Mark 24 nuclear bomb
The Mark 24 nuclear bomb was an American thermonuclear bomb design, based on the third American thermonuclear bomb test, Castle Yankee. The Mark 24 bomb was tied as the largest weight and size nuclear bomb ever deployed by the United States, with the same size and weight as the Mark 17 nuclear bomb which used a very similar design concept but unenriched lithium. The Castle Yankee thermonuclear test was the first bomb to use lithium enriched with the lithium-6 isotope, up to perhaps 40% enrichment (the earlier Castle Bravo test had used the same enriched lithium combination but was not weaponised i.e. was not built as a deployable bomb).
Mark 24 nuclear bomb

Wikimedia Commons · Public domain
- Name
- Mark 24 nuclear bomb
- Field
- aerial bomb
VALÉORINE Encyclopedia
VALÉORINE documentary reading
Documentary summary
The Mark 24 nuclear bomb was an American thermonuclear bomb design, based on the third American thermonuclear bomb test, Castle Yankee. The Mark 24 bomb was tied as the largest weight and size nuclear bomb ever deployed by the United States, with the same size and weight as the Mark 17 nuclear bomb which used a very similar design concept but unenriched lithium. The Castle Yankee thermonuclear test was the first bomb to use lithium enriched with the lithium-6 isotope, up to perhaps 40% enrichment (the earlier Castle Bravo test had used the same enriched lithium combination but was not weaponised i.e. was not built as a deployable bomb).
Admitted source layer · organised and presented by VALÉORINE
Note VALÉORINE
No house-authored Note is published until its assertions and sources pass the VALÉORINE evidence contract. The documentary article remains available in full while that enrichment is being consolidated.
Documentary enrichment in progress · no unsupported statement published
Reference Check
Propose documentary evidence for Mark 24 nuclear bomb. A contribution is never written directly as fact: identity, source, rights and evidence gates still decide.
Sign in to contribute
Documentary evidence
Evidence Panel
not yet certified
- Identity
- resolved
- Independent source families
- 0
- Admitted assertions
- 0
- Open conflicts
- 0
Authority files
wikidata · Q6125322 · wikipedia · Mark 24 nuclear bomb
In this article
Overview
Overview
The device tested was called the Runt II design; other than the enrichment level, it was reportedly very similar to the Runt design tested in Castle Romeo. Castle Yankee had a demonstrated yield of 13.5 megatons. The yield for the weaponized Mark 24 was predicted to be 10–15 megatons. The EC24 bomb was a limited production run of the Castle Yankee test device, with 10 produced and stockpiled through 1954. The EC24 was 61 by and weighed 39600 lb. The EC24 was a purely free-fall bomb design.
Key facts
Key facts
• Name — Mark 24 nuclear bomb • Type — Thermonuclear gravity bomb • Origin — United States • Is Explosive — yes • Service — 1954-1956 • Wars — Cold War • Designer — Los Alamos National Laboratory • Design Date — 1954 • Production Date — EC-24: Mar-Oct 1954 Mk-24: Jul 1954-Nov 1955 • Number — EC-24: 10 Mk-24: 105 • Mass — EC-24: Mk-24: • Length — 24 ft • Diameter — 61.4 in • Detonation — Air burst • Yield — EC-24: MtTNT, Castle Yankee test Mk-24: MtTNT
Design
Design
The production model Mark 24 nuclear bomb was 61.4 by long, with a weight between 41000 and. It was in service between 1954 and 1956, with a total of 105 units produced. The Mark 24 included a 64 ft parachute to slow its descent. The bomb used manual in-flight insertion (IFI) that required a crewmember to crank a handle that was inserted into a hole in the nose of the bomb. This process inserted the weapon's pit into the implosion assembly.
Survivors
Survivors
A Mark 24 casing is on display in the Castle Air Museum in Atwater, California.
Identity
Identity
Mark 24 nuclear bomb is classified as an aerial bomb.
Primary material
Documents and archives
authority record
- Wikidata, structured authority record Q6125322: Mark 24 nuclear bomb
Unverified · Wikidata
reference work
- “Mark 24 nuclear bomb”, English Wikipedia, consulted as further reading
Reputable secondary · Wikipedia
Literature
Scholarly footprint
A count of publications is evidence of attention, not of standing, and is given here only as a measure.
References
Citations
References
Each reference names the institution holding it, so a reader may go to the document itself.
authority record
Partially resolvedreference work
Partially resolved
Further particulars
Held on the record
Further particulars
Open the remaining particulars
Mark 24 nuclear bomb is connected to 1 other published record in the VALÉORINE Encyclopedia.
In public collections
Within the Encyclopedia
The Encyclopedia exists whether or not anything is for sale. Corrections are recorded rather than overwritten, and every version of this record is kept. Published 14 August 2026.
Elsewhere in Militaria
6,095 published records in this field, each with its sources named.
- Mark 21 torpedoTerminology
- Mark 22 nuclear bombTerminology
- Mark 23 torpedoTerminology
- Mark 24 MineTerminology
- Mark 24 TigerfishTerminology
- Mark 25 torpedoTerminology
- Mark 26 Guided Missile Launching SystemTerminology
- Mark 26 nuclear bombTerminology
Best supported in this field
For owners
Own an object connected with Mark 24 nuclear bomb?
A specialist will read what you send and tell you what the house can establish, what it cannot, and whether the object is suited to sale. There is no charge and no obligation. The object stays with you throughout; nothing is shipped to us unless it is arranged in writing beforehand.