The VT Fuze was a proximity fuze developed by the UK and USA for artillery shells and AA guns during WW2. They detected range to the target by radio signals using vacuum tube technology. The purpose of this was to detonate the shell at the best distance, so that the explosion and shrapnel cover a greater effective area.

I would like to know when was the first time they were used in combat? The wiki article surprisingly has no say on this, only mentioning in passing a few uses in 1944.

The closest I've found so far is this Google Book result where it says

The proximity fuze was first successfully emplyed in June 1943, in 5-inch shells fired by the U.S. Cruiser Helena to shoot down a Japanese bomber.

However, that's the first successful use rather than the first use. It reads as though it was the first VT Fuze that scored a kill.

I want to know what was the first actual combat that saw use of the VT Fuze, whether for regular artillery or anti-aircraft artillery.

3 Answers 3


From: APL Technical Digest (Sept-Oct 1962) (PDF):

The Fuze Goes into Action

Since the Combined Chiefs of Staff felt strongly that the fuze should not be used where a dud might be recovered on the ground, the South Pacific, where Japanese land-based aircraft were a constant and serious menace, seemed the area of first importance. First deliveries of the new fuzes, then, were to be made to ships in that area having the 5-in. guns for which the earliest production fuzes were designed. During October 1942, 500 fuzes for shipboard use were produced each day and shipped immediately to the Naval Ammunition Depot, Mare Island, where they were inserted in the fuze cavities of 5-in. shells. Of each day's consignment, 10% were withdrawn and flown back to the Naval Proving Ground, Dahlgren, Va., for test. When 5000 proximity-fuzed projectiles had accumulated, Commander W. S. Parsons, Special Assistant to the Director, OSRD, went to Mare Island to supervise loading of the shells for air transportation to Pearl Harbor. He then flew to Hawaii, leaving the ammunition in the care of three scientists from APL specifically commissioned for this duty: Lieutenants N. E. Dilley, R. P. Petersen, and J. A. Van Allen.

First Strike-Pacific Theater

At Pearl Harbor the shells were loaded into the aircraft tender USS Wright for transshipment to Noumea, New Caledonia, where Commander Parsons reported to Admiral Halsey. Three ships of the Third Fleet received portions of this first shipmentUSS Enterprise, USS Saratoga, and USS Helena- and indoctrination of their personnel commenced immediately. There was a period of relative inactivity in the Third Fleet area at the time, extending into the early months of 1943, an excellent time for indoctrination but giving little opportunity for battle test of the new fuze. On Jan. 5, 1943, however, a Japanese plane was destroyed by a proximity fuze, the first of a long record of encouraging successes that made such an important contribution to total Allied victory.

From: Dilley, N. E. "Development of Proximity Fuzes (VT) for Projectiles - VT Fuzes MKS 32 to 60, Inclusive (General Description)." chapter 1 of The World War II Proximity Fuze: A Compilation of Naval Ordnance Reports by the Johns Hopkins University Applied Physics Laboratory. (Silver Spring MD: The Laboratory, 1950): 1-12. [Declassified 16 Jun. 1976].

(I can't find an original copy of this, it is quoted here)

This test firing of proximity fuzed 5"/38 projectiles against drones was carried out in August 1942 aboard the cruiser [USS] Cleveland [CL-55]. Results of this test were entirely satisfactory and accordingly, full-scale production of proximity fuzes was initiated at the Crosley Corporation in September 1942. Early production was plagued with numerous difficulties but satisfactory material was finally produced. This fuze, which was designated the Mk 32, was delivered to the Fleet during November and December 1942, and the first Japanese plane was shot down with proximity fuzed projectiles by the cruiser [USS] Helena [CL-50] in January 1943.

  • As a side note: Commander Parsons, after successfully leading this program, was transferred to the Manhattan Project. There he lead the group attached to the 509th Composite Squadron devoted to delivery of the bombs. Parsons was the mission commander (overall command) on the Enola Gay at Hiroshima. Post war he became an admiral, the first to have never commanded a ship.
    – Jon Custer
    Commented Aug 18, 2017 at 12:22
  • 1
    Further side note: Lieutenant J. A. Van Allen was later the discoverer of the radiation belts named after him. Commented Aug 18, 2017 at 20:18

This site:


contradicts your source, saying that the VT fuse was first "introduced" to the enemy by the U.S.S. Helena on January 5, 1943, resulting in the destruction of one plane. This phrase unambiguously identifies the first usage in combat- and given the similarity in circumstances it's possible that both your source and this source are referring to the same incident but one has gotten the date wrong.

There are no in-line citations on this page, but the end notes cite:


History of Communications-Electronics in the United States Navy By Captain L. S. Howeth, USN (Retired) 1963.

The History of US Electronic Warefare By Alfred Price, Publisher: Association of Old Crows.

'The K. D. Smith Collection' at the Southwest Museum of Electricity and Communications, Phx. AZ.

In addition, many conceptional views were provided by footage and narration of film from the World War II era. Views were also been provided to me over the past 39 years by those that I came in contact with, that either worked on the Proximity Fuze, or were users of the device. - Edward A. Sharpe Archivist, SMEC.

That website belongs to SMECC: The Southwest Museum of Engineering, Communications and Computation. They appear to be interested in fielding inquiries if you want to track down further information.


In Admiral Nimitz's "gray book" (running account of WW2 in the Pacific) in the entry for Dec 16, 1942:

The INDIANAPOLIS and WILSON conducted firing tests today off OAHU with the 5" AA Mk. 32 fuze. Performance indicates great possibilities and battle distribution of the fuze is underway.

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