Report: Constellation-Class Frigate is Three Years Late, 13% Overweight

The Navy's Constellation-class frigate program continues to wrestle with an incomplete functional design, which has delayed construction on the first hull and may push back delivery on follow-on vessels as well, according to the GAO. At present, the lead vessel is on track to deliver three years behind schedule and an estimated 13 percent overweight.

"The Navy and shipbuilder continue to revise basic design documents, including the ship's general arrangement drawings - the design drawings that all other design aspects are based on - and structural components of the ship," reported GAO on Wednesday. "This approach is inconsistent with shipbuilding leading practices."

The Constellation-class began as an adaptation of the Italian-French FREMM, an existing design that has proven popular in Europe. Initially, the Navy sought to achieve cost savings and reduce technical risk by keeping 85 percent of the original design. Instead, it changed 85 percent of the design to adapt the vessel to Navy requirements, and it has yet to achieve design stability.

In October 2024, the Navy informed GAO that it expects to see about 759 tonnes of weight growth (13 percent) "due in part to the underestimation of applying Navy technical requirements to a foreign ship design." Weight growth can affect performance, and it limits the amount of extra equipment that can be added to the warship in future years to adapt to changing technology. The program office is working with the shipyard to reduce weight "through a phased implementation across the first three ships."

Change orders and delays tend to increase costs. So far, the shipbuilder has asked for equitable adjustment of the contract payment terms five times, GAO reports - a sign that costs will rise. The Navy has not released the amounts of the requests, and the information is "not suitable for public release," GAO reported.