All myths solved

Warship design and construction, terminology, navigation, hydrodynamics, stability, armor schemes, damage control, etc.
VeenenbergR
Senior Member
Posts: 273
Joined: Mon Oct 18, 2004 5:52 pm
Location: Vinkeveen

All myths solved

Post by VeenenbergR »

I recently asked myself which questions remained to be solved on Bismarck:

a): since all 4 damage control rooms were savely placed beneath the main armor deck and turtle-back system AND the 3 fire control rooms were located near the 3 main range finders/ radar sets: these lay out is perfectly allright and Bismarck is no worse off than contemporary US and UK battleships.

The questions then remains were the fire control systems themselvers were located: was that also save? (the systems which were used to compute the exact rotation and elevation values for the guns given the speed/ heading of own and enemy ships).
How hit-proof were the communication pipes to and from the fire control rooms? Were they doubled? Was this worse than other battleships which must have the same problems.

b). Garzke shows the armour on different frames in the Bismarck. The rudders are especially protected by an underwater splinterbelt of 80 mm and horizontal by a 110 mm turtle-back armour layer. Also around the rudder is a special 80 mm Ring of armour. Furthermore are the ruddershafts protected by an internal splinter-box armour.
Given alll these special attentions, why is Bismarck still more vulnerable than contemporary US or UK Battleships?

c). The German layout of the light and medium Flak guns wasn't done efficiently according to Lindemann, nor were the after HF-directors stabelized because of deliveries to Russia. Furthermore the devices of the heavy Flak were not suited for low speed flying aircraft. Together with the bad weather (rough seas) the Bismarck was not succesful in stopping Sworfish attacks. The 15 cm guns were not suited for AA-fire.

d). Bismarck could not steer with the 3 shafts without help from the rudders. This was due the 3 shaft system and the modern push buttons of the steering system.

e). The upper Citadel armour may be outdated and consuming a substantial weight: it stopped effectively many hits (100?) on the Bismarck with only 2-4 penetrations of Rodney and KGV.

f). The main armour belt of 320 mm did stop the torpedo's fired by the Swordfishes except for the hit near the rudders. This belt was not penetrated except for 2 hits by the Rodney above the waterline.

e&f): only 4 real full penetrations were achieved.

g): the sloped armour on the main turrets was not thick enough to withstand 16 inch hits (article Nathan Okun). Survey of the 4 turrets have to by carried out to proof this weakness.

h). Bismarcks underwater system may be inferior to other contemporary US and UK battleships but fact is that the more dangerous hits by PoW did'nt damage any machinery, nor did the shells of the Rodney and KGV.

i). Bismarcks torpedo bulkheads were inferior to other battleships but performed in practise very well because of their flexibility to absorb damage and pressure (see article of Nathan Okun on this subject). Under water cameras which inspected the inside confirmed that the bulkheads were intact.

h). Conclusions on the weakness of the Bismarck:

- the low lying main armour deck meant increased stability and hit-proof spaces below it, but increased the space above it which were not hit proof and here Bismarck suffered in her last fight of direct and indirect (cutting of cable-shafts) damage to here fire control systems.
- the heavy Flak devices were not suited for slow aircraft, the 2 after directors were not fully operational.
- the rudder shafts were placed to close to eachother and the area above the rudder shafts was vulnerable against torpedo explosions, in spite of the protective measures token.
- the Bismarck could not steer with her 3 propellors because of this arangement and the modern push button system.
- the radar systems were not robust enough and broke down ferquently because of the schock of firing the main armament.

NB. IF Bismarck had been able to return to port measures could have been taken to 4 of these 5 weaknesses. So that Bismarck was on her maiden trip and was sunk on this trip no improvements could be made.

i). Conclusions on the strong point of the Bismarck.
- Bismarck was practically unsinkable;
- The essentials of the Bismarck under the turtle back were hit-proof ;
- The Bismarck was a stable and good shooting platform;
- the armour belts, decks and torpedo bulkhead performed exceptionally
well under the extreme heavy shelling, bombardment and hald a dozen
of torpedos.

