YM Uranus

On Friday 8 October 2010 at around 5:30 am, the chemical tanker YM Uranus was travelling from Porto Marghera (Italy) to Amsterdam (Netherlands) when it was hit at the rear on its portside by the bulk carrier Hanjin Rizhao as it overtook. The chemical tanker YM Uranus, built in 2008, was carrying 6,500 tonnes of Pygas (pyrolysis gasoline) and the Chinese bulk carrier, commissioned in July 2010, Hanjin Rizhao, was transporting steel.

Following the collision, the chemical tanker, located around 30 miles west of Ushant Island, found itself in great difficulty, with a significant leak. The Hanjin Rizhao remained onsite to assist the chemical tanker if necessary, which was listing significantly. The Corsen MRCC received a distress call from the YM Uranus at 5:30 am. Cedre was alerted 15 minutes later.

Confronted with a worrying situation, the 13 crew members rapidly abandoned ship on a life raft before being airlifted by helicopter at around 7 am and taken to the naval air station in Lanvéoc-Poulmic.

Situation assessment and towing

An assessment and response team composed of 9 men, including the chemical tanker’s head mechanic, was rapidly established and sent onsite. No pollution was detected around the vessel. The collision caused a crack 8 m long by 5 m high in the rear portside but the cargo tanks and bunker tanks remained intact, efficiently protected by the double hull.  The vessel was in good enough condition that towing could be considered. The port of Brest was chosen to accommodate the vessel as the weather conditions forecast for the coming hours meant that it could not be safely towed to Saint Nazaire, where appropriate facilities to unload this type of cargo are available.

At around midday, the Abeille Bourbon attached a towline with the help of two of the tug’s men onboard the YM Uranus. The weather conditions were favourable and the vessel was towed to Brest at a speed of 4 knots, where it arrived late at night.

Cedre’s participation

Cedre’s response centre was in heavy demand and made contact with many local, national and international organisations. It answered many enquiries on the nature of the product and the associated risks. A member of the management team and an expert from Cedre were present at the maritime authorities headquarters to provide support.

Meanwhile, Cedre’s GIS specialists ran modelling software (ChemMap) to study the behaviour of Pygas when spilt on the water surface, as well as 60 and 100 m deep, in case the tanker were to sink. Calculations were also made to investigate the displacement of the gas cloud which would form if the chemical were to be spilt in the bay.

Cargo type and treatment

When the collision occurred, the chemical tanker was loaded with 6,500 tonnes of Pygas (pyrolysis gasoline, IMO 2). This product is a chemical intermediate, produced in the manufacture of ethylene, and is used to produce benzene, toluene and xylene, used as fuel additives.
 Pygas evaporates easily and is highly flammable. When spilt at sea, it remains on the surface and tends to evaporate.
 The ship also contained 400 tonnes of Intermediate Fuel Oil (IFO) for propulsion.

Once the Uranus arrived in the bay of Brest on Friday 8 October shortly before midnight, it was taken in tow by 2 civil tugs moored in the military port at around 2 am on 9 October. As a precaution, a floating boom was deployed around the ship in dock.

A ballasting operation was conducted to correct the list, before being able to transfer the cargo. A chemical tanker en route from Antwerp, Stolt Teal, was mobilised to lighter the Uranus.

The cargo owner asked an expert to carry out the necessary controls prior to transhipment operations. Operations began on 11 October at around 3 pm and were completed by 9 am the following day. The tank contents were replaced by inert gas. A safety zone was set up 500 m around the vessel throughout operations and firemen qualified in chemical risks ensured the safety of the zone.

Once the tanks had been entirely emptied and decontaminated, the vessel was placed in dry dock.
 The Stolt Teal, loaded with Pygas, set off for the North Sea.

Fortunately, this accident did not result in a spill thanks to the ship’s design (double hull, ice capable), its good condition as well as the favourable weather conditions and the rapid response by the authorities.