Iowa and Alaska Class Conversion Projects

[Dilandu]

Here the whole file, the "16-IN. GUNBLAST EXPERIMENTS" from NAVAL SURFACE WARFARE CENTER (1989):

 

[blackstar]

Given we are talking about a Battleship with the primary role as VLS carrier (or VLS + Aircraft Carrier)

It's very hard to come up with a justification even for doing that. No matter what you do, you're still stuck with a ship with an outdated and aging powerplant (steam). It was an inefficient way to create a VLS carrier if that's what you wanted. A modified Tico or Burke that added VLS cells at the expense of some other capability (like the hangar) would be cheaper and allow the use of the standardized gas turbine powerplant.

 

[publiusr]

I still want a Wave Motion Gun on the New Jersey..for drones...

 

[drwells42]

It's very hard to come up with a justification even for doing that. No matter what you do, you're still stuck with a ship with an outdated and aging powerplant (steam). It was an inefficient way to create a VLS carrier if that's what you wanted. A modified Tico or Burke that added VLS cells at the expense of some other capability (like the hangar) would be cheaper and allow the use of the standardized gas turbine powerplant.

My reasoning might be somewhat different, but I came to a similar conclusion long ago. If you want an Arsenal Ship, build an Arsenal Ship. If you want a light carrier, build a light carrier. It is not worth modifying a battleship into something it isn't. You would lose the big guns in the process, and there's more or less nothing else that can carry them.

DRW

 

[Scott Kenny]

My reasoning might be somewhat different, but I came to a similar conclusion long ago. If you want an Arsenal Ship, build an Arsenal Ship. If you want a light carrier, build a light carrier. It is not worth modifying a battleship into something it isn't. You would lose the big guns in the process, and there's more or less nothing else that can carry them.

DRW

There's a good argument to be made for replacing some of the 5"/38 turrets with Mk11 or Mk13 missile launchers, but that's about all the "arsenal" mods that make sense for the Iowas. And you replace the other 5"/38 turrets with the 5"/54 Mk42 turrets while you're in there.

I'm personally thinking 1x missile launcher per side and 2x 5" guns, but that's me. That would give you 39x Standards or Harpoons per side and might allow replacing the Harpoon canisters topside with another couple of Tomahawk ABLs. Replacing two 5" guns per side would give you an absurd number of missiles to use, but might reduce the 5" firepower too much.

 

[Dilandu]

My reasoning might be somewhat different, but I came to a similar conclusion long ago. If you want an Arsenal Ship, build an Arsenal Ship. If you want a light carrier, build a light carrier. It is not worth modifying a battleship into something it isn't. You would lose the big guns in the process, and there's more or less nothing else that can carry them.

Well, this depend on how many guns would you lose. For example, dismounting the rear turret would still left six bow guns workable - and not only would reduce crew demands, but would also allow to fit something more useful at stern (like SAM launchers in 1950s or Tomahawk ABL's later)

 

[Tzoli]

Erm. Why didn't you ask?

View attachment 757964

Thanks! But is this accurate? 20psi or 1,38 bar or 1,36 atm seems a bit low from around 15-20ft / 4,5-6m away from the barrel. Though for single barrel it might be good, I presume a full 3-gun blast would be close to 3times of these values? Maybe 2,5 times?

Another question rises is what is the pressure tolerance of radar systems?

 

[Dilandu]

Thanks! But is this accurate? 20psi or 1,38 bar or 1,36 atm seems a bit low from around 15-20ft / 4,5-6m away from the barrel. Though for single barrel it might be good, I presume a full 3-gun blast would be close to 3times of these values? Maybe 2,5 times?

Another question rises is what is the pressure tolerance of radar systems?

Well, this is from that article: "16-IN. GUNBLAST EXPERIMENTS" from NAVAL SURFACE WARFARE CENTER (1989). So I presume, this is reasonably accurate.

 

[Dilandu]

, I presume a full 3-gun blast would be close to 3times of these values? Maybe 2,5 times?

Hm, I doubt that. The guns are usually firing with small delay (so the shells would not affect each other), so it would be more like of rapid sucsession of similar blast waves, rather than one resonating wave.

