German Battleships and convoy hunting.

[plan_D]

Even with the extensive protection that the Tirpitz and Bismarck carried, it didn't make them rank up alongside the real greats. Remember, to destroy a ship doesn't mean you have to sink it.

While I agree the Bismarck and Tirpitz were impressive (as were all German pocket battleships), they were able of destruction. You don't have to be lucky to put any of them out of action. Merely wrecking the guns on them would end their days.

And lanc, half of the Royal Navy wasn't chasing the Bismarck. Do you know how big the Royal Navy was!? There was some of Force Group H and the Home Fleet chasing the Bismarck - while that is a lot for a ship ...it's not a drop in the size of the Royal Navy which amassed over 400 combat vessels.

[the lancaster kicks ass]

i realise it wasn't that much i was just saying it to make a point.........

[delcyros]

Take it once more on the main guns.
Shell weight is worth nothing as long as ap capabilities are weak or destruction force is insufficient. The author of combinedfleet mentioned this correctly.
The ap capabilities of the original US 16"/45 and 16"/50 AP Mark V
(2270lbs) is far inferior to those of the 1.780 lbs ap 15"/52 of Bismarck (I wonder why many sources rate it as a 15"/47, it indeed is a 52 calibre length barrel with chamber). Take an hour on Okuns penetration formulars on face hardened armor. It was not until the introduction of the much heavier 2.700lbs ap Mark VIII shell that the US 16"/50 was equal in ap capabilietes at point blanc range (both 30.4" against british cementated, which was the best), the US 16"/45 still being slightly inferior to Bismarck 15". Take notice that the german ap-cap was way superior to US designs even with a 900lbs lighter design!
With enlarging the distance the trajectory is higher and therefor, the heavier weight benefits the US shells. But they are still far away from outclassing the Bismarck. The difference is significant at distances over 20.000yrds. Now we exclude distances of 35.000 yrds and 40.000yrds in the table (no chance to hit anything freely moving at these distances, regardless what fire controll you may have, even 30.000ft show no records in ww2).
Bismarck gets 148.3 and Iowa 157.7 (for comparison: Yamato:167.1, South Dakota 147.6). So Bismarck has the same ap-capabilities than South Dakota, and a comparable to Iowa at distances closer than 15.000yrds, it is outclassed by Yamatos shells, agreed.
Next: Kabooooom force.
I just quote on the author of combined fleet:
Bismarck 4.55 , Iowa/South Dakota: 4.4 (for comparison: Yamato 4.72)
The destructive power of a Bismarck shell is slightly superior to those of 900 lbs. heavier US 16" shells. Yamato is still unbeaten.
Next: rate of fire
And violá! Only with the artificial reduction of Bismarcks high firing cycle, the author could rate Bismarck under SD. However, this is wrong. Firing cycle is stated by him with 3 per minute (which is correct) but he reduced it to 1.8. He couldn´t do otherwise, because Bismarck would turn out as the winner:
With 2 per minute (which is alredy reduced by one third of it´s potential) Bismarck would throw 80 shells in five minutes compared to 77 of Iowa/South Dakota(both 1.7 per minute) and 68 of Yamato(1.5 per minute)! Even with one barrel less Bismarck has a considerably higher main battery output (one rason to favour twin turrets, the firing cycle for full salvos is better because you won´t have problems to feed the middle gun).
You may now multiply these factors as the author did and the corrected figures are:
1.) Bismarck 53.981 points
2.) Yamato 53.632 points
3.) Iowa 53.428 points
4.) South Dakota 50.006 points
The first three are going to be in the same weight class. You may say that we should furtherly ignore point blanc ranges (given) but then the differences wouldn´t be striking. And while the author uses original shells for italian and french ships, he don´t use original ones for the US designs but the later introduced and much better 2.700 lbs shells. Using their original shells, the US BB are way inferior to Bismarck and Yamato.
Not included are trajectory and shells flight time, both goes for Bismarck, nor firing arc (the french ship should suffer), nor gun preciseness (US worser than british and german, japanese and italian worser than US).
So the 5 tons additional shell weight per broadside are worth nothing compared to Bismarck. And again, Radar at 30.000 yrds won´t help and did not helped against freely moving targets. It wasn´t until 1987 that an Iowa class BB hit a training pattern of 250 yrds diameter from 34.000 yrds with all modern tech stuff. But let´s discuss firecontroll later.

