King George V Class Battleship (1911)

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Armament

Main Battery

This section is sourced from The Sight Manual, 1916.[1]

The 13.5-in Mark V(H) guns were in Mark II mountings able to elevate 20 degrees and depress 5 degrees.

The sights were cam-worked and limited to 15 degrees elevation, but the central sights had "20 degree super-elevation strips". Additionally, 6 degree super-elevation prisms would have been provided by 1916.

The deflection gearing constant was 61.3, with 1 knot equalling 2.51 arc minutes, calculated as 2500 fps at 5000 yards. Range drums were provided for full charge at 2450 fps, three-quarter charge at 2000 fps, as well as 6-pdr sub-calibre gun and .303-in aiming rifle. Muzzle velocity was corrected by adjustable scale plate between 2560 and 2260 fps. The adjustable temperature scale plate could vary between 40 to 100 degrees Fahrenheit, and a "C" corrector could alter the ballistic coefficient by +/- 20%.

As in the Queen Elizabeth class, the periscope holder was inclined 1 degree 37 minutes (which may have effectively been 2.5 degrees for mechanical reasons; it equalled .195 degrees at 10,000 yards) to correct for drift. This design did not require the sightsetter to follow a motion of the deflection index to apply it as was required by the system used in Orion.

The side sighting scopes were 43.25 inches above and 39 inches abreast the bore except in Ajax where they were offset 39.5 inches laterally. The central scopes were offset 56.25 inches above and 42 inches abreast.

OOQ open director sights capable of 20 degrees elevation were fitted to King George V and Emperor of India by 1916, with others slated to follow.

Secondary Battery

This section is sourced from The Sight Manual, 1916.[2]

The 4-in guns were 4-in BL Mark VII on P VI mountings.

The mounting could elevate 15 degrees and depress to 7 degrees, but the sight could only elevate 14 degrees (11,000 yards full charge). By 1916 or so, prisms might have permitted 20 degree firing.[Inference]

The sight was a cam-worked design with range dials provided for 2750 fps and 1-in and .303-in aiming rifles. MV could be corrected by a adjustable pointer +/- 150 fps.

Only the sights in Centurion, not those of her two surviving sisters, were FTP in 1916, though the sights were amenable to this alteration.

The deflection gearing constant was 59.73 with 1 knot equal to 2.41 arc minutes, corresponding to 2750 fps at 2000 yards. Drift was corrected by inclining the sight bracket 2 degrees.

The sight lines were 13 inches above the bore, and 11.5 inches to each side.

The sight had temperature and "C" correction by adjustable plates, but no open sights.

Torpedoes

The ships had three submerged 21-in tubes. The broadside tubes bore 10 degrees before the beam.[3]

The broadside tubes forward were depressed 2 degrees and were 14 feet, 1.8125 inches below load waterline with the tube axis 2 feet, 1.1875 inches above the deck. The stern tube was depressed 1 degree and was 8.5 feet below load WL with its axis 1 foot, 8.625 inches above the deck.[4]

The torpedoes for the stern tubes were probably removed sometime during or after 1916 to increase numbers available for broadside use.[5]


Fire Control

Rangefinders

Evershed Bearing Indicators

Evershed Installation
Showing 'X' as a transmitting position.[6]

Most of the units were likely fitted with this equipment before late 1914, except Ajax, who was approved only during 1916.[7]

The transmitting positions (for the 1914 ships, minimally) were

  • CT (periscope transmitters adapted to receive to port and starboard with COS to select one in use)
  • GCT (rangefinder transmitter fitted to Argo rangefinder)
  • 'B' turret
  • 'X' turret

The receiving positions were

  • all 5 turrets had both an open-face and a turret trainer's indicator
  • the periscopes in the CT each had an open-face indicator. The one selected on the local COS would indicate the received bearing
  • the GCT had an open-face indicator

The protocols for handling wooding of the turrets is outlined in the Handbook for Fire Control Instruments, 1914.[8]

Mechanical Aid-to-Spotter

At some point, all ships were equipped with two Mark I Mechanical Aid-to-Spotters, one on each side of the foretop, keyed off the Evershed rack on the director. As the need for such gear was apparently first identified in early 1916, it seems likely that these installations were effected well after Jutland.[9]

Gunnery Control

The control arrangements were as follows.[10]

Control Positions

  • GCT
  • 'B' turret
  • 'X' turret

Some ships had COSes within the control positions so they could be connected to either TS.[11]

Control Groups

The five 13.5-in turrets were each a separate group with a local COS[Inference] so that it could be connected to

  • Forward TS
  • After TS
  • Local control from officer's position within turret

Directors

Main Battery

Training and Elevation Circuits
As shown in Annual Report of the Torpedo School, 1913.

