Went down to Fleet Week in San Pedro today. We toured the Iowa, which had at least six turrets with two 5 inch guns each (in addition to the nine sixteen inchers in three monster turrets!). We also toured the Dewey, an active-duty Arleigh Burke class destroyer. It had ONE turret with ONE five-inch gun–and the sailor leading the tour told us that was the biggest caliber cannon in today’s Navy. Times change.
Actual question time: On the Iowa, there was a little chart of the types of “bullets” that could be handled by the 16s–there were several types of dummy training rounds, regular HE, antipersonnel packed with 1000 grenades, and a penetrating round capable of piercing 30 feet of concrete, or so it claimed.
There at the end of the list with no elaboration was a 20-kt atomic shell called a “Katie.” I was pretty surprised–I’m not a military historian but I didn’t know the Navy had every had artillery nukes. Was that a real thing or just theoretical? Would it have been Korean War-era, or in the 80s after the refit?
Thanks. Were they ever loaded aboard ships though, in readiness for use? Seems like the turret explosion on the Iowa could have been an even worse disaster if so.
Conventional explosives can be detonated unintentionally. Nuclear explosives really can’t be. The worst that could happen would be that some other conventional shell would be accidentally detonated next to one of the nukes and scatter uranium all over the place.
“I can neither confirm nor deny that we have nuclear weapons on board.”
This was what we were actually instructed to say if asked for any ship in the Navy. Be it carrier like mine or battleship.
That said, considering the short range of a 16" gun, it seems like a fairly stupid idea to even have nuclear rounds. This is well after the point were jets could deliver a nuclear payload if so desired.
They are tactical nukes for small contained use.
th 16" gun has more range than a m110 8" land based gun, and the M110 fires 8" tactical nukes W33 and W79.
The things carried on jets tend to do more damage AND cost a hell of a lot more
than an artillery fired nuke.
This is not precisely accurate. Per “Command and Control by Eric Schlosser”, early nukes (until the early 1980s) were not “one point safe”. Some of the early designs were supposed to be, but when tested underground using careful barely critical masses as stand ins, there was fission yield with 1-point detonations. I’ll cite the page number of the book if you want to know more, but you really should read it.
The earliest designs (gun-type) had no safety at all if assembled. In some cases, the procedure was to insert the core using servos once the aircraft was airborne.
I would expect 1962 era artillery shells to :
a. Have no protection against unauthorized use if someone had physical access to the devices.
b. If fully assembled, and then a fire were started in the turret, would probably at least fizzle with fission yield.
c. Their explosives were most likely not insensitive, and at best case if there were a turret explosion, would probably explode and contaminate the ship with chunks of plutonium metal.
For the 16" as mentioned the Mark 23 nuclear shells were real, but just to add to the timeline they were ready for fleet use in 1956 but while all four Iowa’s were recommissioned for the Korean War, Missouri was already back in reserve by then. The other three had their shell handling arrangements modified for the nuclear shell, to handle them separately, but New Jersey was only in commission til 1957 and Wisconsin and Iowa till '58, so not much overlap to have deployed live shells, though no declassified source seems to know if they were. Wisconsin fired a dummy version in a test in 1957. The shells were gone by the time New Jersey was reactivated for the Vietnam War and long gone by the time all four were reactivated in the 1980’s.
The submunition shell was presumably ICM Mark 144 developed during the ships’ final activation. The HE was presumably HC (High Capacity) Mark 13 (or the basically identical Mark 14) which became the ships’ main ammunition in most of their careers after battleship adversaries disappeared, but developed as a partial afterthought to the ships. The older ‘new’ 16" battleships of the North Carolina and South Dakota classes didn’t have those shells yet early in WWII, only Armor Piercing. Massachusetts, notoriously, failed to suppress the French shore battery at El Hank at Casablanca in November 1942 with only AP main battery shells: the small bursting charges were not very effective against such targets unless there was a direct hit on a magazine, which didn’t happen. The ‘penetrating’ shell would have been one of those, AP Mark 8. Delivering those against other battleships was the ships’ original main reason for existence. In their later lives as shore bombardment ships, AP shells were occasionally against very thick field fortifications.