How many 38 cm shells were fired by Bismarck is not clear to me. Are there some calculations made? For example she was able to fire in her last duel with 4 turrets for some 40 minutes. Anton and Bruno were silenced short afer 9.00 to shoot only once more. The rate of fire of turrets C and D was low after the destruction of the 3 main fire control stations. So I guess. A and B fired some 100 shells (13 minutes x RoF 2 x 4 guns, while C and D fired some 150 shells (35 minutes x RoF 1,5 x 4 guns). Bismarck used up a substantial amount against Hood, PoW and Norfolk.
dunmunro
Senior Member
Posts: 4394
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Post by dunmunro »

h). Bismarcks underwater system may be inferior to other contemporary US and UK battleships but fact is that the more dangerous hits by PoW did'nt damage any machinery, nor did the shells of the Rodney and KGV.

i). Bismarcks torpedo bulkheads were inferior to other battleships but performed in practise very well because of their flexibility to absorb damage and pressure (see article of Nathan Okun on this subject). Under water cameras which inspected the inside confirmed that the bulkheads were intact.
The Pow's 14" hit under the belt did flood a generator room and caused leakage into a boiler room, which had to be shut down. The shock from the torpedo hit from Victorious's Swordfish caused the boiler room to flood completely.

The torpedo bulkheads were not fully visible during the underwater inspection, but the PoW's hit that caused the flooding above proves that the torpedo bulkhead was not fully intact.
Bgile
Senior Member
Posts: 3658
Joined: Wed Mar 09, 2005 7:33 pm
Location: Portland, OR, USA

Post by Bgile »

A properly functioning torpedo will not hit the armor belt, but below it. If a torpedo hit below Bismarck's armor belt and functioned properly, it would cause a great deal of damage, just like torpedoes which hit many other warships during WWII. Scharnhorst had a similar system to Bismarck and she suffered greatly from one torpedo hit.

If you are implying that Bismarck was invulnerable to torpedo hits except at the rudder, you are mistaken.
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: All myths solved

Post by lwd »

VeenenbergR wrote:...
i). Conclusions on the strong point of the Bismarck.
- Bismarck was practically unsinkable;
This sounds counter factual to me.
- The essentials of the Bismarck under the turtle back were hit-proof ;
As stated this seams rather extreme. They may have been difficult to reach but "hit-proof"
User avatar
Terje Langoy
Supporter
Posts: 435
Joined: Wed Aug 09, 2006 4:15 pm
Location: Bergen, Norway

Post by Terje Langoy »

It appears to me as quite a common misconception that the Bismarck was practically unsinkable since she posed such a great absorbent of shell fire during her last fight. I'm aware that in these matters, I'm but an amateur but I still have my mind set that during this battle, it was the superstructure of the Bismarck that carried the bulk of shell fire. The British ships sailed in at point blank range thus their shells had a shell trajectory almost horizontal in its flight. If you moved HMS Rodney out to say 20 - 25 000 yards, how would Bismarck then cope against her 16' shells?

What's to be gained by securing the area above the rudder shafts when the rudders themselves still is vulnerable? You simply can't secure yourself against potential rudder damage as long as you use a rudder to steer with. (The only thing I can think of must be a fairly strong bow thruster) And although the Bismarck showed poor steering qualities by propellers only, I think it's important not to forget that the rudder loss didn't occur on a day with calm seas in the Baltic either. Even a ship with a different propeller arrangement would have had a hard time trying to steer only by propellers under the same sea state as the Bismarck suffered.
VeenenbergR
Senior Member
Posts: 273
Joined: Mon Oct 18, 2004 5:52 pm
Location: Vinkeveen

Final conclusions on Bismarcks protection (Nathan Okun)

Post by VeenenbergR »

FINAL CONCLUSION: The BISMARCK's internal vitals could not be directly reached through the side belt armor under any normal circumstances due to the sloped "turtle-back" armored deck design, making its design the best of all given in this article for this purpose.