The ships were fitted with a cam-type tripod-type director in a light aloft tower on the foremast along with a directing gun in 'X' turret.[12]

The main battery could be divided into forward ('A', 'B' & 'Q') and aft ('X' & 'Y') groups for split director control.[13]

A COS in the TS afforded these options:[14]

  • All turrets on aloft tower
  • All turrets on directing gun
  • Forward group on aloft tower, aft group on directing gun

Secondary Battery

The 4-in guns never had directors installed.[15]

Transmitting Stations

These ships discarded the second TS found in earlier dreadnoughts and relied on a single TS.[16]

Dreyer Table

King George V had a Mark III Dreyer Table while the other three units received Mark II Dreyer Tables.[17][18] As of June 1918, they had not been provided Dreyer Turret Control Tables.[19]

Fire Control Instruments

Continuing the pattern established in the Colossus class, all 4 units used Vickers F.T.P. Mark III range and deflection instruments to the gun sights and Barr and Stroud (probably Mark II*[Inference]) instruments for other purposes.[20]

The ships had Gun Ready signals in the TS and control positions, but were the first dreadnoughts to discontinue the use of Target Visible signals that appeared in earlier classes.[21]

In 1916, it was decided that Lion and King George V classes and later should receive instruments such that the fore top could be interchangeable as a gun control position with the GCT.[22]

Torpedo Control

Alternative Torpedo Director Position[23]
Planned as additions in 1910-1911, these were found in 1915 to be too susceptible to gun blast.[24]

By late 1915, Centurion was fitted with a Torpedo Control Plotting Instrument Mark I in the TCT.[25] King George V and Ajax were fitted some time before mid 1917.[26] It is unlikely that Audacious ever received such equipment.[Inference]

Between late 1915 and mid 1917, the remaining ships in the class were provided a Torpedo Bearing Plotting Instrument Mark I in the TCT.[27]

The ships had small armoured hoods fitted and enjoyed frontal protection from the ship's side armour. A 4-inch embrasure as drawn here gave a line of sight from 70 degrees before to 80 degrees abaft the line of the tube, but this was later modified before construction to do 80 degrees on either side of the tube. Hinged shutters allowed the embrasure to be closed when not in use, and the stand for the director could be swiveled to match any gyro angle in use at the tube.[28]

Torpedo Control in King George V
Annual Report of the Torpedo School, 1912, Plate 32.

The TCT had a rangefinder with object glasses in an armoured hood which was dedicated to torpedo control (G. 0639/12). The tower also had a Forbes Speed Indicator. From 1913, it was planned to also equip it with a deflection plotting system of indeterminate type as there was no yet a proven system to choose.

The TCT was to use its own equipment to determine the range, course and speed (or deflection) of the enemy and then to transmit it to all torpedo positions by Barr and Stroud instruments. A C.O.S. in the Transmitting Station permits its transmitters, rather than the TCT's to supply this data.

The broadside tubes could be fired either from the CT or from secondary torpedo control positions in armoured hoods on the beam, situated directly over the broadside tube. The tubes received gyro angles and orders from either the CT or their secondary control position, as determined by COSes in the torpedo flat. The stern tube could only be fired from the TCT, and so had no COS.

The broadside tubes had voicepipes to both the CT and to their secondary control position. A navyphone with a special transmitter connected the TCT to the stern tube.

