Battlecruiser definition?

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Karl Heidenreich
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Battlecruiser definition?

Post by Karl Heidenreich »

Earlier, when referring to Battlescruisers I became confused at the answers I got. :think:
So, first things first. What´s a battlecruiser?
As far as I know a Battlecruiser is:
1. An idea of Lord Fisher to outgun smaller ships and outrun bigger ships.
2. A ship that is lighter and faster than a battleship (dreadnaught?)
3. A ship that can serve as scout of a fleet. Example of it was the use of the Battlecruisers Squadron at Jutland.
4. A concept that rendered very bad results when finally put at test at Jutland Battle.
5. A concept with a sad epilogue as we know of the Hood blowing up to the skies and the Repulse sinking.
6. A British concept that Germans and Japanese copied without any good results. (With the exception of Schanhorst and sister ship that were very harmfull to the British)
I think I put quite simple, but, am I right? :think:
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marcelo_malara
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Post by marcelo_malara »

Karl, in my opinion:

1. An idea of Lord Fisher to outgun smaller ships and outrun bigger ships.

Right.

2. A ship that is lighter and faster than a battleship (dreadnaught?)

Yes, but carrying the same calibre main armament.

3. A ship that can serve as scout of a fleet. Example of it was the use of the Battlecruisers Squadron at Jutland.

Not sure, I believe not. Too expensive to be used as a scout, the function could be cheaper acomplished with a light cruiser. In fact they were not intended to fight the battleships, so a cruiser could do.

4. A concept that rendered very bad results when finally put at test at Jutland Battle.

Fisher´s concept was not to fight a battleship with them, but to fight cruisers and converted merchants commerce raiders. So that they fought against battleships in Jutland was not the test of the concept, in fact the concept was proven in the Malvinas/Falklands battle against Spee´s armoured cruisers.

5. A concept with a sad epilogue as we know of the Hood blowing up to the skies and the Repulse sinking.

Again, the Hood was not intended to match the Bismarck. As stated in another topic, Hood was quiet a powerful ship, but the horizontal protection was rather thin. That, coupled with the known problem with cordite, doomed her.
The Repulse was sunk with the PoW, a true battleship. Another battleship would have been sunk too in the attack.

6. A British concept that Germans and Japanese copied without any good results. (With the exception of Schanhorst and sister ship that were very harmfull to the British)

The Scharnhorst was no in my opinion a battlecruiser, but a battleship that for political and technical reasons got armed with 11" guns.
I am in the process of reading Campbell´s Jutland, and I am surprised of the punishment that German´s battlecruisers received (even 15" shells) without sinking.

(My) conclusion:

The battlecruisers belongs to the 1910 decade era, where the power of the machinery was yet limited, so to have a 3/4 kt advantage, the designers have to cut down the weight of the armour.
In the 1930 the high pressure boilers combined with the geared turbines, allowed the designers to reach powers that allowed a full armoured battleship to reach speeds in excess of the old battlecruisers, hence the term fast-battleships.
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Post by tommy303 »

Fisher's idea of the battlecruiser was similar to his view on the all big gun battleship (dreadnoughts). Dreadnought when she went into service immediately made previous battleships pretty much obsolete, thereby giving Britain a technical edge over the competition, provided of course she could maintain a large enough building program to keep ahead.

The battlecruiser--essentially a ship with the armament of a dreadnought battleship and the speed of a cruiser was aimed at giving the Royal Navy the same technical edge over other nations' armoured cruisers. In Fisher's mind high speed equalled protection, so sacrifices were made in armour thickness in order to attain high speeds. At the time, this had some justification as fire control was in its infancy and it was some years before advances in gunnery caught up and overcame that problem. I believe Fisher himself did not discount the new BCs engaging battleships, although by the time they had a chance to do so, the advances in gunnery had increased the danger of such a tactical use.

Battlecruisers were not necessarily lighter than battleships---in fact most dwarfed their contemporaries since the high speed was attainable only by very massive turbine and boiler installations. Thus the BCs were frequently much longer than a dreadnought of the same generation and were often of similar or even greater weight. The compromise though, was usually armour and they were not armoured on the same scale. German battlecruisers, though, tended to be more modestly armed, but better armoured than contemporary British ones. Still even their armour was less concentrated and generally thinner than their own battleships.

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Post by marcelo_malara »

To illustrate my point I have prepared a comparative of all the battleships and battlecruisers built by the UK between 1905 and 1915. (Sorry for table but I don´t know how to make it look better here).

