KG 5 class underestimated?

[dunmunro]

revised data:

Displacement:
Bismarck Std: 41,700 tons
KGV Std: 36,700 tons (Dec 1940)
Bismarck Full: 50,900 tons
KGV Full: 42,200 tons (Raven lists it as 42,076 tons in Dec 1940)

Dimensions:
Bismarck lenght: 251 mts
KGV lenght: 227,1 mts
Bismarck beam: 36 mts
KGV beam: 31,9 mts
Bismarck draft: 10,2 mts
KGV draft: 9,94 mts

Armour:
Bismarck main belt: 320 mm
KGV main belt: 348-374 mm
Bismarck turrets: 130-360 mm
KGV turrets: 150-324 mm
Bismarck upper deck: 50-80 mm
KGV upper deck: -
Bismarck armoured deck: 80-120 mm
KGV armoured deck: 124-150 mm (95% of the ship protected, but tapered from 124 to 62 mm, fore and aft of the citadel)
Bismarck protected lenght: 70%
KGV protected lenght: 59% (protection against cruiser gunfire over 66%)
Bismarck PC/TC: 17/22 (77%)
KGV PC/TC: 10/21 (48%)
Bismarck armour weight: 17,540 tons
KGV armour weight: 12,612 tons

Armament:
Bismarck main: 8 x 15" L/47
KGV main: 10 x 14" L/45

Powerplant:
Bismarck: 118,00 hp (Theoretical overload = 151,000 hp)
KGV: 113,000 hp (Max overload achieved in May 1941 = 134,000 hp)

Speed:
Bismarck: 28.37 knots at 118,000 hp @ 75% full load displacement (aprox 48,500 tons)
KGV: 27.7 knots at 113,000 hp @ 101% full load displacement (42,530 tons - based upon trials of Howe in Aug 1942)

[marcelo_malara]

At all ranges the 15" shell has a considerable advantage, but even at the muzzle the total energy for all shells shows only a small advantage for Bismarck, while at 20k yds, it is pretty much even.

MAy be, but the penetration is given by the KE PER shell, and not per volley.

[marcelo_malara]

28.3 knots at 115k SHP for Bismarck

To illustrate my previous quoting of D.K. Brown, I offer the followig data. BS is 36 m wide, Hood is 31.7. BS made 28.3 kt at 115000 hp (collected by someone in this thread), Hood made 28.4 kt at 112480 hp (from AOTS Hood). So where is the big disadvantage in being beamier? Remember that Hood is longer, so the 2500 hp less power for the same speed would come mainly from the less wavemaking resistance of the longer hull.

[dunmunro]

MAy be, but the penetration is given by the KE PER shell, and not per volley.

No, penetration is determined by a number of factors, including the energy per square area of the projectiles impact surface.

Here's the penetration in inches (KM/RN armour) from Naab:

14" 15" range (yds)
21.2 22.8 10k
17.9 19.3 15k
15.2 16.4 20k
13.2 14.1 25k

Both guns can penetrate the other's armour at most ranges.

[dunmunro]

28.3 knots at 115k SHP for Bismarck

To illustrate my previous quoting of D.K. Brown, I offer the followig data. BS is 36 m wide, Hood is 31.7. BS made 28.3 kt at 115000 hp (collected by someone in this thread), Hood made 28.4 kt at 112480 hp (from AOTS Hood). So where is the big disadvantage in being beamier? Remember that Hood is longer, so the 2500 hp less power for the same speed would come mainly from the less wavemaking resistance of the longer hull.

BS made 28.34 knots at 117,400 SHP at 75% load (maybe 48.5k tons)

Hood made 28.4 knots at 112,480 SHP at 44.6k tons
Hood made 31.88 knots at 152,200 SHP at 44.6K tons

so Hood was clearly capable of a higher max speed than Bismarck

However, Hood's turbines, props and hull design were 20 years out of date.

Vanguard with similar length to Bismarck, but a higher beam to length ratio, made:
30.38 knots at 51k tons displacement @ 132k SHP,
and 31.57knots @ 135K SHP at 46k tons (BBs by G&D p.297)

so she shows a clear superiority over Bismarck, and she shows off the advances in hydrodynamics made since Hood was designed.

[marcelo_malara]

BS made 28.34 knots at 117,400 SHP at 75% load (maybe 48.5k tons)
Hood made 28.4 knots at 112,480 SHP at 44.6k tons

BS was heavier in the test and shorter, and they made the same speed with less than 5000 hp difference. I still don´t see the penalty of the beamier hull.

Hood made 31.88 knots at 152,200 SHP at 44.6K tons

so Hood was clearly capable of a higher max speed than Bismarck

BS was not capable of that power, her maximum rating is 138000 as by AOTS. So obvioulsly she couldn´t outrun Hood. Hood was the Formula One of the ships for her days.

No, penetration is determined by a number of factors, including the energy per square area of the projectiles impact surface.