The TS had 4 navyphone connections to the CT, the TCT and to the two secondary torpedo control positions at port and starboard. The TCT had a voicepipe as well as a navyphone connecting it to the CT and a navyphone to the GCT. Additionally, navyphones at the ship's exchange could be used as alternatives to the hard-wired network.[29]

In all, the system is a condemning illustration of the Royal Navy's absurd over-emphasis on torpedo armaments in their capital ships. At most, one could expect a single torpedo tube to be pointing toward an enemy, and we see the context created to realize its puny threat if we count up the hardware that would have no use without the torpedo outfit remained in place:

  1. 3 torpedo tubes and stocks of torpedoes
  2. 2 floodable spaces, one large and transverse
  3. 2 dedicated director positions
  4. 12 dedicated navyphones
  5. 2 exchange navyphones
  6. 5 triggers
  7. 6 COS
  8. 1 Forbes Speed Indicator
  9. 10 gongs
  10. 3 circuit breakers
  11. 4 voice pipes
  12. 8 orders instruments
  13. 6 gyro angle instruments
  14. 8 course and speed instruments
  15. 8 range instruments
  16. personnel to maintain and serve this equipment
  17. space taken up in CT and TS

In 1916, a number of further changes were decided upon:[30]

  • Navyphone communication between CT and aft torpedo flat and TCT and fore torpedo flat
  • removal of secondary director hoods
  • "transfer of instruments in the secondary positions" to the CT and TCT. I presume that "secondary positions" means the secondary director hoods.

Rangefinders

The rangefinder in the TCT was a initially a 9-foot F.T. 24 on an M.Q. 10 mounting.[31][32][33]

Sometime, likely not before 1918, these were to be upgraded to 15-foot instruments, probably also F.T. 24, with new armoured hoods and racers and training driving the hood directly rather than through the rangefinder mounting. These rangefinders lacked hand-following gear to facilitate in transmission of range cuts, and when it was considered as an addition around 1917, space concerns were causing issues.1[34]

By 1918, the desire for torpedo control rangefinders was so keen that the ships were told to save their 9-foot instruments upon receipt of their 15-foot models, as new mountings would be sent so that the 9-foot instrument could be mounted elsewhere.[35]

See Also

Footnotes

  1. The Sight Manual, 1916, pp. 4, 23-26, 106, 109, Plates 3-5.
  2. The Sight Manual, 1916, pp. 4, 84, 108, Plate 37.
  3. Annual Report of the Torpedo School, 1918, p. 51.
  4. Addenda (1911) to Torpedo Manual, Vol. III., 1909, p. 155.
  5. Annual Report of the Torpedo School, 1916, p. 36. (T.O. 168/1916)
  6. Handbook for Fire Control Instruments, 1914, Plate 46.
  7. Handbook for Fire Control Instruments, 1914, p. 36, Handbook for Fire Control Instruments, 1914, Plate 46, Handbook for Fire Control Instruments, 1916, p. 145.
  8. Handbook for Fire Control Instruments, 1914, p. 38.
  9. The Technical History and Index: Fire Control in HM Ships, 1919, pp. 25-6.
  10. Handbook for Fire Control Instruments, 1914, p. 7.
  11. Handbook for Fire Control Instruments, 1914, p. 7.
  12. The Director Firing Handbook, 1917. pp. 88, 142.
  13. The Director Firing Handbook, 1917, p. 88.
  14. The Director Firing Handbook, 1917. p. 88.
  15. absent from list in The Director Firing Handbook, 1917. pp. 143.
  16. Handbook for Fire Control Instruments, 1914, pp. 6-7.
  17. Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  18. Brooks, John. Dreadnought Gunnery and the Battle of Jutland, p. 166.
  19. absent from list in Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  20. Handbook for Fire Control Instruments, 1914, pp. 72.
  21. Handbook for Fire Control Instruments, 1914, p. 11.
  22. Handbook for Fire Control Instruments, 1916, p. 145.
  23. Annual Report of the Torpedo School, 1911, Plate 14.
  24. The Annual Report of the Torpedo School, 1915, p. 30.
  25. Handbook of Torpedo Control, 1916, p. 38.
  26. Handbook of Torpedo Control, 1916, p. 38.
  27. Handbook of Torpedo Control, 1916, p. 38. Inference based on Mark II gear being in place in other ships in 1915.
  28. Annual Report of the Torpedo School, 1911, p. 43.
  29. Annual Report of the Torpedo School, 1912, p. 63.
  30. Annual Report of the Torpedo School, 1916, p. 145.
  31. Annual Report of the Torpedo School, 1917, p. 198.
  32. Annual Report of the Torpedo School, 1918, p. 175.
  33. Inferences M.Q. 10 and F.T. 24
  34. Annual Report of the Torpedo School, 1917, p. 198. (C.I.O. 481/17)
  35. Annual Report of the Torpedo School, 1918, p. 177. (C.I.O. 5787/18)

Bibliography

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