WI: After Japan denounces the Naval treaties, the US withdraws and made changes to its initial builds (see post for details)?

[Issei Uzumaki]

So I was thinking, what if after Japan denounced the naval treaties in 1936, the US said screw it and modified the plans for the NC class ships and instead based off their concerns for Japanese and German large cruisers/pocket battleships that were being built, decide to make the following changes.

1. The OTL NC class gets built similar to original design with 14" / 50 guns but slightly changed armor with stronger propulsion system to achieve 30+ knots and is redesignated the Alaska class Battlecruisers, with 6 ordered ( the NC was built at planned 35K tons so definitely doable as a BC). These are designed to be cruiser killers that can take on any cruiser, including BCs, as well as escorts for carriers. They build these first instead of BB's to counter planned or already built large cruisers or "pocket battleships" by Germany and Japan. 4 laid down in '37 instead of two OTL, the next two in '38, meaning all should in service by January 1942.
   (Alaska, Guam, Hawaii, Samoa, Puerto Rico, Philippines)
   
   
2. The new NC Class is laid down with with 4 ordered, but they are OTL Iowa Class in design with the NC as the flagship. Built on same schedule as OTL South Dakota class, so in service by end of 1942. (North Carolina, Washington, South Dakota, and Alabama)
   
   
3. Iowa class gets 4 ordered, (OTL planned Montana class with Quad triple gun turrets of 16" /50), these are laid down following OTL Iowa class build schedule. (Iowa, Indiana, Massachusetts, New Jersey)
   
   
4. Montana class never gets designed or ordered.

Thus, you get 14 Capital ships, just 6 BC and 7 BB instead of 10 BB OTL. Due to this you also never get the OTL Alaska class because they aren't needed with the the BCs being ordered this time. I'm sure a certain board member *cough cough* @CalBear *cough cough* would be happy with that.

Nothing else about the TL changes as far as entry in the war, US still enters war in Dec 1941. How would 6 Alaska Class BC's (OTL NC class) impact the early war, especially in the Pacific? How would getting what was the OTL Iowas, now NC class, change things by being available in 1942? And what impact would the new Iowa (otl planned Montana) have?

Im especially interested in the early battles, like the worst US defeat at Savo island.

 

[CV12Hornet]

The OTL NC class gets built similar to original design with 14" / 50 guns but slightly changed armor with stronger propulsion system to achieve 30+ knots and is redesignated the Alaska class Battlecruisers, with 6 ordered ( the NC was built at planned 35K tons so definitely doable as a BC). These are designed to be cruiser killers that can take on any cruiser, including BCs, as well as escorts for carriers. They build these first instead of BB's to counter planned or already built large cruisers or "pocket battleships" by Germany and Japan. 4 laid down in '37 instead of two OTL, the next two in '38, meaning all should in service by January 1942.
(Alaska, Guam, Hawaii, Samoa, Puerto Rico, Philippines)

No time. Changing the guns was ultimately a tweak that didn’t overmuch delay the North Carolinas. Enlarging them for 30+ knots? That’s a wholly new design that’s probably not going to be ready until two years after the actual North Carolinas. This is unacceptable to Navy leadership, and thus isn’t going to happen.

 

[Issei Uzumaki]

No time. Changing the guns was ultimately a tweak that didn’t overmuch delay the North Carolinas. Enlarging them for 30+ knots? That’s a wholly new design that’s probably not going to be ready until two years after the actual North Carolinas. This is unacceptable to Navy leadership, and thus isn’t going to happen.

I disagree, the SD class had more horsepower and only started in 1939, they had 129K horsepower vs 121K for NC. Couple that with less armor (ie, less weight) as well as the lower weight from the smaller guns and a 28 Knot NC class with higher horsepower engines should be able to make 30 knots or more.

Also, the last part of your response is a bit of a cop out. the point of this question is what IF they did, so "not going to happen" isn't an answer. This is, I repeat, what IF, meaning they do accept per the OP.

 

[CV12Hornet]

I disagree, the SD class had more horsepower and only started in 1939, they had 129K horsepower vs 121K for NC. Couple that with less armor (ie, less weight) as well as the lower weight from the smaller guns and a 28 Knot NC class with higher horsepower engines should be able to make 30 knots or more.

Also, the last part of your response is a bit of a cop out. the point of this question is what IF they did, so "not going to happen" isn't an answer. This is, I repeat, what IF, meaning they do accept per the OP.

The South Dakotas started construction in 1939. Design work began in 1937 and the decision to make a fresh design instead of repeat North Carolinas happened in 1936. There is no way possible you’re getting this new design laid down in 1937 with the redesign decision happening in 1936, it just takes to long to draw up a clean-sheet design.

 

[Issei Uzumaki]

The South Dakotas started construction in 1939. Design work began in 1937 and the decision to make a fresh design instead of repeat North Carolinas happened in 1936. There is no way possible you’re getting this new design laid down in 1937 with the redesign decision happening in 1936, it just takes to long to draw up a clean-sheet design.

I think you are clearly not understanding the initial post. It is the ORIGINAL design, with the only mods being slightly less armor and updating the power plant which wouldnt be installed until a couple of years after construction started.

I'll make it easier, original design with no changes except the power plant. If that is still too much for you please move on as I'm not here to debate ship design, I'm interested in the impact on the war.

