Editing Fire-control system (section)

===World War I===
Then increasingly sophisticated [[analog computer|mechanical calculators]] were employed for proper [[gun laying]], typically with various spotters and distance measures being sent to a central plotting station deep within the ship. There the fire direction teams fed in the location, speed and direction of the ship and its target, as well as various adjustments for [[Coriolis effect]], weather effects on the air, and other adjustments. Around 1905, mechanical fire control aids began to become available, such as the [[Frederic Charles Dreyer#Dreyer Fire Control Table|Dreyer Table]], [[Dumaresq]] (which was also part of the Dreyer Table), and [http://www.dreadnoughtproject.org/tech/essays/FireControl/ArgoAimCorrector/ Argo Clock], but these devices took a number of years to become widely deployed.<ref name="aid">{{cite book
  | last = Mindell
  | first = David
  | title = Between Human and Machine
  | publisher = Johns Hopkins
  | year = 2002
  | location = Baltimore
  | pages = 25–28
  | isbn = 0-8018-8057-2 }}</ref><ref name="reasons">The reasons were for this slow deployment are complex. As in most bureaucratic environments, institutional inertia and the revolutionary nature of the change required caused the major navies to move slow in adopting the technology.</ref> These devices were early forms of [[rangekeeper]]s.

[[Arthur Pollen]] and [[Frederic Charles Dreyer]] independently developed the first such systems. Pollen began working on the problem after noting the poor accuracy of naval artillery at a gunnery practice near [[Malta]] in 1900.<ref>Pollen 'Gunnery' p. 23</ref> [[William Thomson, 1st Baron Kelvin|Lord Kelvin]], widely regarded as Britain's leading scientist first proposed using an analogue computer to solve the equations which arise from the relative motion of the ships engaged in the battle and the time delay in the flight of the shell to calculate the required trajectory and therefore the direction and elevation of the guns.

Pollen aimed to produce a combined [[Calculating machine|mechanical computer]] and automatic plot of ranges and rates for use in centralised fire control. To obtain accurate data of the target's position and relative motion, Pollen developed a plotting unit (or plotter) to capture this data. To this he added a gyroscope to allow for the [[Yaw angle|yaw]] of the firing ship. Like the plotter, the primitive gyroscope of the time required substantial development to provide continuous and reliable guidance.<ref>Pollen 'Gunnery' p. 36</ref> Although the trials in 1905 and 1906 were unsuccessful, they showed promise. Pollen was encouraged in his efforts by the rapidly rising figure of Admiral [[John Fisher, 1st Baron Fisher|Jackie Fisher]], Admiral [[Arthur Knyvet Wilson]] and the Director of Naval Ordnance and Torpedoes (DNO), [[John Jellicoe, 1st Earl Jellicoe|John Jellicoe]]. Pollen continued his work, with occasional tests carried out on Royal Navy warships.

Meanwhile, a group led by Dreyer designed a similar system. Although both systems were ordered for new and existing ships of the Royal Navy, the Dreyer system eventually found most favour with the Navy in its definitive Mark IV* form. The addition of [[director (military)|director]] control facilitated a full, practicable fire control system for World War I ships, and most RN capital ships were so fitted by mid 1916. The director was high up over the ship where operators had a superior view over any gunlayer in the [[gun turret|turrets]]. It was also able to co-ordinate the fire of the turrets so that their combined fire worked together. This improved aiming and larger optical rangefinders improved the estimate of the enemy's position at the time of firing. The system was eventually replaced by the improved "[[Admiralty Fire Control Table]]" for ships built after 1927.<ref>For a description of an Admiralty Fire Control Table in action: {{cite web | url = http://ahoy.tk-jk.net/GentlemansCordite/AglimpseatNavalGunnery..html | title = A Glimpse at Naval Gunnery | publisher = Ahoy: Naval, Maritime, Australian History | last = Cooper | first = Arthur}}</ref>
[[File:HMS Belfast - 6inch transmitting station 1.jpg|thumb|left|[[Admiralty Fire Control Table]] in the transmitting station of [[HMS Belfast|HMS ''Belfast'']].]]