OK, that will be KE/section area. For 25000 yards impacting velocity is 1512 fps for 14" and 1602 fps for the 15" (taken from your post).

Shell Velocity KE KE/section area
14" 460 m/s 7783 kN 50 kN/sqr "
15" 480 m/s 9729 kN 55 kN/sqr "

The 15" still has a 10% advantage here.

Both guns can penetrate the other's armour at most ranges.

It is not just penetrating the armour, but keeping enough KE to make damage inside. You don´t choose a gun for "enough penetration", but for maximum one. The British didn´t choose the 14" because "it had adequate performance for the job", but because of political reasons. Resuming: the 15" shell is heavier, has more velocity, more KE, more KE per section area, more penetration. The only person that can make the analysis you are doing, and reach your conclusions, is the one that bought that guns for this ship and is trying to justify the shit he has done!!!

Kind regards

[Bgile]

We also know that Bismarck's belt armor was only the first thing which had to be penetrated to get into her vitals. It was very difficult for a shell to get through both belt and 4" angled turtleback.

Obviously there are other ways to defeat an enemy battleship, but penetrating Bismarck's belt into her vitals was an unlikely one.

[dunmunro]

BS was not capable of that power, her maximum rating is 138000 as by AOTS. So obvioulsly she couldn´t outrun Hood. Hood was the Formula One of the ships for her days.

Hood and Bismarck date from different eras and their technology is vastly different. Vanguard and Bismarck are directly comparable and Vanguard is much more easily driven.


My conclusion is that 10 14" guns is is equal or better than 8 15" guns. I have never claimed that an individual 14" gun is superior. I have presented the most accurate data possible to illustrate the differences between the guns, not to prove that the RN gun is better, one on one. Remember only two hits from these "inferior" 14" guns left Bismarck with 3000 tons+ of flooding and damage to her machinery spaces, despite BS's "invulnerable" belt after the DS battle! The RN 14/45 was a powerful weapon that was more than capable of inflicting massive damage to Bismarck...If Bismarck had been equipped with 10 RN 14/45 guns, she would have saved over a thousand tons of weight which could have been used for more power or armour so you have to look at the whole package. A KGV equipped with Bismarck's guns would have had to make massive sacrifices in armour and/or speed, while a Bismarck equipped with KGV's guns would be even more powerful, IMHO, because she could then have more protection or more speed, or some combination of both.

[Bgile]

Duncan,

All the world's navies chose to go with fewer, more powerful guns when they had the chance. The US Navy went from 12 14" guns in the New Mexico class to 8 16" guns in the Colorado class for a good reason. They switched from 12 14" guns on North Carolina and went to 9 16" guns and they never looked back. In fact, they went with more powerful 16" guns on the Iowa class.

I believe the British looked at switching to 15" or 16" guns also, and the ONLY reason they didn't do that was the advanced stage of completion of the KGV and the effect it would have on that schedule and on British shipyards.

Your argument is contrary to what all the world's navies believed was the best way to go, with all their testing and experts, and you think you are correct and they were wrong.

I think they were correct. I think 10 14" guns were capable of doing the job, but I think all the other navies had more powerful armament in their contemporary ships.

[dunmunro]

Duncan,

All the world's navies chose to go with fewer, more powerful guns when they had the chance. The US Navy went from 12 14" guns in the New Mexico class to 8 16" guns in the Colorado class for a good reason. They switched from 12 14" guns on North Carolina and went to 9 16" guns and they never looked back. In fact, they went with more powerful 16" guns on the Iowa class.

I believe the British looked at switching to 15" or 16" guns also, and the ONLY reason they didn't do that was the advanced stage of completion of the KGV and the effect it would have on that schedule and on British shipyards.

Your argument is contrary to what all the world's navies believed was the best way to go, with all their testing and experts, and you think you are correct and they were wrong.

I think they were correct. I think 10 14" guns were capable of doing the job, but I think all the other navies had more powerful armament in their contemporary ships.

The USN considered 12 14" in three turrets then went to 9 16" in 3 turrets, the KM is the only country that produced a 4 turret BB during WW2. The KM gun is good, but it is not overwhelmingly good, and I have absolutely no doubt that 10 RN 14/45's in 3 turrets is a superior arrangement to 8 KM 15" in 4 turrets.

The USN and KM guns are superior one on one to the RN 14/45, but only the USN battery is superior, IMHO. The French and Italian 15" are inferior, even one on one, IMHO, because of their excessive wear and dispersion problems. These guns look great on paper but in service they were a disaster, and both ships would have been much better off with an equal number of RN 14/45 guns. Again, we have to look at the whole package, and the Bismarck equipped with 10 RN 14/45's would have been a better ship, IMHO.

[Gary]

and the Bismarck equipped with 10 RN 14/45's would have been a better ship, IMHO.

?

[marcelo_malara]

Hood and Bismarck date from different eras and their technology is vastly different.

Yes, but the Germans designers stayed with a 3 shaft configuration, which limited the power output against a 4 shaft ship. All in all, a 4 shaft would at most have added 2 knots, at the price of protection.