However, there are several drawbacks of the concept of a thin upper deck and lower lying (thin) main deck armor:

(1) The upper hull area can be destroyed at much longer ranges than any other design due to the weak upper belt and deck. Some important equipment, cables, etc. were in this region, compromising the effectiveness of the protection to some (possibly critical) extent

(2) Especially at closer ranges projectiles could penetrate the 1.97" weather deck, deflect downward through the (thin) 3.15" main armor deck can reach the vitals in the midship region. They can also be deflected by structures like barbettes or can be dangerous as ricochet against solid objects.

(3) The requirement for a rather heavy upper side hull armor belt to protect the thin main armor deck from side hits above the main armor belt, which costs considerable weight that could be used to beef up the deck armor or belt armor or both.

(4) The armored transverse bulkheads at each end of the Citadel were weakly protected and had no sloped deck behind them, making the BISMARCK very vulnerable to raking fire from either end, especially as the main magazines were located directly behind these bulkheads.

(5) The shallow extension of the belt downwards under sea level allowed hits below it to frequently occur, as was demonstrated during the fight with the HMS Prince of Wales, bypassing the main armor belt and aggravating any flooding effects that projectiles punching through the belt above the low main armored deck might cause. The same is true for torpedo hits.

Nathan is probably correct in describing the real weaknesses of the armor concept of the Bismarck.

On photo's of the Bismarck the fire control computing rooms ARE placed directly under a heavy armored welded deck. This must be the 3.15" main armor deck.

So the above described weaknesses together with to close placed and to thin protected rudder shafts (because of the shallow stern) are the real objective drawbacks of the Bismarck design. The impossibility to steer with the 3 propellors means that rudder damage doomed the Bismarck. The armor concept meant that when hit critical damage of severing communication lines of the fire control systems occurred rather quick. One reason why Bismarck was silenced rather quick in his final duel.
Otherwise the side belts and torpedo bulkheads proved well in combat against so overwhelming odds.

Bismarck was punnished as no other battleship in WWII. A comparison therfore remains difficult. French warships had also faults in their armor composition (not their thickness). The only gunnery duels of WWII were:

1). Scharnhorst & Gneisenau against Renown near Norway april 1940
2). Cesare & Cavour against old British BB's near Punta Stilo 1940
3). Dunkerque, Strassbourg, Bretagne & Provence against Hood, Valiant & Resolution at Mers-el-Kebir july 1940
4). Bismarck against Hood & Prince of Wales may 1941
5). Bismarck against Rodney & King George V may 1941
6). Massachusetts against Jean Bart in Casablanca nov. 1942
7). Kirishima against South Dakota and Washington near Savo 1942
8) Scharnhorst against Duke of York near North Cape dec. 1943
9). Fuso & Yamashiro against old US battleships near Leyte oct. 1944

As seen in this table the popularity of Bismarck become evident: with Scharnhorst and Hood take part in 2 major sea combats. Bismarck fights against 4 big enemy battleships, 2 carriers and scores of other warships. This remains unparralleled in history.

The final battle of the Scharnhorst at North Cape was a very long gun duel. Both Bismarck and scharnhorst succumbs after more than 700 heavy shells have been fired against them and at least the same number of 8 inch shells. Both fought also against 3 enemy cruisers to make the situation worse. Most of Bismarcks shells were fired and probably all of Scharnhorsts shells. Both were early hit on their main radar and gunnery control station. Both were doomed by ONE lucky enemy torpedo (Bismarck) and 14 inch shell (Scharnhorst).
Both lost their turrets in the same succession: first Anton, then Bruno and (then Dora for Bismarck) and finally Ceasar.
Both German capital ships lost almost all of their crew.
User avatar
Terje Langoy
Supporter
Posts: 435
Joined: Wed Aug 09, 2006 4:15 pm
Location: Bergen, Norway

Post by Terje Langoy »

I would suspect that by placing the rudders further away from each other it would result in a negative effect on her steering qualities as the propeller thrust working directly against the rudder surface would be less exploited. This would lead to a slower rudder response thus her ability to make sharp turns would of course be decreased. She would need more distance to commence turns as well. Last but not least, it would make her steering engines and rudderstocks more vulnerable as they would have to be placed further out from the centre of the stern.

