The "Maximum Battleships", also known as the "Tillman Battleships", were a series of World War I-era design studies for extremely large battleships, prepared in late 1916 and early 1917 upon the order of Senator "Pitchfork" Benjamin Tillman^[1] by the Bureau of Construction and Repair (C&R) of the United States Navy.^[2] They helped influence design work on the Pennsylvania and first South Dakota classes of battleships. The plans prepared for the senator were preserved by C&R in the first of its "Spring Styles" books, where it kept various warship designs conceptualized between 1911 and 1925.

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (March 2021)

During the years leading up to World War I, some members of the U.S. Congress were growing frustrated with what they perceived to be chronic overspending by the U.S. Navy on battleships.^[3]

The only limits on the potential size of an American battleship were the dimensions of the locks of the Panama Canal. The locks measure roughly 1,000 by 110 feet (305 m × 34 m), and so the "maximum battleships" were 975 by 108 feet (297 m × 33 m). The Panamax draft limit during the designing of these battleships was 39 feet 6 inches (12.04 m), however the Department of the Navy required that all designs be limited to only 34 feet (10 m) in draft.^[2]

Tillman's first request for designs of so-called "maximum battleship" in 1912–1913 led to several estimates for battleships unconstrained by cost. Created by the US Navy Bureau of Construction and Repair (C&R), these ships would displace up to 38,000 long tons (39,000 t) and carry 14 inch guns. Although C&R was "appalled," in the words of naval historian Norman Friedman, by the extravagance of these designs, they admitted that far larger warships could transit the Panama Canal's locks, which, due to the US's geography, were often held to be the final limiting factor on the size of a US warship. Such larger designs would be often and seriously proposed within only a few years.^[4]

In 1916, Tillman repeated his request, and C&R produced another series of design studies. C&R drew up four blueprints, all ships having varying characteristics despite being built on the same hull:

The Tillman designs all included five casemate guns mounted aft, two on each side and one at the tip of the stern. Similar "stern chasers" had been previously mounted in Nevada, but were omitted from the Pennsylvania class. These casemates were a return to an older design idea; American battleship designers had abandoned hull-mounted casemates after the New Mexico class. They had transpired to be too "wet" – heavy seas rendered them unusable—and they had been removed from all earlier classes.

The Washington Naval Treaty of 1922 limited naval armaments, causing the cancellation of the South Dakotas and halting all consideration of the "maximum battleships."

• HMS Incomparable
• Gavrilov's battleship project - Russian project proposed by head of Russo-Baltic Shipyard [ru], Ivan Gavrilov [ru], ( Reval 1914, 265/34,4/9,15 m, 16x406/45, 24x152/55, 30 knots)