 

[marathag]

going from a quick glance at Wiki, went from 120,000shp with 9 Babcock & Wilcox boilers on four shafts in 1937 Yorktown, to 8 Babcock & Wilcox boilers doing 150,000shp on four shafts with 1940 Essex

 

[CV12Hornet]

I think you are clearly not understanding the initial post. It is the ORIGINAL design, with the only mods being slightly less armor and updating the power plant which wouldnt be installed until a couple of years after construction started.

I'll make it easier, original design with no changes except the power plant. If that is still too much for you please move on as I'm not here to debate ship design, I'm interested in the impact on the war.

No, I understand just fine. You're the one not understanding that such changes to the powerplant amount to a new design. You have to fit a new, more powerful powerplant, and you need to adjust the hull to be more suitable for 30-knot speeds. All of which means a new design.

 

[SkywalkerT65]

Also, trying to tell someone off like that when they understand what they’re talking about does not endear one to the scenario,

To put it in simple terms:

Hydrodynamics. Ever hear about NorCar’s vibration issues? She is not getting to 30+ knots no matter how much power you shove in there.

EDIT: Frankly, if you want an NC-based battlecruiser, the better option is just to have that replace the SoDaks. One questions why the Navy would do it…

…but it gives actual *time* to make a new design. Not much time. But time.

 

[jsb]

I dont really see why they need 30+Kn? Would 28-29Kn not do fine?

I would just say that they order 6 NCs immediately with 14" guns and 35,000t but with an "understanding" (from FDR to navy) that they can use the 3,000t of the WNT growth/modification allowance as everybody was allowing ships to get larger by 10% so as long as they are 38,000t or 38,500 ish standard legally as designed he will be happy?

Get all 6 laid down fast in 1937 and they can all be ready for 1940 and worked up with maybe 6 matching Yorktown class CVs you also bought at the same time?

 

[Captain Seafort]

I dont really see why they need 30+Kn? Would 28-29Kn not do fine?

You need 30kt+ for a carrier escort, to be able to keep up with them when they've got the hammer down. The USN was looking at about 23kts as normal battleship speed (matching the Nelsons and [as they thought] Nagatos). I think 27-28kts ended up getting pulled out of someone's backside as a halfway house between the two

 

[CV12Hornet]

You need 30kt+ for a carrier escort, to be able to keep up with them when they've got the hammer down. The USN was looking at about 23kts as normal battleship speed (matching the Nelsons and [as they thought] Nagatos). I think 27-28kts ended up getting pulled out of someone's backside as a halfway house between the two

27-28 knots was selected to be able to keep up with the Kongos back when they were 26-knot ships. Then the US learned that oops, the Kongos were now 30-knot ships and that led to the Iowas.

 

[Captain Seafort]

27-28 knots was selected to be able to keep up with the Kongos back when they were 26-knot ships. Then the US learned that oops, the Kongos were now 30-knot ships and that led to the Iowas.

Where's that from? The Kongos were effectively Tiger with a different ensign, so they should have been treated as at least 27-28 knots as built, which would have required 30 knots to overmatch them. Even if you treat both numbers as design/trial speed, you should assume that both ships lose at least as much when converting to sea speed.

 

[naraic]

Where's that from? The Kongos were effectively Tiger with a different ensign, so they should have been treated as at least 27-28 knots as built, which would have required 30 knots to overmatch them. Even if you treat both numbers as design/trial speed, you should assume that both ships lose at least as much when converting to sea speed.

The refits received by the Kongos between 1926 and 1933 added tonnes of weight without improving the powerplant much. They were reboilered but they were 26 knot ships.

In the late 30s the Kongos were refit again. Reboilered (with oil firing boilers this time) and came out as 30 knot ships.

 

[Not James Stockdale]

You need 30kt+ for a carrier escort, to be able to keep up with them when they've got the hammer down. The USN was looking at about 23kts as normal battleship speed (matching the Nelsons and [as they thought] Nagatos). I think 27-28kts ended up getting pulled out of someone's backside as a halfway house between the two

Most of the time, a carrier would not need to get to full speed for flight operations (turning into the wind is enough), and if it did, they usually didn't maintain course and speed for more than about two hours at a time. If that is planned correctly for a group transiting at 20 knots (already pretty fast), North Carolina goes to flank speed a half hour before flight ops and sprints 4 miles (7,000 yards) ahead of the carrier, then the carrier begins its sprint as it goes to flight ops and overtakes North Carolina before ending flight ops and slowing 4 miles ahead of North Carolina. North Carolina continues at flank for the next half hour to catch up. The 4 mile range is within the capability of North Carolina's 5 inch guns to provide AA fire, and the carrier would be accompanied by the faster cruisers and destroyers for close AA escort. Of course, 4 miles is nothing in terms of a daytime surface action, and flight ops like these are only conducted during the day. In a navy powered by oil-fired boilers, flight ops sprints are not something that can happen without warning. Everybody will need time to build up steam before they can answer all bells.

 

[Issei Uzumaki]

Jesus, why are you all so obsessed with the specs, is it so hard to answer the actual question? I don't care about the specs. The point of the question was IF THE SHIPS WERE AVAILABLE? Is that really so hard to comprehend?