MGM-31 Pershing

• 1. Introduction

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  The MGM-31 Pershing missile carried a nuclear warhead with yields reaching 400 kilotons, enough to level a city, and it could be assembled, oriented, and launched by a four-vehicle convoy small enough to disappear into the West German countryside. Named after General of the Armies John J. Pershing, this solid-fueled, two-stage ballistic missile became the United States Army's primary theater nuclear weapon during some of the most tense decades of the Cold War. It replaced older systems that required as many as twenty vehicles to operate, and it eventually grew capable of firing three missiles in quick succession without any pre-surveyed launch site. The story of the Pershing spans from a courtesy call in Alabama in 1956 to the final crushing of the last missiles at the Longhorn Army Ammunition Plant in Texas in 1991. Along the way it navigated political pressure over government contracts, a race to improve reaction times, and ultimately a treaty that made it obsolete.

• 2. Origins and a Courtesy Call

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  George Bunker, president of the Martin Company, paid a courtesy call on General John Medaris at the Army Ballistic Missile Agency at Redstone Arsenal, Alabama in 1956. Medaris mentioned during that visit that the Army would benefit from a missile plant near the Air Force Missile Test Center in Florida. Martin took the hint. The company broke ground on a Sand Lake facility in Orlando, and it opened in late 1957. Edward Uhl, the co-inventor of the bazooka, served as vice-president and general manager of the new factory. That Orlando plant continues to operate today as the Lockheed Martin Missiles and Fire Control facility.

  Also in 1956, the Army had begun studies for a ballistic missile with a range of roughly 500-750 nautical miles. That same year, Secretary of Defense Charles Erwin Wilson issued what became known as the Wilson Memorandum, stripping the Army of all missiles with a range of 200 miles or more. The Department of Defense reversed course in 1958, and development of the new missile class could finally begin.

  The missile was first called the Redstone-S, the S denoting solid propellant and the name Redstone pointing to what it was meant to replace. It was later renamed Pershing in honor of the famous general. Seven companies were invited to submit engineering proposals: Chrysler, Lockheed, Douglas Aircraft, the Convair Division of General Dynamics, Firestone, Sperry-Rand, and Martin. The Secretary of the Army, Wilber M. Brucker, who had served as governor of Michigan, reportedly faced pressure to steer the contract to Chrysler, the only Michigan bidder. General Medaris persuaded him to let ABMA make the call independently. After a selection process run by Medaris and Dr. Arthur Rudolph, Martin was awarded a cost-plus-fixed-fee contract.

• 3. Building for Zero Defects

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  Phil Crosby, Martin's quality control manager for the Pershing program, developed the concept of Zero Defects during his work on the missile. The idea held that defects were preventable if workers understood their precise role in the outcome, and it shaped the production and reliability of the Pershing system. The first launch of an R&D test missile, designated P-01, took place on the 25th of February 1960. The first launch from the tactical transporter erector launcher came on the 26th of July 1960.

  President Eisenhower viewed the Pershing during a visit to Cape Canaveral on the 11th of February 1960, and again at Fort Benning on the 5th of May 1960 as part of Project MAN, which stood for Modern Army Needs. President Kennedy saw the missile three times: during the inaugural parade in 1961, at Fort Bragg on the 12th of October 1961, and at White Sands Missile Range in 1963.

  Original plans called for ten missile battalions, one at Fort Sill, one in Korea, and eight in West Germany. That number shrank to one at Fort Sill and three in West Germany. The first tactical Pershing unit was the 2nd Missile Battalion, 44th Artillery Regiment. A proposed deployment to South Korea, organized in February 1964, was placed on hold and eventually canceled.

• 4. How the Missile Worked

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  Two Thiokol solid-propellant motors powered the Pershing 1 missile. Because a solid-propellant motor cannot simply be switched off, the engineers devised a selective range system using thrust reversal and case venting. Explosive bolts held the rocket stages together; at the right moment, those bolts detonated and the splice band was ejected. Thrust reversal ports opened at the forward end of the stage, igniting propellant in the reverse direction to slow it down. A separate problem emerged during testing: the second stage drafted behind the warhead and caused it to drift off course. Engineers solved this by fitting explosive charges on the motor casing that opened and vented the remaining propellant. The maximum range was 740 km.

