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Revision as of 15:25, 11 August 2012

The Bellerophon class of three dreadnoughts was designed as a follow-up to the revolutionary HMS Dreadnought.

Dreadnought's secondary armament was deemed insufficient to fight close quarter battle with enemy Torpedo Boat Destroyers, and the three ships were given heavier guns. Their internal sub-division was improved to decrease the possibility of sinking from mine or torpedo attack. Unlike Dreadnought the Bellerophon class were given two tripod masts, with two control tops. This was ostensibly to improve sea-keeping capability, but with the main mast just forward of the second funnel, it was frequently inundated with smoke and proved nearly useless in bad weather.

The three ships of the class performed service with the Grand Fleet for much of the First World War, and in 1918 HMS Superb and HMS Téméraire were dispatched to the Eastern Mediterranean for service against the Ottoman Empire. Due to their inferior main armament, all three ships were immediately relegated to non-active duties following the Armistice, and were scrapped during the course of the 1920s.

The ships were visually similar to their successors, the St. Vincents, but can be recognized by their shorter funnels of equal size.[1]

The guns for each cost £116,300, contributing to total costs below.[2]

Name Built at. Machinery by. Laid down Launched Completed Boilers Total
Cost
Bellerophon Portsmouth Fairfield 06 Dec, 1906 27 Jul, 1907 20 Feb, 1909 Babcock £1,763,491
Téméraire Devonport Hawthorn Leslie 01 Jan, 1907 24 Aug, 1907 01 May, 1909 Yarrow £1,641,114
Superb Armstrong Wallsend Company 06 Feb, 1907 07 Nov, 1907 29 May, 1909 Babcock £1,744,287

Radio

According to the ambitions of 1909, these ships had Service Gear Mark II wireless upon completion.[3]

Armament

Main Battery

This section is sourced in The Sight Manual, 1916.[4]

The ten 12-in guns were Mark X mounted in B VIII* turrets. The mountings could elevate 13.5 degrees[5] and depress 5 degrees.

The gun sights were gear-worked sights with a range gearing constant of 48 and limited to 15 degrees elevation, but 6 degree super-elevation prisms would have been provided by 1916. They were the last Royal Navy dreadnoughts to use telescopes, rather than periscopes, in their turret sights.

The deflection gearing constant was 70, with 1 knot equalling 2.52 arc minutes, calculated as 2700 fps at 5000 yards. Range drums were provided for full charge at 2625 fps, reduced charge at 2250 fps, as well as 6-pdr sub-calibre gun and .303-in aiming rifles.

Muzzle velocity was corrected by adjustable pointer between +/- 75 fps. The adjustable temperature scale plate could vary between 60 to 100 degrees Fahrenheit,[Fact Check] and a "C" corrector could alter the ballistic coefficient by +/- 20%.[Fact Check]

Deflection was corrected by inclining the sights (in the centre position only) by 2 degrees and by the additional use of 1 knot permanent left deflection when firing 4 CRH projectiles.

The side position sighting lines were 36 inches above and 42 inches abreast the bore, and the central scopes were 37.5 inches above and 42 inches abreast. The left-hand centre position sight was a free trainer's sight, able to swing freely in pitch.

An arrow was cut in the deflection dial at 1 knot right and inscribed, "Zero for sight testing."[6]

The hydraulic controls in training reflected recent advances from Indomitable though progress was to continue; operated by a single handwheel driving a six cylinder rotary engine, they could permit continual aim at speeds up to 3 degrees per second.[7]

Secondary Battery

This section is sourced in The Sight Manual, 1916.[8]

Sixteen 4-in BL Mark VII guns on P II mountings were arranged for broadside fire. They were similar the the P II* equipment fitted in the St. Vincent, Neptune, Indefatigable classes and other ships.

The mounting could elevate 15 degrees and depress 7 degrees, but though its sight could match the 15 degree elevation, the range dial was only graduated to 11.5 degrees (10,000 yards).

These first-ever cam-worked sights had range dials for 2750 fps, and 1-in and .303-in aiming rifles. MV could be corrected by adjustable pointer through +/- 150 fps.

The range dial was 14 inches in diameter with markings that came closer together at higher ranges. The marks were 3⁄4 inch apart for 50 yards difference at 500 yards and was 1⁄8 inch for 50 yards difference at 9,000 yards.

The deflection gearing constant was 64.277 with 1 knot equal to 2.41 arc minutes, corresponding to 2800 fps at 2000 yards. Drift was corrected by inclining the sight 2 degrees.

The layer's sight line was 14 inches above the bore, and 15.25 inches left. The trainer's sight line was 14 inches above and 12.5 inches right.

The sight had both temperature and "C" correctors.

The layer had an open sight. Neither side was a free sight.

