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Mk49

  • Designer
    • Los Alamos Scientific Laboratory (LASL)
  • Type
    • Implosion
  • Dimension(s)
    • ?
  • Weight(s)
    • 1,600lbs
  • Yield(s)
    • Y1 / 1.1Mt
    • Y2 / 1.5Mt
  • Warhead
    • W49, Mk2 Aeroshell – Atlas B & C
  • Warhead
    • W49, Mk2 Aeroshell – Thor
  • Warhead
    • W49, Mk3 Aeroshell – Atlas D
  • Warhead
    • W49, Mk3 Aeroshell – Jupiter C
  • Warhead
    • W49, Mk3 Aeroshell – Titan I
  • Warhead
    • W49, Mk4 Aeroshell – Thor

Designed by Los Alamos National Laboratory9.2, the Mk49Y1 was used on the Jupiter2.1, Atlas, Thor, and Titan I missiles.4.1

The Mk49 Y1 had a yield of 1.1Mt, with Y2 being a converted Mk28 Y5 at 1.5Mt10.1

Yield of 1.4Mt5.1

First system to utilize PAL hardware, one year before all land-based weapons were required to have them.2.1

Was mated to the Mk1 aeroshell5.1 when used on the Atlas D missile.2.2, 5.2

Was mated to the Mk2 aeroshell when used on the Thor and Atlas B & C missiles.3.3

Was mated to the Mk2 & Mk3 aeroshells when used on the Thor missile. The Mk2 aeroshell used a 5′ x 5′ copper/beryllium heat sink, weighing 1,200lbs3.3

The complete re-entry vehicle with warhead, weighed 2,617 pounds, the Mk49 weighed 1,600 pounds6.1

Was mated to the Mk4 aeroshell when used on the Thor missile.9.1

First production unit (FPU) was produced September of 19585.1, 3.1

Tested in Operation Dominic I, shot Starfish Prime1.1, 8.1 while mated to a Mk4 aeroshell on a Thor (PGM-17) missile 9.1

Used the Python primary.8.2

The Y1 Mod 0 entered the stockpile in September 1958, and was approved for use with the Jupiter Intermediate-Range Ballistic Missile (IRBM), Thor (IRBM), and Atlas Intercontinental Ballistic Missile (ICBM) delivery systems11.1

Mk49 Mod 0 used a Jonah-type initiator10.2

Mk49 Mod 111 added an inertial switch which closed after experiencing a force of 3-10Gs for a total of 10G seconds. Mod 1 also introduced Y2. The Mod 1 also used Jonah-type initiators10.2

Mk49 Mod 211 was modified to be used with the Mk3 ablative re-entry vehicle10.2

Mk49 Mod 311 had an autodestruct switch added in December 1963 for the Y2 configuration10.2

Mk49 Mod 411 cancelled the Mod 2, added external initiators and was used exclusively with the Atlas D

Mk49 Mod 5 was a Mod 3 equipped with a Permissive Action Link (PAL) device, increasing the weight of the warhead by 12 pounds. The AEC manufactured the Mod 4 by refitting the Mod 3‘s inertial switch with a coded pack and a two-piece pressure cover.10.2

On October 19th, 1961, a Jupiter missile armed with a Mk49 was struck by lightning, resulting in deuterium-tritium boosting gas being injected into the warhead pit and activation of thermal batteries in the adaptation kit. The missile was returned to operational status after 76 days. On November 4th, 1961 the warhead was flown back to the Clarksville Modification Center for post-mortem examination1.2

  1. Hansen, C. (1995). Swords of Armageddon: The Development of U.S. Nuclear Weapons—Arming, Fuzing, Safing, and Appendices (2nd Edition, Vol. 7). Chukelea Publications. http://www.worldcat.org/oclc/62490342
    1. p.79 (PDF Page)
    2. p.278 (PDF Page)
  2. Loeber, C. R. (2002). Building the Bombs: A History of the Nuclear Weapons Complex. https://prod-ng.sandia.gov/techlib-noauth/access-control.cgi/2002/020307p.pdf
    1. p.150
    2. p.200
  3. Hansen, C. (1988). US Nuclear Weapons: The Secret History. Crown Publishers Inc. http://www.worldcat.org/oclc/16404602
    1. p.107
    2. p.111 (PDF Page)
    3. p.201 (PDF Page)
  4. Sandia National Laboratory. (1998). Survey of Weapon Development and Technology (No. WR708; p. 650). http://fissilematerials.org/library/snl98.pdf
    1. p.89
  5. Norris, R. S., & Cochran, T. B. (1997). Nuclear Weapons Databook: US – USSR/Russian Strategic Offensive Nuclear Forces 1945-1996. Natural Resources Defense Council Inc. https://fas.org/nuke/norris/nuc_01009701a_181.pdf
    1. p.28
    2. p.23
  6. Stumpf, David K. (2017).Reentry Vehicle Development Leading to the Minuteman Avco Mark 5 and 11. Air Power History, 64(3), 68. https://www.afhistory.org/wp-content/uploads/APH-Fall-2017-Issue-1.pdf
    1. p.24
  7. Norris, Robert S. & Kristensen, Hans M. (2012). The Cuban Missile Crisis: A Nuclear Order of Battle, October and November 1962. Bulletin of the Atomic Scientists, 68(1–6), 583. https://www.tandfonline.com/toc/rbul20/68/1?nav=tocList
    1. p.581 (PDF Page)
  8. Hansen, Chuck. (2001). Beware the Old Story. Bulletin of the Atomic Scientists, 57(1–6). https://www.tandfonline.com/toc/rbul20/57/1?nav=tocList
    1. p.132 (PDF Page)
    2. p.133 (PDF Page)
  9. Norris, R. S., & Cochran, T. B. (1994). United States Nuclear Tests July 1945 to 31 December 1992 (NWD 94-1; p. 74). Natural Resources Defense Council. https://fas.org/nuke/cochran/nuc_02019401a_121.pdf
    1. p.37 (PDF Page)
    2. p.28 (PDF Page)
  10. Goetz, P. A. (2018). A Technical History of America’s Nuclear Arms Volume II – Weapon Systems From 1960 to the Present (1st Edition, Vol. 2). Amazon Digital Services LLC – KDP Print U.S. https://www.google.it/books/edition/A_Technical_History_of_America_s_Nuclear/Ji_azQEACAAJ?hl=en
    1. p.113 (PDF Page)
    2. p.121 (PDF Page)
  11. Information Research Division 3434. (1968). History of the Mk49 Warhead. Los Alamos National Laboratory. https://osf.io/46sfd/
    1. p.6 (PDF Page)