  Guidance came from an analog computer working alongside the Eclipse-Pioneer ST-120 inertial navigation system, known as the Stable Table-120. Jet vanes in the motor nozzles and air vanes on the motor casing handled steering. The warhead could be conventional explosive or a W50 nuclear weapon offering three yield options: the Y1 at 60 kilotons, the Y2 at 200 kilotons, and the Y3 at 400 kilotons. The conventional warhead was never actually deployed.

  By comparison with the Redstone it replaced, the Pershing 1 firing platoon needed only four tracked M474 vehicles manufactured by FMC Corporation. Collins Radio Company built the AN/TRC-80 Radio Terminal Set specifically for the system, which used an inflatable dish antenna for voice and teleprinter communications. The entire erector-launcher, programmer test station, power station, and radio terminal set could be airlifted in fourteen CH-47 Chinook loads.

• 5. The Quick Reaction Alert Upgrade

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  In 1964, a Department of Defense study concluded that the Pershing would outperform tactical aircraft in the Quick Reaction Alert, or QRA, role. The Secretary of Defense assigned the weapon system to that mission the same year. The QRA role meant that one firing battery or a portion of each battalion had to be at combat alert status on a permanent hard site at all times.

  The Pershing 1a development program was approved in 1965, and Martin Marietta received the production contract in 1967. Project SWAP replaced all Pershing equipment in Germany by mid-1970. Secretary of Defense Robert McNamara also directed in 1965 that the U.S. Air Force's MGM-13 Mace cruise missiles would be replaced by the Pershing 1a. The number of launchers per battalion grew from 8 to 36, and launch times dropped. The total number of MGM-31A missiles built reached 754.

  A 1971 upgrade replaced the two separate analog computers in the missile with a single digital guidance and control computer. By 1976, further improvements allowed a platoon to fire three missiles in quick succession from any site without prior surveying. The Automatic Reference System used an optical laser link and a north-seeking gyro to orient the missile, eliminating the need for pre-surveyed points. A Sequential Launch Adapter connected one programmer test station to all three launchers simultaneously. Mean time to repair dropped from 8.7 hours to 3.8 hours, while mean time between failures rose from 32 hours to 65 hours.

• 6. West Germany and Survivability

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  Pershing 1a was deployed with three U.S. Army battalions and two German Air Force wings in Europe, each battalion or wing operating 36 mobile launchers. The constitution of West Germany prohibited the country from owning nuclear weapons, so control of all nuclear warheads remained with the U.S. Army, even when German Air Force crews operated the missiles. The German Air Force units used Magirus-Deutz Jupiter 6x6 tractors in place of the Ford M757 used by U.S. Army units.

  The system was positioned more than 100 km behind the forward edge of the battle area or political border. Its mobility allowed dispersal to clandestine sites during any heightened alert. Firing platoons moved to new positions on a random schedule to complicate targeting by an adversary. During a period of tension, batteries would move from permanent hard sites to previously unused field sites, maintaining coverage on high-priority targets throughout the transition. Because of this combination of mobility and setback, Pershing was regarded as one of the most survivable theater nuclear weapons deployed in Europe.

  After a Pershing II explosion in 1985, the Pershing 1a launchers of the German Air Force were retrofitted with ballistic shields. In 1987, a joint Army and Department of Energy study found it feasible to replace the W50 warhead with the W85 warhead developed for the Pershing II. The signing of the INF Treaty ended that conversion before it began.

• 7. Treaty and Destruction

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  The Intermediate-Range Nuclear Forces Treaty was ratified on the 27th of May 1988, requiring the elimination of an entire class of missiles. Withdrawal of Pershing missiles began in October 1988. The last missiles were destroyed by the static burn of their motors, then crushed, in May 1991 at the Longhorn Army Ammunition Plant near Caddo Lake, Texas. West Germany, though not legally bound by the treaty terms covering its own Pershing 1a inventory, agreed unilaterally to the removal of those missiles in 1991, and they were destroyed in the United States.

  The 56th Field Artillery Brigade, which had managed U.S. Pershing deployments in Europe since its reorganization in 1972, stood down in 1986, three years before the missiles began leaving the continent. The German Air Force's Missile Wing 1 and Missile Wing 2, each composed of two missile groups, were among the final operators to relinquish the weapons they had trained on at Fort Sill. The Pershing 1a's journey from a courtesy call in Alabama in 1956 to a crushing facility in Texas in 1991 closed a chapter in the nuclear balance of Cold War Europe, though the Longhorn Army Ammunition Plant where those final motors burned still stands near Caddo Lake.