HMS Blenheim (AC-1906)

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The Blenheim and Blake were laid down for the Chilean Navy in 1903 as part of the South American arms race then in progress. The Royal Navy agreed to purchase the ships to help defuse the arms race, but this only lasted a couple of years as the advent of the Dreadnought started a brand new race.

Completed in 1906 they were probably the best of the armoured cruiser classes built. This 'best of' lasted less than twelve months as the completion of the Invincible type battlecruisers rendered these ships obsolete. The mixture of 10" and 7.5" was similar to the British armoured cruisers, but the 10" gun was superior to the 9.2" British weapon. Where the US armoured cruisers had 10" guns of similar capabilities the secondary 6" were not as good as the Blenheim's 7.5".



The original design was based on the Swiftsure class battleships and used an armoured cruiser hull type. The armament of 4x10" (2x2) in turrets, and 10x7.5" (10x1) in casemates gave a very useful armament.

The four ships, Swiftsure, Triumph, Blenheim and Blake were used as a group, because of their 10" guns being an out of synch gun type. Most British ships of the time would have had 12", 9.2", 6", only the 7.5" being a common size. During the First World War the four ships operated exclusively in the Mediterranean.


HMS Swiftsure, the ship the Blenheim class were based on.
 

The Blenheim survived the First World War to face an uncertain future. The early 1920's was spent as a training cruiser, as a part of the training fleet. The Washington Treaty meant that the ship would no longer be able to be kept as a cruiser in the Royal Navy. Two choices remained, sale or transfer of the ship to another navy or the scrap heap. The ship could go to one of the South American countries or to a Commonwealth country.

So where should it go? Southern Africa, Australis, Zealandia. All are possibilities. I like the idea of Zealandia as they did not get a lot of their earlier ships from the Royal Navy. The Blenheim was transferred to Zealandia in 1924 and taken in hand for conversion to a more workable training ship that could double as a coast defence ship. Taking the cadets on sea cruises and patrolling the coastal waters. The conversion removed the casemate mounted 7.5" guns, and some of the single low angle 4". New superstructures were fitted to act as classrooms and extra accommodation. In this guise the Blenheim patrolled the Pacific coastal waters.



On e of the main reasons the Blenheim was a good fit for Zealandia was that they already had the same model 10" guns in their inventory aboard two classes of cruiser.

1930 and the Zealandian Navy is in a bit  of a quandary. Only having one aircraft carrier hampers their fleet. Looking around at what is available to the Navy for conversion to a training carrier, there is very little. This is 1930 and the Depression is biting deep into the worlds economies. Money for new ships is non-existent. Of the available shipping, only the Blenheim meets the size requirements needed for an aircraft carrier. What holds it back is the triple-expansion engines. Replace the power plant and the ship would be perfect for the task.

Over in Australis the Iron Duke class ships, they have, are being rebuilt. The older 30,000shp engines being replaced with a new powerplant rated at 80,000shp. A request to Australis for one of the sets of 30,000shp meets with success, and the conversion is on.

The Blenheim is now to be the Fleet Training Ship for both Surface and Air Cadet trainees. The rear half of the ship would be converted to a 'hangar' for aircraft, while the forward upper deck would contain the extra accommodation and classrooms for the cadets.

The ship could only carry 8-9 aircraft for its own air wing. When used as an escort carrier in time of war this was not a problem, as six Swordfish and 3 Griffon fighters were all that was needed. Unless of course your convoy runs into a Japanese fleet and gets decimated.

 

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