Nuclear Weapons of the US Navy

[ivorthediver]

Look forward to reading it Don , Thanks .......

[DonBoyer]

Well, it's bee a lot longer than I anticipated, but the section on Atomic Demolition Munitions (seven of them) is on paper and awaits keyboarding and editing. This Covid-bit got in the way, as has much procrastinating as there were many other things going on with family and work. I hope to have this next to last section online by Monday. That leaves me with a small section on nuclear artillery shells used by the US Marine Corps to finish. Then I can start thinking in terms of a published book hopefully in my future.

Regards to all, and I hope all are doing well and nobody has been affected by this viral tragedy.

[DonBoyer]

Well, blushing somewhat at the long delay, here is the section devoted to the Atomic Demolitions Munitions that were in the Navy/Marine Corps inventory during and after the Cold War. This was a particularly difficult section to write due to the paucity of information and the fact that sources don't agree on details. That aside, its a solid overview of these weapons systems. Good photographs are also problematic, there aren't any at all of some systems in the public domain and others aren't particularly good photos. I have only added twp here because for some reason the system isn't allowing me to place photographs where I want them and then says some are "no longer available," which, in simple layman's terms pisses me off. I'll deal with that by doing a second post later.


ATOMIC DEMOLITION MUNITIONS (ADMs)

The development of Atomic Demolition Munitions (ADMs) stemmed from the perceived Cold War need by NATO, the US Army and the Department of Defense to be able to deny Soviet forces the ability to move freely in any battle scenarios that would inevitably involve a large portion of the European land mass, a situation directly related to the very real threat posed by the potential for the extremely massive Soviet armies to penetrate en mass into Europe in a bid to take over the continent. The European armies of NATO and whatever help they might receive from the US and other allies could not match a full-scale Soviet land attack gun for gun even under the best of conditions, and this was well understood among the military forces that would oppose such an action. ADMs could make a huge impact on the mobility of Soviet ground forces in any battle scenario in Europe by destroying bridges, tunnels, facilities and the like and by enabling opposing forces to deny flanking movements or access to “easy terrain” and gaps that would allow the Soviet army to advance rapidly. ADMs would also be particularly useful in any scenarios involving the retreat of forces against the Soviet push. ADMs were always considered “area denial” weapons, and the fact that they would also kill opposing forces and anyone else in range was always considered secondary to their primary role, or not considered at all, something unique among the nuclear weapons family.

Placement of ADMs would be by specialized teams, and the weapons would be detonated by timer or remote command. The timer option would be effective when destroying facilities like bridges and tunnels when it didn't really matter when the structures were destroyed as long as they went down before the enemy arrived. Using the remote command option would allow choosing the best possible time to detonate the weapon to inflict the most harm on the enemy and the movement of forces regardless of what was being destroyed in the process. Of course use of the weapons would involve intense local fallout since the ADMs would all be used as surface or shallow subsurface weapons which throw up a tremendous amount of irradiated soil and debris absent in air burst scenarios. This long-term radiation in itself would also serve as an “area denial weapon.” (The potential political repercussions from having to detonate nuclear weapons within the borders of a friendly country are obvious, and are well outside the scope of this book.)

Unfortunately for the historian, ADMs “...are the worst documented of all the nuclear weapons ever deployed by the United States.” (Gibson, p. 186.) How these weapons functioned, how they might have been deployed and employed along with how they functioned as weapons are all elements of the US nuclear program that still remain highly classified in comparison to most other nuclear weapons and systems. Plus the services that were responsible for maintaining these weapons – the army, navy and marines – have been less than forthcoming with any history of these weapons programs. As far as the European continent is concerned, ADMs were available to NATO forces for almost 30 years until the Montebello Decision of 1983 called for the removal of all ADMs from Europe. By 1985 there were no ADMs in Europe, but they were still in the inventory and available for use in other arenas until many years later.

Most ADMs were developed base on design requirements proposed by the US Army, sometimes in cooperation with the marines and navy, and all were adaptations of existing nuclear weapons. As far as this author can find, there is no clear historical record of exactly which weapons served with the Marines, so this section proceeds under the assumption that the later more practical ADMs would have been deployed by the Marine Corps based on the fact they were obviously in the navy inventory at one time or another (the author having worked on several of them.) Of course weapons that could be deployed underwater would also have been in the navy inventory for use by SEAL teams as well.

