Boadicea Class Cruiser (1908)

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The two scout cruisers of the Boadicea Class were completed by 1910.

Name Builder Laid Down Launched Commissioned Fate
Bellona Pembroke Royal Dockyard 5 June, 1908 20 March, 1909 February, 1910 Sold 9 May, 1921
Boadicea Pembroke Royal Dockyard 1 June, 1907 14 May, 1908 June, 1909 Sold 13 July, 1926

Armament

Guns

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

The six 4-in guns were 4-in B.L. Mark VII guns on P IV mountings.

The mounting could elevate to 15 degrees and depress to 10 degrees, but though its sight could match the 15 degree elevation, the range dial was only graduated to 8,500 yards (8.5 degrees) at 2,225 fps. This might have been in obeisance to the Admiralty's stated desire that giving a long-ranged gun to a light cruiser is a guarantee that it will go get in a gunfight and abandon its scouting duties.[Inference][Citation needed]

The gear-worked sights, the first F.T.P. models to be introduced, had a range gearing contant of 42.95 and spiral-reading range dials for 2850 fps, 1-in aiming rifle and .303-in aiming rifle. MV could be corrected (downward only) 200 fps by adjustable scale plate.

The deflection gearing constant was 61.7 with 1 knot equal to 2.74 arc minutes, corresponding to 2824 fps at 3500 yards. Drift was corrected by inclining the sight 2 degrees.

The layer's sight line was 16.8 inches above the bore, and 15 inches left. The trainer's lines were 16.8 inches above and 14.9 inches right.

The sight lacked a "C" corrector. A number of temperature scale plates corresponding to MVs varying by 25 fps could be shipped with an index facing the actual MV.

Open sights do not seem to be in the drawing.

Torpedoes

Fire Control

Rangefinders

Evershed Bearing Indicators

Gunnery Control

Control Positions

Control Groups

"Scout" class Gun Control Groups[2]

In 1909, these were described as being similar to the Gem class, but the forecastle and poop guns could be controlled as separate groups or attached to the nearest broadside group on either side. The middle line guns could be connected to whichever side was desired.[3]


Directors

Main Battery

Secondary Battery

Torpedo Control

In 1907, Boadicea (and perhaps Bellona), Swift and the River class destroyers were to be equipped with Fore Bridge Firing Gear.[4]

Transmitting Stations

Dreyer Table

These ships had no fire control tables.[5]

Fire Control Instruments

Fire Control Circuits[6]

By 1909, both in this class were outfitted with the latest Vickers F.T.P. Fire Control Instruments (Mark I in Boadicea, Mark II in Bellona), marking a new wrinkle in equipment by replacing the Barr and Stroud equipment that had taken hold shortly after 1906. The equipment was fitted as follows:[7][8]

  • Range Transmitters: 3
  • Deflection Transmitters: 3
  • Range Receivers: 6
  • Deflection Receivers: 6
  • C.O.S.: 1
  • Vickers Fire Gongs: 6 with 3 keys

None of the ships had Target Visible or Gun Ready signals.[9]

Alterations

By November 1918 the two ships along with the two Blonde class scouts were fitted with rails for 66 mines. The torpedo tubes and guns removed when the mines were shipped could be placed back aboard with enough notice.[10]

See Also

Footnotes

  1. The Sight Manual, 1916, pp. 7, 87, 108, Plate 40.
  2. Handbook for Fire Control Instruments, 1909, Plate 54.
  3. Handbook for Fire Control Instruments, 1909, pp. 51-52.
  4. Annual Report of the Torpedo School, 1907. p. 31. Its design was detailed in ARTS 1906, p. 28.
  5. absent from list in Handbook of Capt. F.C. Dreyer's Fire Control Tables, p. 3.
  6. Handbook for Fire Control Instruments, 1909, Plate 52.
  7. Handbook for Fire Control Instruments, 1909, pp. 57, 60.
  8. Annual Report of the Torpedo School, 1909. p. 148.
  9. Handbook for Fire Control Instruments, 1914, p. 11.
  10. Admiralty. Annual Report of the Torpedo School Mining Appendix, 1917-1918, p. 11. Plate 7.

Bibliography

  • Admiralty, Gunnery Branch (1910). Handbook for Fire Control Instruments, 1909. Copy No. 173 is Ja 345a at Admiralty Library, Portsmouth, United Kingdom.
  • Admiralty, Gunnery Branch (1918). Handbook of Captain F. C. Dreyer's Fire Control Tables, 1918. C.B. 1456. Copy No. 10 at Admiralty Library, Portsmouth, United Kingdom.


Boadicea Class Scout Cruiser
Boadicea Group
  Boadicea Bellona  
Blonde Group
  Blonde Blanche  
Active Group
  Active Amphion Fearless  
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