New Mexico-class Battleship

This ship had 12 14" guns, really powerful.

Sorry, but I need some help. I've never really heard of this ship being in any combat in the Pacific during the war (save Pearl Harbor). Does anyone have any info on this class? Maybe a comparison to other modern Battleships and Battlecruisers of the time? All I can really figure out is that it would kick the Bismarck's ass on a 1-on-1 naval engagement.

 

It's unlikely that would ever happen. The New Mexico was one of the old "slow" battleships which had a top speed of 21 knots. The Bismarck's speed was in excess of 30 knots, so the Bismarck could choose to fight or run. Since any sane captain only fights if he has no choice, or enjoys a decided advantage, a one-on-one fight between the Bismarck and the New Mexico is unlikely unless the Bismarck's skipper believes he has a winning edge.

 

The three BB's of this class all served well in the second world war.

New Mexico class battleship - Wikipedia, the free encyclopedia

As for kicking the butt of the Bismark? Probability "zero". Too old, too slow and with outdated main batteries.

 

Try going here:
U.S. Navy Battleships - USS New Mexico (BB 40)

 

Too old? All the New Mexicos were modernized only 7 years earlier, with improved torpedo protection and modern fire control equipment.

Too slow? If Bismarck chose to fight instead of run, then too slow wouldn't mean anything.

Outdated main batteries? Now, that's just silly. The New Mexico's battery threw a heavier broadside than Bismarck's, and her individual guns/shells were only slightly less potent than Bismark's. NM's 14" guns were more powerful than the British 14" on Prince of Wales/KGV, and threw a heavier broadside than either. NM had been modernized with upgraded FC in only a few years before Bismarck made her sortie.

The smartest thing for Bismarck - or any German battleship encountering any of the New Mexicos - would have been to use her superior speed to run away across the horizon.

 

All data from:
http://www.navweaps.com/Weapons/index_weapons.htm
Ship - shell mass - bursting charge - muzzlevlocity
Bismack - 1,764 lbs. (800 kg) - 41.4 lbs. (18.8 kg) -2,690 fps (820 mps)
KG IV - 1,590 lbs. (721 kg) - 48.5 lbs. (22.0 kg)- 2,400 fps (732 mps)
Tennessee - 1,500 lbs. (680.4 kg) - 22.90 lbs. (10.4 kg) Explosive D - 2,700 fps (823 mps)

Bismarck has a significantly heavier shell with a bigger burster. The British 14" while lower velocity also has a bigger burster. One on one early war I'd give an edge to Bismarck. Late war it flips to New Mexico.

 

Thanks for the very useful info you provided.

One thing you left out of your post was armor penetration - and in that area, the USN's 14"/50 does quite well - better than than KGV's guns, and very nearly as good as German 15". At likely battle ranges, the 14"/50 can penetrate Bismarck's armor about as well as Bismarck's guns can penetrate the New Mexico's. I'm of the opinion that penetration and kinetic energy are more important in a fight against an armored ship, than burster size (no AP shell has much boom to it).

Bismarck's margin of superiority, even in pre-radar FC 1941, was iffy. I agree with your summary, and add... had Bismarck been intercepted by two New Mexicos on 5/24/41, her career likely would have been even shorter. USN BBs were better armored than Hood, with better F/C, and with roughly equivalent gunpower. In fact... New Mexico's had armor comparable to Bismarck's.

Kraut boat would do well to avoid battle.

 

The German 15" AP shells were decidedly better than the AP ordinance this BB's main guns could use.

This ship was too old, too slow and not worthy of anything more than surface bombardment.

 

The Mississippi fired the last rounds ever fired by a battleship at another battleship at Surgiao Straight in 1944.

As for their relevance:

The New Mexico class were all modernized just prior to WW 2. They received bulging and had their torpedo defense systems brought up to later class equivalence. The bulging also allowed for increasing the deck armor to 5.5" with a 2" splinter deck underneath. This gives them more deck armor than the Bismarck and about the same as a KGV or North Carolina class had.
They also got a tower bridge superstructure based on favorable commentary by naval officers about this feature on British battleships. The conning tower was retained however unlike the British version. Fire control was brought up to the latest standard too.
Basically, these ships though slow would have been more than a match for the Bismarck

 

There's lots of different types if armor. And then there is the question of where the armor is located and what thickness. And then theres the question of the ballistic protection the armor has against modern [WW2] AP shells.

The Germans 15" AP rounds were VERY good, and would have devastated the older US BB's, just as the USS Washington did on the Japanese BB at Guadalcanal.

Just because you modernize an old WW1 era battleship to somewhat modern standards, doesnt mean you have a battleship equal to the newer designs of the 1930's.

 

Actually, you have this wrong.

First, the USN added STS armor (triple alloy hardened) to the New Mexico's existing STS armor plating. The New Mexico class also had a 13.5" belt giving it almost an inch more vertical armor than the Bismarck. The turret armor was also thicker.