Torpedoes

In 1913, it was approved, as part of a general reallocation of 18-in torpedoes, to replace the Mark VI** H. or Mark VI*** H. torpedoes on Neptune, St. Vincent, Bellerophon and Dreadnought classes with with Mark VII* or Mark VI**.[9]

Fire Control

Rangefinders

The ships had seven rangefinders as completed: a 9-ft[Inference] in each turret roof and a pair of rangefinders astride the aft boat deck.[10]

Sometime during or after 1917, an additional 9-foot rangefinder on an open mounting was to be added specifically to augment torpedo control.[11]

Evershed Bearing Indicators

Bellerophon and Téméraire were fitted with this equipment before late 1914, but it is not clear whether Superb was included in this.[12]

Transmitting positions were

  • Fore control platform (transmitters to port and starboard with C.O.S. to select one in use)
  • "A" turret
  • "Y" turret
  • Upper aft conning tower

The protocols for handling wooding of the turrets is outlined in the Handbook for Fire Control Instruments, 1914.[13]

Mechanical Aid-to-Spotter

At some point, the ships in this class were equipped with a pair of Mechanical Aid-to-Spotter Mark Is, 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.[14]

Gunnery Control

The control arrangements were as follows.[15]

Control Positions

  • Fore top
  • Main top
  • "A" turret
  • "Y" turret

Some ships had C.O.S.s within the control positions so they could be connected to either TS.[16]

Control Groups

The five 12-in turrets were each a separate group with a local C.O.S. located in the forward T.S. so that it could be connected to:[17]

  • Forward TS
  • After TS

It seems likely that an additional C.O.S. within each turret permitted a choice between the T.S. selected in the C.O.S. above and local transmitters within own turret.[Inference]

Directors

Main Battery

The ships were completed without a director, but were eventually fitted with a geared tripod-type director in a light aloft tower on the foremast along with a directing gun in "Y" turret.[18] The battery was not divisible into groups for split director firing.[19]

Secondary Battery

The 4-in guns never had directors installed.[20]

Torpedo Control

Transmitting Stations

Like all large British ships of the era prior to King George V and Queen Mary, these ships had 2 TSes.[21]

Dreyer Table

Each ship was eventually retro-fitted with a Mark I Dreyer table,[22] but was never given Dreyer Turret Control Tables.[23]

Fire Control Instruments

Fire Control Circuits[24]

By 1909, all three ships were equipped with Barr and Stroud Mark II* Fire Control Instruments for range, deflection and orders.[25]

The Handbook for Fire Control Instruments, 1909 lists the Barr and Stroud Mark II* equipment on this class as:[26]

  • Combined Range, Order, Deflection: 10 transmitters, 27 receivers
  • Group Switches: 5
  • Rate: 4 transmitters, 16 receivers
  • Bearing: none
  • Range: none

Additionally, this class had the following fire control equipment:[27]

  • Siemens turret fire gongs: 10 with pushes in lamp boxes
  • Fire Gongs: none
  • Graham's Captain's Cease Fire Bells: 15 with 1 key

The ships also had Target Visible and Gun Ready signals, with indications of which turret could see the target and which guns were ready being visible in the TSes and control positions.[28]

In 1911, it was decided that the three ships should be fitted with "range, buzzer and bearing instruments for communication between control positions, control turrets and transmitting and plotting stations."[29]

Alterations

In 1916, it was approved that the ships should have fire control instruments fitted for their 4-in armament. What precisely this means is unclear, but perhaps they did not previously have range and deflection receivers?[30]

See Also

Footnotes

  1. ↑ Burt. British Battleships, p. 66.
  2. ↑ Burt. p. 64.
  3. ↑ ARTS 1908 Wireless Appendix, p. 13.
  4. ↑ The Sight Manual, 1916, pp. 4, 39, 106, 108-109.
  5. ↑ I am inferring this is the same as the B VIII mounting)
  6. ↑ I am not sure why this would be.
  7. ↑ Brooks. Dreadnought Gunnery and the Battle of Jutland, pp. 45-46.
  8. ↑ The Sight Manual, 1916, pp. 89-90, 108, Plate 39.
  9. ↑ Annual Report of the Torpedo School, 1913, p. 8.
  10. ↑ Burt. British Battleships, p. 64.
  11. ↑ Annual Report of the Torpedo School, 1917, p. 198. (C.I.O. 481/17)
  12. ↑ conspicuously not named in sections in Handbook for Fire Control Instruments, 1914, pp. 33-9.
  13. ↑ Handbook for Fire Control Instruments, 1914, pp. 34-5.
  14. ↑ The Technical History and Index: Fire Control in HM Ships, 1919, pp. 25-6.
  15. ↑ Handbook for Fire Control Instruments, 1914, p. 7.
  16. ↑ Handbook for Fire Control Instruments, 1914, p. 7.
  17. ↑ Annual Report of the Torpedo School, 1908 Plate 31.
  18. ↑ The Director Firing Handbook, 1917. pp. 88, 142.
  19. ↑ The Director Firing Handbook, 1917. p. 88.
  20. ↑ absent from list in The Director Firing Handbook, 1917. p. 143.
  21. ↑ Handbook for Fire Control Instruments, 1914, pp. 6-7.
  22. ↑ Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  23. ↑ absent from list in Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  24. ↑ Annual Report of the Torpedo School, 1908, Plate 31.
  25. ↑ Handbook for Fire Control Instruments, 1909, p. 56.
  26. ↑ Handbook for Fire Control Instruments, 1909, p. 58.
  27. ↑ Handbook for Fire Control Instruments, 1909, p. 58.
  28. ↑ Handbook for Fire Control Instruments, 1914, p. 11.
  29. ↑ Annual Report of the Torpedo School, 1911, p. 95.
  30. ↑ Annual Report of the Torpedo School, 1916, p. 145.

Bibliography

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