Vanguard and Bismarck

[spicmart]

Which one was the better battleship design wise.

Excluded are "software" like radar, aircraft, anti aircraft capability, crew condition etc..

Just brute force and toughness, resistance against attacks (artillery and torpedos).

[alecsandros]

Which one was the better battleship design wise.

Excluded are "software" like radar, aircraft, anti aircraft capability, crew condition etc..

Just brute force and toughness, resistance against attacks (artillery and torpedos).

Who knows ?

they were both in about the same league... in terms of size and armor protection. Bismarck had significantly thicker armor above the waterline than Vanguard did - main and secondary con tower, turrets, barbettes, upper armor belt. Vanguard though had a deeper belt below the waterline, meaning it could handle underwater projectiles better than Bismarck.

Forecastle and stearing gear armor were comparable.

Armor decks were comparable - 150mm above magazines Vanguard, 150-180mm above magazines Bismarck (but from 2 decks, not 1).

Vertical protection was stronger in Bismarck, but again, in it's thickest form it did not run as deep as Vanguard's...

[spicmart]

But Bismarck had better compartmentation, doesn't she? If so does that mean that she was harder to sink than Vanguard with the compartmention offsetting the advantages that Vanguard has, to say deeper belt ?
Maybe Bismarck also had a better armor scheme below waterline to her advantage?

[Dave Saxton]

The British battleships were well compartmented, with seperate compartments for each boiler room and turbine rooms.

In terms of firepower the Bismarck was more powerful. Its 15" guns were more modern than those used by Vanguard. The barrels were significantly longer which creates greater muzzle velocity. This translates into greater belt armour penetration and greater range sans supercharges. Supercharges were available to Vanguard for use in a pinch though. The German 15" L/4.4 armour piercing shell was also of superior design and could penetrate more heavy armour without breaking up at acute obliqities.

Many sources list the British 15" as giving impressive deck penetration, but post war tests proved that all British battleship guns could not penetrate more than 5" of deck armour at ranges of less than 32,000 yards or about 30km. The Bismarck's gun penetrated 5.2" of deck armour at 30km, so there's virtually no difference there.

The German ship carried a heavier secondary battery of 12 15cm (6-inch) guns and 16 10.5cm dual purpose guns oppossed to 16 13.3cm (5.25") dual purpose guns. The British DP gun at 5.25" was a little too big to be handy and did not carry the punch of a 6" gun, although the mountings on Vanguard were improved compared to those used on the KGV class.

In terms of belt protection the Bismarck was superior to the Vanguard and really all other battleships. It was a heavy belt (320mm) of top quality face hardened armour plus a heavy scarp arranged at an ideal angle. It could not be defeated according to some experts. The German ballistian B Hoyer stated in 1943 that if the scarp was heavy enough, in order for a shell to defeat this type of arrangement its velocity would need to be so great that it would shatter against the face hardened main belt first.

Vanguard's belt was also from top quality armour but it was 360mm and no heavy scarp. Bismarck's hull IZ was essentially from point blank range to 30km vs most battleship caliber guns. Vanguard's IZ was essentially 21km to 30km vs the same guns.

It can now be shown that the Bismarck's two deck system provided at least the sum total of its two armoured decks which would be 130mm over the machinery and 150mm (TP) over the magazines. Vanguard's deck protection was 5" over the machinery and 6" over the magazines, so virtually the same there as well.

Bismarck's turrets and barbets were better protected with 130mm turret roofs and 360mm turret faces, and 350mm exposed barbets. Vanguard's barbets and turret faces were 330mm. The turret roofs are listed as 180mm but that is laminated plates.

The torpedo defense system of Vanguard was revised and improved following the sinking of Prince of Wales. It was of the liquid sandwich (void liquid void) type. This type was also used by the North Carolina and Washington. The Japanese produced scientific evidence that there was virtually no difference between a void liquid void type and the type used by the Germans in terms of effectiveness.

