BB-72 to BB-78, post-Montana battleships ?

[Grey Havoc]

How the United States Navy perceived the likely post-War line up (pre-Truman and Attlee):

History, Politics And Current Affairs • View topic - Post War Navies, March 16, 1945

Very interesting, especially the mention of the 60000 ton battleship design to be possibly built after Illinois and Kentucky. The displacement figure is consistent with Montana class but it is referred as a Gibbs private venture so it could be something completely different. The only post-Midway USN battleship's design activity I've ever heard of is the 106000 ton "super Iowa" conceptual study.

And, pray tell, can you please provide any sources or images related to this study?

There are scarce notes about it in Garzke and Dulin "Battleships: US battleships in WW2". If the memory assist me, it was a 1944 contemplating a battleship of 1160 feet in length and 140 feet wide, approximately the maximum dimensions permitted by the planned '40s enlargement of Panama canal. The study combined main armament equal to Montanas (12*16") and speed equal to Iowas while I don't remember any mention regarding armor. As Tzoli said, the drive to dimensional increase was anti torpedo protection. There never were any intention to build battleships of such scale, especially at the end of the war, but the study reflects an ongoing internal debate on the future role of battleships.

 

[Grey Havoc]

Actually there was another post Montana study made by two University Students for a small Battleship from around 1942.

But this Gibbs & Cox proposal is new to me as well! This firm did produced battleships designs for the Soviets in 1936-39 so it's not impossible they continued to propose such for the USN when war broke out. Question is does this firm had any archives which survived the past 75 years?

That 106.000ton Super Iowa study you referring are a qucijk study of how large should the Iowa be to be basically unsinkable by torpedoes. Most of the extra tons went into underwater protection.

I'm intrigued by the funnels. That's either a lot of internal ducting or an unusual location for the engines.

 

[Grey Havoc]

Here is the armour layout:
View attachment 630514

There is an article about this design somewhere but I have to find it first.

 

[drwells42]

The BB72-78 “battleships” were and still are the product of the media. Firstly the wartime press who, in the absence of any authorised data, speculated on what could possibly follow the Montana designs. Currently the BB72-78 “design” is enjoying a second lease of life courtesy of the internet – notably Wikopedia which has an unreferenced entry on this topic. This data appears, with the same wording, on a number of other sites which do not appear to have any interest in the authenticity of their information. It is interesting that many of the naval history web-sites that deal with authenticated warship designs and projects make no mention of the BB72-78 battleships.

There is no mention of the BB72-78 in Friedman’s “US Battleships a Design History” nor in Dulin & Garzke’s “Battleships - United States battleships of in World War II”, but Polmar in “Ships and Aircraft of the US Fleet” (P128/129) does mention the speculation that took place in regard to this “design” during the war years.

The reality is that other than a small number of design studies that were not intended for production the Montana class design was the end of the US Navy's battleship designs.

While I strongly agree that BB-72 through 78 were products of media speculation, I would be quite interested in knowing what media sources did the original speculation. I suspect that there's a magazine article somewhere, (Popular Mechanics???) but I haven't found anything so far. If anyone has a source, please let me know.

I'm gathering data for an eventual webpage debunking the "Super Montana" class.

David R. Wells

 

[любитель военных кораблей]

There are mentions of it in Friedman's book about U.S. battleship design history. It was a project to adapt Montana's armor and torpedo defence design to the lessons of the war. Hull form was the same but expanded to the dimensional limit of the new panama locks (1200 ft. long and 142 ft. wide). It was never intended for production, you can consider it the american equivalent of german H design series from H-42. Armament was the same while speed was greater thanks to the better length-beam ratio. A real but short lived Montana follow on project was instead for 8 new battleship with same dimensions and main armament of BB67 but with an increased AA armament, a slight decrease in speed (to the same of South Dakota, so from 28-29 knots to 27) and some minor modification to armor. Sorry for my bad english

Hi, did I understand you correctly? A battleship with a displacement of 106500 tons should be armed with 4/2 457 mm guns and with a speed of 27 knots

 

[drwells42]

Hi, did I understand you correctly? A battleship with a displacement of 106500 tons should be armed with 4/2 457 mm guns and with a speed of 27 knots

The table in Dulin & Garzke does indeed say twelve 16" guns in four triples, but it also notes that this is the authors' estimate. Since the purpose of the design, (to the extremely limited extent that there was a design) was to explore torpedo protection, main armament (except for turret position) might not have been a consideration. FWIW, D&G did not mention speed.

On the one hand, four twin 18" turrets would certainly fit, and the weight would not have been a problem, but the USN was very pleased with the 16"/L50 Mk 7 at the time, and even the large Montana ancestors such as BB65-8 still had 16" guns.

From my reading of D&G, this 106,000 ton ship from July 1944 barely qualifies as a design study, and certainly was not considered for production.