 

[Tzoli]

I will intend to make a drawing based on the diagram showing the various blast value zones at different firing angles.

 

[Dilandu]

I will intend to make a drawing based on the diagram showing the various blast value zones at different firing angles.

It would be great!

P.S. There are many other graphs and diagrams in this article, including schemes for Phalanx CIWS placement in relation to shockwaves.

 

[Foo Fighter]

Going totally off the reservation, the only things that I can makes sense of would be:-

Go fully glow in the dark for propulsion, gives more electric generation.

Add some missiles in place of the secondary, or MOST of the secondary guns.

Make space for some vertical launch drones and control room.

Make use of 'FLAG' facilities to make them the C&C choice.

Update the radar as much as possible.

Likewise communication.

NEVER send them anywhere alone.

It's OK, I am putting my shoes on now.........

 

[PappyVF477]

It's very hard to come up with a justification even for doing that. No matter what you do, you're still stuck with a ship with an outdated and aging powerplant (steam). It was an inefficient way to create a VLS carrier if that's what you wanted. A modified Tico or Burke that added VLS cells at the expense of some other capability (like the hangar) would be cheaper and allow the use of the standardized gas turbine powerplant.

I agree 100%. Which is why I was Commenting on the huge financial impact of such a conversion to AEGIS. YES it could be constructed and work, if you threw enough money at it and it could likely survive a 16" over-pressure from the #1 turret. I haven't read the Over-pressure article yet and am still going by my own knowledge from 25+ years ago.

The Iowa Conversion we got in the early-late 1980s is IMHO the second best choice other than spending zero money on the Iowas and instead ordering more ship construction from the still extant ship yards that are now gone. Or even just perfecting, ordering and producing the 8" MCLWG would have been a better investment But that is a case of coulda woulda shoulda.

 

[PappyVF477]

Thanks! But is this accurate? 20psi or 1,38 bar or 1,36 atm seems a bit low from around 15-20ft / 4,5-6m away from the barrel. Though for single barrel it might be good, I presume a full 3-gun blast would be close to 3times of these values? Maybe 2,5 times?

Another question rises is what is the pressure tolerance of radar systems?

A lot of people cite the video of cinematographers filming the USS New Jersey on the helicopter pad filming the firing of a salvo from Turret #3 in the 80s. In the video you can see them all brace and lean into their equipment / the blast and the actual effect on their clothing from wind was negligibly different. So Physiologically there was minor effect. That isn't to say the psychological effect wasn't massive. They didn't used to call what we call PTS "Shell Shock" back in the day for nothing.


Mind you Getting this third person from it being shown on either Drachinifel or USSNewJersey YouTube channels, I do not remember which featured it right now.

 

[Foo Fighter]

A lot of people cite the video of cinematographers filming the USS New Jersey on the helicopter pad filming the firing of a salvo from Turret #3 in the 80s. In the video you can see them all brace and lean into their equipment / the blast and the actual effect on their clothing from wind was negligibly different. So Physiologically there was minor effect. That isn't to say the psychological effect wasn't massive. They didn't used to call what we call PTS "Shell Shock" back in the day for nothing.


Mind you Getting this third person from it being shown on either Drachinifel or USSNewJersey YouTube channels, I do not remember which featured it right now.

What you are talking about has zero to do with what used to be called shell shock, and now is referred to as PTSD.

 

[blackstar]

The Iowa Conversion we got in the early-late 1980s is IMHO the second best choice other than spending zero money on the Iowas and instead ordering more ship construction from the still extant ship yards that are now gone. Or even just perfecting, ordering and producing the 8" MCLWG would have been a better investment But that is a case of coulda woulda shoulda.

I remember hearing somewhere that the powerplant on the Iowas was good for about 20 years in-service life, and that's what we got. If the Cold War had continued into the 1990s, I suspect they still would have been retired.

They were modernized a little too late for VLS. I would have liked to see VLS in place of some of those 5-inch guns, but the timing was wrong.

