MK-23 16 In. Naval Shell (Most Powerful Naval Shell Ever)

[Kyler]

The Mark 23 was a further development of the Army's Mk-9 & Mk-19 280mm artillery shell. This was a 15-20 kiloton nuclear warhead adapted to a 16 in naval shell used on the 4 Iowa Class Battleships. While the USN had capable aircraft and missiles to use in the delivery of nuclear weapons, their thought was that the Mk 23/Mark 7 16in/50caliber cannon combination was extremely accurate and usable in any weather condition compared to early jet aircraft and missile technology. 50 weapons were produced starting in 1956 but shortly after their introduction the four Iowa's were mothballed. The weapon stayed in the nuclear inventory until October 1962. There is no known case of the weapon ever being deployed to an operational battleship.

Specifications
L: 5.3ft, W: 1,900lbs,

Performance
Range: Based on 23 mile range of a 2,700lb shell
Yield: 15-20 Kilotons.


Info Source: Nuclear Weapons of the United States

This in theory would give each Iowa class Battleship capable of delivering 135-180 kilotons worth of explosives in one salvo. An unique capability that would have proved decisive in any conflict on sea or on land. The nuclear tests with the Mk-9 (11in Army shell) had the shell detonated as an aerial burst. The nuclear tests at the ABLE detonation showed an air burst detonation did little structural damage to battleships. It is unknown from the material I have read if the Mk-23 was designed to detonate on impact or under water which would most likely cause an explosion much like the BAKER nuclear test that caused considerably more damaged to the test fleet. Even with a single air burst detonation a Mk 23, it would have damaged or destroyed much of the enemy battleship fragile equipment it would need to fight if they survived the explosion. Thus leaving for any of the Iowa's easy pickings with their conventional 16in shells.

Thoughts of Comments

[Mostlyharmless]

There was a slightly less serious mention of this round on another forum http://www.thefiringline.com/forums/sho ... ight=katie.

[Karl Heidenreich]

This shell will definitely defeated Yamato´s armour.

[Kyler]

This shell will definitely defeated Yamato´s armour.

A direct hit most definitely, most likely vaporizing most or all of the ship in the process.
I would love to know what fuse configurations existed. An aerial burst proved not nearly as
effective as an underwater nuclear explosion. While the blast was contained under water
it structurally damaged many more ships then an aerial burst. A large side effect as well was
the large amount of nuclear fallout, making the ships unfit to have a crew aboard.
Prinz Eugen was so contaminated from the explosion there was nothing the USN could do
to save her after the explosion without risking men to repair her. She slowly sank due to
the damage she received in the BAKER Test.

For more info wikipedia article is pretty good, the fate of the USS Arkansas is especially interesting.
http://en.wikipedia.org/wiki/Operation_Crossroads

[RF]

How does this shell compare with those used by Yamato, which obviosly had wider calibre?

[lwd]

How do you want to compare a shell with an atomic warhead to one without?

[tommy303]

well...explosive yield of the 18-inch common would be .068-tons of TNT (more or less as the Japanese used a different explosive), while the 16-in MK23 yielded 15-20 kilotons. That is about the only way I can think of to compare the two.

[Legend]

Like comparing the potential damage between a grenade and a Mk-8 16in shell.

[Kyler]

Mk 9, 19, and 23 series weapons were the largest yield nuclear weapons ever deployed in artillery shells by the US Military.

Later nuclear shells had variable yields from 1-10 kilotons. Making them more effective tactical weapons

[RF]

How do you want to compare a shell with an atomic warhead to one without?

Sorry, I overlooked the fact that a nuclear warhead was involved here.

Had an 18.1 inch calibre of this shell been developed (notwithstanding that the US did not have a gun capable of firing it) the destructive power would have been about three times greater than the 16 inch version?

[Kyler]

How do you want to compare a shell with an atomic warhead to one without?

Sorry, I overlooked the fact that a nuclear warhead was involved here.

Had an 18.1 inch calibre of this shell been developed (notwithstanding that the US did not have a gun capable of firing it) the destructive power would have been about three times greater than the 16 inch version?

Are talking about a coventional or nuclear weapon?

[Bgile]

How do you want to compare a shell with an atomic warhead to one without?

Sorry, I overlooked the fact that a nuclear warhead was involved here.

Had an 18.1 inch calibre of this shell been developed (notwithstanding that the US did not have a gun capable of firing it) the destructive power would have been about three times greater than the 16 inch version?

Are talking about a coventional or nuclear weapon?

For some reason he is implying that an 18.1" nuclear shell would have three times the yield of a 16" nuclear shell. I don't understand the logic, but whatever ...

[lwd]

How do you want to compare a shell with an atomic warhead to one without?

Sorry, I overlooked the fact that a nuclear warhead was involved here.

Had an 18.1 inch calibre of this shell been developed (notwithstanding that the US did not have a gun capable of firing it) the destructive power would have been about three times greater than the 16 inch version?

Or not. I believe this round adopted an existing design so an 18" version (The US did actually have a couple of 18" guns at least one survived into the 1980s) it would likely have used the same warhead. So destructive power would have been equal.

Where did the 3 come from by the way?

[tommy303]

Just out of interest, the USN had developed an 18-inch gun:

http://www.navweaps.com/Weapons/WNUS_18-48_mk1.htm

[Kyler]

The theory based on the power a shell exponentially goes up due to its circumference has nothing to do with nuclear weapons.

At the time of the production of the Mk9/19/23 that was probably the smallest reliable nuclear weapon they could deploy in artillery shell.

Hypothetically if such a shell was to be produced again today, it could have a substantially higher yield due to the combination of a fusion boosted fission nuclear weapon. Probably talking about 16in. shell capable of several hundred kilotons (?200-700 kilotons?).

If Japan had nuclear weapons the 18.1 in shell would probably be better because of its larger size, but it doesn't mean it necessarily would have had a larger yield. Yield has more to do with the type & materials of the "gadget" than the size of the shell.

The Mk 23 was a compression fission weapon, when they were in production it was the beginning of much of the effort to shrink fission devices. The Mk 23 was an adaption of the Mk 9 (11in.) so theoretically they could have put a large bomb in the Mk 23, but then you get into the danger the larger the "gadget" the bigger the danger the weapon is to the ship that fires it. The Hiroshima bomb caused massive damage in a 10km radius, with the range of 16in project being 38km you can see how a larger yield could seriously damage or sink the firing ship.

Here something to help visualize the effect. http://www.fas.org/programs/ssp/nukes/n ... tentId=367