From: De Eye-lands, Mon
Why would anybody build battlecruisers after Jutland? Didn't happen IRL.
True, nobody built BCs, qua BCs. But the evolution of cruisers from their Protected Cruiser/Armored Cruiser origins should be examined. The AC evolution into a substitute BB was a doggie’s lunch. Didn’t work, but the name stuck, so anything in that milieu is painted with a broad brush. I prefer the term CB, to suggest it’s a “classic” cruiser mission with big zagongas, rather than BC which suggests a “battle line” mission with weak knees.
Number of ships vs armor thickness vs number of guns vs size of guns vs rate of fire, etc.. is subject of extensive mathematical analysis in a great article by Joe Czarnecki over at NavWeaps (http://www.navweaps.com/index_tech/tech-076.htm) based on math methods developed and published by Bradley A. Fiske and Frederick W. Lanchester, in the period 1905 to 1920. An even more formal and in-depth analysis is in Fleet Tactics: Theory and Practice, Wayne P. Hughes, Jr, Naval Institute Press, 1986. Highly recommended.
It discusses several aspects of ship/gun design/disposition.
a) “more barrels” vs “heavier barrels” on the same number of ships (basically the Baltimore v Cleveland question); turns out it’s a wash.
b) “quality” vs “quantity ” (fewer ships with bigger guns vs more ships with adequate guns) where the larger ships are also more rugged (basically the two Yamatos vs a bunch of SoDaks); turns out more ships wins every time.
c) “quality vs power” (same number of ships but one side has lighter guns but more armor) advantage (slight but significant) goes to the more rugged side. This modifies a) to a degree given the slightly thicker armor of the Baltimores.
d) gun range, all other things being equal, is significant. Actually, it’s the differential in the immunity zone of the various ships vs the particulars of the gun/ammo combo shooting at them. Time within the immunity zone is a first order effect.
So, pop the cork on a cab, grab some double gloucester, pull out Mahan, and start thinking like a 1920s Naval planner.
To be faster, a ship needs to be longer. But longer means heavier, so more SHP for a given HP/Dspl ratio. Ok. But a cruiser needs to have legs, so it’s either more bunkerage (heavier and thus even more SHP – a never ending cycle) or a more efficient power plant and an acceptance of less than supercalifragilistic extralidocious top speed. Ok. Armor costs money, armor costs speed, armor costs endurance. So what is the point of big armor in a “cruising cruiser”? Ok.
So I would stretch out cruisers a bit and fit them with the new hi-T/hi-P plants and fill them up with 6” because they are more flexible than 8” and gun power doesn’t seem to matter much, but the 6” designs are much less expensive. The Treasury thanks me. And obviously none of these are designed to take their place in the battle line. That is not their mission.
But there’s a gazillion of these pesky cruisers all over the place and if I’m looking to do some commerce raiding or littoral power projection, I need something significantly more powerful. So I take a page from the Kriegsmarine and make a “hunting cruiser”. A long, light, fast, ship with big, long range guns. But see b) and d), above. I might armor them up for a reasonable immunity zone against standard cruiser weapons (see item c) above). A ‘hunter’ needs to have the same legs as the cruisers it’s hunting. So power plant, design coefficients, etc.. need to be in the same ball park (but up the stats and up the cost).
That’s about it so far as cruisers go. I would build lots of 6”ers, size depending on mission, but a large planforn for efficient speed/endurance and gun carrying capability. A very few 8”; basically my bore is bigger than your bore, but not very useful in a practical sense. And some “hunting cruisers”, with 11/12” long range weapons. Not heavily armored, because that reduces their speed/range, makes them uneconomical, and doesn’t really protect them from jack, if you read and understand the references, but makes them vulnerable to case b), so some thought as to immunity zones with respect to an opponent’s expected weaponry might be appropriate.
Mission, mission, mission, mission. And all the marginal dollars, pounds, francs, marks, lire, and yen I save goes into the big boys; at least till the airplane comes into its own, but that won’t matter squat to the guerre de course operational requirements of cruiser thought.
Nous n'avons pas peur! Vive la liberté! Moi aussi je suis Charlie!
Yippy Ki Yay.