Battle cruiser, Armed Cruiser or Battleship. how or why they are designate

[dgbot]

This is a topic that popped up on a facebook group about battleships.  A very interesting and informative discussion into politics displacement, armor, speed and firepower.  I am wondering how the knowledgeable people here would go about classifying these vessels and the reason for doing so.

David B 

Edited April 27, 2016 by dgbot

[grsjax]

A battle cruiser is a battleship with less armor.  The idea is that it could outrun anything it couldn't fight and beat anything it couldn't outrun.  Jutland sort of ended this idea although it stuck around until WWII.  An armored cruiser is just that, a cruiser with more armor.  Originally there were light cruisers, protected cruisers and armored cruisers.  Light cruisers were essentially large destroyers used for scouting and screening the fleet.  Protected cruisers were heavier but did not have much armor, the protection was from placing the coal bunkers and water tanks around the machinery and other vulnerable spaces.  The armored cruisers were armed much like the protected cruisers but had heavier armor.  Protected cruisers were used like big gunboats, show the flag missions, isolated postings with limited possibility of encountering a heavily armed enemy and as flag ships for detached squadrons.  Armored cruisers worked with the fleet.

 

This is just a quick view of a subject that is really pretty complex.  The history of warship design from the 1870s up to WWII has many examples of ships that do not fall into any defined catagory but are lumped in with catch all groups like "protected cruiser".

 

An interesting thing is the last of the battle cruisers were the USS Alaska and USS Guam.  The were designed as flag ships for fast carrier squadrons and combined fleets.  They were launched in1944.  The Navy called them large cruisers but their designation was CB (battle cruiser) and they match the original idea of what a battle cruiser was.  Both were laid up in 1947 and scraped in 1960.

Edited April 28, 2016 by grsjax

[Les T]

With regard to Battle Cruisers at Jutland,they were not designed to fight in a major fleet battle against enemy Battleships and Battle Cruisers, their reason for being was in operations such as the battle of the Falklands where they had both the speed and firepower to destroy von Spee's inferior squadron. The other factor in the loss of the three Battle Cruisers at Jutland was the British practise of keeping all flash doors open and stowing ammunition in passageways etc to aid rapid firing.

[CharlieZardoz]

Plus the Bristish battlecruises had much lughter armor than their German counterparts. Even the Hood which was possibly the finiest battlecruiser ever built had virtually no armor protection on deck which ultimately led to her tragic end.

[doggido]

Wouldn't the Deutschland Class ships fall under this post?

What is their actual designation?

[Canute]

The Germans classed them Panzerschiffe

[doggido]

But what did the english class them as? Apart from "Pocket Battleship" which was only a nickname.

[Talos]

In the 1937 edition of Jane’s Fighting Ships, the Deutschlands are listed as “armored ship”, with the German “panzerschiffe” in parentheses. That term was used by the Germans to get around the Washington Naval Treaty that said they couldn’t have any battleships. It was an older term they used in WWI as the rough equivalent of the armored cruiser, while linienschiffe (ships of the line) were the battleships. So technically they were counted as “heavy cruisers” under the WNT. The armament of 11” guns was about the maximum they could get away with without being openly building battleships and was their standard battlecruiser armament in WWI. All the other navies were moving to 14-15” guns on battleships (minus Nelson and Rodney with their 16” guns and a smattering of other calibers). The other propsed armaments were 4 x 15” guns and 6 x 12” guns before they settled on 6 x 11”.  

 

Heavy and Light Cruisers replaced all the old terms under the WNT, with the former armed with roughly 8” guns and the latter 6”. With the older types, the major difference (besides size) between armored cruisers and protected cruisers was armored cruisers had a battleship-style armored belt at the waterline (though thinner, of course), while protected cruisers were armored with an angled, armored deck and subdivision, coal bunkers, gunshields, etc. Armored cruisers in the Royal Navy were armed with 9.2” guns in the manner of pre-dreadnaughts. The first battlecruisers were intended by Fisher to be an evolution of armored cruisers,  armed with multiple 9.2” turrets, but they were given 12” battleship guns instead, which was the cause of their difficulties later on because they were misused in the battle line instead of their intended job. Basically they were big and expensive and the RN couldn’t afford not to put every ship armed with battleship-grade guns in the main fleet, no matter their lack of armor.

 

They were actually more survivable than most people give them credit for. The extreme length of the ships tended to absorb damage. The biggest vulnerability in the British ships was poor ammo handling safety, including crews leaving flash doors to the magazines open or even removing them entirely to speed up loading. They weren’t /that/ much lighter armored than the German ships.

 

EDIT: One way to look at the difference between armored cruiser and battlecruiser is the latter is the all-big-gun dreadnaught equivalent to the pre-dreadnaught armored cruisers.

 

Pre-dreadnaughts were built on a "hail of fire" concept. They would engage with the two heavy turrets further out, then close in and use the multiple light (6-8") casemates to decimate the unprotected/lightly protected parts of the topsides of a ship. Bridge, guns, masts, directors, uptakes, etc. After a ship was disabled like that, they would pull away and use the battleship's submerged torpedo tubes to dispatch the helpless wreck.

 

Due to overreaction to torpedoes in the late Victorian Period, there was a push to hugely increase the battle range for battleships so they could engage outside of the expected range for torpedoes. At that range, the only way to really ensure a reasonable number of hits was salvo fire, which requires multiple guns to do. Dreadnaught's layout and armament was designed to be able to do this against a target in nearly any direction. Her lack of superfiring turrets was due to the use of open sighting hoods on the roofs of turrets, which were vulnerable to blast damage. Having the two side turrets able to fire forward actually gave her more foreward firepower than the later all-centerline ships, which was more suited for the frequent chases battleships engaged in during the war.

Edited May 9, 2016 by Talos