DRW

 

[любитель военных кораблей]

The table in Dulin & Garzke does indeed say twelve 16" guns in four triples, but it also notes that this is the authors' estimate. Since the purpose of the design, (to the extremely limited extent that there was a design) was to explore torpedo protection, main armament (except for turret position) might not have been a consideration. FWIW, D&G did not mention speed.

On the one hand, four twin 18" turrets would certainly fit, and the weight would not have been a problem, but the USN was very pleased with the 16"/L50 Mk 7 at the time, and even the large Montana ancestors such as BB65-8 still had 16" guns.

From my reading of D&G, this 106,000 ton ship from July 1944 barely qualifies as a design study, and certainly was not considered for production.

DRW

thank you for answering my question so quickly

 

[Tzoli]

That study was for studying what is required for an Iowa or Montana hull to become "unsinkable" by torpedoes. The extra displacememt went into mostly the TDS.

 

[Dilandu]

That study was for studying what is required for an Iowa or Montana hull to become "unsinkable" by torpedoes. The extra displacememt went into mostly the TDS.

I wonder what the initial assumptions were. Had they assume 21-inch torpedoes only, or they already took Japanese super-heavies into consideration?

 

[Tzoli]

More like an extended West Virginia type layout (I think that ship had the best TDS) maybe a 5-7 layered one, West Virgina had 5 if I remember.

 

[YourChair]

Hi, did I understand you correctly? A battleship with a displacement of 106500 tons should be armed with 4/2 457 mm guns and with a speed of 27 knots

Note that the 457mm guns used would be the 457/48 Mark 2, not the 457/47 Mark A.
The difference is that the Mark A is just a modified version of the 1920s 457/48 meant as an experimental gun, and the Mark B would be the modern gun (just as the old 406/50 became the Iowa's gun), with a muzzle velocity increased to 762 m/s. The gun itself would be lighter.

More like an extended West Virginia type layout (I think that ship had the best TDS) maybe a 5-7 layered one, West Virgina had 5 if I remember.

The TDS would probably resemble Montana more, seeing as her underwater protection actually accounts for diving shells

 

[YourChair]

There are mentions of it in Friedman's book about U.S. battleship design history. It was a project to adapt Montana's armor and torpedo defence design to the lessons of the war. Hull form was the same but expanded to the dimensional limit of the new panama locks (1200 ft. long and 142 ft. wide). It was never intended for production, you can consider it the american equivalent of german H design series from H-42. Armament was the same while speed was greater thanks to the better length-beam ratio. A real but short lived Montana follow on project was instead for 8 new battleship with same dimensions and main armament of BB67 but with an increased AA armament, a slight decrease in speed (to the same of South Dakota, so from 28-29 knots to 27) and some minor modification to armor. Sorry for my bad english

A bit of a necropost, but this is actually true, unlike what was asserted before -- except the 32 guns was based on a misunderstanding. Because of frustrations ealrywar with heavy AA control, it seems the plan was actually to reduce the battery (though better firing arcs would have been bought). The 32 guns comes from mistaking the "16 guns" figure as 16 turrets.

 

[Colonial-Marine]

The ways they were reviewing the AAA battery is interesting, although the wisdom of option (c) seems very questionable even when considering the difficulties with fire control being experienced in early 1942.

Given experience later in the war I think a more ideal layout would look similar to the suggestion by Admirals King and Nimitz for BB-65/66 to be finished to a modified design. A more compact superstructure, perhaps with just one larger funnel, and two of the 5"/54 caliber twin turrets moved from the sides to the centerline, superfiring over the main battery similar to the design of many wartime USN cruisers.

 

[Scott Kenny]

Given experience later in the war I think a more ideal layout would look similar to the suggestion by Admirals King and Nimitz for BB-65/66 to be finished to a modified design. A more compact superstructure, perhaps with just one larger funnel, and two of the 5"/54 caliber twin turrets moved from the sides to the centerline, superfiring over the main battery similar to the design of many wartime USN cruisers.

The "cruiser style" secondary battery is definitely better arranged than the "battleship style".

If you assume 8 turrets for 16x guns (used on the BBs with squadron command spaces added), the battleship style only lets you put 4 turrets into each broadside while the cruiser puts 6 turrets into either broadside. 50% improvement in firepower.

It's less of an improvement if you're using 10 turrets, though. 10 turrets battleship style means 5 turrets on each broadside, while 10 turrets cruiser style still means 6 turrets on each broadside. 20% improvement.

 

[любитель военных кораблей]

Note that the 457mm guns used would be the 457/48 Mark 2, not the 457/47 Mark A.
The difference is that the Mark A is just a modified version of the 1920s 457/48 meant as an experimental gun, and the Mark B would be the modern gun (just as the old 406/50 became the Iowa's gun), with a muzzle velocity increased to 762 m/s. The gun itself would be lighter.


