Monthly Archives: January 2014

Bent Spears, Broken Arrows and Empty Quivers

In my research for a previous post I came across the US’s official list of nuclear weapons-related codewords, and they are some of my favourite codewords ever.

PINNACLE is a codeword (technically a flagword) that indicates that a message is of interest to the major command units of the military. It’s mentioned here because whilst it can be used on its own, it is often used, or must be used, in combination with the codewords listed below.

BENT SPEAR is used to report incidents involving nuclear weapons that are “of significant interest” but which are not categorised as NUCFLASH or BROKEN ARROW. The incident in which six AGM-129 cruise missiles with live 150 kiloton W80-1 nuclear warheads (which were supposed to have been removed) were loaded onto a B-52 Stratofortress bomber and left unguarded at Minot and Barksdale Air Force Bases was classified as a BENT SPEAR.

NUCFLASH is used to report incidents that could create a risk of nuclear war. This includes any incident involving the actual or possible detonation of a nuclear weapon, or any incident in which a nuclear-armed or nuclear-capable aircraft deviates from its approved flightplan. It also covers incidents with the possibility of, or the appearance of, a nuclear detonation or attack, such as a ballistic missile launch, the presence of cruise missiles on non-friendly aircraft that are not on an approved flight path, or objects from space reentering Earth’s atmosphere. A PINNACLE NUCLFASH report has the highest priority of any report in the US military.

BROKEN ARROW is used to report incidents involving US nuclear weapons that do not create the risk of nuclear war. This includes the nuclear or non-nuclear detonation of a US nuclear weapon, the burning or jettisoning of a nuclear weapon or radioactive contamination or other hazard from a US nuclear weapon. The incident in which a nuclear-armed Titan-II missile caught fire and exploded in its silo was classified as a BROKEN ARROW, as were a number of incidents in which B-52 bombers carrying nuclear weapons crashed. (The incident in the 1996 movie Broken Arrow would actually have been classified as EMPTY QUIVER.)

EMPTY QUIVER is used to report the seizure, theft or loss of a nuclear weapon. The incidents in which the USS Scorpion submarine sank with two eleven kiloton Mark 45 nuclear torpedoes aboard, or the incident in which an A-4E Skyhawk aircraft carrying a one megaton B43 bomb fell over the side of the aircraft carrier USS Ticonderoga would probably be classified as EMPTY QUIVER events.

DULL SWORD is used to report minor incidents involving nuclear weapons or systems which could impair their ability to be deployed. This includes damage to systems capable of carrying or deploying nuclear weapons but which are not carrying nuclear weapons at the time. FADED GIANT is used to report incidents involving military nuclear reactors, or any other military radiological incident that does not involve nuclear weapons.

Two less cool-sounding codewords are EMERGENCY EVACUATION and EMERGENCY DISABLEMENT. The EMERGENCY EVACUATION codeword is used when nuclear weapons have to be removed from their approved location at short notice, without advance planning, e.g. if an Air Force base or silo holding nuclear weapons was being overrun by enemy forces. EMERGENCY DISABLEMENT refers to the use of the weapon’s command disable system, in which a warhead is deliberately made inoperational, preventing its use by enemy forces. The method by which this is achieved is unknown, but it is thought to operate by destroying either the warhead’s power supply, the sensitive electronic components within the warhead, or another part of the warhead’s triggering system.

The Hoba Meteorite

The Hoba meteorite is an ataxite iron-nickel meteorite that landed in northern Namibia at some point in the last 80 000 years. Because of its shape and trajectory (it’s thought possible that it “skipped” across the atmosphere like a stone on a pond) it landed at subsonic speeds, and didn’t bury itself particularly deep, leaving no crater behind.



The Hoba meteorite was discovered by a farmer as he was ploughing a field, and has never been moved due to its large size; it has a mass of around 60 000 kilograms. (It was estimated to be about 66 000 kilograms when it fell, but its mass has been reduced by erosion, sampling and vandalism.) The Hoba meteorite is the world’s largest meteorite, and the most massive naturally occuring piece of iron on Earth’s surface.

Unconventional Nuclear Weapons

When people think of nuclear weapons they tend to think of bombs and missiles, but there have been (and possibly still are) some more unusual nuclear weapons.

Conventional Nuclear Weapons

Most nuclear weapons states (NWSs) use ballistic missiles as the primary tool in their nuclear arsenals. These can be battlefield (with a range less than 100 km), tactical (range up to 300 km), theatre (up to 3500 km), intermediate (up to 5500 km) or intercontinental (beyond 5500 km). These ballistic missiles can be land-based, either in underground silos or aboard mobile launchers, or submarine-launched; NWSs prefer SLBMs because they give a secure second strike capability (the UK’s only nuclear weapons are SLBMs).


A Trident II SLBM (as used by the USA and the UK) ignites its first stage rocket motor.


A Russian SS-25 Sickle ICBM aboard a transporter erector launcher vehicle.