As for the German rounds: First, from what we know historically only about one in five to one in eight German heavy naval rounds actually worked properly when it hit a target. The US gets about 8 or 9 out of 10 to work properly. Second, the Bismarck's 15" guns used a relatively light and high velocity shell. This combination is great for antitank rounds but terrible for naval artillery. There are several reasons for this but the explaination is long so, for now I'll leave it at that.

Then there is the fire control system. The US Mk 3 system on the New Mexicos is comparable with that on the Bismarck. It uses a three axis stable element and can fire the guns automatically at the zero roll, pitch, yaw point. The Mk 8 FC system on newer US ships is much better.

Basically, the USN wasn't stupid. They went for armor and firepower over speed.

 

How so? Provide some specifics? Apart from being a bigger gun - it should be more potent - how was it decidedly better? How were the German shells decidedly better?
The 14"/50's heavy 1500 pound shell was introduced in the mid-30s, along with the upgraded versions of the guns added during modernization. At 20K yards the 15" penetrates 16.5" vertical armor, the 14" penetrates 13.75" - and horizontal penetration is the same for both at that range. As the range closes, both can penetrate the other. Now consider this: Bismarck's broadside weighs 14,112 pounds, while the New Mexico throws an 18,000 broadside - and 50% more projectiles per broadside than Bismarck.
Bismarck certainly was newer, bigger, and faster - but clearly superior in a shoot-out? Not a chance. More like... rough parity, maybe.

Anyhow... I'd like to hear how German AP shells were clearly superior to the AP shells used in the 14"/50. Do tell?

 

I just PM'd the guy who looked at armor and AP shell charachteristics and seems to know his stuff.

Lets see if he chimes in on this discussion.

 

Good deal... I'll look forward to what he has to say.

Here's a thought: at 9,000 yards, BB gun size doesn't matter all that much. How much damage would Kirishima's shells have done Washington, if she'd hit her nine times at that range? At 9K yards, the Jap 14"/45 may not have hurt as much as a 16" shell weighing 1200 pounds more, but they'd have done serious damage. AP shells prob would have blown right through South Dakota's armor at that range; even HE shells would have hurt badly, that close.

 

It gets worse: The US battleship would open fire initially using salvos of 6 guns firing ladders to range in. The Germans would be using four gun salvos. The reason this is done by navies of the period is they want more salvos with a shorter interval between them to get the range quickly. This also saves ammunition while ranging in. The larger number of rounds in a US salvo gives it a wider spread than the German one. This is a big advantage in getting on target faster.
You might note that this is one reason both Tennessee and California with 14" guns were modernized while the 16" gunned West Virginia was the only one of her class that got that treatment and then only because she was so heavily damaged at Pearl Harbor.
Twelve 14" guns are alot more valuable than eight 15".

History also shows that on the receiving end a bigger battleship round is only marginally more worthwhile than a smaller one. The crossover point is at about 14".

Anyway, I too would like a explaination of how German naval rounds were superior to other navies shells....

Here is a detailed synopsis of every battleship on battleship action in WW 2:

http://www.militaryhistoryonline.com/wwii/articles/capitalshipsurfaceactions.aspx

 

Washington apparently hit Kirishima with ~20 16" rounds. There's a very good analysis of the damage done on line. See:
http://www.navweaps.com/index_lundgren/Kirishima_Damage_Analysis.pdf

New Mexico got an up grade of her radar suite in 44. Does anyone know if this included an upgrade to the Mk8 or Mk13 fire control?

 

The USN went for the "all or nothing" armor plan, even before WW1 and the construction of its battleships post-WW1. As T.A. Gardner pointed out, America used the STS armor in its ships, from the first of the "superdreadnought" production. Originally the New Mexico displacement and size was thus:

BB-40

displacement. 32,000 tons
length. 624'
beam. 97'
draft. 30'
speed. 21 k.
complement. 1,084
armament. 12 14", 14 5", 4 3", 2 21" tt.
class. New Mexico

See:

http://www.hazegray.org/danfs/battlesh/bb40.htm

Then:

Mindful that age was catching up with its NEW MEXICO and that newer developments rendered her somewhat outmoded, the U.S. Navy on March 5, 1931 ordered her to check in at the Philadelphia Navy Yard for modernization. Complete re-engining, re-boilering and reworking on internal protection was affected, while a tower bridge was installed and cage masting reduced to a minimum. When the NEW MEXICO was modernized, she was converted to conventional turbine propulsion similar to her sister ships rather than her then unique electro-drive propulsion system.

Additional defenses against submarine and air attack, warranted by the rapid rise of both these threats to surface craft, were incorporated in the NEW MEXICO, e.g. "blisters" and additional armored deck protection. During the early ‘30s the two other battleships of the NEW MEXICO Class (MISSISSIPPI – BB41; IDAHO – BB42) were brought up to date in the same manner, making the trio the Navy’s most effective units.

