Belt Armour - what is it good for !

[Cavalry Corp]

Question

Was it to stop Torps or shells , if it does not stop torps what is the point of it being so thick and in game terms is it anygood?

Cav

[Mike Scholl]

Belt armor was to prevent shell penetration along the vital areas of the waterline.  Torpedo defense was generally based on bulges and compartments designed to absorb the force of the explosion without permitting excessive flooding.

[JohnDillworth]

Japanese shells, at least the 8"" ones had a blunter nose than Allied ones. It was found that they traveled underwater a bit better that way. I don't know if it ever came into play in actual combat, but someone was thinking about it. It seem BB's can take 1 or 2 torpedoes and get away but most other ships are in big trouble. I don't know if that is a product of armor or sheer tonnage.

[xj900uk]

Belt armour was originally designed to absorb 'horizontal' fire ie shells whizzing in like exocets just above the waterline.  However by extending the armour more below the waterline it does offer some protection against torpedos (unless you have a mark 14 trying to explode under the ship)  However,  anti-torpedo bilges (particularly on the big, slow US battlewagons) seem more effective to absorb the impact of a fish and protect a larger ships vital areas (unless you happen to be British - the Royal Oak and the Barham had big anti-torpedo bilges and we all know what happened to them...)
 

[Cavalry Corp]

OK all interesting comments

So a torp of anysize cannot be stopped by belt armour of any thickness?

Cav

[JohnDillworth]

Additional question. Do they have to penetrate the armor to do serious damage. Although it can 1,000 + lbs. of explosives unless it penetrates a BB it doesn't seem it would do fatal damage. Might buckle a ton of plates, take on some water, and shake the &*($ out of the systems and crew but it seems most of the energy would dissipate outward, upward and downward (path of least resistance). History has clearly proven that I do not understand this (POW and Repulse vs 18 inch torpedoes)but I would love to understand why I am wrong.

[LoBaron]

ORIGINAL: JohnDillworth

Additional question. Do they have to penetrate the armor to do serious damage. Although it can 1,000 + lbs. of explosives unless it penetrates a BB it doesn't seem it would do fatal damage. Might buckle a ton of plates, take on some water, and shake the &*($ out of the systems and crew but it seems most of the energy would dissipate outward, upward and downward (path of least resistance). History has clearly proven that I do not understand this (POW and Repulse vs 18 inch torpedoes)but I would love to understand why I am wrong.

No in fact they don´t.
The majority of damage by underwater explosions is done by the sudden increase of water pressure in the area (as opposed
to explosions in clean air where the pressure dissipates more easily like you described)

[Shark7]

ORIGINAL: JohnDillworth

Japanese shells, at least the 8"" ones had a blunter nose than Allied ones. It was found that they traveled underwater a bit better that way. I don't know if it ever came into play in actual combat, but someone was thinking about it. It seem BB's can take 1 or 2 torpedoes and get away but most other ships are in big trouble. I don't know if that is a product of armor or sheer tonnage.

It probably has nothing to do with armor and a lot to do with sheer size...not necessarily tonnage though. BBs being as large as they are simply have more water-tight compartments to work with, as well as larger torpedo bulges.

[Nikademus]

ORIGINAL: cavalry

OK all interesting comments

So a torp of anysize cannot be stopped by belt armour of any thickness?

Cav

In game terms, every torpedo device in the game has a penetration value greater than the thickest belt armor value. Torp hits only strike the 'Belt Armor' hit location so essentially yes, in game-terms no belt armor will prevent a torpedo from "penetrating" the belt armor and thus causing some form of SYS and/or FLT damage....usually signifigant though sometimes with a good role you can end up with minor damage.

[Nikademus]

ORIGINAL: JohnDillworth

Japanese shells, at least the 8"" ones had a blunter nose than Allied ones. It was found that they traveled underwater a bit better that way. I don't know if it ever came into play in actual combat, but someone was thinking about it. It seem BB's can take 1 or 2 torpedoes and get away but most other ships are in big trouble. I don't know if that is a product of armor or sheer tonnage.

once at least. An 8inch shell hit on Boise 'dived' underwater and pentrated into her forward magazine and detonated. Miraculously, Boise just escaped a potential magazine explosion due to rapid flooding.

[crsutton]

ORIGINAL: JohnDillworth

Additional question. Do they have to penetrate the armor to do serious damage. Although it can 1,000 + lbs. of explosives unless it penetrates a BB it doesn't seem it would do fatal damage. Might buckle a ton of plates, take on some water, and shake the &*($ out of the systems and crew but it seems most of the energy would dissipate outward, upward and downward (path of least resistance). History has clearly proven that I do not understand this (POW and Repulse vs 18 inch torpedoes)but I would love to understand why I am wrong.