 

[JoeCalPo]

If you want to consider a more likely AEGIS battleship, the Kentucky or Illinois if finished as a BBG with launchers aft or fore-and-aft, though they too would have had issues. If they'd been so completed they likely would have been actively used through the Cold War, and so used up by the time VLS systems were coming online.
VLS would been useful to add more Tomahawks, but as other, modern VLS ships were being commissioned (later Ticos) or converted (Spruances), the USN didn't need the launchers.
The battleships were excellent show-the-flag vessels for their time, and while they might have served another decade, they were crew-intensive with antiquated machinery. Retiring them free people, funds, and supply space.
MAYBE if just Iowa and NJ were reactivated first, and then they retired after a decade, their crews and leftover ammo and spare arts going to Wisky and Missou, which could have been proto-arsenal ships with multiple VLS in place of the 5" and a proper hangar. Maybe.

 

[Scott Kenny]

Going totally off the reservation, the only things that I can makes sense of would be:-

Go fully glow in the dark for propulsion, gives more electric generation.

Add some missiles in place of the secondary, or MOST of the secondary guns.

IIRC a nuclear conversion was looked at, but would have been ruinously expensive. In the general level of "build another carrier" expensive. Plus, merely going nuclear doesn't really make for lots more electrical generation. You could mod the boilers to make more steam and install larger generators to the existing plant.

Adding missiles would have been relatively easy, as I've said the Mk11 and Mk13 missile launchers fit inside the same circle as a 5"/38 twin mount (Or rather, fit inside the 5"/54 Mk42 mount which fits inside the 5"/38 twin). Stick a Mk13 in the middle secondary turret mount on each side, turn the aft two turrets into platforms for the Tomahawk ABLs.

I remember hearing somewhere that the powerplant on the Iowas was good for about 20 years in-service life, and that's what we got. If the Cold War had continued into the 1990s, I suspect they still would have been retired.

They were modernized a little too late for VLS. I would have liked to see VLS in place of some of those 5-inch guns, but the timing was wrong.

installing VLS also would have involved a lot of rebuilding, likely requiring cutting out a lot of armor in the superstructure. And that would be really expensive.

 

[Foo Fighter]

IIRC a nuclear conversion was looked at, but would have been ruinously expensive. In the general level of "build another carrier" expensive. Plus, merely going nuclear doesn't really make for lots more electrical generation. You could mod the boilers to make more steam and install larger generators to the existing plant.

Adding missiles would have been relatively easy, as I've said the Mk11 and Mk13 missile launchers fit inside the same circle as a 5"/38 twin mount (Or rather, fit inside the 5"/54 Mk42 mount which fits inside the 5"/38 twin). Stick a Mk13 in the middle secondary turret mount on each side, turn the aft two turrets into platforms for the Tomahawk ABLs.




installing VLS also would have involved a lot of rebuilding, likely requiring cutting out a lot of armor in the superstructure. And that would be really expensive.

My point was that the steam plant was basically done so would need to be replaced, plus the people to run that plant were retired or about to be.

The Iowa had one turret completely out of use so the space in the second turret COULD have been used for VLS as they are doing with the Zumwalts.

Going full glow in the dark for propulsion? Basically if you cannot do that, put the money into new build ships and get more bang for the buck Rodgers.

 

[Scott Kenny]

My point was that the steam plant was basically done so would need to be replaced, plus the people to run that plant were retired or about to be.

The US still had a pretty significant number of large steam-powered ships at the time, like the LHD/LHAs and several of the Fleet oilers, plus a bunch of conventional carriers.

Sure, the boilers would need to be rebricked at the very least, but that's a relatively cheap option.

The hard part about crewing the Iowas was actually gunners and the techs that knew how to maintain the mechanical fire control computer.

The Iowa had one turret completely out of use so the space in the second turret COULD have been used for VLS as they are doing with the Zumwalts.

Yes, that's a theoretical option.

If the lower sections of the B turret weren't damaged you could pull the after turret out and mount that forward, sinking the VLS into the turret barbette. However many cells will fit in there. You'd still have to add ballast to compensate for the ~1500 tons of steel that you removed.

 

[Foo Fighter]

The US still had a pretty significant number of large steam-powered ships at the time, like the LHD/LHAs and several of the Fleet oilers, plus a bunch of conventional carriers.

