Structural design

[ArmchairGeneral]

Why'd he stop coming over here? Too busy? There was a lot more interesting stuff to read in the Naval forum when he was active.

[lundgrenr]

Yes, it is Galrahn's blog

The article is entitled The Greatest Battleships in History August 5, 2008.

I just type in Iowa in the search blog area and it will come up along with other articles that may include the Iowa's as a subject.


I simply disagree with his opinion thats all. Stark was actually saved by the simple armor placed around her magazine. It helped prevent it from cooking off. If they had provided 1.5-2.0 inches of steel to her exterior the exocet would have been rejected.

I will have to find it again but I had an article that approached ship survivability using Stark, Cole and the other recent ships damaged as examples. In this article they used the figure for the bomb damage on Cole as an equivalent charge of 500 lb TNT. This is why I used my figure of a 1,000 lb bomb. Cole showed no recovery Vs choice weapon. There was some discussion if she had been at sea she may have sunk. Both ships were mission killed and this is the real definition of survivability, can the ship withstand a hit and remain on station. If the ship has no recovery from the hit then the damage inflicted is similar to a hard kill. How many years before Cole could return to active status?

When people say a ship is more survivable because she is less susceptable to being hit is this really true? DDG-1000 is supposed to have a reduced radar signiture and be less susceptable to being hit at the expense of being more vulnerable to heavy seas and lacking in reserve buoyancy if she does take damage. A mine will not care if the ship's radar signiture is low.

I do not know who started the logic of building ships based on susceptability to attack Vs making ships more invulnerable to attack. Susceptability is in constant change and failure is demonstrated by Stark, Cole, and the other recent US ships damaged. You simply can not reduce the risk to zero so building a ship that is more vulnerable once a hit is scored is not logical when they now cost billions of dollars each.

Many individuals maintain armor is useless because weapons can penetrate it. Armor also contains damage as well as limits damage and penetration of armor does not translate always into massive damage behind the plates. If Cole had a 1.5" STS hull the warhead would not have caused the amount of damage seen and she may have been able to get underway on her own power. Had it not been for the small amount of armor on Stark she would have been lost.

You do not need Iowa's level of protection to have a large increase in making a ship less vulnerable to the most common threats today. In order to fit all the modern electronics onto the new ships their displacements keep rising and they are getting top heavy. Burkes tend to be top heavy. Placing a certain amount of exterior armor as well as a significant amount of splinter protection within the hull would go along way to making the hull girder much stronger, she would be able to absorb damage better, have a better chance at recovery after damage, and the added weight low in the ship will make her more stable.

It is my opinion that for a warship the physical hull structure needs to be looked at again and their has been too much compromise in this area on a myth that reduced susceptability actually makes a ship more survivable when in reality it does not.

[ArmchairGeneral]

Burkes are not the offensive arm of the fleet with all other ships supporting them so they are not capital ships.

By that definition neither were the Iowas. Their primary function was to defend the carriers.

[Gun Grape]

I simply disagree with his opinion thats all. Stark was actually saved by the simple armor placed around her magazine. It helped prevent it from cooking off. If they had provided 1.5-2.0 inches of steel to her exterior the exocet would have been rejected.

Stark was saved through good old fashion DC. She wasn't even in MC Zebra
when the attack happened. She was in Yoke.

The magazine was saved because they kept it wet down. Not because the 3/4 alum armor deflected the blast of the shaped charge warhead. She was struck aft of the magazine. Both times.

For the weight of that armor, what capabilities do you want to give up?

Perrys had weight problems from the start. And you want to add more.

And 1.5 -2 in of steel isn't going to stop a 165kg shaped charge warhead.

A 155mm ICM sub-munition will punch through 2in of rolled homogeneous steel armor. And its HE filler is measured in oz's.

In this article they used the figure for the bomb damage on Cole as an equivalent charge of 500 lb TNT.

They were wrong. FBI and DoD had over 1000 lbs of HE detonating.

How many years before Cole could return to active status?

14 months. So a little over 1 year.

When people say a ship is more survivable because she is less susceptable to being hit is this really true? DDG-1000 is supposed to have a reduced radar signiture and be less susceptable to being hit at the expense of being more vulnerable to heavy seas and lacking in reserve buoyancy if she does take damage. A mine will not care if the ship's radar signiture is low.

3 DDG 1000s are being built as tech demonstrators. I'm pretty sure that the team that designed them looked into the "vulnerable to heavy seas" and "Reserve buoyancy" issues.

If Cole had a 1.5" STS hull the warhead would not have caused the amount of damage seen and she may have been able to get underway on her own power. Had it not been for the small amount of armor on Stark she would have been lost.

Thats your opinion

You do not need Iowa's level of protection to have a large increase in making a ship less vulnerable to the most common threats today. In order to fit all the modern electronics onto the new ships their displacements keep rising and they are getting top heavy. Burkes tend to be top heavy. Placing a certain amount of exterior armor as well as a significant amount of splinter protection within the hull would go along way to making the hull girder much stronger, she would be able to absorb damage better, have a better chance at recovery after damage, and the added weight low in the ship will make her more stable.