Both battleships could make 30knots. Vanguard was a bit heavier displacement (45,214 metric tons standard displacement vs 42,700 metric tons, and 52,245 metric tons full load vs 50,900 metric tons).

[spicmart]

I wonder if a more powerful main armament could be installed on Vanguard.
So with the TDSs being equal Bismarck should have had the better overall protection.

[alecsandros]

I wonder if a more powerful main armament could be installed on Vanguard.
So with the TDSs being equal Bismarck should have had the better overall protection.

Yes, with the mention that Vanguard had a deeper belt (5.7meters IIRC vs 4.8 meters Bismarck)

[Dave Saxton]

Bismarck's belt was 5 meters deep. It extended 2.3 meters below the waterline at operational displacements, but only 1.5 meters at konstruction displacement.

What is interesting is the POW's deeper belt did not prevent below the belt hull penetrations at Denmark Strait.

If the belt extends too far it can create complications for an effective TDS design.

There is an interesting discussion on the issue of below the belt penetrations here:

viewtopic.php?f=36&t=1647&p=16683&hilit=Tosa#p16683

I think that Bismarck's belt was deep enough in most normal situations and normal cases of shells landing short of the target. These hits can occur when the wave forms at certain speeds around the hull uncover the belt in some small specific areas though.

[alecsandros]

Bismarck's belt was 5 meters deep. It extended 2.3 meters below the waterline at operational displacements, but only 1.5 meters at konstruction displacement.

What is interesting is the POW's deeper belt did not prevent below the belt hull penetrations at Denmark Strait.

If the belt extends too far it can create complications for an effective TDS design.

There is an interesting discussion on the issue of below the belt penetrations here:

http://www.kbismarck.org/forum/viewtopi ... osa#p16683

I think that Bismarck's belt was deep enough in most normal situations and normal cases of shells landing short of the target. These hits can occur when the wave forms at certain speeds around the hull uncover the belt in some small specific areas though.

It's debatable.
H-39 design had a deeper belt than Bismarck...

[Dave Saxton]

It's debatable.
H-39 design had a deeper belt than Bismarck...

Indeed it would have. H-39 was an improved design. My figures for Bismarck are taken from the official KM drawings, so they are correct. In that light, Bismarck's belt depth does not compare unfavorably among its contemporaries.

Vanguard's belt extended 8 1/2 feet below the waterline or 5.6 meters. Thus Vanguard's belt is only 30cm (11.8") deeper than Bismarck's. How did KGV compare to Vanguard?

[Mostlyharmless]

These depths of armour belts depend on the load. The belt on the King George V class was 23 ft 9 inches and at deep load was intended to have 9 ft 9 inches of armoured freeboard, which was calculated as a minimum so that the ship would not have to return to port immediately after the explosion of a bomb near the side above the main deck. Thus KGV should have 14 ft of submerged belt at full load although the thickness fell at the lower edge to 5.5 inches abreast the magazines and 4.5 inches abreast the machinery (actually the thickness was 220 lb and 180 lb). Vanguard was supposed to have a deeper belt than KGV although Wikipedia gives it a 24 ft belt which would only be 3 inches deeper. Of course, the actual fighting displacement would probably be with the oil tanks between 2/3 and 3/4 full, so the belt will not extend to 14 ft. deep, although most ships ended up displacing more than originally calculated. However, I suspect that it would be hard to lighten Vanguard enough that only 8 1/2 ft of belt were submerged unless you mean only 8 1/2 ft of full thickness before the belt started to taper down to about 110 mm.

