page_title: Naval artillery
section_title: Fire control
hierarchical_section_title: Naval artillery / Industrial era / Fire control
caption_attribution_description: English: Radar and Electronic Warfare 1939-1945 Naval Radar: Diagram to illustrate the chain of command in High Angle Fire Control. Signals are picked up by the aerial array. The Radar operator (bottom) sees the 'echo' and transmits its range to the gunnery calculating position. The Layer and Trainer in the gun director transmit to the gunnery calculating position the bearing of the target. If the target cannot be seen the Radar display panel (left) is used to provide a radar bearing and the guns are thus able to fire 'blind'. The remainder of the crew are members of the gunnery team.
context_page_description: Naval artillery is artillery mounted on a warship, originally used only for naval warfare, later also for shore bombardment and for anti-aircraft use. The term generally refers to tube-launched projectile-firing weapons and excludes self-propelled projectiles like torpedoes, rockets, and missiles and those simply dropped overboard like depth charges and naval mines.
context_section_description: When gunnery ranges increased dramatically in the late 19th century, it was no longer a simple matter of calculating the proper aim point, given the flight times of the shells. Increasingly sophisticated mechanical calculators were employed for proper gunlaying, 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.
  The resulting directions, known as a firing solution, would then be fed back out to the turrets for laying. If the rounds missed, an observer could work out how far they missed by and in which direction, and this information could be fed back into the computer along with any changes in the rest of the information and another shot attempted.
  The situation for naval fire control was highly complex, due to the need to control the firing of several guns at once. In naval engagements both the firing guns and target are moving, and the variables are compounded by the greater distances and times involved. Rudimentary naval fire control systems were first developed around the time of World War I.
  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. 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 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. He added a gyroscope to allow for the yaw of the firing ship. Again this required substantial development of the, at the time, primitive gyroscope to provide continuous reliable correction. Trials were carried out in 1905 and 1906, which although completely unsuccessful showed promise. He was encouraged in his efforts by the rapidly rising figure of Admiral Jackie Fisher, Admiral Arthur Knyvet Wilson and the Director of Naval Ordnance and Torpedoes (DNO), John Jellicoe. Pollen continued his work, with tests carried out on Royal Navy warships intermittently.
  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 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 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.
caption: Accurate fire control systems were introduced in the early 20th century. Pictured, a cut-away view of a destroyer. The below decks analog computer is shown in the centre of the drawing and is labelled "Gunnery Calculating Position".
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