USS Philadelphia (LPD 32) keel-laying ceremony held at Ingalls Shipbuilding

The US Navy, alongside industry partners, recently held the keel-laying ceremony for the future USS Philadelphia (LPD 32), the 16th amphibious assault ship of the new San Antonio class. The event was held on 3 March at Ingalls Shipbuilding, the Huntington Ingalls Industries (HII) division and US shipyard. This milestone represents a key stage in the vessel’s construction, marking the transition from design work to the physical creation of the ship that will eventually join the US Navy’s amphibious fleet.

The ship is named after the city of Philadelphia, recognising its historical and maritime legacy in the United States. The city is regarded as the birthplace of both the US Navy and the US Marine Corps (USMC). It was also home to the historic Philadelphia Naval Shipyard, which operated from 1801 to 1995 and built numerous warships for the US Navy.

USS Philadelphia (LPD 32) keel authentication ceremony

Keel authentication is a naval tradition dating back centuries and denotes a significant point in a ship’s construction. On this occasion, authentication was completed when the initials of the vessel’s sponsor, Maureen Paparo, were welded onto a steel plate that will subsequently be permanently attached to the ship’s hull. Paparo is from Philadelphia and is the wife of Admiral Samuel Paparo, the 27th commander of US Indo-Pacific Command (USINDOPACOM).

During the event, Captain Matthew Tardy, Amphibious Warfare Programme Manager at the US Navy’s Programme Executive Office Ships (PEO Ships), underlined the importance of the project. “The future USS Philadelphia honours one of the United States’ founding cities and its continued support for the Navy and the maritime domain,” said the officer, adding that “this keel laying marks the ceremonial beginning of construction, and we look forward to delivering this ship to the fleet.”

San Antonio-class ship capabilities

San Antonio-class amphibious transport dock ships (LPD) are intended to embark, transport and land landing-force units across a range of expeditionary warfare missions. The platforms can also take part in humanitarian assistance and disaster-relief operations, giving the US Navy and US Marine Corps modern sea-based capabilities designed to operate alongside 21st-century systems.

They can work with landing craft air cushion vehicles (LCAC), modern helicopters and vertical take-off and landing aircraft, such as the MV-22 Osprey (MV-22). This combination enables San Antonio-class ships to serve as amphibious power-projection platforms with high levels of interoperability and survivability in demanding operational environments.

Construction background

Construction of the USS Philadelphia forms part of the expansion programme for the US amphibious fleet. In January 2025, HII announced the start of the vessel’s construction process. It will be among the ships configured to the San Antonio-class Flight II standard. The first ship of this variant was launched in October last year and will soon enter US Navy service as USS Harrisburg (LPD 30).

Huntington Ingalls Industries is currently the sole shipyard responsible for building this class, having previously delivered vessels from LPD 17 through to LPD 29. The company is simultaneously working on USS Harrisburg (LPD 30), USS Pittsburgh (LPD 31) and USS Philadelphia (LPD 32), while in September 2024 the US Navy signed an agreement worth more than 5.8 billion dollars to construct three further vessels: LPD 33, LPD 34 and LPD 35.

Cover image for illustrative purposes.