One critique of the ADM program that almost always surfaces in any discussion of the use and deployment of ADMs is the contention that these weapons in reality could never be used because adequate security could not be maintained around them, leaving them vulnerable to capture and disarmament by the enemy or even exploitation by terrorists. While this assumption seems logical and reasonable, it is actually completely fallacious. The military and the weapons designers were not foolish enough to overlook these possibilities, and all these weapons would have had safety devices specifically designed to prevent such a scenario. Once emplaced and armed, ADMs would no doubt react immediately and probably very violently to any efforts at tampering. For enemy forces, the best that could be hoped for would be to be able to destroy the weapon with explosives before it detonated. For terrorists there was no best scenario, as it should be.

The following discussion of the various ADMs includes the earliest versions as historical bench marks, even though they are very unlikely to have been part of the navy or marine inventory.

THE T-4

This earliest known ADM is somewhat of an enigma in the published material, primarily because there is disagreement over which warhead was used in the development of the weapon. One source says the T-4 was derived from the warhead for the MK 4 implosion warhead, the first big improvement to the Fat Man type bomb and the first nuclear warhead to be mass-produced in large numbers (see the section on the MK 4 bomb.) While the MK 4 had variable yields, making it very suitable as an ADM, it was also very large, heavy and unwieldy and internally very complex, requiring a large number of personnel and considerable time to prepare and arm. Also the time the weapon could remain armed and ready to use was very limited due to the limited-life batteries used in the weapon for arming and fuzing. The size of the warhead alone, plus the container it would have to be transported in makes it highly unlikely as a candidate for surreptitiously sneaking it into a country and emplacing it.

The late Chuck Hansen's book on US nuclear weapons (p. 209) states the ADM was manufactured from recycled MK 8 “Elsie” penetration bombs, a gun-type device that was much smaller, lighter and more easily made “man-portable” and did not have the drawback of limited-life batteries, a much more likely candidate for an ADM.. (See the section on the MK 8 bomb.) There is no publicly-available information on how the weapon was actually intended to be deployed beyond the statement it was designed to be carried by a five-man team to get it in place and armed. (One can imagine the fun of lugging two sets of shielded radioactive components and the “gun” and arming/fusing components in the field under adverse conditions of terrain or weather.) There are no details on how the weapon would have been detonated other than the obvious use of timers or remote command. There is also no information available on it's weight and dimensions as an ADM. Yield, if it was close to that of the MK 8 bomb would have been in the 25-30 kiloton range, although it would not have been technically difficult to reduce this yield by modifying the nuclear components. There is no information this author can find that the marine corps had this weapon in their inventory although it is far more likely than the MK-4 to have been.. The weapon was in service between 1957 and 1963 and was replaced in the inventory by the Medium Atomic Demolition weapon using the much smaller MK 45 warhead.

ADM MK 7

This ADM was based directly on the MK-7 free-fall fission bomb warhead also used in the BOAR air to surface rocket, the MK 90 depth charge and the Corporal and Honest John ballistic missiles. It is known that this weapon was actually deployed to the miltiary forces. Development of the ADM version of the Thor warhead began around 1953 and the weapon was eventually designated as the ADM B. Approximately 300 of the ADM versions were built. The Thor warhead was approximately 30.5” wide and 56” long and weighed around 900 lbs. Bomb yields were variable (depending on the core used in the bomb) and it is stated that the ADM yield was around 90 tons in one source and 5 or 19 kt in another. (The higher yields would have been easily obtainable by changing the weapon's core.) The MK 7 bomb was the first nuclear weapon equipped with a permissive action link (PAL) device, in this case a Type A, and it is presumed the ADM also had the same safety device. This ADM had many of the disadvantages of many early bombs, having a complex and time-consuming preparation and arming process and limited-life battery components as well as being bulky and heavy. The MK 7 ADM was in service from 1954 to 1959. No photographs of this weapon system is in the public domain as far as this author can determine. Since the MK 7 bomb was in the navy inventory, it is reasonable to assume the ADM version was also available.