[delcyros]

Once more on the Bismarcks firing rate:
18-22 sec. for Bismarck (resp. 3.2-2.8 rounds per minute) are for elevation 2.5 degrees (the usual loading elevation). The barrels could be elevated at 6 degrees per second, maximum elevation was -5.5 - +30 degrees (35.5 degrees, roughly 10 seconds up and down from loading elevation). The theoretical firing cycle is limited by the practical ammo feed, also. The turrets elevators of Bismarck allow 23-25 shots per minute (for 8 guns), so the best practical sustainable rof is 2.9-3.1/minute.
So the firing cycle is 28-32 sec. with a middle at 30 sec. (2.0 rounds per minute) at 30 degrees elevation (~38.000 yrds). Keep in mind that this is the worst cyclic firing rate of Bismarck. Only Tirpitz ever fired at distances (against ground installations near Spitzbergen) comparable with them. Any closer distance would improve the firing cycle. Of course there may be an additional delay for the first rangefinding salvos in order to notice the flashes and correct the datas.
Iowa had a max elevation of 45 degrees (36.900 yrds with 2.700 lbs ap)and could move the guns with amazing 16 degrees per second (roughly 6 seconds at max elevation up and down) and a optimal firing cycle of 2 per minute (30 sec.). The theor. ammo feed is somehow lower at 18 rounds per minute (for 9 guns) So at comparable distance fired the Iowa would have a worst firing cycle of 36 sec at max elevation (1.7 rounds per minute). Any closer distance would benfit the Bismarck even more compared to Iowa.
Factoring firing cycle, armor penetration, destructive force and battery layout, the Bismarcks 15"/52 are in my view the best heavy battery, it was inferior to Yamato´s 18.1" in terms of penetration and destructiveness but had a much better firing cycle. Differences between US 16"/50 and german 15"/52 are neglectable, the first having a slightly better penetration at far distances, the later having a better punch and shooting more frequently. The main reason for me is that this was achieved with an 900 lbs lighter ap shell design. However, if you rate plunging fire as more important You would probably shift importance to South Dakotas 16"/45, because it has unmatched deck penetration. But in my view there are no hits probable in these very far distances, where a 16" shell has a flight time of close to 3 minutes. All sea battles in ww2 were fought at much closer distances, where the Bismarcks layout would be excellent for.

[hartmann]

I agree 100% with Delcyros.
Other important point in gun´s efficiency is the design of the turrets. While the German turrets had two well spaced guns which could fire at the same time, the most part of triple and quadruple turrets couldn’t properly make it because the blast of other guns disturbed the projectiles and these tended to be less accurate if shoot at same time (and some of these turrets had not same number of projectile elevators to guns, so it reduced a little more the RoF of the guns).
Best regards and merry chrismast to all.

[delcyros]

Next step: Armor (I would rather prefer the term "protection")

