Thomaston-class

The Thomaston class consisted of eight dock landing ships constructed for the United States Navy by Ingalls Shipbuilding between 1953 and 1956. Developed under project SCB 75, the class succeeded the World War II-era Casa Grande class and preceded the Anchorage class. The series was named after Thomaston, Maine, the home of the first U.S. Secretary of War, Henry Knox.

The design represented the third generation of U.S. Navy dock landing ships. These vessels were larger and faster than the preceding Ashland and Casa Grande classes. A notable design departure from the Ashland class was the relocation of machinery spaces from the port and starboard sides of the well dock to a position beneath it. The ships featured a well dock covered by removable segments capable of supporting the weight of two medium helicopters. For cargo handling, the ships were equipped with two cranes. The class was designed to transport various amphibious assets, including Landing Craft Utility (LCU), Landing Craft Mechanized (LCM), and amphibious tractors such as the LVT-5 and LVTP-7.

The eight ships of the class entered service between 1954 and 1957. In the mid-1980s, the USS Spiegel Grove served as a primary trial platform for the Jeff(A) and Jeff(B) landing craft; the data gathered from these trials contributed to the development of the Landing Craft Air Cushion (LCAC). The United States Navy decommissioned all units between 1983 and 1990. Following their U.S. service, the Alamo and Hermitage were transferred to the Brazilian Navy, where the class remained in commission until 2016. Other vessels in the class were sold for scrap, utilized as target ships, or, in the case of the Spiegel Grove, scuttled to serve as an artificial reef.