B61 Family The B61 Family is a series of thermonuclear bomb s and thermonuclear warheads based on the B61 nuclear bomb . B61 nuclear bomb . Initial development . The B61 bomb was developed by Los Alamos Scientific Laboratory ( LASL ; now Los Alamos National Laboratory ) starting in 1960 . The intent was to develop an aircraft bomb which was high yield ( up to over 100 kilotons ) and yet was small enough and had low enough drag to carry under the wing of a fighter or fighter - bomber type aircraft . One major feature was Full Fuzing Options ( allowing various air and ground burst usage options ; free fall air burst , parachute retarded air burst , free fall ground burst , parachute retarded ground burst , and " laydown " or parachute retarded time delay after impact ground burst ) . The B61 project started in 1960 with a study contract analyzing the potential of such a weapon . The official development program was funded in 1961 , and the weapon was designated TX - 61 ( Test / Experimental ) in 1963 . The original models of B61 used PBX 9404 HMX based plastic bonded explosive to implode the fissile material in the primary stage . Newer models use TATB based PBX 9502 , which is an insensitive high explosive ( IHE ) and will not detonate due to fire , shock , or impact . Specifications . Bomb . The overall B61 bomb was diameter by long , and weighed 695 - 715 pounds depending on version . This includes the outer aerodynamic shell , a crushable nose cone , parachute section in the tail , tail fins , etc . ( Weight includes tail fins ; diameter is of the bomb body itself , without fins ) . Nuclear core . The nuclear device within the outer B61 core is probably the same overall dimensions as the W80 warhead , which is in diameter and long . Warheads . W69 . The W69 missile warhead was produced in the early 1970s for use in the AGM - 69 SRAM Short Range Attack Missile . The W69 was in diameter and long , weighed 275 pounds , and had a yield of 170 - 200 kilotons . 1 , 500 W69 warheads were produced . W73 . The W73 missile warhead was designed for the AGM - 53 Condor air to ground missile . Other than being described as a derivative of the B61 , details of the W73 design are poorly documented . Both the W73 and the Condor missile were cancelled and never entered service . W80 . Two versions of the base W80 cruise missile warhead were designed and deployed . Both were the same basic size and shape and weight : 11 . 8 inches in diameter , 31 . 4 inches long , and weight of 290 pounds . W80 - 0 . The BGM - 109 Tomahawk TLAM - N cruise missile was equipped with a W80 - 0 warhead . The W80 - 0 used supergrade plutonium with less inherent radioactivity , due to missile storage in close proximity to submarine crew . It also has an outer shielding or case around the " front " end of the weapon , presumably some sort of radiation shielding . The W80 - 0 had a variable yield of 5 or 170 - 200 kilotons . 367 W80 - 0 warheads were produced . W80 - 1 . The AGM - 86 ALCM and ACM cruise missiles used the W80 - 1 variant warhead . It had a yield of 5 or 150 - 170 kilotons . 1 , 750 W80 - 1 warheads were produced . W81 . The W81 missile warhead was designed for use on the SM - 2 missile . An enhanced radiation version was proposed , but the final version was fission - only . Detailed dimensions and weight are unknown . Yields are described as 2 - 4 kilotons . The W81 was cancelled and never entered service . W84 . The W84 was a LLNL design based on the B61 , used in the Ground Launched Cruise Missile . It was slightly larger ( 13 inches diameter , 34 inches long ) and heavier ( 388 pounds ) than the otherwise similar W80 warheads , possibly to make it safer for ground handling in the field . Between 300 and 350 W84 warheads were produced . They remain in US inactive inventory . W85 . Used on the Pershing II IRBM missile , the W85 was a cylinder in diameter and long . The warhead weighed 880 pounds . It had a variable yield from 5 to 80 kilotons . 120 W85 warheads were produced . They were recycled into B61 Mod 10 bombs after the Pershing II was scrapped . W86 . The W86 warhead was a planned earth - penetrating warhead for the Pershing II missile . The W86 was cancelled after the Pershing II was changed from hard target to soft target missions in its design phase . No units were ever produced .