2.1.: Qualities:
The author of combined fleet is correct here. According to post war analysis of Face hardened armor:
1.00: britisch cementated
0.98: german KC new
0.93: italian face hardened
0.93: US Class "A" face hardened
0.89: japanese Vickers made face hardened
unknown: french face hardened
homogenious is a lot harder to deal with. No overall agreed solution has been found but all agree that US homogenious is the best and japanese the worst. homogenious is a lot weaker than face hardened but it can be made in smaller thickness and it doesn´t have the bad sclaing effects typical for face hardened armor.
2.2.: armor belt
The author gives the Bismarck a 5.5, which is the worst figure of all contenders. Why? Because it is possible to penetrate with 15"/52 at 29.000yrds (compare: Yamato at 17.700 yrds, Iowa at 16.400 yrds) the main belt.
However, this is technically true but a worthless information. Penetrating the main belt doesn´t mean to damage the vitals as the author might suggest here. Some ships do have additional defenses some, like Littorio, doesn´t have. Bismarck has the best of all.
Behind the main belt is a 45 degrees inclined 100 mm Wotan hard belt. Behind this one is a 45 mm Wotan soft torpedo bulkhead to contain blast effects and fragmentation. A penetration into the Bismarcks vitals via main belt is impossible, even with Yamato´s 18.1"at 0 distance.
All other contenders are vulnarable under 10.000 yrds into their vitals via main belt using Bismarcks 15"/52. So this can only be reflected with Bismarck getting a 10 and the best following getting a 7 or less figure.
2.3. Deck penetration
I agree with the author. Bismarck was designed for flat trajectory combats, not for long engagments in the bad weather of the North Atlcantic. =7.01
(compare Yamato: 10, Richelieu 9.5, Iowa and South Dakota 9)
2.4. Composite figure:
again, something very speculative: The author is telling us that deck penetration is 1.5 times as important than belt penetration. Umm, checking the combat records doesn´t confirm this: (sorry for repetition) Longest Distance hit against freely moving target in ww2: Gneisenau vs. Glorious (A carrier, what a large target size!) at 27.000 yrds. At these distances you would record more often (depending on the gun used) belt than deck penetrations. Hood can be explained with belt penetration, too (although often is referred as deck penetration. Knowing the 15"/52 ballistics this is improbable).
2.5.: Originally not included: protection of superstructures. This, clearly isn´t a benefit of Bismarck but must play a role here, too. Yamato is by far the best(10). Iowa and South Dakota suffer from the use of weaker homogenious armor instaed of face hardened, but this is offsetted by it´s huge thickness on turrets(8.5). KGV suffers from worse conning tower protection (7.5), Richelieu shows no striking weaknesses (8.0), Bismarck is at best mediocre (7.0), Littorio worse at all (6.5)
2.6: (not included) waterline protection:
the percentage of waterline protected by the armor zone (the shorter the armor zone is, the easier it is to sink the ship without critical hits)
Bismarck 8.4 (84%), Richelieu: 6.0 (60%), Iowa:5.8; South Dakota: 5.2, Yamato: 4.9
2.7.: Final rating: Bismarck would get a much, much better rating than 6.0.
Indeed it´s perfect protection of their vitals is bringing the ship on top of all, dependand on how important deck penetration is for you.
I would rather multiply all factors:

1.)Yamato: 3185
2.)Bismarck: 3165
3.)Iowa: 3105
This figure is much closer to each other, which makes me "feel" more correct.

[DerAdlerIstGelandet]

Im with you delcyros.

[Glider]

Delc I doff my hat to you. I know a fair bit about Naval combat it being my main interest over and above aviation, but I wouldn't have come close to this level of detail.

Excellent post

[DerAdlerIstGelandet]

Agreed. It is very interesting to me the way he analyzed it. I am not that big on Naval Warfare. While I enjoy and hightly interested in it, it is not my strong area.

[syscom3]

I reread his (okuns) analysis and I'm sticking with him on it. He pointed out the vulnerabilities in the Bismarks armour design and how the diving projectiles could get into the "vitals".

Untill hes proven wrong using the formula's provided, then his ratings atand.

[syscom3]

Originally Posted by hartmann

I agree 100% with Delcyros.
Other important point in gun´s efficiency is the design of the turrets. While the German turrets had two well spaced guns which could fire at the same time, the most part of triple and quadruple turrets couldn’t properly make it because the blast of other guns disturbed the projectiles and these tended to be less accurate if shoot at same time (and some of these turrets had not same number of projectile elevators to guns, so it reduced a little more the RoF of the guns).
Best regards and merry chrismast to all.

This was never a problem encountered by any combatant.

[Glider]

I am afraid that there were problems with Turret designs. Certainly in the UK the twin 15in had a reputation for being utterly reliable. The Triple in the Nelson was OK during the war but it took a number of years to get right. The Quad 14in was terrible for reliability all through the war. The Twin 14in was as good as the twin 15in.
As for the blast of the shells I doubt that would be a problem as the shell is out of the barrel before the blast and is by definition on its way. What might have caused this story is the standard pracice in the RN to fire half broadsides until the range was achieved.
This was done to help find the range quickly. If you thought the range was 25,000 yards you could fire a half at 25,000 and then another at 24,500 whilst the first is in the air. You could then walk the shot onto the target allowing for the one in the air.

