44 years ago, the worst man-made disaster in U.S. history occurred in Damascus, Arkansas. It involved nuclear weapons. Human carelessness, a series of ill-considered decisions, lying to superiors, and a piece of metal weighing four kilograms could have caused a nuclear explosion with a yield of nine megatons (700 Hiroshimas!). Therefore, the consequences that actually occurred: the destruction of the Titan II ICBM and its launch silo, one dead and 21 injured – can be considered child’s play.
arkansasonline.com
Officer Virginia Sullivan stands in the debris field left by Titan II Missile Launch Complex 374-7, Damascus, 1981.
It all started with a routine procedure. On September 18, 1980, at about 7 p.m., a group of military engineers descended into the launch silo for scheduled maintenance of the Titan II ballistic missile. The ICBM was truly titanic: 30 meters high, with a launch weight of 154 tons.
The rocket was liquid, meaning its engines ran on a mixture of aerosol-50 and nitrogen tetroxide. This fuel is very toxic, capricious and dangerous, but only it gave the Titan enough power to launch a nine-megaton thermonuclear warhead 15,000 kilometers.
Technicians David Powell and Jeffrey Plumb donned protective suits and went to inspect the second stage tanks. According to the instructions, the valves had to be opened and closed with a torque wrench with a preset load. The engineers forgot the wrench in the truck they arrived in, but before going into the shaft, there were socket wrenches with attachments for less delicate work. The length of such a wrench is about a meter, weighing 11 kilograms. The attachment to it weighs 4 kg. The technicians took this tool.
Powell had not made sure the nozzle was properly secured in the wrench and had carelessly placed the rubber flange that prevented objects from falling from the repair platform into the launch silo. When he picked up the wrench to unscrew the valve, the head came off, slid along the flange, and fell eight stories down. It hit something on the wall of the silo, ricocheted, and went through the thin wall of the first stage fuel tank.
A fuel leak began, and the concentration of toxic vapors in the shaft increased. Powell reported fog on level seven, but kept quiet about the incident with the key. Soon, the emergency alarm went off at the control point of launch complex 374-7, but the duty crew did not understand what was happening and decided not to rush to report to command.
Poster for the film “Command and Control”, which is based on the events of 1980 in Arkansas.
The vapors of aerosol-50 began to decompose rapidly when combined with air, the temperature in the shaft increased sharply and the fire alarm went off. The duty shift reported to headquarters in Little Rock about the fire at the launch complex. It was not possible to ventilate the shaft – the automatic system blocked the opening of the ventilation ducts.
By order of the launch complex commander, all people were evacuated from it. The police began evacuating the residents of Damascus – the ICBM silo was located six kilometers from the city limits.
Six hours later, two specialists were sent to the mine to try to stop the fuel leak. The technicians found that they could not stop the aerosol from flowing into the mine, and that the concentration of explosive vapors in it continued to increase and would soon reach a critical level.
They were quite accurate in their prediction. The explosion occurred when they had moved a few steps away from the silo. Or rather, there were three explosions. The first occurred after the oxidizer tank ruptured and nitrogen tetroxide mixed with fuel vapor. The entire energy reserve of the first stage of the rocket was released in one moment, throwing the armored lid of the silo, weighing 740 tons, 60 meters into the sky. A blinding column of fire hit the atmosphere, illuminating the surrounding area.
The second stage of the Titan followed suit. Its fuel tanks were also damaged, and their components came together in the Arkansas sky, causing a third explosion. From the outside, it looked like a huge fireball, which gave rise to rumors of a nuclear detonation and panic among the civilian population of Damascus.
In fact, the thermonuclear warhead flew 30 meters away. Its charge, capable of burning the entire city and a good part of the state, did not detonate, and there was no leakage of radioactive substances into the atmosphere.
The cause of the accident was determined to be human error. The investigation established that to avoid explosions, it would have been enough to open the lid of the missile silo, as advised by technicians, and ventilate it bypassing the blocked systems. In this case, the excess pressure inside would not have crushed the oxidizer tank and would not have started a chain of accidents.
The Titan II ICBMs remained in service with the US Air Force until 1987, when they were converted into launch vehicles and flew into space for another 16 years.
Because Damascus residents flatly refused to live near the explosive launch site – even if it had burned down – city authorities placed a logistics hub and a parking lot for trucks there.
Source: rodina-history.ru
