6x 20", 9x 18" or 12x 16"??

[fbs]

If you were the lead designer for the A-150 class (intimately known as Fluffy or Super Yamato), would you go with 6x 20" as they wanted, leave as 9x 18" or go back to 16" in 3 quad mounts?

The other way of asking is this: who in the world needs 20" guns (or 18" for that matter), when 16" can get the job done quite nicely?

[herwin]

ORIGINAL: fbs


If you were the lead designer for the A-150 class (intimately known as Fluffy or Super Yamato), would you go with 6x 20" as they wanted, leave as 9x 18" or go back to 16" in 3 quad mounts?

The other way of asking is this: who in the world needs 20" guns (or 18" for that matter), when 16" can get the job done quite nicely?

The damage done by a penetrating AP hit was proportional to the cross-sectional area of the shell. The trade-off between sustained RoF and damage done at these calibres tended to favour the smaller calibre--ceteras paribus--but armour penetration, range, and accuracy tended to favour the larger calibres. YMMV.

[topeverest]

I would prefer ship speed, maneuverability, and effective rate of fire. The relative difference in penetration performance with the three caliber choices seems minimal to me.

[castor troy]

I would go with the most barrels, hence the 16 inch. Guess the 16 inch could knock out every opposing ship too so why going with 6x20 if you can have 12x16?

[John Lansford]

IIRC the 18" shell's penetration ability was no better than the Iowa's 16", and with all the massive engineering involved in building turrets and other machinery to hold the bigger guns, ISTM that going with smaller weapons would have been the way to go.  Problem is, the Japanese had no modern 16" guns in development, and only had the ones from Nagato and Mutsu to work with.  Those probably had no better performance than the West Virginia class had.

[CarnageINC]

I would go with 20" just to say I have bigger guns than you do [:D]

[Terminus]

Neither the 46cm or 50cm guns were sufficiently superior to the 16in guns in either navy to warrant the expense of their construction. I would go with a 3x3 40cm setup, and spend some resources on armour protection and speed.

[mbar]

Interesting comparisons can be found here
"Mirror, Mirror, on the Wall Who's the Baddest of Them All?"

And here is a pdf on fast battleship design philosophy
"Development of the World's Fastest Battleships"

[chesmart]

I will go for the USS Montana setup 12X16 inch with lots of armour and speed increased to 29 knots

[Nikademus]

six heavy barrels i have always considered a bare minimum for a Dreadnought type Capital ship. A minimum of 8 is preferable.

[Terminus]

Six is nowhere near enough.

[Nikademus]

hence the term bare minimum.

Only two examples existed....Renown and Repulse. (The pre-dreadnought Brandenburg's i don't count as their middle pair of 11inch guns were of a smaller caliber than the primary 4 x 11's in the traditional fore and aft locations)

The two R's were "useful" but as stressed, having only six barrels limited their total broadside. Of course the old adage that it only takes one good hit applies. On the whole though i'd rather have 8-12 which was standard.

[Terminus]

I would call it "below minimum", but hey-ho. Anyway, if I fire 12 rounds everytime you fire 6, chances are better that I land the damaging blow first.

[Dili]

You have much less rounds in the ship. Unless the accuracy increases enough to offset the less number rounds. There is still less salvo number. Even assuming that rate of fire remains unchanged for every salvo with 6 guns instead of 9 you send less 33% of rounds.
To make damage you do have to get an hit first. That is why i have my doubts of even going to 9x15/16" in WWII was right. 12x14" or something near that caliber could have been better, after all for their power Battleships seldom hit.

[Nikademus]

I agree its not desirable but i count it because technically HMS Refit and Repair [:'(] are considered Dreadnought era Capital ships.

At least they were six of one of the best battleship guns that ever saw service.

[Terminus]

Show me one battleship action where the combatants ran out of ammunition.

[Nikademus]

Faulklands.

Invincible and Inflexible nearly empited their shell rooms sinking Scharnhorst and Gneiseau in a long range shootout.

[Terminus]

The operative word being "nearly".

[John Lansford]

I think 12 16" guns in triple turrets was probably the best arrangement, but the Japanese didn't have a lot of experience with triple turrets.  They liked the dual turret because they felt the ROF was higher.  With such large guns, reloading must have taken a lot of time, increased even more in a 3x turret.  Would they have gone with
4 3x16" turrets or tried to build a "Super Fuso" with the amidships 2x turrets?

[Nikademus]

Actually it was the Germans who didn't have the experience and given their enforced holiday on battleship building they opted for a standard 4 x 2 pattern. This suited their fire control procedures anyway (they considered the arrangement optimal).

Japanese got their experience with Yamato and i'm not aware of any issues with them (unlike the British experience with Nelson and Rodney). The reason for the 3 x 2 arrangement was the massive size and weight of the 20inch gun that was to have manned the turrets.