Frederic Charles Dreyer

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Sir Frederic Charles Dreyer GBE (1878-1956) was an officer of the Royal Navy who developed a fire control system for British warships. He retired at the rank of Admiral.

Frederic Dreyer was born on 8 January 1878 and educated in Armagh. He was the son of the Danish astronomer J.L.E. Dreyer who was director of the Armagh Observatory.

[edit] Royal Navy career

He joined the navy and attended HMS Britannia from 1891. He became Lieutenant (in Gunnery) on HMS Exmouth, the flagship of the British Home Fleet where he served from 1904 to 1907. He was then posted at the request of the First Sea Lord to the first modern battleship HMS Dreadnought on her experimental cruise of 1907 on "Special Service" to assist with gunnery trials.

He continued his activities in gunnery improvements, acting as Assistant to Director of Naval Ordnance until 1909. He commanded his first ship, HMS Vanguard, from 1909-1910. He was Flag Commander to Vice Admiral John Rushworth Jellicoe 1910-1912 and joined the War Staff in 1912.

He was in command of the cruiser Amphion in 1913. From there he moved in 1913 to the battleship Orion until 1915. He was Flag captain (commanding officer of the flagship) Iron Duke Admiral Sir John Jellicoe serving at the Battle of Jutland in 1916.

He moved to the Admiralty as the Assistant Director of the Anti Submarine Division. In 1917 at the Admiralty he became Director of Naval Ordnance. This was followed by positions as Director Naval Artillery and Torpedo, Chief of Staff to Admiral Jellicoe and on the Naval Mission to India and Dominions on HMS New Zealand, 1919-1920.

This was followed by a spell as Director of the Gunnery Division at the Admiralty from 1920 to 1922. He returned to sea commanding the battlecruiser HMS Repulse for a year before serving as Aide-de-camp to the King. He continued to alternate posts on ship and in the Admiralty: Lord Commissioner of Admiralty and Assistant Chief of Naval Staff (1924-1927), commander of the Battlecruiser Squadron on the flagship Hood (1927-1929), Lord Commissioner of Admiralty and Deputy Chief of Naval Staff (1930-1933), and Commander-in-Chief of the China Station (1933-1936)

He retired in 1939 only to be re-employed on the outbreak of World War II. Starting off as "Commodore of Convoys" (1939-1940). He was on the staff of the General Officer Commanding-in-Chief Home Forces in 1940, Inspector of Merchant Navy Gunnery (1941-1942). His final post was as Chief of Naval Air Services (1942-1943).

His autobiography was published as The Sea Heritage (Museum Press, 1955)

His son was Vice Admiral Desmond Parry Dreyer, who followed him as a gunnery officer and won his DSC at the Battle of the River Plate.

[edit] Dreyer Fire Control Table

The introduction of centralized "Fire Control" for warships gave a significant improvement to the accuracy of gunnery. The increasing range of naval guns led by several years the necessary advances to control their fire. Over a ten year period techniques such as centralised spotting of fall of shot, mechanical computation of rate of change of range (rate), mechanical clocks to calculate range over time for any given "rate" and long baselength optical rangefinders were introduced. In order to make sense of this data manual plotting of rangefinder ranges, from single or multiple rangefinders as well as other data began to find favour. The Royal Navy sponsored research into these techniques, and two groups emerged, a commercial group lead by Arthur Pollen, and a Naval group lead by Dreyer. Both camps aimed to produced a combined mechanical computers and automatic plot of ranges and rates for use in centralised fire control. Both systems were ordered for new and existing ships of the Royal Navy, although the Dreyer Table, as the Dreyer system was called eventually found most favour with the Navy in its definitive Mark IV* form. Advances in electronic transmission of range to the guns added further value to the centralised fire control systems.

The addition of director control facilitiated 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. But with the longer practical ranges came the increased time of flight. The Fire Control System now had to account for more variations and more complicated corrections than was originally planned. The Dreyer Table had some mechanical flaws, particularly when additional loads were introduced. The system was eventually replaced by the improved "Admiralty Fire Control Table" for new build ships after 1927, although Dreyer Tables went to war a second time in World War II, notably amongst Britain's unmodernised battleships and battlecruisers.

The choice between the Dreyer and Pollen systems was controversial at the time. Pollen in 1925 won an award for £30,000 from the Royal Commission on Awards to Inventors for elements of his design that had been used without his permission. At the same time Dreyer applied for a similar grant but due to the fact that in 1915 he had been awarded £5,000 for his services to fire-control, and due to his position in the Royal Navy at this time (he was a Vice Admiral) his request was refused.

Subsequent research seems to indicate that Dreyer was unfairly treated and his system was not only largely original but clearly superior to Pollen's.