Anti-Invasion Floating Mortar
|Name:||Anti-Invasion Floating Mortar|
|In service:||Never built|
|General characteristics (as designed)|
|Length:||80 ft (24 m)|
|Beam:||30 ft (9.1 m)|
|Propulsion:||Steam engine, single screw|
|Speed:||More than 10 knots (19 km/h; 12 mph)|
|Armour:||10 ft (3.0 m)|
Also known as Naysmyth's Submarine Mortar and the Steam Ram, the Anti-Invasion Floating Hammer was a semi-submerged naval ship design conceived and published by inventor James Nasmyth in 1853. The mortar had a length of 80 feet (24 m) and a beam of 30 feet (9.1 m) and was equipped with a small steam engine that drove a single propeller. The walls of the mortar were 10 feet (3.0 m) thick, protecting it against potential enemy gunfire of that period. At the front of the boat was a hollow brass cap shaped like a ram that was 9 feet thick. Inside the ram was a case filled with a heavy charge of explosive powder. With only the funnel and a domed structure covering the pilot being visible above water, the mortar sought to attack enemy ships by ramming the hull with the explosive-filled ram at speeds of over 10 knots (19 km/h; 12 mph). Because of potential dangers associated with its means of attack, the Anti-Invasion Floating Mortar was never built.
- Smiles, Samuel, ed. (1912). James Nasmyth Engineer: An Autobiography. London: John Murray.
- Jackson, G. Gibbard (1930). The Romance of the Submarine. Philadelphia: J. B. Lippincott & Co.
- Newbolt, Henry (1918). A Note on the History of Submarine War. London: Longmans, Green & Co. p. 11. Retrieved 26 June 2012.