the strength needed in preventing the turret from sliding sideways. When not in use, the turret rested on a brass ring on the deck that was intended to form a watertight seal. In service, however, this proved to leak heavily, despite caulking by the crew. The gap between the turret and the deck proved to be a problem as debris and shell fragments entered the gap and jammed the turrets of several s, which used the same turret design, during the First Battle of Charleston Harbor in April 1863. Direct hits at the turret with heavy shot also had the potential to bend the spindle, which could also jam the turret. The turret was intended to mount a pair of smoothbore Dahlgren guns, but they were not ready in time and guns were substituted. Each gun weighed approximately . Monitors guns used the standard propellant charge of specified by the 1860 ordnance for targets "distant", "near", and "ordinary", established by the gun's designer Dahlgren himself. They could fire a round shot or shell up to a range of at an elevation of +15°. Culmination of 1871 and of 1872 represented the culmination of this pioneering work. These ironclad turret ships were designed by Edward James Reed. They were also the world's first mastless battleships, built with a central superstructure layout, and became the prototype for all subsequent warships, leading directly to the modern battleship. Surviving examples The only preserved steam and sail turret ship in Europe is the mid 19th century Dutch ironclad HNLMS Schorpioen. The Chilean and Peruvian flagship Huascar is a memorial at Talcahuano. The Chinese battleship Dingyuan was rebuilt as a museum ship in 2003. Footnotes References Notes Bibliography Ship types Shipbuilding