RUR-4 Weapon Alpha
The RUR-4 "Weapon Alpha" (originally Weapon Able) was an American naval ahead-throwing anti-submarine rocket launcher. It was designed between 1946 and 1949, and was installed on warships from 1951 to 1969. Unlike depth charges, it was designed to attack enemy submarines without requiring the attacking ship to be located directly above the submarine being attacked.
Also recorded as Weapon Able
RUR-4 Weapon Alpha

U.S. Navy photo NH 94158 · Public domain
- Name
- Weapon Alpha
- Field
- anti-submarine weapon · rocket artillery
- Region
- United States
VALÉORINE Encyclopedia
VALÉORINE documentary reading
Documentary summary
The RUR-4 "Weapon Alpha" (originally Weapon Able) was an American naval ahead-throwing anti-submarine rocket launcher. It was designed between 1946 and 1949, and was installed on warships from 1951 to 1969. Unlike depth charges, it was designed to attack enemy submarines without requiring the attacking ship to be located directly above the submarine being attacked.
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 RUR-4 Weapon Alpha. A contribution is never written directly as fact: identity, source, rights and evidence gates still decide.
Sign in to contribute
World of VALÉORINE
Documentary connections
Only confirmed graph relationships appear here. Images are shown only when their identity and reuse rights both pass the documentary gate.
Documentary evidence
Evidence Panel
not yet certified
- Identity
- resolved
- Independent source families
- 0
- Admitted assertions
- 0
- Open conflicts
- 0
Authority files
wikidata · Q4047914 · wikipedia · RUR-4 Weapon Alpha
In this article
Key facts
Key facts
• Name — Weapon Alpha • Origin — United States • Type — Anti-submarine rocket • Is Missile — yes • Service — 1951–1969 • Used By — United States Navy Japan • Designer — Naval Ordnance Test Station • Design Date — 1946–1949 • Spec Label — Mark 1 • Weight — 525 lb • Length — 2.6 m • Diameter — 12.75 in • Filling — High explosive • Filling Weight — 250 lb • Detonation — Depth charge • Engine — 5.25 in rocket • Vehicle Range — 800 yd • Speed — 190 mph • Propellant — Solid fuel • Launch Platform — Ships
Development
Development
Similar to the earlier American Mousetrap, 375mm (14.8") Swedish Bofors, and 250mm (9.8") and 300mm (11.8") Soviet systems, all of which use multiple rockets, Weapon Alpha was developed toward the end of World War II, in response to the German Type XXI U-boat. Begun in a crash program in 1944–5 and put in service before undergoing operational evaluation, it emerged in 1949 as a 227-kg (500 lb) 127mm (5") rocket with a 113-kg (250 lb) warhead that sank at 12 m/s (40 ft/s) (compared to a depth charge, which sank at 2.7–5 m/s (8.9–16.5 ft/s)), an influence or time pistol, and a range of 360–730 m (400–800 yd). Coupled to the new SQG-1 depth-finding sonar (for setting the time fuse, rather than the hydrostatic pistol of a depth charge), it was to be fired from a revolving Mark 108 launcher (with 22 rounds of ready ammunition) at up to twelve rounds per minute. The ready-service magazine could not be reloaded while Weapon Alpha was in use. It was replaced by the RUR-5 ASROC, which was developed by the U.S. Navy in the 1950s. Nonetheless, Weapon Alpha remained in service through the 1960s until supplanted by ASROC.
Gallery
Gallery
• Illustration — A dismounted Mk 108 launcher at the Intrepid Sea-Air-Space Museum. • Illustration — The RUR-4's rocket round. • Illustration — RUR-4 launch from Wilkinson, 1956.
Places
Named by the record
Places
Only places the record itself states, plotted where the house gazetteer settles their coordinates. Nothing is inferred from a name or a nationality.
- United States
References
Citations
References
Each reference names the institution holding it, so a reader may go to the document itself.
reference work
Partially resolvedreference work
Partially resolved
Connections
Knowledge graph
Connections
Each connection was recorded deliberately, with the basis for it kept on the internal record.
Broader subject
2- anti-submarine weaponTerminology
Established from a fact already recorded on a verified source.
- rocket artilleryTerminology
Established from a fact already recorded on a verified source.
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.
- Ruger XGITerminology
- Ruger-57Terminology
- Ruhrstahl X-4Terminology
- RUM-139 VL-ASROCTerminology
- RUR-5 ASROCTerminology
- Russian 12 inch/40 gunTerminology
- RWGŁ-3Terminology
- S-125Terminology
Best supported in this field
For owners
Own an object connected with RUR-4 Weapon Alpha?
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.