Sure, the boilers would need to be rebricked at the very least, but that's a relatively cheap option.

The hard part about crewing the Iowas was actually gunners and the techs that knew how to maintain the mechanical fire control computer.



Yes, that's a theoretical option.

If the lower sections of the B turret weren't damaged you could pull the after turret out and mount that forward, sinking the VLS into the turret barbette. However many cells will fit in there. You'd still have to add ballast to compensate for the ~1500 tons of steel that you removed.

I was thinking more of adding the VLS in the B turret space, no need to reballast the boat. Possibly.

 

[Firefinder]

The original Refits of the Iowa called for the removal of the gun tubes and any other weight in the turrets to allow for another like.. 3 ABLs per turret I think it was.

Only the Marines wanted the guns and the Navy needed their lobbying to get congress to fund the refits. So the guns got refitted as well.

To MANY problems ranging from bad powder and lack of logi support to the Deaths in Iowa Turret 2.

The Guns were honestly a rarely useful niche due to their range. Even the Army 155s were matching their range at this time.

Even with the larger size of the shells it still be another decade til any decent guide Artillery shells with range extrantions be actually viable.

By then the Iowas be past 40 years old, that was past their design life even with the stays in mothballs. The Amount of repairs and refits needed...

 

[Tzoli]

Okay as I thought the blast of the 16" guns was not an issue.
Here are the pictures:
Broadside:


Extreme angles:


As you can see the blast issue is minimal, mostly 2 psi (1 barrel so around 4-5 psi for a full turret) around the top of the superstructure. So the radars are pretty safe or you can just put a slightly thicker plastic cover on them for extra protection. Also note that I doubt the turrets would be fired at that extreme angles in a shore bombardment mission.

 

[Yellow Palace]

IIRC a nuclear conversion was looked at, but would have been ruinously expensive. In the general level of "build another carrier" expensive.

That would be because you can't merely 'convert' to nuclear power. It would amount to removing everything aft of B turret and forward of X turret, and building an entirely new midsection. At which point you may as well add Aegis, Trident II, laser cannons and a shark pool, because you left fiscal responsibility behind about a thousand miles ago.

Plus, merely going nuclear doesn't really make for lots more electrical generation. You could mod the boilers to make more steam and install larger generators to the existing plant.

I'm not quite sure why people think that going nuclear magically gets you more power. You can sustain the same power for longer, since it takes a while to run out of neutrons, but unless you change the turbomachinery, reduction gearing, generators, etc., the maximum power is the same.

From the ship designer's viewpoint, a nuclear reactor is just a way of making steam that comes with lots of extra paperwork.

The US still had a pretty significant number of large steam-powered ships at the time, like the LHD/LHAs and several of the Fleet oilers, plus a bunch of conventional carriers.

Heck, the SACRAMENTO class were still running around with the exact same engineering plant in active service. And the MIDWAYs were of the same vintage.

I was thinking more of adding the VLS in the B turret space, no need to reballast the boat. Possibly.

The turret itself is a heck of a lot of weight, and high up. Hard to say without having the stability book, but I'd be surprised if removing it didn't result in excessive GM and high roll acceleration.

 

[BlackBat242]

A lot of people cite the video of cinematographers filming the USS New Jersey on the helicopter pad filming the firing of a salvo from Turret #3 in the 80s. In the video you can see them all brace and lean into their equipment / the blast and the actual effect on their clothing from wind was negligibly different. So Physiologically there was minor effect. That isn't to say the psychological effect wasn't massive. They didn't used to call what we call PTS "Shell Shock" back in the day for nothing.


Mind you Getting this third person from it being shown on either Drachinifel or USSNewJersey YouTube channels, I do not remember which featured it right now.

What you are talking about has zero to do with what used to be called shell shock, and now is referred to as PTSD.

"Shell shock" was what they called anything that affected your mental capabilities in WW1... and encompassed both what we now call PTSD* and what we now know as TBI (traumatic brain injury).

TBI was not known as a condition separate from PTSD back then, but the concussion of an explosive shell just outside lethality range certainly caused neurological trauma... much less dozens of them over the course of the war (yes, many soldiers served "for the duration of hostilities" on the front lines back then.)