The TDS would probably resemble Montana more, seeing as her underwater protection actually accounts for diving shells

457/48 mark2? what is this? This is the first time I've heard of such a gun

 

[Scott Kenny]

457/48 mark2? what is this? This is the first time I've heard of such a gun

USA 18"/48 (45.7 cm) Mark 1, 16"/56 (40.6 cm) Mark 4 and 18"/47 (45.7 cm) Mark A - NavWeaps

www.navweaps.com

Developmental piece the US was messing with.

 

[YourChair]

USA 18"/48 (45.7 cm) Mark 1, 16"/56 (40.6 cm) Mark 4 and 18"/47 (45.7 cm) Mark A - NavWeaps

www.navweaps.com

Developmental piece the US was messing with.

Not quite: apparently the Mark 2 (a 457/48) was intended to be the production version of the "Mark A" super heavy shell gun (a 457/47 modified from the 457/48 Mark 1), just like the Iowa gun was originally a modified 406/50 in storage from the original cancelled South Dakotas and Lexingtons from 1920.

 

[Tzoli]

457/48 mark2? what is this? This is the first time I've heard of such a gun

It would had been the productuon version of the 18"/47 Mark A

 

[Scott Kenny]

Not quite: apparently the Mark 2 (a 457/48) was intended to be the production version of the "Mark A" super heavy shell gun (a 457/47 modified from the 457/48 Mark 1), just like the Iowa gun was originally a modified 406/50 in storage from the original cancelled South Dakotas and Lexingtons from 1920.

Right, but that's the place that has specs and background on the gun.

I gotta admit, the idea of a US battleship throwing 3800lb super-heavy AP around makes me giggle. especially when I watch replays on WoWS YouTube, usually The Mighty Jingles or Yuro.

But IIRC 9x 2700 at 2rpm beats the heck out of 6x 3800 at 1.5rpm. 48,600lbs versus 34,200lbs broadside per minute. You need to assume 4x2 guns before it closes the gap (45,600lbs/min), though that also assumes engagements with about 20,000 yards so that you aren't waiting for shells to land before sending the next volley.

But for fights outside about 25,000 yards, the 18" guns would do better. You're now limited to one volley every 40 seconds due to time of flight. 24,300lbs per volley from the Iowa's 9 guns, 22,800lbs per volley from a hypothetical "18-inch Iowa" with 3x2 guns, and 30,400lbs per volley from an "18-inch Montana" with 4x2 guns.

 

[Tzoli]

Ehy go 3x2 or 4x2 when the USN already had a 3x3 18" design? The Iowas high speed cost so much.

Slow Battleship Study II by Tzoli on DeviantArt

www.deviantart.com

 

[Scott Kenny]

Ehy go 3x2 or 4x2 when the USN already had a 3x3 18" design? The Iowas high speed cost so much.

Slow Battleship Study II by Tzoli on DeviantArt

www.deviantart.com

I'm assuming dropping a 2x18" Mk2 turret into the same barbette as the 3x16" Mk7.

So literally a Kentucky or Montana with 18" guns dropped in instead of the 16". Not a bespoke 18" gun battleship.

 

[Tzoli]

A one-on-one swap is possible but both hulls allow the install of triple 18" turrers for new constructions

 

[Yellow Palace]

A one-on-one swap is possible but both hulls allow the install of triple 18" turrers for new constructions

It's not really 'installing different turrets in the same hull', though. The hull lines might be the same, but you'd have different auxiliary machinery, fire control, layout, scantlings, subdivision.... and it goes on.

The design change to substitute a two-gun 18-inch turret for a three-gun 16-inch turret is significantly reduced. You'll still have to modify the magazines, and some local structural modifications are likely, but the ship basically works as-is.

A completely new design isn't necessarily a bad thing. But it's important that the customer understands that they've asked for a new design, and what that means for programme cost and schedule.

 

[Colonial-Marine]

The way I see it, the best solution would be to take the Montana hull and powerplant and work from there. Fitting 3x3 18"/48 caliber turrets on that displacement shouldn't be a problem. There would be more design work (and money) needed versus just dropping twin turrets in the place of the triples, but the largest USN shipyards able to build battleships (and fleet carriers) of such sizes already had a backlog of work. Even if these hypothetical battleships were given some priority, I can only imagine construction starting after Montana or one of her sisters had cleared the drydock.

Two ships of the Montana class were planned to be built in New York Navy Yard, two in Philadelphia Navy Yard, and one in Norfolk Navy Yard. I'm not sure what capability any of these yards had to work on more than one simultaneously, especially since the Montanas were to supposedly be built in drydock versus starting construction on a slipway and then being launched like prior USN battleships.

