Comparison of WWII battleship firepower

It goes to show you how much free time some of us have. After some research, I come up with a rough estimation of each ships's firepower based on the number of guns, shell weight per broadside, and rate of fire, and the weight of shell it can put in the air per minute. Most WWII battleships fires at a rate of 25-40 seconds per round.

Example: Yamato: 9 guns, 3,219 lb/shell, 28,971 lb/broadside, rate of firing 35 seconds (or 1.7 broadside per minute); therefore its metal weight per minute is 28,971 lb x 1.7 = 49,665 lb.
Comparing with Iowa: 9 guns, 2,700 lb/shell, 24,300 lb/broadside, rate of fire 30 seconds, thus metal weight per minute is 24,300 x 2 = 48,600 lb

Class #of guns wt/broadside cyclic rate wt of shell per minute

Yamato 9 28,971 lb 35 sec 49,665lb
Iowa 9 24,300 30 48,600
S. Dakota 9 24,300 30 48,600
Bismarck 8 14,112 25 33,869
KG-V 10 15,900 30 31,800
Hood 8 15,360 30 30,720
Nelson 9 18,432 38 29,491
Richelieu 8 15,592 32 29,235


Interesting to note that the shear broadside weight of the "powerful" bismarck was less than 60% of the Iowa and 50% of the Yamato. Even though is broadside weight was slightly less than the KG-V, Richelieu, Hood, The Bismarck can throw more metal weight into the air per minute because of its faster cyclic rate.

Of course, the quality of the ammo, the range of guns, the fire-controll systems (i.e radar, range-finder) and the quality of the gun crew are also key factors. In which case the Iowa probably prevails since its firing control system is second to none, and its metal weight per minute is nearly equal that of the Yamato

 

I would have to agree.

"Speed is fine. Accuracy is final!" - Pat Garrett

:smok:

 

It is not possible to assign a firing cycle. Maximum rate of fire is something that almost never figures in battle. Also, the number changes with numerous other factors. For example, Yamato's minimum firing cycle at short range would be 30 seconds. At extreme range, it would be over 40 seconds. If the sea state is such that she is rolling, she may have to slow her firing to facilitate accurate gunnery. If her target is off the bow, the need to minimize trunnion tilt may limit her firing opportunities. All sorts of things enter into this. Even at very short range at Guadalcanal, Washington achieved only about 1.7 rounds per gun per minute.
Japanese and American shells carried small bursters. The American burster consisted of Explosive D, which was less powerful than TNT but unlikely to explode prematurely. The Japanese used TNA, more powerful than TNT but liable to premature explosion.
A shell that penetrates is more destructive than one that doesn't. Colorado was considered to have more firepower than Tennessee though their broadside weights and their firing cycles were the same. And a shell that breaks up is less destructive than one that stays together. American shells had higher proofing standards than Japanese or German shells.
The frustrating thing is that statistics reduce things to the purely objective, which would seem a good vehicle for unbiased comparison; yet there is no way to integrate all the factors into a statistical system.

 

Again, all great points. Those theoretical figures I generated are all based on normal operational conditions: calm sea, perfect weather, experienced gun crew, etc... which probably never happens in a real battle. My main points were to compare the shear weight of the ship's broadside and their projected metal weight in the air per minute under perfect conditions.

 

One additional point is that the max RoF wasn't necessarily used even when it could have been. IIRC battleships tended to wait after each salvo or broadside for the fall of shot to be spotted so they could correct the aim for the next shoot, which at long range would take well over a minute. So they generally didn't fire any faster than that.

Tony Williams: Military gun and ammunition website and Discussion forum

 

There's also the matter of reliability. Some weaponry simply proved more reliable than others. KGV's guns were notoriously prone to casualties, while the RN 15-incher was as sweet as could be.

 

Why the 14-inch for KG-V?

Near the end of WWI, while most of the world's navy were still using the 12 and 13.5 inch guns, the British came up with the legendary 15-inch design which fired a heavier shell at a longer distance. The admiralty found that it took only 8 of these new guns to surpass the broadside weight of the 10 older 13.5 inch guns (e,g Iron Duke class and KG-V class), this extra weight-savings meant more armour can be added the ship. These powerful guns were mounted on the new Queen Elizabeth and Revenge class battleships, as well as the ill-fated battlecruiser HMS Hood.
For whatever reasons however, when the new King George-V was laid down in 1936, the 14-inch guns were chosen instead of the 15 or even a new 16-inch design. Was it because of naval treaty limitations? The post-WWII Vanguard class returned to the 8 x 15-inch design.

 

Re: Why the 14-inch for KG-V?

Naval limitations. Second London Treaty 1936, Part II, Article 4:

Only British followed that rule.
When WW2 started, all those limitations were lifted and British decided to use those "leftover" turrets from Courageous and Glorious for Vanguard. Also Lion-design was coming with 16" guns, 3x3 if I remember correctly.

Edit: Fixing stupid typing error

 

Re: Why the 14-inch for KG-V?

North Carolina was also designed to carry twelve 14in guns, just as KGV was, with three quad mounts. The difference was that the Americans felt they could afford the time and money to simultaneously design a 16in triple they could fit onto the 14in barbettes if it became possible to take advantage of the 16in loophole. A comparison of the KGV quads and the Lion triples shows the British could have done a similar switch if they'd felt the freedom to try it, though this obviously would cancel the armor changes that resulted from switching B turret to a 14in twin.

 

Re: Why the 14-inch for KG-V?

I'm glad NORTH CAROLINA was fitted with the 16-inch guns; all those 14-inch mounts would have really cramped her (for a BB, she's not as big as one might expect, especially compared to the IOWAs). I've been aboard her, and she's a real beauty, especially in the multi-shade blue dazzle camouflage they recently repainted her in.

 

Re: Why the 14-inch for KG-V?

The increase in firepower from the 14in to 16in versions is monumental. Maybe if the US had developed a super-heavy 14in, the lesser caliber would not have mattered so much.

 

Re: Why the 14-inch for KG-V?

There are always those in any armed forces to whom bigger always means better. This instance is no exception.