The naval warhead and the army atomic cannon were phased out before I was a nuker (and I’m really old). The 16"/50 naval shell was a modified army artillery 280mm (11") round. The naval round had a sabot to get up to the 16" diameter of the gun. Here’s some info (good) from wiki regarding US gun type nuclear weapons: (from Gun-type fission weapon - Wikipedia which includes a good generic diagram of a gun type warhead)
“The method was applied in four known programs. First, the “Little Boy” weapon which was detonated over Hiroshima and several additional units of the same design prepared after World War II, in 40 Mark 8 bombs, and their replacement, 40 Mark 11 bombs. Both the Mark 8 and Mark 11 designs were intended for use as earth-penetrating bombs (see nuclear bunker buster), for which the gun-type method was preferred for a time by designers who were less than certain that early implosion-type weapons would successfully detonate following an impact. The second program was a family of 11-inch nuclear artillery shells, the W9 and its derivative W19, plus a repackaged W19 in a 16-inch shell for US Navy battleships, the W23. The third family was an 8-inch artillery shell, the W33. Later, South Africa also developed six nuclear bombs based on the gun-type principle, and was working on missile warheads using the same basic design – See South Africa and weapons of mass destruction.”
Since they were gun type weapon assemblies, U235, no plutonium was used. Plutonium can’t be assembled into a super critical mass fast enough by gun system. The plutonium will fission apart before you get the big bang. I believe firing the rings (donuts) over a cylinder target was the preferred method though I know of no reason you couldn’t do it by firing the cylinder into the center of the rings. Just get them together fast enough along with extra neutrons from a generator and boom. An fire/accident in the turret before the rounds were assembled would get some uranium contamination but not catastrophic. The diagram mentions high explosive as the power to ram the cylinder and rings together but it’s actually a low explosive propellant charge.
As to storage safety aboard ship, I’m spit-balling base on what we did with the army 8" gun type shell. The target rings were stored separately from the shell which contained the cylinder. The shell had an oversize manhole cover screwed into the fuze well. It was secured with a integral combination lock. In this form, you could not assemble a fuze to the projectile or ram it into a gun barrel. Story time - these are long ago retired so I’m not expecting a visit from some dudes in dark glasses - These Permissive Action Link devices (PALs) were hardened steel. Well as you harden the steel it can become brittle. We were doing initial receipt inspection of a batch of PALs; visible inspection plus manipulating the combo lock multiple times to verify ability to lock/unlock/reset combos. We took a break and one individual did not chock his PAL on the work table. As we walked away, there was a loud crash and a shattering sound. The PAL fell to the floor and broke into thirty pieces (we counted, this was a big deal). The $*it hit the fan; fortunately the investigation showed the locks were improperly heat treated. And dammit, it was Permissive Action Lock, not Link, until either JFK of Johnson misread the statement and the toadies went and changed all the regulations and manuals to match error.
BAck to the naval nuke round. Only one battleship was modified to carry the nuke projectile. One turret had it’s magazine modified to hold the shells and provide security. I believe it’s the Missouri according to a private citizen website I can’t pin down anymore that’s devoted to the Iowa class battleships and 16"/50 guns. While I cannot confirm of deny, rumor has it that some projectiles were carried at the end of the Korean conflict.
One point safe. A blast, projectile, or fragment strikes a nuclear weapon - what happens. In theory, if the impact detonates the high explosive surrounding the nuclear (almost always plutonium) core, the asymmetric detonation will only produce an additional explosive force of 4 lbs net explosive weight from the fission reaction. Of course the radioactive pieces get scattered all about making a localized dirty bomb. All US Army warheads and warhead sections (warhead section = physics package /warhead + adaption kit) had a dot on the item and the packaging where Explosive Ordnance Detachment (EOD) personnel or trained security folks could place an emergency destruct shape charge and disable the warhead/section. There would be spots every 90 degrees depending on the shaped charge setup. This was a design requirement - in theory. Not a whole bunch of testing with live nukes were carried out. This covers implosion weapons.
For a gun type nuke; it would have to have the target ring/cylinder assembled and an incredibly lucky and powerful shot get through the hardened steel projectile and hit detonator/initiation charge built into the propellant charge and cause a designed ignition. A partial or incomplete initiation of the propelling charge would result in radioactive parts crumbling with minimal radioactive contamination.We’re talking near zero probability plus the impact through the shell casing would most likely distort the casing/pathway that the cylinder/rings have to traverse and match up precisely. Moot since all these items have been retired and disassembled/recycled.
Another story. One of the warheads that was being retired (really old - a close cousin of the original implosion design) had a test done each time it was moved or worked on. Verified continuity in the circuitry. We got an emergency message saying to stop the test, gather up all the test devices and never let the two meet again. The test sets were worn from decades of use and the warhead was probably/possibly not one point safe at the testing port.:eek::eek::eek:
A quick note on the US Army 8" gun type shell. The U235 cylinder was fired into the center of target rings unlike the bomb diagram where the rings were fired over the target cylinder.
