CBO finds that maintenance for Navy destroyers and amphibious warfare ships has often taken longer and required more labor than planned. Those delays affect the fleet's readiness and reflect aging ships, late inspections, and other factors.
The Navy has experienced chronic delays and labor overruns in maintenance on its large conventional ships (that is, ships that are not nuclear-powered). Those delays can affect deployment schedules and limit the operational readiness of the Navy's fleet. In this report, the Congressional Budget Office analyzes maintenance events for two types of such ships—destroyers and amphibious warfare ships—from October 2010 to September 2024.
Maintenance for large conventional combat ships often takes longer than expected. CBO projects that DDG-51 class destroyers will spend an average of nine years, or more than a quarter of their planned service life, out of the fleet for maintenance. That is more than twice as long as estimated in their 2012 class maintenance plans.
Schedules for overhauls underestimate their duration, and changes to those schedules have not closed the gap. Maintenance events often take 20 percent to 100 percent longer than estimated in the Navy's final schedules for those events. The Navy has raised its estimates, but the delays have continued to increase—especially for older ships, which have longer scheduled overhauls.
Interactive
Maintenance delays are driven by many factors. Several likely causes of maintenance delays were reported by representatives of the Navy, the private shipyards that maintain the Navy's conventional ships, or both:
The aging of the fleet,
Late inspections and contract awards,
Unexpected additional work and contract negotiations,
Delays in obtaining parts and materials,
Poor integration of modernization (which is performed separately by contractors) with maintenance work, and
Contract incentives that emphasize keeping costs low over completing work on time—although some Navy officials disagreed with that characterization.
In previous analyses, CBO found that capacity constraints at Navy shipyards had led to delays in nuclear ship maintenance. CBO did not identify capacity constraints as a driver of delays in maintenance for conventional ships.