TACTICAL ATOMIC DEMOLITION MUNITION (TADM)

The TADM is sometimes referenced as the XM-113 ADM, but that designation is actually that of the casing it was carried in, which was made to look like a section of corrugated piping, thus the bomb's nick-name as “the sewer pipe bomb.” The TADM used the W-30 warhead adapted from that used in the Talos missile. The warhead was 22” in diameter and 48” long, weighing about 430-490 lbs. The casing was 26” in diameter, 76” long and with the weapon weighed around 840 lbs. The TADM had two yields according to the most reliable sources at 5 kt and 19 kt. Production of the TADM began in 1961 and withdrawal from the inventory began around 1966.

ADM MK 31

The MK 31 ADM was a fission weapon adapted from the warhead used in the Nike Hercules and Honest John missiles. The ADM used the W-31 Mods 1, 2, and 3 warheads with dimensions of about 30” in diameter and 39” in length. Weight was between 900 and 945 lbs depending on the mod. The warhead was approximately 29” in diameter and 30 to 39” in diameter and weighed about 900 to 945 lbs depending on the mod. Yields for the missile warhead versions are listed as 1, 2, 12, 20 and 40 kt, with the lower yields most likely used in the ADM version.

Approximately 300 were manufactured starting in September of 1960.The weapon was retired by the end of 1965.



THE MEDIUM ATOMIC DEMOLITON MUNITION (MADM)

The MADM was an adaptation of the boosted-fission MK 45 warhead used in the Terrier and Little John missiles. The warhead was the first deployed product of the Teapot and Redwing tests of 1955/56 at the Nevada Test Site that proved the feasibility of small-diameter boosted-fission weapons.

The MK 45 Mod 1 ADM began production in January of 1962. The Mod 3 version of this weapon began production in 1965 and had a retrofit kit that included a five-combination PAL lock and a waterproof casing allowing for deep water deployment. Approximately 350 weapons were built between January of 1962 and June of 1966. All were retired by 1984.

The W-45 warhead was 11.75” in diameter and 27” long, weighing about 150 lbs. With its casing, the ADM weighed about 350 lbs. Yield was variable between 1 and 15 kt. It is known that this ADM underwent a full nuclear test at the Nevada Test Site during the Johnnie Boy shot of Operation Dominic II on July 11, 1962. It was probably deliberately unboosted and yielded about .5 kt.

THE SPECIAL ATOMIC DEMOLITION MUNTIONS (SADM)

The SADM was the smallest and probably the most practical of the ADMs (along with the MADM) and was developed in response to an army requirement for a man-portable nuclear ADM with a sub-kiloton yield. The warhead used was the existing W-54 used in the Falcon missile and the Davy Crockett tactical battlefield rocket. Development of the ADM included the requirement for an underwater pressure case for deep water emplacement.

The MK 54 Mod 1 SADM entered the national stockpile in August of 1964, production having been delayed by issues in developing the time fuse system. The Mod 2 version began stockpiling in June of 1965. Approximately 300 SADMs were produced and they remained int the nuclear inventory until 1987.

The SADM was a truly man-portable weapon, but delivery and emplacement would always be by two-man teams in order to maintain the integrity of the “two-man rule” regarding nuclear weapons. The SADM used a combination lock PAL system and was time-fused. Yield could be selected between about 10 tons and 1 kiloton according to some sources, although the yield is often cited as being about .25 kt. The SADM package including case weighed around 163 lbs. The W-54 warhead was a spherical implosion fission device measuring 10.75” long by 15.75” in diameter and weighed about 54 lbs. With casing, dimensions were 16” by 24”.

Two views of the MK 45 SADM one all-up in it's casing and the other showing the various components. In the second photo, the casing is on the left, the W-45 warhead in the middle and the PAL/Combination Lock and fuzing and firing elements on the right.

[Brian James]

You have surpassed yourself once again Don...well written and most informative for us of the lay profession..Regards Brian.

[ivorthediver]

Well worth the wait Don and thank you for your perseverance in producing this for us all to share on the Forum .