So what gadgets do you want to take off? Its a zero sum game. More for armor means less weapons, or less sensors, reduced handling capabilities.

[RustyBattleship]

As a project leader on some of the FFG-7 class ships, we were already aware of serious weight problems.

One solution was the 3100 ton Shipalt. One of the fuel tanks had been converted to a ballast tank with lots of lead ingots clamped in. Every new black box had to be within 50 feet of its antenna or the warranty was void, thus putting them up above the main deck.

For stiffening we added doubler plates nearly the full length of the shell at the shear strake, bilge strake and garboard strakes. It was that stiffening that saved the Roberts or she would have broken in two. One of our engineers had to go over there to help assess the damage and figure out a way to get the ship back home. We filled it with concrete so it wouldn't bend anymore.

All that added weight caused another problem. The discharge openings (sewer lines from the heads and galley) were now below waterline. We had to redesign them to be a foot higher and still have a down slope (more or less). As you well know, sh&t does not run uphill.

As for 3/4" steel armor around magazines, the only ships I designed that for were the Spruance class Destroyers and the Tarawa class Assault ships.

On the Spruances we added up to 1 3/4" Aluminum armor in some places and much less in others depending upon how many bulkheads were between a critical black box and a near miss throwing frag all over the place.

Only some of the Perry's and some of the Spruances received PCM Shipalts that made it harder for a missile to lock on.

[lundgrenr]

Displacement

There are no more treaties limiting displacement this is a totally self limiting and artificial limitation we set for ourselves. There is no need to not design ships with better structural integrity but I believe it needs to be incorperated as a design requirement before the ship is built. If it adds 3,000 tons (I only use this figure as an example) so be it. You do not compromise on your standards for either capability or invulnerability so these ships can continue to fight. Better subdivision and splinter protection to contain damage.

The Navy really needs to abandon the physcological ideology such as destroyers must be small displacement ships.

The principle attack force today will remain the carrier and in a total war the sub. If AAW escorts due to the weapon systems need to be 28,000 ton ships who cares if by adding armor to the design it goes up to 32,000 tons if this makes such an investment more survivable. I am not sure if helicopters remain effective for ASW which can easily be added and on such a ship ASuW is also possible.

The small surface combantant is what is becoming obsolete because as you say too many compromises are needed so capability goes down or survivability goes down. We are the only Nation which can build such ships so there will not be an arms race. Right now the decision has been made to sacrifice survivability and at a cost of 2 billion dollars per ship does this make sense?

Numbers you established based on carrier task forces and the gator navies needs. If a carrier requires two such escorts and we operate 11 carriers then 22 for them and maybe 6 for the gator fleet for 28 ships. The navy will shrink but there is no real risk to command of the seas in the foreseeable future where large numbers of ships will be needed if ever again. In the end it is cheaper to maintain 28 ships Vs over 60 less capable ships.

Again this is just my opinion and in the end means nothing. I just don't agree with the design concepts now being used. If DDG-1000 cost 6 billion dollars and can not even float in heavy seas without capsizing this is rediculus. If Cole can be taken out by three guys and a speed boat for 14 months something is fundamentally wrong. If the Navy builds 28,000 ton ships we will spend the money anyway so build a structurally sound ship and not a paper tiger.

If you wish to fight pirates use Coast Guard cutters with a 5-inch gun. They do not need the massive firepower of a Burke type ship. Put the merchants into a convoy so one cutter can guard many merchants. Have assemply points to the north and south and four ships could guard and end piracy. One ship each guard the assemply areas. One ship each guard the north/south convoy. The fact that the world navies say they can't stop it is another joke.

As for WWII the battleship remained a capital ship because carriers could not operate their aircraft at night. The battleship and the naval gun were still required as the principle offensive weapon at night. Thus the naval battles of Guadalcanal and the night action off Leyte when Yamashiro and Fuso was sunk. Though cruisers took the main brunt of the surface battles this was largely due to the Washington treaty which severly limited the number of modern battleships at the beginning of the war.

It was only Admiral Halsey's two errors that took task force 34 away from the center force and then again an error once he was in position to attack the northern force and he turned the fleet again away that kept Iowa and New Jersey from fulfilling there primary function. Halsey should have taken Lee's suggestion to stay or stuck to his decision and simply answered Nimitz (Task force 34 is attacking norther force!) Hindsight is great however.

Kinkaid had enough forces to defeat Kurita it was the surprise/shock factor that sent his staff into panic. Both Admirals were at fault for not communicating their intentions to each other. Ultimately this was Nimitz's fault for the split command at this battle. Carrier air power made the Naval Gun only a support role in gunfire support once carriers could operate aircraft 24 hours a day.

Again just my opinion.