* In WW2 it was called "battle fatigue".

 

[acelanceloet]

Okay as I thought the blast of the 16" guns was not an issue.
Here are the pictures:
Broadside:
View attachment 758185

Extreme angles:
View attachment 758186

As you can see the blast issue is minimal, mostly 2 psi (1 barrel so around 4-5 psi for a full turret) around the top of the superstructure. So the radars are pretty safe or you can just put a slightly thicker plastic cover on them for extra protection. Also note that I doubt the turrets would be fired at that extreme angles in a shore bombardment mission.

I doubt you could actually protect radars with just an additional piece of plastic, I suspect it has more to do with vibrations (or quick changes of the pressure) then the actual pressure levels. Remember, we do know that the Mk 29 was considered unusable on the Iowa's due to blast reasons, and "strengthening" an Mk 29 should be easier then doing the same for an radar antenna.

 

[Tzoli]

Radomes?
In case of the fixed AEGIS SPY Radsrs I do not know how sensitive they are to such overpressure and vibration issues.

 

[CV12Hornet]

Heck, the SACRAMENTO class were still running around with the exact same engineering plant in active service. And the MIDWAYs were of the same vintage.

At the same time most of those ships were just as on the way out as the Iowas. Even the Sacramentos had already had their replacement, the gas-turbine Supplies, in the building queue.

The remaining steam-powered ships were of significantly newer vintages with more modern plants.

 

[Dilandu]

Okay as I thought the blast of the 16" guns was not an issue.
Here are the pictures:
Broadside:

Great! Thank you for this schematic!

 

[Scott Kenny]

At the same time most of those ships were just as on the way out as the Iowas. Even the Sacramentos had already had their replacement, the gas-turbine Supplies, in the building queue.

The remaining steam-powered ships were of significantly newer vintages with more modern plants.

Immaterial, because that means that you could pull senior leadership, even down to the E5s, from those ships to operate the Iowas.

 

[Firefinder]

Immaterial, because that means that you could pull senior leadership, even down to the E5s, from those ships to operate the Iowas.

And still doesn't fix the issue of both parts and age.

All those ships, besides the Sacramentos, used new post 1950 high pressure boiler design the navy went to. Those needed less crew since they were more automated. Even the Sacramento boilers got modified at the factory before gettimg installed.

They all will need retraining to use the more primitive Iowa boilers which you CANT mod unless you cut them out of the ship.

 

[Grey Havoc]

They were modernized a little too late for VLS. I would have liked to see VLS in place of some of those 5-inch guns, but the timing was wrong.

They were seriously looking at fitting the Iowa-class with both Aegis and the Mk 41 VLS right up to the end of the Cold War. For example, from an old post of mine in another thread:

Interestingly enough, one of the things that led up to the MEU design was the failure of the USN to get an Surface Action Group optimised (at the expense of NSFS capability) Iowa class conversion past the USMC. That particular plan included removal of all the 16-inch turrets and installing, among other things, 324 Tomahawks, 100 Standard Missiles, and an Aegis system (a custom variant of the Baseline 2 AN/SPY-1A most likely).

 

[Dilandu]

They were seriously looking at fitting the Iowa-class with both Aegis and the Mk 41 VLS right up to the end of the Cold War. For example, from an old post of mine in another thread:

Well, more "presistently" than "seriously". From all I knew - admittedly, not much - it was not so much a serious consideration, but "whoa, those old girls are really big, could we put all out best stuff on them?"

 

[SSgtC]

And still doesn't fix the issue of both parts and age.

All those ships, besides the Sacramentos, used new post 1950 high pressure boiler design the navy went to. Those needed less crew since they were more automated. Even the Sacramento boilers got modified at the factory before gettimg installed.

They all will need retraining to use the more primitive Iowa boilers which you CANT mod unless you cut them out of the ship.