Your comments on deployment are truly salient and chilling but viewed on a "War" footing you can not help but look not only at the cost to life but also the deterrent to the enemy , having said that our Cold War V Bomber force knew that they were on a " one way ticket" only and knew the cost which was tempered by the certain knowledge that IF they did manage to get back to base it would most probably be a charred mass of radiated terrain .

Thanks again for laying the facts available open to us .

[DonBoyer]

Thanks, Ivor, kind words.

No nuclear scenario I've seen has a bright and cheerful side for the "winners" as opposed to the losers. Everybody at the pointed end who was responsible for delivery knew it clearly and it colored their whole lives in the military. Maybe the submarine guys had a more cheerful outlook, but I doubt it.

Looking back, and as scary at the time as it was, I think the Cuban Missile Crises of 1962 was actually of great benefit politically for the nuclear powers once the dust settled from winding up all those weapons for delivery. While the histories generally ascribe astute politics with the credit for de-escalating the situation back to what passed for normal, it was actually numbers that drove the de-escalation, for which politics provided the convenient cover since "numbers" were classified at the time. At the height of the crisis, the Soviets, ever the bluffers about their vaunted nuclear forces, realized that they might, on a good day get maybe 50 or 60 of their weapons in play at best -- 100 tops if the missiles in Cuba were able to get away before Cuba became a fused glass skating rink, because of their actual poor systems. Now that wold be a devastating number of weapons to land on somebody's turf, assuming they all got through, but their problem wasn't what might land on the US, it was what was almost certain to land on them -- the US had about 2800 weapons locked and loaded -- on bombers already in the air and orbiting Soviet airspace, in the missile silos, on the subs, on the tactical aircraft aboard carriers, with the forces of NATO, etc. The great majority of those would have been able to get through. That is not a ratio for success, and the Soviets blinked. That was the real politics, not Kennedy or Khrushchev speeches and backroom phone calls and newspaper headlines. Atomic numbers.

While this proved nuclear weapons were a successful deterrent, the situation also put shit streaks in about everybody's pants on both sides of the Iron Curtain because everybody knew that if just one of those weapons got loose, it was all over everywhere. Shortly after, the scientists and such started playing with those numbers and realized just how radioactively fatal such an exchange would be to almost all life on the planet and therefore how absurd the nuclear inventory had gotten, facts that spread to the public and politicians and resulted in the beginnings of the era of "let's back off this crap a bit," which has been of benefit to us all. Closer cooperation with the Soviets also slowly ensued, with a communication link set up to hopefully avoid any misunderstandings in the future. So far, it seems to be working. American nuclear numbers topped out in 1967 at about 32,000 warheads in the active inventory, and has gone down every year since to our current level of about 5200.

I was living on Hickam Air Force Base in Hawaii at the time of the crises and when they spun everything up, my dad, a COL in the Air Force, happened to be home when the call came in for the big alert. He had me drive him to the base HQ so we'd have a car at home while he was gone. In the car, my dad basically told me without revealing any details that "if things went south, he wouldn't be back, ever." He also said by the same token if that happens, "you and your mother are pretty much fucked too, because Hawaii is a class A target. Get used to the idea, don't panic, and take care of your Mom as long as you can." My dad wasn't much for mincing words. Never been so proud of anyone in my life as my dad and I shook hands in the parking lot near the flight line (he wasn't a hugger) and I watched him walk away. He never looked back, probably because he had the same tears in his eyes as I did. We never talked about it after. I think it was this incident that prompted my interest in nuclear weapons history more than my years of service in the nuclear weapons program.

[ivorthediver]

Thank you very much Don for confiding in us , and fully understand how you must have felt at the time although sadly my father and I did not share a close relationship and I try hard to put my feelings for him in a box and bury it , but I am heartened to hear that you enjoyed a "normal" period of home life .

Like you I clearly remember all the tension of that time and the anxiety everyone this side of the pond felt at the time .

Over the years I have gleaned a little of your character which has all been positive and admire your stance in this and your frankness controlled by an educated mind .....not a reactionary half wit given to theatrical outbursts or Sabre Rattling .....I doff my hat to you Sir ..and in the unlikely event that we should met I will gladly get legless with you .

