Our system
(International patent application No. PCT/CA2008/002288)
There is a strong need for new technology which will operate effectively in heavy seas and heavy, dynamic ice. The EST system, like all current systems, can efficiently recover oil in calm waters but only EST offers the best potential to effectively deal with waves higher than 3m. In recent tank tests and sea trials the EST system demonstrated that can operate at speeds radically higher than any other system. This will enhance its usefulness in normal oil spill situations.
The key innovative features of the EST system
- There are no moving parts other than rugged pumps. This feature avoids breakdowns at critical times and greatly reduces maintenance. Our system can endure rough handling without breaking or bending. There are no plastic or sheet metal parts or drive shafts to bend.
- There are no vulnerable V- sweeps or conveyor belts for the waves to strike, causing damage or scattering the oil. Most conventional equipment that moves through the water uses V-sweeps to gather the oil to a focal point where it is picked up.
This "crowding" of the water creates turbulence unless the vessel travels very slowly, usually 1-2 kts. The EST system is much wider so V-sweeps are not necessary and there is no turbulence. This allows much higher vessel speeds. - The EST system is ultra-shallow draft and can operate easily in 0.5m of water. Consequently, modern jet drives can be used to great effect to eliminate damage to propellors, and their air-cooled main engines eliminate the risk of damage to the cooling systems by contaminated water and oil.
EST vessels for shallow water use air-cooled Deutz engines which are not affected by debris-contaminated, oily water or sand. These reliable engines are connected to UltraJet units which are ideal for this application.
The impellers are encapsulated inside the jet with the protection of an intake grill. Other suppliers use propellers, shafts, rudders and struts in the water flow which are more likely to be be damaged by flotsam or to pick up lines. When something small enough to get by the intake grill does go into the jet, it can generally be removed from inside the boat without someone having to go over the side. If it gets by the intake grill, generally it will be too small to do any significant damage.
Waterjet propulsion is very common for oil spill recovery vessels due to the need to work around and over retaining booms and ropes. The multi-mission requirement (high speed sprint to the oils spill, then low speed, good maneuvering at the spill) plus the thrust needed to pull booms into place also makes waterjets the prime choice.
Oil through the jet is not a concern for short term operation. The oil film should be pressure-washed clean along with the hull at the end of the recovery mission. - EST vessels are built with modern, lightweight materials which provides the additional option for those models under 15m to use powerful outboard gas engines such as the Yamaha High-Thrust series which can easily push a heavy workboat.
- Low maintenance, air-cooled Deutz diesel engines and fibreglass, aluminum and HDPE construction materials minimize corrossion and clean-up. The only steel in our vessels is stainless steel. Cleaning the equipment is quick and easy because of the extreme simplicity. No anti-freeze is required.
- Ours is the only system to utilize electronic technology in key applications. Electronic sensors detect the presence of captured oil and automatically control the pumps that transfer this oil to storage tanks. This reduces crew requirements and helps protect against mistakes caused by fatigue. The unique characteristics of the EST system allow this feature.
This makes life very easy for the vessel operator and eliminates the risk of overpumping and filling the storage tanks with water instead of oil. That is a big problem with many other types of oil spill skimmers.
The simplicity of our system simplifies crew training and eliminates the need for multiple support vessels with crew. Our vessel is designed for maximum self-sufficiency. - The oil entrapment chamber is immune to wave action. The oil entrapment zone is isolated from wave impact because it is located beneath the vessel. An existing and very successful system shares this feature, but requires conveyor belts and V-sweeps which are completely vulnerable to waves that disrupt their operation.
- Ours is the only system in the world with no free-surface effect, so our vessel can recover oil in much rougher seas and at higher speeds. The oil and water in the EST entrapment chamber cannot surge about and mix together. The unique EST design means that once it has been collected, oil cannot escape even when operating in rough seas.
An oil buoyancy system to recover sunken oil is under development and will have the capacity to be retro-fitted to our existing vessels. - EST vessels have two main engines, two oil transfer pumps, two powerpack and two oil pickup systems, crosslinked and rigged for instant backup use in the event of failure of any one component. These key items are the best quality and available worldwide. In this way both oil pickup systems continue to function even if one engine or hydraulic pump fails. An EST vessel can function well on a single engine if necessary. Some competing designs have two propellors but only one engine.
- The EST vessel is a multi-use vessel, not just a piece of machinery that sits in storage until required. When the vessel is not cleaning up oil, the debris and oil collection systems can be quickly removed and replaced with deck panels. It is a modern, high-speed work vessel that can range from 5m to 75m in length and can be used for continuous duty in many applications: search and rescue, work vessel, ferry, fire boat, etc. It can be made in several configurations, including landing craft or high-speed catamaran versions resembling those pictured below.
Debris collection system
The Debris collection system consists of three parts:
- At the bow is a hydraulically operated gate that can be raised or lowered. It uses a grate or screen so that oil and water can pass through but debris is stopped.
- Behind the bow gate is a bucket which is also a grate and is normally in the down position to intercept debris. The bow gate is normally in the up position to allow debris to float back into the bucket. When the bucket is full, the operator lowers the bow gate to prevent more debris from entering.
- The operator then engages two hydraulic rams to raise the bucket and dump its contents into a grated debris bin before repeating the cycle.
When the debris bin is full, it can be removed by crane and emptied onshore. The debris bucket, the debris gate and the debris bin are all built like a grate so oil and water can flow through them but debris cannot. Grate dimensions are approximately a 5-cm square grid.
This debris system is installed internally in the EST vessel and does not project from the bow or become vulnerable to damage. It is a modular unit that can be installed in the vessel in less than an hour. The vessel operator can activate the unit from the helm with minimal effort.
(Note: A close-up image of the debris system will be provided here shortly.)
Click here for videos of prototype testing in Halifax harbour (October 2008 and October 2009), and scale-model tank testing in China (December 2009).