Difference between revisions of "Cambrian Class Cruiser (1915)"

Revision as of 21:25, 18 July 2012

The four light cruisers of the Cambrian Class were completed in 1915 and 1916. They were sometimes considered repeats of the earlier two-ship Calliope class.

Machinery

Generators

In 1916, it was stated that ""C" and "D" class light cruisers" have three 52.5 kw dynamos at 105 volts.^[1] As ever, it is anyone's guess where the "C" class designator begins top apply.

Armament

Guns

The ships of Caroline, Calliope and Cambrian classes had their gun armament increased as the war went on.^[2]

Original:

• Two 6-in 45cal BL Mark XII guns aft on P VII mountings, able to elevate 15 degrees.^[3]
• Eight semi-automatic 4-in 45cal QF Mark V guns; 2 in tandem forward, 3 on each beam

This configuration drew criticism and it was proposed in 1915 to place a third gun forward in lieu of the pair of 4-in guns originally situated there as:^[4]

• the 6-in guns had superior range and hitting power
• the German 4.1-in gun on the opposing light cruisers was found to outrange the British 4-in QF Mark V guns
• intelligence indicated that the next German light cruisers might move to 5.9-in guns and the older ships may also get larger weapons
• it was desired to augment the firepower in closing actions

This resulted in the configuration, decided upon in June 1916 to effect the alteration (all completed by summer 1917) for 12 ships described as the "Calliope class", but by the number 12 almost certainly indicating Calliope, Cambrian and Caroline classes:^[5]

• Two tandem 4-in guns forward replaced by third 6-in gun.
• One 4-in HA gun on an ad hoc "HA I" or "HA II" mounting to replace 3-pdr Vickers HA gun, with a second to appear when guns and proper HA III mountings became available.

The 6-in mountings were modified to a 20 degree elevation limit, increased from the original limit of 15 degrees, as the ships were refitted for director firing in late 1917-1918.^[6][7]

In October 1916, Commodore, Harwich Force recommended removing all 4-in guns but the forward-most pair which would be converted to HA mountings. By removing five 4-in guns, a fourth 6-in gun could be mounted abaft the funnel. A variation on this was to be applied in 1918, though logistics slowed the work:^[8]

• all 4-in guns removed except the single HA mounting (presumably, HA III. There is no solid evidence that the second one was ever shipped)
• Fourth 6-in gun on elevated CL platform abaft funnels (on P VII* mountings, as the P VII supplies were nil)

A final 1918 rearmament was to provide two 3-in HA guns in the positions where 4-in HA guns had previously been discussed. This plan was never was put into effect.

By the end of 1918, all the Cambrians but Castor had four 6-in P VII 20 degree mountings and one 4-in HA gun. Castor had merely had her three 6-in mountings modified for 20 degree elevation, but was brought up to spec after the Armistice and prior to 1921.^[9]

Torpedoes

2 Service Bar 21-in submerged broadside tubes amidships depressed 4 degrees and bearing 90.^[10]

Fire Control

Mechanical Aid-to-Spotter

By 1920, these ships were equipped with two Mechanical Aid-to-Spotter Mark II*s with Evershed Bearing Transmitters.^[11] The installations generally consisted of placing one on each side of the foretop, driven by flexible shafting from a gearbox on the director tower.^[12]

Supplies of these devices began in June 1918.^[13]

Range Dials

As of 1920, none of the ships seem to have been equipped.^[14]

Rangefinders

Sometime during or after 1917, an additional 9-foot rangefinder being handed down from a battleship or battlecruiser (likely an F.T. 24) was to be added specifically to augment torpedo control.^[15]

Evershed Bearing Indicators

The Centaur class were the first light cruisers fitted with Evershed gear for gun control, but it is not clear whether older light cruisers were ever fitted.^[16]

Orders for Evershed installations for searchlight control from February 1917 first applied to the Danae class, but seem unlikely to have applied to earlier ships.^[17]

Gunnery Control

Directors

In 1916, it was approved that the ships of this class should be retrofitted with directors as time, resources and opportunity permitted.^[18]

All four were fitted with their directors in 1917 and 1918.^[19]

The director was on a pedestal mounting without a tower. Likely, there was no directing gun.^[20]

The elevation limits of their weapons may have increased in late 1917 or early 1918, resulting in orders for adapting their director systems issued 13 November, 1917. It is not clear whether these alterations were for the entire class or just Cambrian herself, or when they were effected.^[21]

Transmitting Stations

Dreyer Table

These ships had no fire control tables.^[22]

Fire Control Instruments

In 1916, it was approved that the Cambrian (and conceivably her class), should have range receivers in the fore top to show rangefinder ranges, presumably transmitted from the T.S.^[23]

Torpedo Control

In 1916, it was decided that all light cruisers of Bristol class and later should have torpedo firing keys (Pattern 2333) fitted on the fore bridge, in parallel with those in the CT, and that a flexible voice pipe be fitted between these positions. ^[24]

Additionally, all light cruisers with submerged tubes were to receive torpedo order and gyro angle instruments between torpedo flats and both control positions. The C class (which may or may not encompass the Cambrian class) was to receive Chadburn Torpedo Telegraphs to meet this need. Otherwise, Barr and Stroud would be a likely choice.^[25]

See Also

• Wikipedia

Footnotes

Bibliography

Template:Cambrian Class (1915)

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