Take Care dear friend and please give your cat a hug from another Cat admirer

[DonBoyer]

Very kind of you to speak of me that way, Ivor, I appreciate it. I've made some dear friends over the years since that day I first joined the WNSF (RIP), and I've really enjoyed the comradeship I was shown by my oppos in the RN and the people from the UK in general. I was very lucky to have been able to host Brian James and his lovely wife Lyn at our hovel out here on the north shore, and hope some day others will manage to drop by, sample the BBQ, pet the dog and cat and hoist a few to God and Queen..

[ivorthediver]

Our pleasure Don , you have earn't your place on this Forum dear Sir , and we look forward to your continued posts and responses

Take good care of those around you and our thanks to your good lady for her backing with these posts and the work behind the scenes

Kindest regards Ivor and Karen, Cambridge [ crawling out of lockdown ]

[DonBoyer]

About time I got back into the swing of things here with the FINAL section on the US Navy's nuclear weapons 1945 - 1992, this one on Artillery Fired Atomic Projectiles (AFAP) of which the US Marine Corps used several over the years in addition to the navy's single entry in that category, the MK 23 "Katie" 16" shell, the section on which is repeated here from an earlier section as I decided to move it to this last section in the book I am hoping to finish this year. I have several sections of the book that will not be included here on the site as not being directly related to the weapons themselves so this latest entry is the end of the road so to speak. Poured ten years of research and procrastination into this stuff!

ARTILLERY FIRED ATOMIC PROJECTILES (AFAPS)

The navy only developed one atomic shell for its ships, the 16” MK-23 “Katie,” for the Iowa-class battleships. It was an adaptation of the same warhead used by the U.S. Army for it’s 280 mm atomic cannon, itself an adaptation of the Navy’s MK-8 penetrator bomb warhead. (As far as is publically known, only one other ship-born atomic shell was ever developed, a 155 mm shell for the Soviet Sverdlov class light cruisers.)

For the purposes of this book, the U.S. marine corps is assumed to have had the same tactical atomic shells available for use during the Cold War as the U.S. army did. However, public information on the marine corps nuclear weapons program is severely lacking in comparison to the navy. All artillery fired atomic projectiles were developed by the U.S. army, but since the marine corps used the same weapons, it is assumed they also had the same tactical atomic capabilities as the army (with the exception of the Davy Crockett, which the marine corps apparently did not use, although they did have the same warhead in the Special Atomic Demolition Munition (SADM).

All the early atomic shells, being “gun-type” devices, were inherently wasteful of nuclear material due to the inefficiency of the nuclear burn caused by high-speed “compression” of two nuclear masses of Uranium as opposed to the much faster and more complete implosion method of initiating a nuclear reaction using and equivalent amount of Uranium (or other nuclear material such as Plutonium). This problem was overcome later when the principles of linear implosion allowed for the development of an atomic shell that did use Plutonium. The later warhead also used Tritium, which was the key component in the development of the “enhanced radiation” weapons, also known as the “neutron bomb,” a publically very controversial system. Tritium fusion in the Plutonium core of the weapon produced high-energy neutrons which, released as ionizing radiation of extreme high speeds, causes enormous damage to living cells.

The following sections focus on the various artillery-fired nuclear projectiles themselves, the technical specifications of the artillery pieces used with these weapons are thoroughly covered in existing historical sources.

THE MK 23 “KATIE” 16” SHELL

(covered earlier.)

THE W-33 WARHEAD

The W-33 warhead was developed for the M110 8” Howitzer (including the marine corps M110A2 weapon); this self-propelled gun was the largest field artillery piece fielded by the army and marine corps during the Cold War. The gun used two different nuclear warheads, the W-33 in an M422 shell and the later W-79 in the M753 rocket-assisted shell using the W-79 warhead.

Development of the W-33 warhead actually began in April of 1952 (as the “T-317”) well before the 280mm atomic cannon shell was even tested, probably because the army recognized the extreme difficulties that would be associated with tactical deployment of the huge atomic cannon and its prime mover and associated equipment and the consequent vulnerability of the system to counter-attack. There were several excellent advantages to the development of this smaller shell, primarily that it could be fired from standard existing smaller cannons then available, making supply chain issues less complex and reducing the amount of training needed for gun crews. The purpose of the round was to deter “’mass attacks’ by a numerically superior, technologically inferior enemy.” (Hansen, p. 173.)