[delcyros]

These differences were considered back in ww1 by TK of High sea fleet. They analyzed the triple gun turrets of the austrian Viribus Unitis (now on the bottom of the Pula harbour in Istria/Croatia) and noticed that gun preciseness wasn´t comparable to twin turrets. The protection factor (higher loss of firepower if one turret was knocked out) was against it, there were problems to feed the middle gun, the weight of three triple turrets was comparable to four twin ones and so on. However, using triple turrets may enshorten the amorzone and therefore spare armor weight if the protection philosophy is going to be a raft body concept.
The Iowa´s triple turrets represent the best ever executed turret design but postwar comparisons with Vanguard underlined the worser gun preciseness of Iowa against the twin turretted british ship.
Syscom, I don´t need to disprove Okun, I actually use his formulas and have to underline that his calculations made a major step forward to understanding of armor piercing processes. However, his conclusions are based on the idea of a comparison of historical Bismarck and "what if" Bismarck designed in the US protection philosophy. The later one is going to be more impressive on the paper, but it is ahistorical.
He himself proved that Bismarck´s vitals cannot be reached even with Yamato´s 18.1" from distance zero: (1.)AP shell penetrates the 320 mm KC main belt and loses windshield, ap-cap, fuze is set off, speed is reduced greatly-
2.) shellbody reaches the 45 degrees inclined 105 mm Wh armor belt and recochet off or (only at direct impact angles at both, longitudinal and azimuthal) reaches Naval limit and penetrates the belt and reducing it´s speed to almost zero (in most cases with broken body) and is finally stopped by the 45 mm Ww torpedo bulkhead)
We all agree that Yamato had the best ap guns ever. The Ww bulkhead also containes the blast effects. If the heaviest fragmentation is also contained I am not sure.
One design flaw, pointed out by Okun is that at distances from (have to reread the details) 15.300-15.700 yrds(?) Bismarck is vulnarable to it´s own 15" guns.
Digging deeper, shows that this is only possible with Bismarcks 15"/52 because of their exceptionally flat trajectory and great ap capabilities. No other gun can do it. The only exception could be the italien 15"/50 but the apshell is of worser quality and cannot therefor pierce the main armor deck. Since armor cannot be qualified simple in ratings, I am going to prepare a graphic for the immune zones of some bb soon. I don´t care by what method (deck or belt penetration) the vitals are reached but it will show that Bismarcks vitals are impossibly hard to reach by belt penetration and reachable by deck penetration from distances were only flukes ever hit a freely moving target (Gneisenau for example).

[syscom3]

Agreed about the armour for flat trajectory shots. However, as okun points out, "flukes" tend to happen in more often that naught because nature sides with the hidden flaw.

I would also like to point out to you that the USS Washington had no problem with accuracy with its triple turret design while slugging it out with the Kirishima.

[delcyros]

This fluke, as mentioned by Okun, would never happen. Or are you going to say Bismarck would battle Tirpitz? Tirpitz was the only other ship to carry the guns, which may get such a fluke.
On the last battle of Bismarck, the KGV stayed exactly in this dangerous distance in order to get some hits from plunging fire, while Rodney closed in for point blanc ranges. While KGV innumerously hit the ship in this distance, the Bismarck did not blew up. No fluke. It´s vitals remained untouched.
Washington had no problems to DEAL with Krishima. An old ww1, later modernized bc, not comparable to this good ship (Wahsington).
Why?
#1:Well, you don´t need precise guns at ranges under 10.000yrds.
#2: The amount of gaz effects firing the 16"/45 is less worrisome than those of Iowa´s 16"/50, in this view the 16"/45 is somehow more precise.
One remark on the discussion who won over Bismarck:
While it is technically true that her vitals were intact and those 7 torpedo hits did not lead to it´s sinking primarly, I have to poinbt out that there cannot be a doubt that the british forces and the heavy impacts on her superstruktures are responsible:
The decision to scuttle the ship was made under the impressions of the heavy bombardment, so it´s caused directly by Rodney and KGV.
Even if not, with the disruption of her steering controll it no longer was operational and therefor doomed.