32

Following up on this answer...

@mark, in the answer, writes that "[i]n the event that the crew of Enola Gay had to abort their mission, they had no intention of trying to land with the bomb still aboard".

That sounds like there was a plan to drop the bomb somewhere else if they were forced to abort the mission. Was there such a plan?

38

There was discussion of options. The "gadget" was an atomic bomb.

From the minutes of the Target Committee for 10 May 1945:

  1. Gadget Jettisoning and Landing

A. It was agreed that if the aircraft has to return to its base with the gadget and if it is in good condition when it has reached there, it should make a normal landing with the greatest possible care and with such precautions as stand-by fire equipment being held in readiness on the ground. This operation will inevitably involve some risks to the base and to the other aircraft parked on the field. However, the chance of a crash when the aircraft is in good condition and the chances of a crash initiating a high order explosion are both sufficiently small that it was the view of those present that the landing operation with the unit under these circumstances was a justifiable risk. Frequent landings with inert and H.E. filled units have been made in the past. Training in landing with the unit should be given to all crews who carry an active unit.

B. In case the aircraft returns to its base and then finds that it cannot make a normal landing it may be necessary to jettison the bomb. In the case of the Fat Man this can probably best be accomplished by dropping the bomb into shallow water from a low altitude. Tests on this will be carried out with both inert and live units. In the case of the Little Boy the situation is considerably more complicated since water leaking into the Little boy will set off a nuclear reaction, and since the American held territory in the vicinity of the base is so densely filled that no suitable jettisoning ground for the Little Boy has been found which is sufficiently devoid of moisture, which is sufficiently soft that the projectile is sure not to seat from the impact, and which is sufficiently remote from extremely important American installations whose damage by a nuclear explosion would seriously affect the American war effort. The best emergency procedure that has so far been proposed is considered to be the removal of the gunpowder from the gun and the execution of a crash landing. In this case there is no danger of fire setting off the gun and the accelerations should be sufficiently small to prevent seating of the projectile by the impact. Tests on the feasibility of unloading the gun powder in flight will be conducted.

C. It was agreed that prior to actual delivery some form of instructions should be prepared as a guide to the senior man on the aircraft as to procedures to be followed in cases of different types of disasters.

Captain Parsons, the weaponeer aboard Enola Gay in the actual mission, was present at this meeting.

Full minutes may be found at https://nsarchive2.gwu.edu/nukevault/ebb525-The-Atomic-Bomb-and-the-End-of-World-War-II/documents/011.pdf

  • 3
    "since water leaking into the Little boy will set off a nuclear reaction" - I'm curious why this is the case - I know there was a war going on, but it seems unlikely the engineers would have designed a nuclear bomb that could be set off by rain... wasn't there an arming mechanism that would have rendered it safe under most conditions like modern bombs do? – Dai May 9 at 19:40
  • 23
    @Dai, when they say "water leaking into Little Boy", they're referring to the level of leakage you'd expect from dropping the bomb into the ocean. To maximize the explosive power of the bomb, the two halves of the core are each nearly of critical mass in open air; water acts as a neutron moderator, so if you fill the bomb with water, those two subcritical halves are now critical masses, producing a great deal of radiation and possibly a small explosion. – Mark May 9 at 19:59
  • 11
    Little Boy was of an extremely crude design: inefficient, probabilistic chance of fizzling, and as the above mentions, unsafe. That said, it was extremely likely to work, such that the designers didn't even bother testing it (the "gadget" of the Trinity test site was of the Fat Man design). Modern weapons use explosive lenses that compress a subcritical mass, which is a) more efficient because you don't actually need a critical mass at standard conditions, b) safer as the lenses need to go off with very tight timings. – Nick T May 9 at 20:59
  • 14
    First they called it a gadget, but then they called it a bomb and mentioned nuclear reactions - why? – user253751 May 9 at 22:25
  • 4
    @chrylis: No more a euphemism than the use of the term "gun powder" to refer to the propellant in actual firearm cartridges - Little Boy used cordite as its propellant, just like most firearms and artillery of the time. – Sean May 10 at 4:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.