Hi
Now that I'm back from colon cancer surgury, I'M BACK !!!!! At the time the first dreadnoughts{H.M.S. Dreadnought & the American Carolina class} were being built. Ad. Jackie Fisher first concieved the idea of the "Battlecruiser". It was planed as a ship with BIG guns{12" at first, then up to 15" during the "Great War", with one being built with 2-18" guns.}, and whatever battleship she could not out shoot, with lighter armour she could out run with more powerfull engines. The battlecruiser as planed by the Brits had a much larger engineering section, thus most battles cruisers where longer than battleships being built in the same timeframe. They were designed to replace the older class's of "Armoured Cruisers".
At the WWI "Battle off the Dogger Bank", a force of German ships including Battlecruisers, one Armoured Cruiser{the Blucher}, took on a British force that included the Battlecruiser "Invincible" fought it out. The Germans retired but the Blucher which was designed similar design as the deadnought type ships, was only armed with 8.1" guns. The British Battlecruisers were armed with 12" guns, no contest. The Blucher was easily overwhelmed by the bigger guns. Just as Ad. Graf Spee's squadron of older Armoured Cruisers were overwhelmed by the Invicible and one of her sister ships at the "First Battle of the Falklands" at the earlier part of the war.
However at the "Battle of Jutland", the British had 3 Battlecruisers blow up while they fought it out with German Battleships.
The German counterpart of the British Battlecruiser, were of similar large size, but the Germans gave their Battlecruisers more armour than their British counterparts{German guns started at 11" and grew to 15" in later models}.
The Graf Spee and her sisters ships were officialy classed as "Armoured Cruisers", but the armour did not stand up well to well aimed shots of British 6" and 8" guns.
Likewise the Scharnhost Class Battlecruisers were built along the lines of their WWI ancesters, also with 9/11" guns. But it was planned to when war broke out to enlarge both ships from 9/11" guns, to 8/15" guns as used in the Bismarck Class Battleships. Lucky for the Brits that never happened.
Steve H.
P.S. There are those that claim, that the Bismarck was heavily engaging the Prince of Wales. That the shot that blew up the Battlecruiser Hood came from the Heavy Cruiser Prinze Eugen. Intriging huh?