My conclusion is that 10 14" guns is is equal or better than 8 15" guns.

In what sense? The only aspect that the 10 barrels are superior to the 8 ones, is in the throw weight. But remember that the added KE is less and that is what counts.

If Bismarck had been equipped with 10 RN 14/45 guns, she would have saved over a thousand tons of weight which could have been used for more power or armour so you have to look at the whole package.

The MkII turret weights 915 t, the MkIII 1582 t. So they sum 4079 t. BS turrets weights 1052 t each, so they sum 4208 t. Where is the 1000 t saving?

Besides, the next class the British laid up, reverted to 15" guns. Why would they do so if the 14" was as successfull as you seems to believe. And what would have happened if the enemy produced a new battleship whose belt could not be defeated by the 14"? That gives points to the 15" in lifespan, since it could tolerate more an upgrade of the enemy staff.

[dunmunro]

Hood and Bismarck date from different eras and their technology is vastly different.

Yes, but the Germans designers stayed with a 3 shaft configuration, which limited the power output against a 4 shaft ship. All in all, a 4 shaft would at most have added 2 knots, at the price of protection.

My conclusion is that 10 14" guns is is equal or better than 8 15" guns.

In what sense? The only aspect that the 10 barrels are superior to the 8 ones, is in the throw weight. But remember that the added KE is less and that is what counts.

If Bismarck had been equipped with 10 RN 14/45 guns, she would have saved over a thousand tons of weight which could have been used for more power or armour so you have to look at the whole package.

The MkII turret weights 915 t, the MkIII 1582 t. So they sum 4079 t. BS turrets weights 1052 t each, so they sum 4208 t. Where is the 1000 t saving?

Besides, the next class the British laid up, reverted to 15" guns. Why would they do so if the 14" was as successfull as you seems to believe. And what would have happened if the enemy produced a new battleship whose belt could not be defeated by the 14"? That gives points to the 15" in lifespan, since it could tolerate more an upgrade of the enemy staff.

The Vanguard reverted to 8 x15" because those turrets were available from stock, and this reduced the cost considerably.

Your figures show that on turret weights alone Bismarck was penalized 130 tons, but then there is the weight of 4 barbettes (remember that X turret barbette must also be much heavier due to the extra hight) versus 3, and the ammo weights, by the time this is all added in, the differential is well over 1000 tons, which is a extreme penalty for both ships, additionally the citadel must be lengthened to accommodate the 4 turrets for an additional cost in weight. Vanguard has many fine qualities, but in a Denmark Strait type battle I consider her to be inferior to KGV despite her extra displacement. On the same displacement Vanguard could have easily mounted 12 14" guns in a 3 x quad turret arrangement, but this would have increased the cost considerably. If Bismarck had been given KGV's guns, the weight saved would have allowed a 4 shaft machinery layout, yet Bismarck's offensive capabilities would not have suffered, IMHO.

[marcelo_malara]

If Bismarck had been given KGV's guns, the weight saved would have allowed a 4 shaft machinery layout, yet Bismarck's offensive capabilities would not have suffered,

Sorry, one last time, can you please justify why the 14" is at least equal to the 15"?
Are you aware of the problems the British turrets had in DS, BS final battle and North Cape?

[dunmunro]

If Bismarck had been given KGV's guns, the weight saved would have allowed a 4 shaft machinery layout, yet Bismarck's offensive capabilities would not have suffered,

Sorry, one last time, can you please justify why the 14" is at least equal to the 15"?
Are you aware of the problems the British turrets had in DS, BS final battle and North Cape?

There's a whole thread on that issue here:

http://kbismarck.org/forum/viewtopic.php?t=1234

and the final consensus of opinion is that the problems with the quad turrets were exaggerated, so I won't go into that here, but here is a nice summary of the final action:
http://www.navweaps.com/index_tech/tech-016.htm

I will say this:

a) 10 14" guns have a greater broadside weight
b) the 14" gun can penetrate deck armour better
c) the 14" shell has a more reliable fuse
d) the 14" shell has better potential to dive under armour belts
e) the 14" shell can penetrate most vertical armour at typical combat ranges
f) the 3 turret arrangement of KGV is at least a 1000 tons lighter than Bismarck's armament.
g) a 5 gun salvo is more likely to strike the target, than a 4 gun salvo
h) the 14" shell has a larger burster charge
I) the 14" gun has a longer barrel life

a1) Bismarck's guns have a greater danger space
b1) Bismarck's guns have slightly better theoretical penetration
c1) Bismarck's shells have more kinetic energy

a2) both guns have an equivalent maximum range

The 14" shell's better diving ability and larger salvo size gives it a better chance to hit the target, given equivalent fire control, the larger burster of the 14" shell will compensate for its lower kinetic energy, while it's armour penetration is sufficient to defeat most of Bismarck's vertical armour at typical combat ranges. Sorry, but 10 RN 14/45's is a better armament, than 8 KM 15".