The 5" guns in dual turrets are 5"/38. The barrel of the gun is 5" X 38 = 190" long. The current 5" guns on destroyers/cruisers/frigates are 5"/54 with a barrel length of 270". Much longer range; greater length to accelerate the projectile. The projectiles are more aerodynamic (not interchangeable from new to old system) and the propellant charges are more energetic. The Old twin turrets were manually loaded, guys in the turret. My uncle was in a WWII destroyer 5/38 turret in the Pacific during WWII doing shore bombardment. His hearing was destroyed. The modern 5/54 guns are autoloading; fire 20 rounds per minute (water cooled) longer ranged and far more accurate. The 5/38s on the battleship were for engaging closer in targets and anti’aircraft fire. A couple of 5/38 turrets were removed on each side to fit missile launchers (harpoons and tomahawks) and CIWS turrets.
Smithsb : I want to thank you for your service. Both in the military and for your service in answering so many of these questions accurately. That’s a really neat method you talk about with the gun type nukes to make them semi-safe, by making it the ring that moves, not the cylinder, such that if the propellant charges don’t detonate at the same time it won’t be aligned right.
And I take it that with the gun-type, the ‘target rings’ you are talking about is a physical ring made of nearly pure U-235 that was kept in a different place.
As a nuclear weapons technician? did you routinely actually see the cores? Would there just be rings of pure U-235 be lying exposed on a shelf or did they have some kind of system kind of like the way CD-roms were packaged for a brief time, where the actual core is not normally exposed to the air and soldier’s fingers.
Didn’t see your questions, was a no-show in User CP. Maybe the new look?
Anyway. Going back 35+ years, I was the Quality Assurance guy on team that worked with the old (gun type) and newer (implosion-plutonium) 8" projectiles. The rings were kept in sealed metal container. The container was pressurized (dry nitrogen) and desiccated. The “live” rings were U235; practice/training rings were U238 (depleted Uranium). Because the whole fission thing required tight tolerances, the machining was precise; no gaps or bevels. The assembled cylinder+rings=boom also needed extra neutrons; there was a generator; and to keep some/most? of the neutrons around for splitting the atoms; a reflector. Beryllium or tungsten carbide was used if I remember correctly. The reflector material was only on the exterior parts of the ring. Handling was done with gloves. The rings were extremely heavy (uranium is dense). You had heavy metal poisoning as a possibility. Radiation was mostly alpha which is only a threat if particles are ingested, inhaled, or got into an open wound. And there were particles. Uranium spontaneously fissions (half-life and all that). The surfaces would spall off pieces of the metal. Inspection points for rejection were if there was spall of a certain diameter/area or if multiple areas had spall (they all did) and the cumulative area of spall was a certain dimension. The rounds were all obsolete but still in the system for some reason (backup to the newer round?). Some had their U235 recycled earlier into another munition. Wiki on dates of retirement and disposition are dubious. We were shipping all the old projectiles back to Sandia by my time and inspection was just to verify condition. We did clean up the spall particles and sent them and the wipes back to Sandia as well. I trained on all the systems in the Army but the old 8" was the only one were you could actually see/handle any of the active components.
Wow. So you would actually see the machined U-235 surfaces, and they had the system built in a way where in the field you’d basically know how it worked since you could see the parts that mattered. Also, in the unlikely event that you’d get called to use an 8" nuclear artillery round, you’d have to hand assemble a live nuclear shell by installing the target ring!?!
At sea, in a battleship?!
Now I’m wondering under what sort of war scenario that they think you’d manage to get a battleship into range of someplace that needed to get nuked. Wouldn’t it take so long that both sides would be mostly radioactive ruins before you got into range.
No, the shells was created in the 1950s, before the big buildup of ICBMs and SLBMs. In the early 1960s, the USSR only had only a handful of weapons, rising to hundreds by the mid-60s, and around 2500 by 1970. So at the time that the shell was made, a nuclear war would result in a huge mess in Europe, but it wasn’t until a decade later that the USSR would have the number of weapons and range to plan on devastating the US proper or secondary military assets like fleets (the primary targets would be NATO forces in Europe). Also before ICBMs, nuclear weapons were seen more as just ‘big bombs’, so it was expected they could be used tactically without provoking a general war.
Assembly at sea is no problem; a battleship is pretty stable notwithstanding my favorite old newsreel show, “Victory at Sea.” They would have had a trained crew. At the time these rounds were developed, none of our potential adversaries had a substantial naval/submarine presence and the US Air Force controlled the skies. The battleships cruised right up to Korea/Vietnam/Lebanon/Kuwait to lob shells inland. Also, there was not a threat of massive ICBM exchanges so the nuclear wasteland scenario was not relevant. The shells were discontinued shortly after IRBMs and ICBMs became the dominant nuclear threat as Pantastic stated.
Further checking, It appears the Wisconsin had the modified magazine, not the Missouri though I haven’t found anything concrete.