The ability to steer only by propellers could not have helped the Bismarck in the seas she experienced when the rudders was lost. Maintaining both a longitudinal and diagonal forward thrust at the same time against those waves would simply be too hard to handle for the screws, no matter their arrangement. In fact, the jammed rudders would ocassionally have generated a thrust that worked against the desired heading as well. What I am implying is that she might could have turned her bow up against the seas by propellers alone but no way she would be able to generate a forward thrust at the same time. Her prop-arrangement seems a rather pointless issue to argue if you don't take the external conditions into consideration as well.
User avatar
Karl Heidenreich
Senior Member
Posts: 4808
Joined: Thu Jan 12, 2006 3:19 pm
Location: San José, Costa Rica

Post by Karl Heidenreich »

About the rudder arragement: Which WWII (or contemporary BBs) had a rudder arragement that would have prevented a similar situation if hit by a torpedo as Bismarck was?

Kind regards.
An appeaser is one who feeds a crocodile, hoping it will eat him last.
Sir Winston Churchill
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: Final conclusions on Bismarcks protection (Nathan Okun)

Post by lwd »

VeenenbergR wrote:....
Bismarck was punnished as no other battleship in WWII. A comparison therfore remains difficult. ....
While the second sentence is correct I'm not sure the first is. If you are talking overall punishment the Yamato and Musashi arguably took more. If you are talking surface engagements The Yamashiro took a lot of punishment and depending on how you define it may have taken more than Bismark.
User avatar
tommy303
Senior Member
Posts: 1528
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Post by tommy303 »

The questions then remains were the fire control systems themselvers were located: was that also save? (the systems which were used to compute the exact rotation and elevation values for the guns given the speed/ heading of own and enemy ships).
How hit-proof were the communication pipes to and from the fire control rooms? Were they doubled? Was this worse than other battleships which must have the same problems.
The main, secondary, and heavy flak calculating rooms and transmitting stations were below the armoured deck; additionally, they were duplicated fore and aft so there was a 100% reserve capacity.

thomas

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.
VeenenbergR
Senior Member
Posts: 273
Joined: Mon Oct 18, 2004 5:52 pm
Location: Vinkeveen

Some answers

Post by VeenenbergR »

to Tommy: about the fire control rooms AND damage control rooms, which were all at least doubled and all under the armored deck together with the propulsion systems.

This means that the "vitals" above the armored deck only consisted of cables leading from the brigdes (navigation) and the cables from the 3 directors towards the fire control rooms. The cables probably ran through the 2 armored pipes leading from the 3 director posts towards the main armor deck. If this is all true the protection system of the Bismarck is almost perfect, except then for the height of the main armor belt, which extended to short beneath the water surface.

As you all state yourselves could the rudders not be placed more apart, since the hull aft was to shallow.

to Karl Heidenreich:

IOWA had there a more broad hull and 4 propellors and therefore the 2 rudders were more placed apart than on the other battleship classes.
IOWA would probably have fared better under the same harsh situations of the Bismarck: having a greater range, speed, better arrangement of the rudders, thicker armor deck, better under water protection, better and more stable raders which could be used for accurate shooting, better and stronger AA and stronger armored main turrets. IOWA would probably have succeed in escaping her persuers, but like Bismarck also be unable to ward of all Swordfish attacks. And when confronted by R & KGV the IOWA was able to knock at least Rodney completely out, since you all have pointed out that the AON armor and short belt left may vitals (bridge) AND all directors, like Bismarck, open for destruction.

Last but not least: Bismarck fared bad in her last engagement. She was mortally hit very early in the battle which knocked out her main director (on top of the combat-tower) AND silenced miraciously both forward heavy gun towers!!! How exactly is stil the question. This early bad-luck coupled with a doomed and exhausted crew, pessimistic admiral, her own erratic course and slow speed: all explain why after the first 15 minutes the defense of the Bismarck collapsed so quick.