[Dave Saxton]

These depths of armour belts depend on the load. The belt on the King George V class was 23 ft 9 inches and at deep load was intended to have 9 ft 9 inches of armoured freeboard, which was calculated as a minimum so that the ship would not have to return to port immediately after the explosion of a bomb near the side above the main deck. Thus KGV should have 14 ft of submerged belt at full load although the thickness fell at the lower edge to 5.5 inches abreast the magazines and 4.5 inches abreast the machinery (actually the thickness was 220 lb and 180 lb). Vanguard was supposed to have a deeper belt than KGV although Wikipedia gives it a 24 ft belt which would only be 3 inches deeper. Of course, the actual fighting displacement would probably be with the oil tanks between 2/3 and 3/4 full, so the belt will not extend to 14 ft. deep, although most ships ended up displacing more than originally calculated. However, I suspect that it would be hard to lighten Vanguard enough that only 8 1/2 ft of belt were submerged unless you mean only 8 1/2 ft of full thickness before the belt started to taper down to about 110 mm.

That doesn't make sense that a greater % of the belt was below the deep waterline than above. Indeed the launching photos of POW with the deep waterline clearly showing, and the area that the belt will be mounted to, clearly show a greater % of belt above the deep waterline than below. Sure its not 9" 9" below instead of above?

[alecsandros]

It's debatable.
H-39 design had a deeper belt than Bismarck...

Indeed it would have. H-39 was an improved design. My figures for Bismarck are taken from the official KM drawings, so they are correct. In that light, Bismarck's belt depth does not compare unfavorably among its contemporaries.

Vanguard's belt extended 8 1/2 feet below the waterline or 5.6 meters. Thus Vanguard's belt is only 30cm (11.8") deeper than Bismarck's. How did KGV compare to Vanguard?

... Well still Bismarck had a main belt with a lower overall height than Vanguard, Richelieu and KGV. The 4.8m figure is for the 320mm portion. With the 170mm lower belt it was around 5.2 or 5.3 meters, IIRC.

KGV had a 7.2 meters main belt, of which some 5 meters were 380mm thick , the rest tapering down to 140mm at the bottom - still considerable protection against a considerably slowed-down diving shell.

What Bismarck had that compensated that was a longer protected length - about 72% of waterline length covered by main belt vs about 55% in KGV.

Ship loads would greatly affect draft and thus submerged height of the belt. Tirpitz draft at 43000tons was around 9.5m, while at 53000 tons it was around 11m - a 1.5m difference, translated into a 1.5m portion of belt submerged or not...

[Mostlyharmless]

I am deeply shocked that you doubt the famously reliable source Wikipedia, http://en.wikipedia.org/wiki/King_Georg ... %281939%29, which has:

“The main armour belt was 23.5 feet (7.2 m) high and covered the hull side from the main armoured deck to finish 15 feet (4.6 m)[20] below the deep waterline.[26]”

This is referenced to Raven & Roberts British Battleships, which naturally I have not read although perhaps someone loves me enough that this Christmas... However, we can get a few extra clues from Brown's “Nelson to Vanguard”, pages 29-30, which has:

“The very deep main belt extended from 8 ½ ft below the designed (standard) waterline to the main deck, a total depth of 23 ½ ft. It was arrainged in three strakes of about equal depth with plates in each strake keyed to plates above and below and to neighbouring plates at the butts. The upper two strakes were 15 ins abreast the magazines and the lowest one tapered from those thicknesses to 5 1/2 and 4 1/2 ins at the bottom.”

The problem with interpreting that is what is meant by designed waterline and whether the tapering strake is included in the main belt. I suspect that the two upper strakes roughly cover the main deck to the middle deck and the middle deck to the lower deck. Then the tapered section would be below the lower deck. I suspect that the middle strake is mostly exposed when there is very little fuel on board and mostly submerged at full load.

[Dave Saxton]

Look at the first photo in this series:

http://www.maritimequest.com/warship_di ... _wales.htm

[Mostlyharmless]

Thank you for the link. I looked at page 3 and it seems to me that the two pictures at Singapore illustrate the problem. In the first, perhaps taken shortly after arrival, the top of the armour belt seems to be more than twice the height of the sailors above the waterline. In the photograph of Prince of Wales leaving Singapore, presumably after refuelling, the height of the top of the armour belt seems to be less than twice the height of the figures near Y turret above the waterline.