OIL SPILL RESPONSE Self-inflating boom designed for easy and swift deployment

March 1, 1997
The Roto Drum oil skimmer. A comprehensive range of oil spill equipment, newly introduced by Ecoroc, has already gained acceptance in numerous areas around the world. The chief components are the Walboom series 350 and 450 booms developed with Bohus Invest. The Walboom is self-inflating, expanding the minute it is released, and is used in conjunction with an oil cleaning unit. The boom is made of a tough, durable polyamid-coated material which gives maximum resistance to hydrocarbons, sunlight,
The Roto Drum oil skimmer.
A comprehensive range of oil spill equipment, newly introduced by Ecoroc, has already gained acceptance in numerous areas around the world. The chief components are the Walboom series 350 and 450 booms developed with Bohus Invest.

The Walboom is self-inflating, expanding the minute it is released, and is used in conjunction with an oil cleaning unit. The boom is made of a tough, durable polyamid-coated material which gives maximum resistance to hydrocarbons, sunlight, sea water, abrasion and solvents.

Designed in a diamond shape, the boom contains an internal reinforced pre-sprung frame and a pre-sprung stainless steel spring that increases air intake and allows the boom to inflate rapidly. Inflation and deflation is automatic so that no damage is caused to the boom by manual handling, and this also means the boom can be reeled in from both sides. Inside, special valves equipped with hoses leading to the bottom of the boom operate automatically in the event of leaks: any water forces the valves to close, thereby maintaining full buoyancy.

Ballast is provided by a bottom tension chain and a tension band attached to a coupling which releases tension from the fabric and is welded away from the main part of the boom to avoid any back leakage should damage result to the boom inside the tension pocket. The selections are easily connected with an integrated coupling hook which makes the process safe and quick. The connectors themselves are elastic and designed to allow the boom to work effectively as an integrated unit in waves or during towing.

Walboom is designed to be fitted onto Ecoroc's Rotopac system which delivers the boom rolled up onto a cassette. The latter also retrieves the boom after use: rolls up to 608 metres long can be accommodated onto one cassette. This compares well with competitive systems where boom lengths of around 100m are normal. The supplied length of the Walboom depends on handling weights specific to the boat using the system. As an example, tug boats with a handling weight of 5 tons can accommodate 550m of Walboom.

Easy cleaning

With previous systems, problems have traditionally been experienced retrieving used booms and during cleaning where booms are laid out and manually cleaned one side at a time with solvents. The Walboom Rotopac system is designed to be used with a Roto boom cleaner which automatically cleans the boom through an enclosed, sealed unit.

The dirty boom can be cleaned on site by pulling it through one end of the cleaning machine and rewinding it directly onto a Rotopack cassette at the other end. There is no cumbersome unhooking of heavy sections from each other so no heavy lifting work is required to feed the boom into the cleaner, which has separate and enclosed chambers for solvents and flushed water.

Ecoroc market and project manager Ove Klockare is enthusiastic about the system. "The Roto boom cleaner provides an environmentally safe cleaning method with only one man required to operate it. The boom receives minimum manual handling, so it's a very cost-effective and efficient way of cleaning. Also, it can be easily reused afterwards."

With the patented Walboom/Roto Pac system, Ecoroc claims the design has taken into consideration past weaknesses and faults experienced with other types of booms. Systems have already been sold to the Swedish Caostguard, Clean Seas California, Chinese Petroleum Corp and the Korean National Marine Police.

Other elements of the oil spill package include the Roto fast boom layer system 450, a multi-purpose vessel and an oil skimmer. In the fast boom layer system, pre-reeled lengths of Walboom are loaded on trimaran-shaped vessels and then onto lorries for easy mobilization. The vessels are then launched at the quay and travel at speeds up to 30 knots to the oil spill site. Once there, a typical boom length of 465 metres can be deployed in three to four minutes. Recovery takes about 20 minutes.

Ecoroc's multi-purpose vessel was designed to function as an oil skimmer and service vessel with the ability to clean up patches of oil and floating debris in harbors. This is a lightweight aluminium vessel delivered as a knockdown kit which takes three men six hours to assemble. The vessel is capable of retrieving harbor garbage as well as all grades of oil from light diesel to heavy fuel oil, even mixed with debris. Booms at the front of the vessel give a sweeping width of 8m, drawing oil and debris into Ecoroc's patented Roto Drum oil skimmer. This is available in six different sizes with capacity from 30 up to 130 cu m/hr. It can also be tailor-made for industrial purposes.

This skimmer has three curved shovel blades rotating within the drum which can handle oils of all viscosities, even oil mixed with debris. Powered by an hydraulic motor, oil is pumped out through a discharge pipe. Used on the multi-purpose vessel or on its own, the skimmer will continue to retrieve oil long after disc, weir, mop and most belt machines lose their effectiveness, Ecoroc claims.

For more information contact Ove Klockare, Ecoroc: telephone +46 930 31400, fax +46 930 10600, e-mail:
ove(a)ecoroc.se or http://www.ecoroc.se/.