If Bismarck had a stable course and high speed she could have placed destructive early hits on Rodney like she did on Hood, perhaps destroying the un protected command bridge or knocking out a big turret. The course of the battle then could be totally different.........

Conclusions: Bismarck was a very big modern battleship with a beautiful sharp design, large and strong armament, sophisticated equipment, large novice crew, 2 captains.... an armor scheme which protected as much as possible with a compromising formula: 2 thin armor decks meant risks on distances > 20.000 yards. Steep diving shells under the belt too.
If under heavy fire the superstructure would suffer but not her vital direction centers nor her machinery. The 3 main directors on top of the ship could never be protected for destructive hits.... and when the ship was targeted by 70 (2 x 10 + 9 + 8 + 8) heavy shells per minute at least 5-7 (10%) would hit after the thirst 10-12 minutes of practise shooting.
If you compute the probability that the 3 rangefinders are hit under this barrage you will find out that they are hit after 15, 20 and 25 minutes of fire. So all were hit at 8.47 + 25 minutes = 9. 02 (top), 9.07 (on conning tower) and 9.12 (aft). This is exactly what happened.

To Yamashiro, Yamato or Musashi. The latter were strafed, bombed and torpedoed. On Bismarck about 1000 of her crew died (4 main turrets, all secondary turrets, AA positions, Conning-tower, 3 director stations, damage control parties, 4 hits through belt in mess, canteen.

On Musashi and Yamato there were hundreds of casualties because of the air attacks but not 1000 death. The deaths came when Yamato blew up and Musashi slowly sank by the bow in the deepest Sea on Earth.

Yamashiro was mortally torpedoed by MTB's and destroyers before reaching the US Battleships. Fuso with her Samurai like (and very high) Pagoda mast steemd in the very mouth of destruction. Both old battleships were lost in a short time span to overwhelming damage and heavy loss of life, but not a protracted ordeal like the tough and very well armored and thoroughly subdivided modern Bismarck had to sustain: from 8.47 to 10. 35: almost 2 hours of intense fire and destruction.

If looking to all the articles about the Bismarck, the surveys in and round the wreck the Bismarck is less weak (or badly armored) than I first thought. Richelieu, the King George V class and the Littorio's would not have done better in every circumstance of the Bismarck if equiped with the same novice crew and 2 captians on one ship. Nor would have done the 2 Nelsons or the 2 Washingtons.

Slightly better chances would have the South Dakota's and the Yamatos'and defenitely better chances would have the Iowa's. There designs showed less weaknesses and they also had better fire controls and a better armament.

To give the ranking:
Best and strongest battleships were the Iowa's and Yamato's; followed
by the South Dakota's, Bismarck's, Richelieu and the Washingtons
Third come the KGVs, Littorios and Nelsons
Fourth then the Scharnhorst's, Dunkerque's and Alaska's.

When Bismarck sailed on her maiden trip in 1941 she belonged (looking to this ranking) together with the Richelieu to the 2 strongest and best battleships then afloat.
User avatar
Karl Heidenreich
Senior Member
Posts: 4808
Joined: Thu Jan 12, 2006 3:19 pm
Location: San José, Costa Rica

Post by Karl Heidenreich »

VeenenbergR:
To give the ranking:
Best and strongest battleships were the Iowa's and Yamato's; followed
by the South Dakota's, Bismarck's, Richelieu and the Washingtons
Third come the KGVs, Littorios and Nelsons
Fourth then the Scharnhorst's, Dunkerque's and Alaska's.
Which it goes more or less along the same with the one posted today in the Top Ten Battleship list:
1.Yamato Class
2. Iowa Class
3. South Dakota Class
4. North Carolina Class
5. Bismarck Class
6. Richelieu
7. Nelson Class
8. Nagato Class
9. Littorio Class
10. KGV Class
Kind regards.
An appeaser is one who feeds a crocodile, hoping it will eat him last.
Sir Winston Churchill
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: Some answers

Post by lwd »

