The Thomaston class was the third class of U.S. Navy dock landing ships. The class was designed under project SCB 75 and approved in the early 1950s. Compared to the Ashland and Casa Grande-class dock landing ships of World War II, the ships of this class were about a third larger and five knots faster.[3] The class was designed to be able to transport:
The dock was covered by removable segments that were able to carry the weight of two medium helicopters. Both cranes could lift weights of up to 50 tons. The machinery spaces were located underneath the dock, in contrast to the earlier Ashland class, where the machinery spaces were located to port and starboard of the dock.
Originally, all ships were armed with eight 3"/50 caliber gun Mark 33 twin mounts. The number was later reduced.
Spiegel Grove was a trial ship for the Jeff(A) and Jeff(B) landing craft in the mid-1980s. Jeff(B) was then developed into the Landing Craft Air Cushion. All ships were decommissioned by the U.S. Navy between 1983 and 1990, Alamo and Hermitage were sold to Brazil in 1989–1990.[4]
