Michael KreponAmchitka

I’ve always counseled our son and daughter to go the extra mile. During the Cold War nuclear competition, the Soviet Union and the United States went a bit further than the extra mile. In one particular instance, the Nixon administration drilled down to 6,150 feet – a distance equivalent to four Sears Towers stacked on top of each other – to test the warhead associated with the Spartan missile defense interceptor.

Since the only way to make missile defense intercepts successful in the 1970s was by means of a nuclear detonation, and since the Spartan was designed to serve as an area defense, its warhead had to be a big bruiser, with a design yield of five megatons. (A detonation of this magnitude would wreak havoc on the radars required to cue and plan intercepts, but never mind.) Among the reasons behind the Nixon administration’s decision to test the Spartan’s warhead at full yield were to demonstrate resolve, reinforce deterrence, and leverage the Kremlin in on-going SALT negotiations.

Conducting the largest U.S. underground test in the environs of Las Vegas was not in the cards. The search for an alternative location somehow fixed on the Aleutian Island chain jutting out into the Bering Sea, off the Soviet coastline. The sacrificial island was named Amchitka. Local Tribes that held the belief that the Aleutians were imbued with Spirit and not a suitable place for nuclear testing were not well represented on K Street.

For details of the test, I recommend Dean Kohlhoff’s book, Amchitka and the Bomb: Nuclear Testing in Alaska (2002), my source for these particulars. Drilling to this depth in the Arctic and placing a warhead weighing approximately 850,000 pounds down the shaft were no easy feats. The horizontal blast chamber, which needed to be drilled by hand, had a radius of twenty-six feet. Cabling must have been an adventure.

The test was carried out on November 6, 1971, registering 7.0 on the Richter scale – the same reading as the earthquake that rocked San Francisco and interrupted the World Series in 1989. The Amchitka test uplifted a fault line in the Bering Sea by forty-two inches.

Update | 8:05 am 7 July 2010 Here is a video of the test.


  1. Captain Ned (History)

    850,000 pounds?? According to this site, the all-up weight of the Spartan at launch was 29,000 pounds.


  2. Alex W. (History)

    Amchitka is interesting as a major P.R. issue for the Atomic Energy Commission (AEC) and US government, since the domestic political opposition was very strong to it as a specific nuclear test (rather than generalized anti-testing opposition). The AEC spent a lot of time in this period trying to decide how much information to release about it. They felt pretty strongly that if “the public” knew what it was for and why they were doing it, they would support it.

    (This period was also when the AEC really began to lose its luster in the public eye along a number of fronts, and to increasingly find its paternalistic applications of expertise, and secrecy, under general attack. Brian Balogh’s Chain Reaction: Expert Debate and Public Participation in American Commercial Nuclear Power, 1945-1975 (1991) is a great source on this general development and its consequences.)

    The DOD of course was not interested in declassifying the information, even though it was clear that a lot of the information was already pretty well known by the general public, because one doesn’t want one’s enemies knowing the details of your defense systems.

    Here is an excerpt from a January 1971 memo that I found interesting. (Original memo is part of document NV0076111 in the Nuclear Testing Archive, Las Vegas, NV.) Written by Edward B. Giller (Major General, USAF, and AEC Assistant General Manager for Military Application) and Charles L. Marshall (Director, AEC Division of Classification), it is trying to argue the pros and cons about releasing the information, and strategizing on how to get the DOD to come around to AEC’s point of view:

    Under these circumstances [of strong domestic opposition], we feel that we should do everything we reasonably can to increase public understanding of the need for and probable environmental effects of CANNIKIN. Providing the public with an official statement on the predicted yield and purpose of this test could be a step in this direction, a step which we feel might tend to decrease opposition to the test. Another consideration is the extent to which the yield and purpose of CANNIKIN are already known to the public. …
    As far as our announcement of an accurate predicted yield for CANNIKIN, again we must agree with the DOD that this might tend to remove the uncertainty in the minds of the USSR and Communist China as to the yield of the SPARTAN warhead. This information would be helpful to the Communist side in planning the employment of their strategic offensive forces.
    Although yields have been published for many weapons program tests, it has not been the practice to announce the specific purpose of such tests in terms of which weapon system warhead was being tested. Thus, our declassification of both the yield and _ purpose _ of CANNIKIN might be considered as constituting a major AEC policy change. It should be pointed out, however, that in view of statements made by authoritative government sources, e.g., Senator Jackson and Dr. Wiesner, the purpose of the test at the Amchitka STS is for all practical purposes already unclassified.
    Authoritative statements about the yield have been less clear but the multimegaton nature of the event has been publicly stated. …
    We believe careful consideration should be given to their reasoning in this matter before further attempts are made by the AEC to convince the DOD that declassification of this information would be in the national interest. It is pertinent, however, to note that in view of the fact, as illustrated above, that the information involved here is essentially already in the public domain, there can be little or no effect now on the national defense, as a result of formal declassification.

  3. Kyle Mizokami (History)

    I used to work with a guy who was a retired LLNL nuclear weapons designer. (Actually I’m assuming that’s what he was, he didn’t really talk about it.)

    I don’t know how we got onto the subject, but he mentioned he’d been involved in the CANNIKIN test. He’d been to the very bottom of the shaft and said it was 130 degrees Fahrenheit down there.

  4. C.D. (History)

    Thanks for the post. I’ve studied the Amchitka shots and find them very interesting. Not to be a smart ass or anything, but in the YouTube video, the aerial shot that shows the ground shock moving away from ground zero was from Long Shot (10/29/65), not Cannikin.

    Long Shot Video from Nuclear Testing Archive

    Time Magazine Article


  5. Allen Thomson (History)

    IIRC, the reason for doing a full-yield test was that the intended kill mechanism required massive and directional emission of x-rays from the weapon. Which, for reasons I could speculate about but won’t, probably required a very unconventional design of the secondary. I.e., they weren’t sure it would a) work at all and b) provide the desired x-ray emission.

    If you look at the picture of the W71 warhead on the Wikipedia page, there’s a cylinder at the large end of the device that I think is probably an x-ray window and maybe collimator next to the secondary.

  6. John Blankenbaker

    To Captain Ned’s question above, I’m pretty sure the 850,000 pound figure represents not just the warhead and missile body, but the giant instrumentation package (which was 264 feet long!) that had to be lowered over a mile down the 90 inch borehole.


  7. Captain Ned (History)

    Ok, after reading the GS article it’s pretty clear that the 850,000 pounds meant everything they stuffed down the hole.

    That said, I’m still in awe of the acceleration capability of the Sprint missile.

  8. MK (History)

    this from Amb. Meerburg:

    Thanks for this interesting story on Amchitka. I justed wanted to remind
    you (but you probably know this already) that the test lead to the first
    action of Greenpeace who were against the explosion because inter alia
    it would disturb the sea otter.

    Yours sincerely,

    Arend J.Meerburg
    former ambassador of The Netherlands

  9. anon

    We didn’t build many but she was unique & interesting to assemble.

    -The Sugar & Orange folks.

  10. user_hostile

    Captain Ned,Wait till you see the Sprint. I was in Mitchell county, NC in ’99 and ran into a person who worked on the program with Bell labs. He told me that designing the electronics to work at the high G’s was a major challenge. Didn’t quite grasp it until I saw the video. He and his wife run a pottery place in Penland, NC and said he was a lot happier playing with mud instead of missiles.

  11. Will (History)

    Has the video been removed from the post?