One you start changing the size/shape of the hull itself I'd have to assume the design/planning phase takes a lot more time.

 

[Scott Kenny]

The design change to substitute a two-gun 18-inch turret for a three-gun 16-inch turret is significantly reduced. You'll still have to modify the magazines, and some local structural modifications are likely, but the ship basically works as-is.

It may also be possible for the other shipyards to build 18-inch turrets and install them on older battleships (like Iowas, SoDaks, NoCarolinas). For example, Puget Sound Naval Shipyard has cranes big enough to handle the 3x16 Mk7 turrets, so they should be able to handle a 2x18 Mk2 turret.

Modified magazines and updated fire control computer cams.

Relatively short and simple conversions, to be done when the battleships return to PSNS for work.

A completely new design isn't necessarily a bad thing. But it's important that the customer understands that they've asked for a new design, and what that means for programme cost and schedule.

Yep. And in this case, it's mostly program schedule that matters, not cost. While the war is still on, cost is pretty much no object. But time-till-service-entry is king.

 

[Yellow Palace]

Yep. And in this case, it's mostly program schedule that matters, not cost. While the war is still on, cost is pretty much no object. But time-till-service-entry is king.

Cost itself may not, but cost-as-resource-proxy does. Would you rather have your ship designers creating a new battleship design, or working on several smaller ships - escorts, landing craft, supply ships - to be built in greater numbers?

 

[Scott Kenny]

Cost itself may not, but cost-as-resource-proxy does. Would you rather have your ship designers creating a new battleship design, or working on several smaller ships - escorts, landing craft, supply ships - to be built in greater numbers?

Okay, yes, the constraints in terms of "what else could we build with those drydock slots" are a very valid concern. Only so many docks big enough to build BBs and CVs, after all. For example, all 6 Iowa-class hulls were laid down before the US entered the war, and the last 2 were launched with no superstructures on them to clear the slips for IIRC the Midway class carriers.

But once you have decided what class of ship to build in those docks, how soon can this new ship be in service is a very important question when there's a war on.

And since the 2x18" Mk2 turret requires little redesign of the rest of the ship, an "18-inch Montana" or "18-inch Iowa" would be the fastest way to get 18" guns into service.

 

[EwenS]

Only 4 Iowas were laid down before 7 Dec 1941. All big warship construction took place on the east coast, close to the necessary industrial infrastructure.

BB-66 Kentucky was laid down on a slipway at Norfolk Navy Yard 7 March 1942. Construction had not risen above her bottom structure before it was launched on 10 June 1942 to clear the slip for LST production.

http://www.navsource.org/archives/01/016602.jpg

Work then restarted in Dec 1944 when that bottom structure was placed into Dry Dock No 8. It continued spasmodically, with various plans created and dropped for her until her hull was floated out in Feb 1950 and laid up.

BB-65 Illinois is a bit more of a mystery. Some work seems to have begun on her in Dec 1942 but was quickly torn down. She was relaid on a slipway at Philadelphia Navy Yard on 15 Jan 1945, cancelled on 12 Aug when 22% complete and broken up on the slip.

In 1938 funding was approved for improvements to the various US Navy Yard dock facilities. When the Montanas were designed they were too wide for the existing slipways so new dry docks had to be built to allow them to be constructed (by then ships were becoming too large to launch from traditional slipways, due to the risks of overstressing their long hulls during launch). 1 at Norfolk NY, 2 at Philadelphia NY, and 2 at New York NY with work starting in June 1940 for completion in 1942/43. Until these were available the Montanas couldn't be laid down, which accords with reports of ship building plans. These docks were 1,092ft long and 150ft wide.

HyperWar: Building the Navy's Bases in World War II [Chapter 8]

When FDR relented and finally approved construction of the first 2 Midways, construction of Midway herself was allocated to the civilian yard at Newport News which had been specialising in building carriers, which already had a dry dock large enough to take her hull.

The second ship, that was renamed USS Franklin D Roosevelt while under construction, was allocated to the New York NY and built in one of the new large dry docks, by then (Oct 1943) freed up by virtue of the cancellation (July 1943) of the Montanas scheduled to have been built there.

The third ship, Coral Sea, approved some months later, was allocated to Newport News.

Also worth noting that the Panama Canal locks in 1940 were 1,050ft long 110ft wide (ship limit 106ft beam) and 41ft deep. The Montanas exceeded that width, which was only deemed acceptable because of plans to build a new set of locks 1,200ft long, 140ft wide and 45ft deep. Work on that expansion began on 1 July 1940, but was abandoned in 1942. Some of the excavations are still visible. It was the 21st century before new larger locks were built.

Edit:- The contractual completion dates for the Montanas lay between Nov 1945 & Nov 1946. So plenty of time, in pre-war planning terms, for work to progress on new Panama Canal locks.