Laydown delivery

Laydown delivery is a mode of deploying a free-fall nuclear weapon in which the bomb's fall is slowed by parachute so that it actually lands on the ground before detonating. Laydown delivery requires that the weapon's case be reinforced so that it can survive the impact, and generally involves a time-delay fuse to trigger detonation. Laydown mode can be used to increase the effect of the weapon's blast on built-up targets such as submarine pens, or to transmit a shock wave through the ground to attack deeply buried targets. An attack of this type produces large amounts of radioactive fallout.

It has the additional advantage of allowing the carrier aircraft to fly very low and still get away without being destroyed in the detonation. This is particularly important where high-yield nuclear weapons such as the B41 and B53 nuclear bombs are concerned. The low altitude delivery also helps hide the aircraft from surface-to-air missiles. It was for this reason that laydown was selected for the Vickers Valiant bomber of the Royal Air Force, as this design became increasingly vulnerable to Soviet weapons, especially the SA-2 missile. Laydown was referred to as "Equipment 2 Foxtrot" in RAF parlance, with Echo referring to toss bombing and Hotel to a particular climbing delivery method used by the Avro Vulcan.

See also

• Air burst
• Toss bombing
• Nuclear bunker buster
• B53 nuclear bomb - a 9 Mt nuclear weapon designed for laydown delivery