20 Friday Sep 2013
Written by Mark Christ
The Titan II ICBM Missile Silo 374- 7 Site is nationally significant by virtue of its unique and exceptionally important history within the Titan II program: it was the site of a September 1980 accident that severely damaged the launch complex, killed an airman, destroyed the rocket, and brought the safety of the entire Titan II program into question. Its singular history makes it eligible for listing on the National Register of Historic Places under Criterion A with national significance within the historic context Titan II Launch Complex Sites Associated with the 308th Strategic Missile Wing. That same history allows it to meet the “exceptional importance” requirements of Criteria Consideration G: Properties That Have Achieved Significance Within the Last Fifty Years.
Construction began on 30 January 1961 and the site was placed on alert on 18 December 1963. Launch Complex 374-7 was taken off strategic alert on 21 September 1980 as the result of a catastrophic missile explosion. The headworks were destroyed as a result of this explosion.
Launch Complex 374-7 was involved in two incidents. The first took place on morning of 27 January 1978, at approximately 0915, when the oncoming missile combat crew approaching the launch complex noticed oxidizer vapors rising from the missile complex. They drove to Damascus and contacted the command post, which in turn notified the Missile Potential Hazard Team (MPHT) members. By 0945 the MPHT directed the missile combat crew commander at the complex to turn off the circuit breakers to the heaters on the oxidizer transport trailers. The heaters were used to keep the oxidizer between 42 and 60 F in preparation for flowing into the holding trailer. Meanwhile, a helicopter from the 37th Air Rescue and Recovery Squadron was sent to provide aerial surveillance of the situation. At 1030 the helicopter crew confirmed the presence of oxidizer vapors rising from the trailer and crossing State Highway 65 in a cloud approximately 3,000 feet long, 300 feet wide and 100 feet in height. The MPHT immediately directed the Van Buren County Sheriff’s Department to block Highway 65 and requested evacuation of civilians in the path of the oxidizer cloud, including an elementary school 1.5 miles north of the complex. At 1042 a second helicopter with propellant transfer personnel in rocket fuel handlers clothing outfits was dispatched. Upon arrival at the complex, the team reported that the oxidizer trailer tank was at 101 F and leaking around the manhole cover, the safety rupture discs had not yet burst. They sprayed water on the tank to cool it off and tightened the manhole cover bolts, decreasing the amount of vapor considerably. By 1405 Highway 65 was reopened to traffic. By 2120 the oxidizer had been transferred to the holding trailer and the hazard situation was terminated. Four civilians displayed some symptoms of contact with the vapors and were transported to the Little Rock AFB hospital for evaluation. Two were released the same day and two were held overnight for observation, subsequently released, readmitted and released on 4 February 1978.
The second incident, and the one that makes this launch complex exceptionally significant within the context of the entire Titan II program, took place at 1835 hours 20 September 1980, during a routine Stage II oxidizer tank repressurization procedure. An 8.75 pound socket wrench socket was inadvertently dropped from a work platform in the launch duct on Level 2. After a drop of approximately 66 feet, the socket hit the missile thrust mount and bounced in towards the missile, puncturing the Stage I propellant tank, filled with Aerozine 50, a 1:1 mix of unsymmetrical dimethyl hydrazine and hydrazine. A Missile Potential Hazard Team was formed and the surrounding civilian population evacuated as a precautionary measure. A propellant transfer system team was formed to attempt to penetrate into the launch control center and into the launch duct area.
At 0300 hours on 21 September 1980, the accumulated fuel vapors were ignited, causing an explosion that destroyed the missile silo. The silo closure door, which weighed 740 tons, was thrown several hundred feet upwards and landed 625 feet to the northeast of the silo. The W-53 warhead was found damaged but basically intact without a detectable leakage of radioactive material.
Amazingly enough, only one person was fatally injured: Senior Airman David Livingston, one member of a two- man propellant transfer team investigating the status of the silo just prior to the explosion.
A 40-member Eighth Air Force Mishap Investigation Board and a separate Missile Accident Investigation Board evaluated the accident and concluded that the near-disaster was caused by human error and gave high marks to the silo, which largely contained the massive explosion, and the warhead, which was not blown up by its conventional explosive components. In fact, a partial glass of Coca Cola abandoned in the control center did not spill in the massive explosion, a testament to the facility’s shock-absorbent design.
Four days after the accident at Launch Complex 374-7, Secretary of the Air Force Hans Mark announced an independent committee formed to review the Titan II weapons system. They reviewed a seven-month old report on Titan II that had been submitted to the Senate and House Armed Forces Committees regarding the physical condition and maintainability of the Titan II system in addition to the Air Force accident reports. The committee concluded in January 1981 that Titan II remained a reliable system and that the system’s on-going safety studies were effectively monitoring the Titan II program. The committee concluded that human, not mechanical, error was at fault in every fatal accident at a Titan II launch complex; the system was reliable, but unforgiving.
The cost to totally replaced the massively damaged Launch Complex 374-7 was estimated at $225,322,670, while demolition and cleanup was expected to cost a mere $20 million. Between October 6-11, 1980, personnel scoured a one-half mile radius around the complex to gather the scattered debris from the explosion, debris ranging from pieces as small as an acorn to as large as 30 tons. Some 100,000 gallons of water were pumped from the launch duct and neutralized and water wells were tested to determine whether they suffered contamination. None had.
The 308th SMW in mid-1981 held a conference to determine how to seal and make safe the remains of Launch Complex 374-7 in a way that would preserve its integrity should restoration be considered feasible at a later date. Ultimately, the decision was to seal the site with soil, gravel and small concrete debris, allowing access at a later date. Later that year, the decision was made to retire the Titan II program as part of President Reagan’s modernization program.
The number and integrity of site features at the Titan II ICBM Missile Silo 374-7 site show that the overall site has a high degree of integrity of location, design, setting, materials, workmanship, feeling and association of the complex’s 19-year life span from construction to demobilization. In addition, this site has added historic importance by virtue of the 1980 explosion that took place there, the only such disaster in the history of the Titan II program. As such, it meets the requirements for listing on the National Register of Historic Places under Criterion A within the historic context Titan II Launch Complex Sites Associated with the 308th Strategic Missile Wing in Arkansas. Because of its unique place within the nationally significant role the Titan II missile complexes of the 308th SMW played in the nuclear strategies of the Cold War, it also meets the “exceptional importance” requirements of Criteria Consideration G: Properties That Have Achieved Significance Within the Last Fifty Years.
“Ballistic Systems Division Management Data System Titan Master Schedule, March 1965.” Air Force Historical Research Agency, Maxwell AFB, Alabama. This document is classified SECRET. The information used is unclassified.
“Titan Deactivation Program, Little Rock AFB, Arkansas.” Headquarters, Strategic Air Command, Maintenance Directorate. Titan Missile Museum Archives, Sahuarita, Arizona.
“Histories of the 308th Strategic Missile Wing, 1963-1987,” Air Force Historical Research Agency, Maxwell AFB, Alabama. These documents are classified SECRET. The information used is declassified.
Stumpf, David K. “Titan II: A History of a Cold War Missile Program,” Fayetteville, AR: University of Arkansas Press, 2000.