No, torpedoes never penetrated armor. Ideally with magnetic exploders the torpedo would pass under the ship and then explode under the ship. The ability of water to transmit shock waves would do the rest and in an ideal situation the keel of the ship would snap in two.

However, magnetic exploders for both sides suffered major teething problems and both German and American subs tended to rely on contact explosions which required the torpedo to be set at a shallower depths so that it would strike the ships sides and explode on contact. Torpedoes never would penetrate the side armor of a ship. (two slow and blunt) they hit the side and exploded and the force of the explosion did the damage. A 1000 pound warhead exploding in the water next to a ship has tremendous power and could literally blow in the sides of even the thickest armor if the conditions are right. Even if the bomb or torpedo did not blow in the side of a battleship, it usually stressed the hull, fracturing and weakening plates so that other nearby hits would finish the job.

And the effects could be random. American submariners gave up on the magnetic exploder and just set all of their torpedoes to explode on contact. Sometimes they would have to hit a lowly frieghter or tanker with three or four torpedoes to sink it. Then again sometimes one well aimed shot against the biggest ship would do it it. Lot of factors in play.

[Nikademus]

A shallow running torpedo that strikes the belt armor can signifigantly reduce damage. Bismarck is a good example of this. Prior to the hit to her steering gear she was hit by a couple torps on the belt armor which only caused minor damage due to the armor absorbing much of the blast.

Ideally one would set a torpedo to run deeper vs. a battleship type target in order to avoid hitting the belt armor.

[awadley]

Belt armour on a US battleship only goes several inches below the waterline and is not intended to stop torp damage.

[Nikademus]

US battleship belt armor on the Standard's and newer classes was not that shallow. Belt armor's primary role is to stop shellfire but it also can provide additional protection against torpedoes "if" the torpedo runs shallow enough. The primary anti-torpedo defense is provided by the TDS system which can include bulges.

[String]

ORIGINAL: awadley

Belt armour on a US battleship only goes several inches below the waterline and is not intended to stop torp damage.

No, several inches below the waterline would expose the unprotected areas with even moderate seas and speed..

[Mike Scholl]

ORIGINAL: JohnDillworth

Additional question. Do they have to penetrate the armor to do serious damage. Although it can 1,000 + lbs. of explosives unless it penetrates a BB it doesn't seem it would do fatal damage. Might buckle a ton of plates, take on some water, and shake the &*($ out of the systems and crew but it seems most of the energy would dissipate outward, upward and downward (path of least resistance). History has clearly proven that I do not understand this (POW and Repulse vs 18 inch torpedoes)but I would love to understand why I am wrong.

Water is an incompressible medium, a ship isn't. [:D]

[wwengr]

From an engineering point of view, belt armor has four effects that afford a measure of protection to the ship against muntions directly striking the ship with a component of force perpendiculr to the side of the shp at or near the waterline:

1) The Armor dissipates energy from the impact and explosion by transmittting force perpendicular to the impact to the areas of armor around the point of impact, thereby reducing the pressure at tthe point of impact.
2) It dissipates energy by cracking, fragmenting, and melting at and around the point of impact, thereby reducing the force transmitted to the hull and the comaprtments inside (this characteristic of protection was not well understood back in WWII, but today armor systems are built to optimize this effect.
3) It triggers fuses on explosive munitions while slowing them down, thereby keeping the explosion out of the ship or with less penetration.
4) It stops or slows down kinetic energy munitions reducing amount of force transmitted to the hull or internal compartments.

[Q-Ball]

Kaigun has a fascinating summary of IJN gunnery tactics to take advantage of shallow armor belts. In summary, they worked on firing solutions to aim short, so the shell would hit the water, and impact the target several feet below the waterline. During test firing on the TOSA, the IJN found that these "short shots" did a tremendous amount of damage, and thought they should replicate that in battle. In practice it was very hard to do, but that was the theory anyway.

[JohnDillworth]

Miraculously, Boise just escaped a potential magazine explosion due to rapid flooding.

So the Boise was lucky in real life too? I swear there is code there to make this a better ship.

[Nikademus]

well not as lucky as she appears to be in the game [:D]

Sometimes i do suspect there's a hidden Boise line of code hidden in all that spagetti.

Maybe Gary has a soft spot for Boise ID. [:D]