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From Rod van Ausdall, June 2004

Mating the W31 Nuclear Warhead
to the Nike Hercules Missile

The Assembly operations required to mate (attach) the W31 Nuclear Warhead to the Nike Hercules Missile was probably the most closely scrutinized, by Technical Proficiency Inspection Teams, of any Nike site operation.

Initial Test operations of the missile (less booster and warhead) in the Assembly building included use of the RF Test set and associated wave guides and wiring harnesses to cause the missile to perform all in-flight operations including receipt of the burst command,flight commands, operation of all electronic and hydraulic systems and exercise of the Hydraulic Power Unit (HPU - early versions called the Auxilliary Power Unit or APU). These tests were accompanied by the tremendous and sudden "clang bang" of the aerilons and fins moving "hard over" and the ear splitting whine of the APU / HPU coming up to speed at a extremely high number of revolutions per minute.

Upon completion of these tests the missile was mounted on a missile trailer and moved downrange (two man rule and passwords in effect now) to the warhead building and positioned with the forward end of the missile facing the lid of the buttoned up XM401 warhead container.

Mating of the warhead was usually a very business-like but relaxed , atmosphere but when a TPI team was present, it became a little tense, as might be expected when every minute operation and technique were under intense scrutiny by the members of the TPI Team. Things such as minute inspection and handling of an attachment bolt (and it had better be the correct bolt),cleansing of various surfaces and tools, proper sequence of events as evidenced by a comprehensive check list, proper routing of cables, calibration of test equipment properly certified as up-to-date, knowledgeable personnel present (as determined by sharp questioning of selected individuals), proper grounding of certain equipment, missile, and warhead, lifting equipment properly certified, fire extinguishers and other attendant equipment in working order, and if any lighter, matches, or fire making device was present one might as well give it up you were finished, and of course the two man rule was in effect (the two man rule specifies not only must two men be present but they must be equally knowledgeable and qualified as to the operation they are conducting.)

The first operation after the missile was present and grounded was to open the warhead can and a Test Set must be present and monitoring the air to detect any presence of nuclear related contaminate. The use of this Tester was later discontinued.

A pressure gauge was then used to determine the pressure inside the warhead container (ideal was 5 psi) and deviation from the norm caused special procedures to be followed.

When the warhead container was opened and the warhead, riding on rails, was slid forward, beginning the sequence of attaching a lift bar to the 1100 pound warhead and bringing it with a hoist to the attach points at station 87.5 of the missile. (stations are merely the number of inches from the nose of the missile to the rear of the missile body ((full configuration)).

Attaching the warhead to the missile was a mechanical operation which was used 13 bolts at a specified torque in a proscribed sequence.

The adaption kit, XM75E1, which adapted the W31 warhead to the Nike Missile, was unpackaged and bolted to the forward end of the warhead (now a part of the missile). Keep in mind the W31 could be used in other systems by the use of other adaption kits and the AK XM75E1 was the adaption kit for the Nike Hercules. The missile, less booster, was now almost completely assembled except for the nose cone section, which carried the "stovepipe" or "mushroom" guidance package and the barometric probe.

After installation of the adaption kit and attachment of all electrical cabling, tests of the Cartridge/warhead circuitry were required and for this the T4014 test set was used. The tests were primarily go/no-go except for the testing of the barometric switches which must operate properly at certain altitudes. Simply put, the baro switches allowed final arming of the warhead at a setting (to be determined at the appropriate time) and also to insure failsafe operation when passing through a set altitude (i.e. if a missile gets away and falls unguided the baro switches operate and cause a low altitude one-point destruct of the warhead to occur) . A one point destruct merely means the warhead is detonated from one point (as opposed to an implosion detonation) and results only in a High Explosive (HE) detonation (about 550 pounds of explosive) with no nuclear yield or at least a very small amount. During TPIs using the T74 Trainer round and Training warhead, faults were introduced to the test sets and corrective action was taken by the warhead crew. Of course this never occurred in actual mating operations.

The operation of the Surface to Surface plug, Surface to Air plug and the Safe Plug were tested and ended with the installation of the safe plug.

Upon completion of the XM75E1 cartridge checkout the nose cone is mounted and the missile is taken to the launcher and by use of a crane, mounted on the launcher (the booster is already emplaced on the launcher) with the "boat tail" of the missile sliding in to the space provided in the booster cluster.

Various electrical checks are made, the baro settings are finalized by the use of the Launch Control Indicator in the launching section. The final operation is the examination and installation of the barometric probe on the nose section and installation of the probe cover ("doghouse") .

We have now tested, war headed, tested again, and "joined" the missile to the booster on the launcher and have in effect released the missile to the launcher section chief for normal operations.

I may have made a small error or two in the above but I don't think so. After all it has been several decades.

Rod van Ausdall


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