See:

BB-40 History | USS New Mexico

Modernization:

All three of her class underwent extensive reconstruction during the 1930's; this work was generally similar to the Pennsylvania/Arizona, but was more limited in scope, because the ships were already more modern. All three ships received new turbines and boilers; the armor deck was thickened by 2". New 5"/25cal AA were fitted; no relocation of their 5"/51cal guns was needed. Plans originally included new tripod masts in place of the cages, but instead lower, tower-style bridge superstructures were constructed. (emphasis mine)

Post-reconstruction specifications were as follows:

Displacement: 33,420 tons normal; 36,157 tons full load (up by 1420 tons)
Dimensions: 624x106x31 feet/190.2x32.4x904 meters (9’ wider,1’ deeper draft)
Propulsion: Steam Turbines, 4 boilers, 4 shafts, 40,000 shp/22 knots (up from 31,200 shp/21 knots of its electro-drive)
Crew: 1443 (up 359 men)
Armor: 8-13.5 belt, 5.5 inch deck, 4.5 inch barbettes, 5-18 inch on main turrets, 4-16 inch CT
Aviation: 2 catapults; 2 floatplanes
Armament: 12-14"/50 caliber (4 triple), 12-5"/51 caliber, 8-5/25 caliber AA

See:

World Battleships List: US Dreadnought Battleships

When the New Mexico class were built, the were the newest of the "all or nothing" armoring concept. In 1912 the design staff of the American Bureau of Construction persuaded the Department of the Navy of the benefits to be gained by returning again to "all-or-nothing" principles.

The Oklahoma (BB-37)and Nevada (BB-36) were equipped with a single deep 13 1/2-inch verticle belt extending over the machinery, magazines, turret bases, conning tower, and funnel base; with a thinner belt of some 8 inches over the propeller shafts, and so on, up to 18 inches on the turrets; and 3 inches on the deck. The newer New Mexico (BB-40) followed these statistics until she was "upgraded" in the 1930s with 2" of armor added to her already thicker deck armor making it 5.5 inches thick.

The Bismarck was undoubtedly better armored in the horizontal from plunging shells in its decks, but the New Mexico class were better armored than the Hood:

Decks (Horizontal)

Forecastle: 1¾ - 2in / 4.4cm - 5cm
Main: 1 - 3in / 2.5 - 7.6cm (averaged 2in / 5.1cm on the slope)
Upper: ¾in - 2in / 1.9cm - 7.6cm
Lower: 1 - 3in / 2.5 - 7.6cm (3in / 7.6cm amidships in vicinity of boiler rooms)

The broadside throw weight for all the old USN ships like the New Mexico class with twelve 14in guns was 18,000 lbs (they had switched to newer shell-types in 1936-37.) The primary advantage to German fire control (FC) in 1941 is their radar which could help supply range data. This is nowhere near a true blind-fire capability and their own main gun’s concussion sometimes "knocked it out", but it is an advantage of sorts. American optical FC was pretty good none the less. The Bismarck’s broadside throw weight out of her eight 15" mains was 14,112 lbs with its 1,764 lb shells, and the main guns could only be elevated to 30 degrees maximum for firing, which limits it plunging fire angle at any but extreme range.

A Bismarck class would likely defeat a single New Mexico, but an American victory by "fluke hit" would not be much of a surprise if it happened either. I myself would describe Bismarck as hard to sink but easy to cripple. The New Mexico class were among, but not the most powerful of the old USN’s battleships in 1941, sadly it was found that their modernized bulged hull form with new blisters performed poorly in the North Atlantic, making them a less than stable gun platform. Stage this conflict in the South Pacific (somehow) in calmer seas, and things could be different.

The turret armor of the Bismarck was vulnerable to all twentieth century battleship caliber shells from distance, i.e. it was impossible for Bismarck to find a range where her primary weaponry was safe from enemy fire. The Bismarck was well subdivided, making it hard to sink, its best characteristic. But like its turret armor, the deck armor wasn’t all that great really, but this didn't matter too much in it’s final demise, the British decided to make things a knife-fight at close range and attacked its heavy belt armor rather than using plunging fire from a greater distance.

But stepping away from the New Mexico class and the 14" guns, against the Bismarck, how about an US Navy battleship like the Tennessee, California, or West Virginia with their 16" main guns? These were certainly the most powerful, best armored older battleships of WWII. Any one of them might have defeated a Bismarck class ship as they had been modernized as well, and their crews were always well trained. The U.S. Navy made considerable use of homogeneous armor grade STS (special treatment steel) in its battleships for the upper hull, major bulkheads and major decks both when they were built and later upgraded, a rather lavish design detail due to the higher cost of this metal.

All three of the"aging" New Mexico class survived the war and many battles including kamikazi attacks, the Bismarck didn't survive its maiden voyage.

 

Very interesting thread.

Great links too.

 

I wonder if the gunnery logs and evaluation documents from the USN gunnery training are still around. A study of those from 1940-41, and the 1930s, would be interesting. I've been told much of the test data and calcualtions the USN did for naval armor penetration from that era is still restricted. Sounds odd, but still a bit believable.

Did the Bismarck obtain any hits on the enemy ships in its last fight?