Ballistic missile forces are frequently supplemented by cruise missiles, usually air-launched by fighter or bomber aircraft. Cruise missiles differ from ballistic missiles in that they do not follow ballistic paths but rather fly point-to-point, close to the ground (in a process known as terrain hugging). Ballistic missiles use rocket engines and can operate outside of Earth’s atmosphere, whereas cruise missiles are powered by air-breathing fanjet or ramjet engines (and are therefore unable to operate outside of the atmosphere), and generate lift and steer just as aircraft do.


A French Mirage 2000N fighter carrying an ASMP-A nuclear-capable cruise missile on its centre hardpoint.

Only the United States and China still use air-dropped nuclear bombs as part of their nuclear deterrent. The nuclear weapons programmes of Israel, India, Pakistan and North Korea are shrouded in secrecy, so it is possible – but unlikely – that they possess bombs as part of their arsenals.


A B83 bomb, the most powerful weapon in the US arsenal at 1.2 megatonnes TNT equivalent.

Unconventional Nuclear Weapons

Nuclear Land Mines (AKA Atomic Demolition Munitions)

The conventional nuclear weapons listed above are all designed to be delivered to their target remotely, whereas atomic demolition munitions (ADMs) are designed to be transported and emplaced by soldiers in the field. The US and the USSR/Russia developed a number of ADMs but no current weapons are known, though it is alleged that Israel have placed ADMs in the Golan Heights to secure the area.

sadmSource: flickr/rocbolt

The most recent ADM, the US’s Special Atomic Demolition Munition (shown above) was decommissioned in 1989. It used the tiny W54 warhead, with a yield of 0.01-10 kilotons TNT equivalent, and had a mass of around seventy kilograms. It was designed to be carried in a backpack and emplaced by a team of paratrooper Special Forces.

Perhaps the strangest nuclear weapon of all falls into the ADM category. Blue Peacock was a 1950s British project to place ten kiloton nuclear landmines on the North German Plain to guard against a Soviet invasion from the east. The bomb’s designers were concerned that the cold weather would prevent the bomb’s electronics from operating correctly, and one suggestion was that live chickens be placed inside the bomb with a source of food and water and that the heat from the chicken’s bodies would be sufficient to keep the bomb operating correctly. The project was cancelled in 1958 before any bombs were placed.

So-called “suitcase nukes” also fall into the ADM category. A number of people have alleged that the US, USSR and Israel have produced suitcase nukes, but most nuclear scientists and engineers do not believe it to be possible to shrink a warhead – both in terms of size and mass – small enough to fit in a suitcase and be easily man-portable.

Nuclear Artillery

The W54 warhead used in the SADM was originally developed for the Davy Crockett recoilless rifle system. The Davy Crockett was fielded by US units between 1961-1971 and was designed to fire an M388 nuclear projectile containing a 0.01-0.02 kiloton W54 warhead up to four kilometres, and was envisaged as primarily an anti-personnel and area denial weapon due to the fallout it would produce.


An M388 nuclear projectile attached to the Davy Crockett system.

The US developed a number of other shell-firing nuclear artillery pieces: the M65 atomic cannon firing fifteen kiloton W9 and twenty kiloton W19 warheads; the M110 and M115 howitzers firing W33 warheads with a selectable yield up to forty kilotons; and the M109, M114 and M198 howitzers firing 0.072 kiloton W48 warheads. The USSR also produced a number of shell-firing nuclear artillery pieces, and the US, USSR, France and others operated nuclear rocket artillery pieces.

Nuclear Depth Charges

The UK, USA and USSR have all at one time fielded nuclear depth charges for use in anti-submarine warfare. The Mark 101 Lulu was an eleven kiloton nuclear depth charge fielded from 1958-1971, and the twenty kiloton B57 nuclear bomb (1968-1993) could also be used in this role.


A Mark 101 Lulu nuclear depth charge.

Air-to-Air and Surface-to-Air Rockets

Most nuclear rockets and missiles are air-to-surface or surface-to-surface, but some air-to-air and surface-to-air nuclear missiles have been created. Air-to-air nuclear missiles, such as the one-and-a-half kiloton AIR-2 Genie (1957-1985) and the 0.25 kiloton AIM-26 Falcon (1961-1972) were designed to guarantee a hit against incoming aircraft, and to destroy multiple aircraft with one device.


An F-106 Delta Dart fires an AIR-2 missile.

Surface-to-air nuclear missiles have also been used in anti-aircraft roles, but were, and are more commonly used in an anti-ballistic missile (ABM) role. The current Russian ABM system (A-135) uses ABM-3 Gazelle missiles with 10 kiloton nuclear warheads, and previously used much more powerful ABM-1 Galosh missiles with 2-3 megaton warheads. These ABM nuclear missiles are designed to destroy incoming ballistic missiles by damaging their electronic components via intense X-ray bombardment and neutron flux.

vnukovo-stitchSource: wikimapia/ogima

The image above shows the A-135 ABM complex at Vnukovo (click to enlarge). Blue control buildings are on the right, and the sliding silo covers are visible to the left. There are a total of twelve silos at this site, with a further fifty-six silos spread between four other sites surrounding Moscow.