Admiralty Fire Control Table
Encyclopedia
The Admiralty Fire Control Table (A.F.C.T.) was an electromechanical analogue computer fire-control system
that calculated the correct elevation and deflection of a Royal Navy
cruiser
or battleship
s' main armament, so that the shells fired would strike a surface target. The AFCT MK 1 was fitted to and in the early 1920s, while battleships , , and , and the battlecruiser
, received Mk VII tables in the late 1930s. Battleships of the King George V class
received a Mk IX table, while received the final variant, the Mk X. The AFCT was the successor to the Dreyer tables, developed by Captain (later Admiral) Frederic Charles Dreyer
and the Argo Clock, developed by Arthur Pollen
, and received developmental input from both men.
The Admiralty Fire Control Clock (AFCC) was a simplified version of the AFCT and was used for the local control of main armament and primary control of secondary armament of battleships and cruisers, and the main armament of destroyers and other small vessels. Some smaller cruisers also used the AFCC for main armament control. The chief difference between the AFCT and AFCC, was the provision of a paper plotter in the former, which could plot both own ship and target ship movement and record the mean point of impact of the salvoes fired.
The AFCT and AFCC were used for gunnery control against surface targets. The High Angle Control System and Fuze Keeping Clock
were used for gunnery control against aircraft.
Fire-control system
A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more...
that calculated the correct elevation and deflection of a Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
cruiser
Cruiser
A cruiser is a type of warship. The term has been in use for several hundreds of years, and has had different meanings throughout this period...
or battleship
Battleship
A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...
s' main armament, so that the shells fired would strike a surface target. The AFCT MK 1 was fitted to and in the early 1920s, while battleships , , and , and the battlecruiser
Battlecruiser
Battlecruisers were large capital ships built in the first half of the 20th century. They were developed in the first decade of the century as the successor to the armoured cruiser, but their evolution was more closely linked to that of the dreadnought battleship...
, received Mk VII tables in the late 1930s. Battleships of the King George V class
King George V class battleship (1939)
The King George V-class battleships were the most modern British battleships used during World War II. Five ships of this class were built and commissioned: King George V , Prince of Wales , Duke of York , Howe , and Anson .The Washington Naval Treaty of 1922 limiting all of the number,...
received a Mk IX table, while received the final variant, the Mk X. The AFCT was the successor to the Dreyer tables, developed by Captain (later Admiral) Frederic Charles Dreyer
Frederic Charles Dreyer
Admiral Sir Frederic Charles Dreyer, GBE, KCB was an officer of the Royal Navy who developed a fire control system for British warships...
and the Argo Clock, developed by Arthur Pollen
Arthur Pollen
Arthur Joseph Hungerford Pollen was a writer on naval affairs in the early 1900s who recognised the need for a computer-based fire-control system...
, and received developmental input from both men.
The Admiralty Fire Control Clock (AFCC) was a simplified version of the AFCT and was used for the local control of main armament and primary control of secondary armament of battleships and cruisers, and the main armament of destroyers and other small vessels. Some smaller cruisers also used the AFCC for main armament control. The chief difference between the AFCT and AFCC, was the provision of a paper plotter in the former, which could plot both own ship and target ship movement and record the mean point of impact of the salvoes fired.
The AFCT and AFCC were used for gunnery control against surface targets. The High Angle Control System and Fuze Keeping Clock
Fuze Keeping Clock
The Fuze Keeping Clock was a simplified version of the Royal Navy's High Angle Control System analogue fire control computer. It first appeared as the FKC Mk1 in destroyers of the 1938 Tribal class, while later variants were used on sloops, frigates, destroyers, aircraft carriers and several...
were used for gunnery control against aircraft.
External links
- The RN Pocket Gunnery Book
- Illustration of the AFCT
- B.R. 901/43, Handbook of The Admiralty Fire Control Clock Mark I and I*, 1943
- Illustration of the AFCC
- HMS Prince of Wales's Gunnery Aspects Report with discussion of, and plotter output from, her AFCT Mk IX
- BRITISH MECHANICAL GUNNERY COMPUTERS OF WORLD WAR II
