Fire Control
At the turn of the century, the quality of big guns in warships was improving rapidly, with increasing accuracy and longer ranges. However, to shoot the guns to good effect and obtain an adequate percentage of hits on any given target efficient rangefinding equipment was vital. This applied in particular at ranges over 8,000 or 9,000 yards.
Optical rangefinders of various types were fitted in all warships, and many experiments took place to obtain a suitable system. By the time Dreadnought had arrived in 1906, rangefinders had evolved into a practical standard type of instrument; the best known, and most widely used in the world’s warships, was the Barr and Stroud ‘coincidence’ system, which was a short-base, split-image rangefinder of varying length (depending on position, between 3ft 6in and 9ft). The largest of these was quite capable of taking ranges accurately up to 8,000 yards. This system of improved rangefinding, however, did not give provision for passing information to the gunlayers within the turrets in order to modify ranges relative to the target’s course and speed. Electro-mechanical equipment had been introduced for this purpose some years earlier (basically an electrical transmitter that conveyed information from the rangefinders to the guns), but it did not prove successful. Later Captain J. S. Dumaresq and Sir Percy Scott developed improved types, while the fitting of Vickers rate-of-change clocks provided some further answers. A follow-the-pointer system was introduced in 1908; in this the range and deflection were transmitted from the fire control position direct to the sights of the guns by means of electrically-controlled pointers, which were rotated in front of the respective dials and indicated the point to which the dials had to be set for correction.
By 1916, the Royal Navy was using what was considered a highly elaborate ‘director control’ to back up a first class armament, a combination quite unmatched in foreign navies. Witness progress aboard Bellerophon, for example: she was fitted with a revolving tower aloft in which was located a 9ft Barr and Stroud rangefinder and a Vickers fire control table. Personnel in the tower consisted of the control officer, the rangefinder and rate keeper. This method was relatively new within the Royal Navy, but quickly became standard procedure. Most of the Grand Fleet’s battleships and battlecruisers were fitted with similar equipment, backed up by extra rangefinders in the turrets and bridgework. Doubts among contemporary fire control staff can be ascribed to inefficient training and hunting arrangements within the electro-mechanical gear. The principle itself was sound enough, allowing as it did the personnel to retain the same position regardless of the angle of the target; but the director towers in all British battleships afforded a restricted view because of the tripod masts.
After Jutland, in May 1916, director control came under close examination. It was now fully realized that this was one of the most important departments of a fighting ship, and certain aspects of the systems then in use had failed during the battle – the Barr and Stroud rangefinders had not given the required results because of the poor lighting conditions during the action. It was generally known that the Germans had Zeiss stereoscopic rangefinders, and a different method of fire control; the former was slightly superior to that used in British ships, but the latter, according to intelligence reports, was inferior to British equipment, and not up to requirements laid down by the Admiralty. This was borne out in 1919 after tests had been carried out in the captured battleship Baden: although much of the equipment had been sabotaged by the Germans, the fire control gear was examined and found to be relatively primitive.
From 1917, the Admiralty strove for a balanced and adequate fire control system, but an ideal layout was not in service until the middle of 1918. The war was nearly at an end by the time inclinometers were introduced, and highly trained staff were functioning with much improved director towers. By the end of 1918, all existing British capital ships were fitted with improved fire control, placed aloft as usual, but if possible the towers were repositioned on the control top rather than underneath it; if this were not possible, then additional rangefinders were fitted on top of the control top to give them an all-round vision. Small towers for the secondary armament were also being fitted on each side of the bridge, and there was also provision for director control to be worked from within one of the main turrets (usually ‘X’ turret). The towers themselves had been revamped and consisted of improved rangefinders, with many of the Barr and Stroud types having been replaced by different makes, and improved Dreyer or Argo electro-mechanical equipment. Personnel and their functions for the control was as follows.
Port quarter of Ajax in Devonport 1914. Note the director fire control in place.
HM King George V, Sir George Callaghan and Prince Albert on the forecastle of Neptune watching competition rough weather firing trials to try out Sir Percy Scott’s director system which was fitted to Thunderer against Orion without the system. Thunderer scored eight or nine hits compared with none for Orion.
1. Control officer: spotted the fall of shot to correct elevation and direction with direct fire, and maintained communications with the plotting and transmitting stations.
2. Rate officer: worked the inclinometer and decided the rate of fire due to enemy movement in conjunction with the transmitter office and the station rate officer.
3. Direction layer: laid and fired, but also worked the gyro direction training lamp.
4. Direction trainer: trained the tower on to the target and worked the synchronized training transmitter (by power or hand) and corrected the vertical datum line.
5. Direction sight setter.
6. Telephone operator.
7. Rangefinder.
8. Voice pipe and human link operator.
9. Tower trainer (back up).
10. Inclinometer operator (back up).
The crews for the secondary directors were identical, except that numbers 8, 9 and 10 were not required. Further aids to control were seen at the end of 1917, when deflection scales and range clocks came into existence. The deflection scales were painted on turret sides and tops (usually ‘B’ and ‘X’) and told the leading or following ship the angle of fire. They were only used if the ship ahead or astern could not use her own rangefinders owing to smoke or other conditions affecting her vision. The range clocks told other ships what range the guns were firing at (in thousands of yards) so that all ships could fire their guns in a concentrated effort even if only one ship could see or had operable rangefinding equipment.
Armour and Protection
The subject of armour applied to British and German ships has long furnished fuel for heated debate. The main armour strakes fitted to both nation’s ships were generally considered adequate to withstand heavy shell impact under normal battle ranges of the day. (It was envisaged that action would take place in about the 10,000-yard zone.) Although the German ships were given slightly thicker belts than their British opponents, there was very little to choose between them. War experience was to show, however, that as battle ranges frequently increased to over 10,000 yards, shells reached the target at a steeper trajectory, so that it was the deck armour that was threatened rather than the side of the ship. Here both British and German designs were deficient.
With regard to the oft-quoted superior strength and quality of German steel plates, it is interesting to note that when tests were carried out in the captured battleship Baden in 1919, only a slight difference was found between British and German steels; and when fired upon during the tests, her plates did not meet the strict standards required of British plates. Baden’s vitals were protected by Krupp armour, and it was very gratifying for the British to discover that the armour plates used in their later dreadnoughts were slightly superior to the Krupp process.
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