physics

Special Atomic Demolition Munition

Special Atomic Demolition Munition is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Special Atomic Demolition Munition rather than just read about it. In short: The Special Atomic Demolition Munition (SADM), also known as the XM129 and XM159 Atomic Demolition Charges, and the B54 bomb was a nuclear man-portable atomic demolition munition (ADM) system fielded by the US military from the 1960s to 1980s but never used in combat. It had an estimated yield of up to 1 kiloton of TNT.

Key takeaways

Special Atomic Demolition Munition belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Special Atomic Demolition Munition to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Special Atomic Demolition Munition from memory before moving on to harder problems.

Reference excerpt

The Special Atomic Demolition Munition (SADM), also known as the XM129 and XM159 Atomic Demolition Charges, and the B54 bomb was a nuclear man-portable atomic demolition munition (ADM) system fielded by the US military from the 1960s to 1980s but never used in combat. It had an estimated yield of up to 1 kiloton of TNT.

History and design

At the time of the weapon's development, the existing Atomic Demolition Munition (ADM) was the T-4 Atomic Demolition Munition. Its transport required 4 men, each carrying a 40-pound (18 kg) section of the weapon. Development began in June 1960 and an interim Mark 54 Mod 0 (now called the B54-0) weapon was put into production in April 1963. Production of the B54 Mod 1 SADM began in August 1964. The weapon was 12 inches (305 mm) in diameter, 18 inches (457 mm) long, and weighed 58.5 pounds (26.5 kg). It included the warhead, a fuzing and firing system with a mechanical timer, a ferroelectric firing set, and a sealed housing. The body was constructed with aluminum forgings and molded fiberglass, and foam-rubber insulation was used between the warhead and case. Dials were illuminated with tritium-phosphor paint for easy night-reading. A housing for underwater emplacement was provided that included external controls. The B54 Mod 2 started production in June 1965. The weapon was the same size as previous mods but now weighed more – 70 pounds (32 kg). The yield was estimated to be 10 to 1,000 tons of TNT (42 to 4,184 GJ). Yield options were known to be selectable from 0.1 or 0.2 kiloton presets.

Use

Offensive use ADM employment manuals describe the use of ADMs tactically in both offensive and defensive operations. In offensive operations, ADMs are described as being useful for improving flank and rear security of a unit, impeding counterattacks and assisting in enemy entrapment.

Engineering and defensive use ADM employment manuals describe the use of ADMs defensively for combat engineering purposes. Possible targets described include bridges, dams, canals, tunnels, airfields, railroad marshaling yards, ports and industrial plants, and power facilities. Extensive tables were provided to enable the selection of the correct yield for each particular target. These tables accounted for various employment particulars such as depth of burial, fallout considerations, and minimum safe separation distances between adjacent weapons and personnel.

Suicide attack allegations

On December 27, 2018, the Green Bay Press-Gazette interviewed veteran Mark Bentley, who had trained for the Special Atomic Demolition Munition program to manually place and detonate the SADM. Bentley stated that he and other soldiers training for the program knew this was a suicide mission, because soldiers would probably be ordered to secure the site before the timer went off. Employment manuals specifically describe the firing party and their guard retreating from the emplacement site, at which point security of the device is provided through a combination of passive security measures, including concealment, camouflage, and the use of decoys, as well as active security measures including booby traps, obstacles (such as concertina wire and landmines), and long-range artillery fire. Further, the SADM included a Field Wire Remote Control System (FWRCS), a device that enabled the sending of safe/arm and firing signals to the weapon via a wire for safe remote detonation of the weapon.

Illustrations

Worked examples

Example 1 — a first encounter with Special Atomic Demolition Munition

Start with the simplest possible case. Write down what Special Atomic Demolition Munition claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Special Atomic Demolition Munition before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Special Atomic Demolition Munition ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Special Atomic Demolition Munition

In research: Special Atomic Demolition Munition appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Special Atomic Demolition Munition in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Special Atomic Demolition Munition is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1960s in the United States, Atomic demolition munitions, Cold War weapons of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for Special Atomic Demolition Munition outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Special Atomic Demolition Munition in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Special Atomic Demolition Munition means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Special Atomic Demolition Munition out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Special Atomic Demolition Munition in simple terms?

Why does Special Atomic Demolition Munition matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Special Atomic Demolition Munition?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Special Atomic Demolition Munition.