VeenenbergR wrote:t,,,,
Yamashiro was mortally torpedoed by MTB's and destroyers before reaching the US Battleships. Fuso with her Samurai like (and very high) Pagoda mast steemd in the very mouth of destruction. Both old battleships were lost in a short time span to overwhelming damage and heavy loss of life, but not a protracted ordeal like the tough and very well armored and thoroughly subdivided modern Bismarck had to sustain: from 8.47 to 10. 35: almost 2 hours of intense fire and destruction.
Fuso was the one that was torpedoed but by US DDs and broke in two. While Yamashiro didn't last as long as Bismark it may well have absorbed as many or more hits and almost certainly as much weight of ordenance. The US BBs for the most part straddled from the first salvo on and were apparently hitting with more regularity than KGV and Rodney, In addition there were 6 of them although only 3 were firing for most of the battle.

See:
http://www.navweaps.com/index_tech/tech-079.htm
and
http://www.combinedfleet.com/atully06.htm
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: Some answers

Post by lwd »

VeenenbergR wrote:...
To give the ranking:
Best and strongest battleships were the Iowa's and Yamato's; followed
by the South Dakota's, Bismarck's, Richelieu and the Washingtons
Third come the KGVs, Littorios and Nelsons
Fourth then the Scharnhorst's, Dunkerque's and Alaska's....
I'd quibble with that a bit.
Yamatos and Iowas are definitly in first place.
South Dakota's and North Carolinas next
Hard to differentiate between the Richelieus, Bismarks, Nelsons, Nagatos, Littorios, and KGVs
All the US standards as well as the Kongos, Ises, and Fusos are probably better than Sharnhorst with the Dunkerques ranking the Japanese BBs and the 14" gunned standards.

The Akaskas weren't battle ships and so don't belong in the ranking.
VeenenbergR
Senior Member
Posts: 273
Joined: Mon Oct 18, 2004 5:52 pm
Location: Vinkeveen

Ranking of ships.

Post by VeenenbergR »

IwD. Don't agree with lists which rank older (but modernized) battleships higher than modern battleships.
In practice the older slower battleships seldom could use their guns in fast moving battles (Midway) and were often a victim of air and submarines.
The british used their 3 modernized old batteships with great vigor and slaughtered the modern big German Z-Jäger nar Narvik and the heavy armoured beautiful Zara heavy cruisers at Matapan.

Sorry for changing the Fuso and Yamashiro. The destruction of both ships was swift!!!

Back to the ranking:

First come the 10 modern US, 2 modern Japanese, 2 modern German, 3 modern Italian, 1 modern French and 5 modern British battleships,

Second the 6 modern battlecruisers. Each of them in battle inderior to the modern battleships.

All these ships had higher speed, better horizontal armour and better equipment than the older ships. They were therefore more handsome and better suited for all tasks than the older and slower battlewagons.

Third/ fourth come the 2 slow Nelsons and the older but modernized battleships and battlecruisers.

Fifth come all old and slightly modernized battleships.

Within these 5 categories one can then rank from the best to the worst.

Based on their displacement:

1). Yamato (2), Iowa (4); Bismarck (2), Richelieu, Littorio (3), South Dakota (4); Washington (2); KGV (5);

2). Scharnhorst (2), Dunkerque (2), Alaska (2).

Each of these battlecruisers (battleships?) could easily outrun the ships of group 4 and if paired together were formidable task forces.

3). Hood, Renown, Kongo (4), Cavour (2), Doria (2), Repulse, modernized Queen Elizabeth Class (3), Nagato (2); Ise (2); Fuso (2),

Each of these ships were faster than the ships belonging to group 4:

4). Nelson (2). Quite modern, heavily armed but slow.

5). West Virginia (3); California (2), unmodernized Queen Elizabeth Class (2), New Mexico (3), Arizona (2), Nevada (2), Revenge (5); Marat (3); Lorraine (3), Texas (2); Arkansas.

So never rank a Nagato higher than a Scharnhorst, Dunkerque or Alaska or a Nelson higher than a Hood, Renown aso.

In battle however a Nelson is superior to many ships in higher categories and this also apply to many ships of category five.
Post Reply