THE CATASTROPHE COULD HAVE BEEN EVEN WORSE

OIL POLLUTION: The drama of the oil tanker ’Prestige’ which broke in two and sank off the north Spanish coast, could have had much more serious consequences, had not a Danish company contributed to a very inventive clean-up method at a depth of 3000 metres

Ro-Clean Desmi’s Dop 250 special pump, constructed for pumping highly viscous oil

On 12 November 2002, the 25 year old tanker ’Prestige’ sailed out of the English channel and into the Bay of Biscay. Its cargo consisted of 70,000 tons of heavy fuel oil. The ship came from Ventspils in Latvia, and was en route to Singapore.

The ship never got that far. A typical winter storm in the Bay of Biscay damaged the single hulled ship and the oil started leaking. The captain requested permission to sail to a French or Spanish port. Both countries refused, and instead several tugs were sent to tow the ship further out into the Atlantic Sea in an attempt to prevent a potential oil catastrophe on shore.

Catastrophe
But all was in vain. While most of the crew were rescued by helicopter, the ship broke in two the next day, and sank to a depth of more than three kilometres, 130 nautical miles west of the Spanish coast. Before sinking, the ’Prestige’ had already produced a five kilometre long oil slick. The sinking itself caused an oil pollution catastrophe exceeded only by the ’Exxon Valdez’ catastrophe in Alaska 14 years earlier.

The oil pollution didn’t stop after the Prestige sank. In one half of the sunken wreck, there were still large amounts of oil in the tanks, which constantly leaked from numerous cracks and caused pollution along the coasts of Portugal, Spain and France.

Creative solution
The large quantity of oil in the tanks of the wreck and the considerable leakage from it threatened a catastrophe to which the authorities had to respond. The Italian company Sonsub, a subsidiary of the oil giant ENI, was commissioned to recover the oil from the wreck. It was a highly complex task

because of the sea depth and the properties of the oil, one of the heaviest grades on the market. But it initiated creative thinking in a number of companies worldwide which do clean-up operations after oil pollution, especially in the Danish company Ro-Clean Desmi, which supplies oil clearing equipment packages worldwide.

Sonsub immediately carried out pump tests of several potential pumps in Spain to select the most suitable pump for the purpose. Desmi’s Dop 250 screw pump was chosen after highly successful pump tests. In the meantime, all the holes in the wreck were sealed using Sonsub’s remote controlled submarines. From the outset, Ro-Clean Desmi was also involved in optimisation of the pump solution, which had never been tried before under similar conditions.

Catastrophe avoided
A special submersible tank which could contain 350 m³ oil was constructed and lowered down to the wreck. Holes were drilled in the hull, over which the tank was kept in place. The difference between the density of the water and the oil caused the oil to float up into the specially designed tank. When the tank was full, the hole in the wreck was closed with a valve, and the tank raised to 60 metres below the surface of the sea, where Ro-Clean Desmi’s Dop 250 special pump, constructed for pumping highly viscous oil, was connected to the tank. Water was pumped into the tank and the oil was recovered onto a waiting tanker and taken for destruction.

In a few months the wreck’s oil tanks were successfully and very professionally emptied of almost 14,000 tons heavy fuel oil, and the threat of further pollution on top of the catastrophe caused by the sinking of ’Prestige’, was avoided.

They are involved when the environment needs protection When large oil spills threaten to cause pollution catastrophes anywhere in the world, you can be sure that specialist equipment from Ro-Clean Desmi is in place for the containment and clean-up of oil. Since the 1980s, the Danish company has been among the key players in this niche area, where major environmental catastrophes and enormous sums are at stake for cleaning up the environment and for compensation. “We don’t do the cleaning up ourselves, but we supply the necessary equipment for the task,” says director Dennis W. Larsen of Ro-Clean Desmi. “Our three core products are oil containment booms, skimmer types which remove oil spillages from water surfaces or on land, and a number of special Desmi pumps which can handle all forms of oil or sludge regardless of the viscosity. We also develop a number of special products which may be necessary, depending on the character of the task.” Fortunes at stake The company was originally a joint venture between two firms which each provided know-how in the area. A/S Roulunds Fabrikker had technological competence in rubber production used for development of reliable and durable oil containment booms, which today are marketed under the name Ro-Boom. The other company, Desmi A/S had a core competence in pumps and skimmers, which are marketed under the name Desmi. Both companies have been active in the clean-up area since the 1970s. In 1996, the joint venture was established, enabling Ro-Clean Desmi to supply specialist equipment for any clean-up task following oil pollution. In 2005, Desmi took over 100% ownership of Ro-Clean Desmi A/S. “There is often an environmental disaster and financial costs running into millions at stake when a catastrophe occurs, so the time factor is very important” says vice president Frands Pilegaard Jensen, who has been with the Desmi Group for 15 years and has actively participated in a number of clean-up operations following oil spillages. The faster the oil leak is contained and removed before it gets close to coastal or sensitive areas, the less damage the oil causes to the environment, and the clean-up and subsequent compensation are minimized. The catastrophe following the sinking of ’Prestige’ had serious consequences because political wrangling caused the ’Prestige spill’ to drag on. Today attitudes have fortunately changed, and many countries are realising the necessity of having an optimised and efficient readiness in case a catastrophe occurs. Ro-Clean Desmi has just entered two large equipment contracts in France and Malta in connection with the EU’s recent 2006 EMSA projects. Frands Pilegaard Jensen is very satisfied that Ro-Clean Desmi’s proven equipment was chosen, and underlines that it is important that oil clearing equipment is fully tested and works every time. http://www.ro-cleandesmi.com