Los Alfaques Disaster

The Los Alfaques Disaster was a road accident and tanker explosion which occurred on July 11, 1978 in Alcanar, near Tarragona, in Spain. A tanker truck loaded with 23 tons of highly flammable liquid propylene experienced a fire and subsequent BLEVE (Boiling Liquid Expanding Vapor Explosion) while on the N-340 highway directly in front of the "Los Alfaques" campsite, located between the road and the sea. 217 people (including the driver) were killed and 200 more were severely burned.

The campsite, which has been renovated and still exists today, is located at km 159 on the N-340 national road, 2 km south of the town of Sant Carles de la Ràpita.

Circumstances

The truck, consisting of a tractor unit registered M-7034-C and a tanker trailer registered M-7981-R, was owned by Cisternas Reunidas S.A. At a few minutes past 10:00 that day, the truck, driven by 50-year old Francisco Imbernón Villena, went to the state-owned ENPETROL refinery of Tarragona to be loaded with propylene for another state-owned company (Paular S.A.) from Puertollano.

At 12:05 the truck left the refinery carrying 23 tons of propylene, nearly 4 tons over the maximum design load of 19.35 tons. The tanker drivers were under instructions to take the smaller N-340 national road instead of the larger A-13 (now A-33) motorway when carrying cargo to Barcelona, in order to avoid the 15€ motorway toll. The N-340 was much narrower and more winding than the A-13, and also carried drivers directly through several densely populated areas.

The accident

There are several different witness reports as to the events directly preceding the blast, all of which are more or less equally plausible. Some reported the tank was already leaking as it approached the site, or sprung a leak with a loud bang while passing the site, and was then stopped by the driver. Others reported the bang being caused by a blown tire which caused the truck to swerve out of control and strike the wall separating the campsite from the roadside, possibly overturning in the process.

In either case, the leaking tanker formed a cloud of gaseous propylene that partially entered the campsite and also drifted on the wind towards the discotheque to the northeast. The white cloud attracted the attention of campsite patrons, who approached the cloud with curiosity as it continued to spread. As the cloud began to permeate the crowded discotheque, it reached an ignition source and immediately flashed back into the tanker, causing a fire that nearly instantaneous ruptured the weakened tank and ignited the full load of gas in a massive BLEVE.

At that time the campsite to the south was crowded with nearly 1000 vacationers, mostly German and other foreign tourists, packed tightly in trailers and tents. The blast and fireball (which was estimated at over 1000°F and left a 65'x5' crater) destroyed everything — cars, trailers and buildings — within a 300-metre radius, gutting over 90% of the main camping area. The discotheque to the northeast, which contained almost 100 people and was later determined to be the likely source of the ignition, was also razed to the ground, killing all inside.

The victims

It is estimated that about 150 victims, including the driver, were instantly killed by the explosion and the 1000° fireball, while the rest died of severe burns due to the subsequent fires and explosions of cars and gas cylinders used by the tourists.The total number of people who subsequently died during the following days and weeks due to severe burns is much higher than 270.

Many of the victims were burned beyond recognition. Most of the them were wearing only swimming suits, and the building where their documents were stored was destroyed in the explosion. As a result of the tremendous work done by the forensic teams from the countries where the tourists originated from, all the victims were eventually identified.

The inquiry

The official inquiry identified that the truck had been severely overloaded, and also lacked emergency pressure release valves, which are designed to help prevent a BLEVE in case of a fire. Tests on the remnants of the steel tank revealed microscopic stress cracks consistent with corrosion caused by previous loads of improperly overpressurized anhydrous ammonia. Combined with whether the tanker suffered an impact that caused additional structural damage, these factors likely led to the almost instantaneous rupture of the tank when the flames flashed back into the tanker. Even without safety valves, a structurally sound and properly filled tanker should been been able to maintain structural integrity in a fire long enough to at least allow nearby people to escape.

The inquiry also revealed that overloading of tankers was usual at Enpetrol refineries. The Tarragona facility lacked either a meter to measure the amount of gas dispensed or an automatic shut-off device to prevent overfilling, and consequently most tanks were consistently overloaded. The driver, Imbernón, was neither informed of the overloading, nor about the type and class of the cargo, and there was no means for him to check the pressure level of the tank before he departed or to monitor it in transit. Furthermore, he had not attended the HAZMAT training program for drivers of dangerous goods, because the company considered his experience of 20 years as a truck driver to be sufficient.

Aftermath

After the tragedy, the transit of populated areas by vehicles carrying dangerous cargo was prohibited in Spain.

In 1982, 4 employees of ENPETROL and 2 of Cisternas Reunidas were convicted of criminal negligence ("imprudencia temeraria"), and were sentenced to prison for between 1 and 4 years. Later, four of them were released after appealing the Court's decision, and all prison sentences were suspended or reduced. The two companies paid an equivalent of 138.23 million € (not allowing for inflation) as compensation to the victims.

In popular culture

* The accident was the subject of the 2007 film directed by Peter Keglevic, "Tarragona - A Paradise In Flames".

References

*The Czech magazine "Svět motorů" (The World of Motors) No.36/1978
*Hymes, Boydell, Prescott, & The Institution of Chemical Engineers (Great Britain). "Thermal Radiation 2: Physiological and Pathological Effects". IChemE Pub, 1996. Appx. 5, Case Hist. 1, pp. 97-110.

External links

* [http://www.time.com/time/magazine/article/0,9171,946862,00.html Time magazine article]
* [http://www.elpais.com/articulo/espana/TARRAGONA/Alrededor/150/muertos/centenares/heridos/explosionar/camion/gas/camping/elpepiesp/19780712elpepinac_4/Tes An article about the accident in "El Pais" (in Spanish)]
* [http://www.elpais.com/articulo/sociedad/TARRAGONA/CISTERNAS_REUNIDAS/EMPRESA_NACIONAL_DEL_PETROLEO/_SA/Manana/comienza/Tarragona/juicio/catastrofe/camping/Alfaques/elpepisoc/19820117elpepisoc_5/Tes An article about the trial in "El Pais" (in Spanish)]