Developmental work on the shell was completed around January of 1952, with the Army Ordnance Corps authorizing development in June of the same year. Production of the shells began in February of 1955. A W-33 warhead was tested at the Nevada Proving Grounds during Shot Laplace of Operation Plumbob on 8 September 1957, with a yield of about 1.25kt. For an accurate assessment of the ground effects of this weapon, designed for airburst (with a contact backup), the test warhead was suspended 750’ off the ground from a balloon. Two variants of the W-33 were produced, the Mod 1 which became operational in 1957 and the Mod 2 which became available in 1964. Approximately 2000 W-33 warheads were produced.

The shell used with the W-33 was 37” long and 8” in diameter, weighing about 243 lbs. The nuclear gun assembly within the shell was approximately 22” long and 5.5” in diameter. Three different gun assemblies were available for this weapon, with yields ranging between 5 – 10kt. For safety, the nuclear components were kept separate and well apart from the fuses and shell casings. The W-33 had a combination lock PAL device. Retirement of the W-33 began in 1981, the warhead having been replaced by the much improved W-79. The W-33s were dismantled and their nuclear material used for the newer warhead on a one-for-one basis.

THE W-79 WARHEAD

The W-79 warhead was developed as a replacement for the W-33 and was developed from specifications for technologically advanced and up-to-date designs specifically aimed at producing a shell that “maximized personnel casualties while minimizing collateral damage to the surrounding environment.” (Hansen, p. 175.

Development of the new warhead was assigned to the Lawrence Livermore Laboratory in January of 1975 as an “enhanced radiation weapon, i.e., a “neutron bomb” type device. Political fallout over use of this type of weapon held weapons development back until around November of 1978. Production units of the W-79 began delivery in July of 1981, with quantity production beginning in September of the same year. 550 warheads had been completed when production ceased in August of 1981 with about 550 warheads being produced, 350 of which were of the enhanced radiation version (many of which were rebuilt as Mod 0s until about only 40 of the enhanced radiation versions remained in the inventory by late 1987. The W-79 became the warhead for the M753 rocket-assisted 8” shell and was produced in two mods, the Mod 0 dual capable version (standard and enhanced radiation) and the Mod 1 version with no enhanced radiation capability. The enhanced radiation version was never forward deployed but was available if needed. The W-79 Mod 0 warhead had selectable yields ranging from a few tons up to 10kt. The Mod 1 warhead had three yields ranging from a few hundred tons to 2kt.

The M753 shell using the W-79 warhead was 43” long and 8” in diameter weighing about 215 lbs. The weapon used a Category D PAL device and had advanced systems to enhance targeting and the height-of-burst and contact options. The W-79 utilized Plutonium and Uranium alloys and used the “linear implosion” method of detonating the warhead. The 8” shell included a rocket booster, allowing for an increased range for the weapon of about 18 miles. All W-79 warheads were removed from the war reserve inventory by late 1991.

THE W-48 WARHEAD

The W-48 warhead was developed for the 155 mm (6.1”) M44 self-propelled howitzer, the M109 howitzer and the M198 howitzer utilizing the M454 shell and based on an army requirement for a small low-yield projectile. Development of this requirement began in early 1955 with both Los Alamos and the UCRL (later the Lawrence Livermore Laboratory) sharing the design work, along with a large number of sub-contractors. The shell for the warhead was developed by the army’s Picatinny Arsenal. Developmental testing of the warhead was conducted at the Nevada Test Site during Operation Hardtack. Production of the W-48 warhead began in October of 1963. Delivery of a later version, the W-48 Mod 1 began in 1969. Approximately 1060 MK 48 warheads were manufactured between October of 1963 and March of 1968. Retirement of the Mod 0 weapons was completed in 1969. By mid-1987 only 925 Mod 1 weapons remained in the stockpile. The M454 shell for the MK-48 was 34” long, 6.1” in diameter and weighed around 128 lbs. Yield was about 100 tons (.1kt). The warhead was fired by a variable timed mechanical fuse and used a combination lock PAL device. The weapon was plutonium fueled and utilized the linear implosion system.