Year.Type.Class.............Displ.....LOA.......HP...Speed..Mach. Armour
...................................................................................weights
1905 BB Dreadnought..18110..160,60..23000..21......1898...5000
1905 BC Invincible........17250..172,82..41000..25......3300..3460
1906 BB Bellerophon....18800..160,30..23000..20,5...1936...5389
1908 BB Collingwood....19550..163,40..24500..21.....1983...5500
1908 BC Indefatigable..18750..179,83..43000..25......3555..3735
1909 BB Colossus.........19680..166,40..25000..21......2036..5474
1909 BC Lyon................26350..213,36..70000..28......5190..6140
1910 BB Conqueror.......22200..177,10..27000..20,5.....?......6460
1910 BC Queen Mary.....27000..213,36..75000..28......5310.6575
1911 BB Ajax................23300...181,90..27000..21,7.....?......6960
1912 BB Benbow..........25800...189,80..29000..21......2580..7700
1912 BB Barham...........33400...195,00..56000..23......3691..10570
1912 BC Tiger...............28490...214,58..85000..28......5630..7400

What I notice looking at the table, is that to make a battlecruiser faster than the same year battleship, the designers had to get a sheer increase in the machinery output (meaning heavier and bulkier machinery), and to increase the hull lenght, to acomodate the longer machinery and to reduce the wavemaking resistance. Obviously, to maintain the displacement within limits (and not need a further increase in power), the excedent machinery weight had to be taken from the armour weight. In some cases where the armour weight could be maintained, it had to be distributed on a longer hull, which means thinner armour.
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Karl Heidenreich
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Post by Karl Heidenreich »

So, to conclude:
1. Indeed, the Battlescruiser was an idea of Lord Fisher
2. Their golden era was pre WWI and the WWI
3. The main idea was not to be a scout but to operate as an independent squadron and/or unit to patrol the high seas and defy cruisers, raiders and so forth.
4. Their use at Jutland was merely tactical.
5. Their "bad day" at Jutland was not a concept error but a design and construction flaw (not to say "malpractice").
6. After WWI the navies still had them (and decided to stay with them). That´s why Hood, Repulse, etc. stayed in service. Anyway there was no suppossed adversary and neither a WWII expected at the 1920s.
7. German WWI Batlescruisers were more armoured than British ones.
8. Pre WWII the Germans used the concept of Battlecruiser to build potent surface ships that cannot be considered as Full Battleships (Schanhorst...)
9. Hood´s fate was a weakness of it´s original design and Admiral Lancelot Holland knew this. That´s why he rushes to close the distance with Bismarck at Denmarck´s Straits.
:!: But. This design flaw was not, as many said before, a problem with the hatches and bulkheads in the battlecruiser´s turrets (the ones that connected them with the magazines) :negative: but an horizontal armour weakness (on the main decks). That´s it? :think:
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Post by marcelo_malara »

I agree with points 1 to 4 and 7.
5) In Jutland engaging other battlecruisers was parcially justified: they outnumbered the Germans BC and they have the support of the 5th Battlesquadron with their 15" guns.
6) After WWI, the Washington and London Conferences dictated that capital ships with less than (not sure) 20 years could not be replaced by newer ones, so it was to keep them or to have fewer capital ships.
8) In my opinion Scharnhorst is a battleship, inspite of the 11" guns, because of her armour.
9) Nobody can say for sure if Hood´s explosion was caused by a shell exploding in the turret (and the explosion reaching the magazines) or a shell piercing the horizontal armour (and exploding in the magazines itself). Read an interesting discussion on this in http://www.navweaps.com/index_inro/INRO_Hood_p1.htm.
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Karl Heidenreich
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Post by Karl Heidenreich »

"Nobody can say for sure if Hood´s explosion was caused by a shell exploding in the turret (and the explosion reaching the magazines) or a shell piercing the horizontal armour (and exploding in the magazines itself)"

Sorry, I stated the previous point wrong. I wasn´t talking about Hood when stated about the magazines and/or turret blowing. I was talking about the BCs that decided to blow up at Jutland.
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Post by Ulrich Rudofsky »

The German Imperial Navy's apparent equivalent for a battlecruiser was the "Großer Kreuzer" i.e., large/great cruiser. However, I don't know if the two were really equivalent in size, firepower, speed, and purpose and war fighting efficiency etc. Certainly, there were no "Großer Kreuzer" ships in WW2. I wonder what would be the equivalent to the GK in terms of RN ships?
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Post by Dave Saxton »

Would a panzerschiffe be some form of WWII grosser kruezer?
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Ulrich Rudofsky
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Post by Ulrich Rudofsky »

I really don't know. :stubborn: It could be that the Panzerschiff was eq. to the Große Kreuzer, but would that make it a battlecruiser ???????
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Post by marcelo_malara »

Karl:
According to Campbell´s Jutland, there were no cases of shells piercing the horizontal armour and reaching magazines or machinery in either British or German battlecruisers. What there was, were shells penetrating turret armour (partially or totally) and starting propellant fires from charges within. In the case of the German´s, those fires were controlled. In the case of the British, who used cordite, led to the lost of three battlecruisers.
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Post by Matthias »

Could had it been due only to the difference of propellant? :think:
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Post by marcelo_malara »

Of course!!! The cordite had by then a long history of accidentals explosions in warships. It reacted violently when burned in confined spaces, instead of burning slowly like the German RPC propellant.
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Post by marcelo_malara »

Ulrich:
Which is the exact translation of:
Linienschiffe
Schlachtschiffe
Panzerschiff
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Post by Matthias »

marcelo_malara wrote:Of course!!! The cordite had by then a long history of accidentals explosions in warships. It reacted violently when burned in confined spaces, instead of burning slowly like the German RPC propellant.
I am a chemist, I know...;)

The translation should be

Ship of the Line,
Battle-ship
Armoured-ship, literally.Am I mistaken?
"Wir kämpfen bis zur letzten Granate."

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