They will need minimal retraining. They aren't learning a whole new system, just the differences between the two classes. That's something that can be done over a few days, compared to the weeks or months needed to learn an entirely new system

 

[Firefinder]

They will need minimal retraining. They aren't learning a whole new system, just the differences between the two classes. That's something that can be done over a few days, compared to the weeks or months needed to learn an entirely new system

That only true for the Sacramentos, which at best, are two Iowas worth of crew. Who are more worth on the Supply ships. And Maybe the Midway bit she herself had another near 2 decades worth of use as well.

The Belknaps, Shermans, or the Wasps? Are all entirely different systems and set up compare to the Iowas. The Navy complete redid how it boilers work between 1945 and 1952, the Iowas used a 2k psi system, while the Sherman's used a 3 to 4k system. It a completely different design.

We not looking at the difference between South Dakota and Iowa, but the Nautilus compare to the Virginia. While there a alot of similarities there is enough differences that you going need a hot minute to reconfigure you mental settings. Especially since what normal operating readings on the Sherman is Oh-fuck-we-all-going-to-die on the Iowa.

 

[A Tentative Fleet Plan]

Iowas and other US wartime ships were 600psi, the newer 1950s were 1200psi (although IIRC, the Forrestal was still using 600psi).

The 1200psi plants had problems, as a result they were considering a return to 600psi machinery in the mid-1960s, until marinised aircraft Gas Turbines proved to be mature enough to render steam plants obsolete.

 

[SSgtC]

That only true for the Sacramentos, which at best, are two Iowas worth of crew. Who are more worth on the Supply ships. And Maybe the Midway bit she herself had another near 2 decades worth of use as well.

Yeah, so those ships? That's more like 10 crews worth of personal. Why? Because for every sailor assigned to the boiler or engine room on the ship, there's 3-5 serving in a shore billet. While the Midway class did not use the same system as the Iowas, it was similar enough that again, minimal retraining. Lexington was also still in service at this time (and two of her sisters had just decommissioned in 75 and 76 as well), and she shared a ton of similarities in her engineering plant with the Iowa class as well. And let's not forget, that the Navy didn't dispose of the last of their Gearing class destroyers until 1980 as well. If anything, bringing the Iowa class back into service actually helped the Navy in regards to their Boiler Technicians. They now had more billets available for all those sailors that had been extensively trained and experienced in WWII era steam plants.

the Iowas used a 2k psi system, while the Sherman's used a 3 to 4k system. It a completely different design.

So, you actually don't know what you're talking about, do you? The Iowas (and the other WWII era ships still in the Fleet) used a 600 psi steam plant, not 2,000. And no Navy ships have ever used a steam plant even approaching 3-4,000 psi. 1,200 psi was about the max the Navy ever used.

We not looking at the difference between South Dakota and Iowa, but the Nautilus compare to the Virginia. While there a alot of similarities there is enough differences that you going need a hot minute to reconfigure you mental settings.

Yeah, this isn't the shining example you think it is. Want to guess what kind of reactors the Navy is using to train it's reactor techs on before sending them out to operate the reactors on LA and Virginia class boats? They use the S1W as installed on USS Nautilus (located in Kesselring, NY as part of the Naval Nuclear Propulsion School).

Especially since what normal operating readings on the Sherman is Oh-fuck-we-all-going-to-die on the Iowa.

You do realize that there are gauges on the plant, right? And that those gages are very clearly marked with what is and is not a safe operating range? Not to mention that the safety valve on the boiler is going to blow looooooong before the plant even gets close to what a "normal" reading on a 1,200 psi plant would be?

 

[Tzoli]

Guys clam down or the Admins will take action.

 

[Scott Kenny]

And frankly, if the old boilers were in bad enough shape that they'd need to be replaced anyways, you drop 1200psi boilers in there and call it good.

 

[CV12Hornet]

And frankly, if the old boilers were in bad enough shape that they'd need to be replaced anyways, you drop 1200psi boilers in there and call it good.

You're kidding, right?

Reboilering a battleship is Major Ship Surgery - there's a reason most navies didn't bother unless they literally couldn't buy more battleships, it costs a very significant percentage of just buying a new ship since you need to cut open the armored deck to replace them. They don't call the battleship modernizations involving new boilers "reconstructions" because it was an easy task.

For another example, recall how much work had to be done on Victorious to reboiler her. Same deal.