Frederic Charles Dreyer - Dreyer Fire Control Table

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 such 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 led by Arthur Pollen, and a Naval group led by Dreyer. Both camps aimed to produce a combined mechanical computer 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.

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. 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 in the form of unauthorised accoutrements concocted by individual gunnery personnel, but on the whole performed in a satisfactory manner. The system was eventually replaced by the improved "Admiralty Fire Control Table" for ships built after 1927, although Dreyer Tables went to war a second time in World War II, notably in Britain's unmodernised battleships and battlecruisers.

The choice between the Dreyer and Pollen systems was controversial at the time. The Royal Navy had repeatedly tested Pollen's designs and had given him what it considered very preferential terms for them. Pollen in 1925 won an award for £30,000 from the Royal Commission on Awards to Inventors for elements of his Argo Clock 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 his request was denied.

While Dreyer's table certainly owes some of its features to Arthur Pollen, it was still his creation and for all the claims of the navy protecting its own, Pollen's inventions received a fair trial at the Admiralty—a fact which he himself admitted.