, rather than a like-for-like comparison with the initial award.

A five-month window accommodates more work

NAVFAC's 27 August account reports the completion milestone on 26 August. The original September 2025 task order awarded to Kiewit-Alberici was USD 377.7m. A May update said its initial work had finished in April, five months early, and set out further soil and structural improvements. The completion account puts the expanded contract at USD 517m, including quay-wall reinforcement, pump-well work and removal of redundant keel blocks.

Ground investigation changes the anchor design

NAVFAC attributes a reduction from an initial estimate of 1,000 anchors to 600 to geotechnical investigation and modelling. Each anchor uses 12 cables passing through the dock wall and drainage layer into native soil. The reported lateral-movement limit is a seismic design criterion, not a measured response to an earthquake. The engineering result connects site investigation to installable quantities and construction duration.

Evidence conclusion

Scope and operating access carry the commercial lesson

The scope comparison is between the original work package and the expanded intervention, not the two headline dollar amounts alone. The May announcement described a limited opportunity to add resilience without reserving a separate future dock outage. Quay walls beside the caisson, the pump well and waterfront laydown space affect a different set of interfaces from the perimeter anchors. For other live shipyard retrofits, completion sequencing matters alongside structural design: access, pumping, material handling and the next maintenance availability must align. This milestone concerns the existing Dry Dock 4 retrofit. Delivery of a new multi-mission dry dock and the next vessel's entry need separate evidence.

Outstanding evidence

  • Handover and return to the next scheduled dock availability
  • Operational interfaces at the caisson, pump well and adjacent quay walls
  • Scope-specific cost records rather than headline award-value comparisons
  • New dry-dock approvals and delivery milestones distinct from this retrofit

Related records 1

Subject index

Related subjects

These subject pages bring together related projects, technical articles, reports, and evidence methods.

Sources used 4

Source collections