GEL LIFT SYSTEM
We think differently
Gel Lift System (GLS) is Aubin's patented enabling technology for installing and recovering structures in subsea environments. At the heart of the concept is an environmentally acceptable low density fluid that can act as a form of "pumpable" buoyancy. Utilizing archimedes principle this fluid can be used to create a buoyant force effectively changing the "weight" of a submerged object.
Problems solved by this technology
Applications of GLS
Here are some potential applications for GLS
- Wind turbine installation
- Tidal stream machine installation
- Manifold installation
- Salvage
- Decommissioning
Features of GLS
- Transferable, "pumpable" buoyancy
- Low density (550 Kgs/M3) liquid this means that roughly one tonne of GLS will give one tonne of buoyancy in seawater.
- Safe, Environmentally acceptable chemical formulation
- Capable of 150m water depth
- Cheaper, simpler and safer than cranes
- Buoyant force independent of depth
Benefits of GLS
Benefits
- Precise and safe way to place, move and recover structures from depth
- Not weather-dependent
- GLS gives control when moving structures. Structure can be moved very slowly when ascending or descending through the water or even suspended mid water
- Suited to tidal, wave and wind turbine installation applications
- Enables a wider range of existing vessels to be used for installation and removal reducing costs and improving operational flexibility.
Benefits of GLS over air bags
Divers have been using air bags to provide buoyancy for many years. But gases have a problem, they are compressible, that is, as you put pressure on a gas you reduce its volume according to Boyle's Law. To understand this imagine a 10 m3 container of air at 10 metres water depth it weighs almost nothing and so in exerts a buoyant force equivalent to the mass of 10 m3 of water that is 10 tonnes. If we pull this container down to 20 metres the pressure of the water is twice the atmospheric pressure causing the volume of the balloon to decrease to 5 m3 and reducing the buoyant force by 5 tonnes. This makes loads very difficult to control with air bags. By contrast because GLS is incompressible the buoyant force at the bottom of the sea is exactly the same as at the surface making the system much safer and more controllable.
Problems solved by this technology
Problems solved by GLS
- GLS offers a safe means to lift, move and place structures on/off seabed without a crane
- For subsea turbine installation the number of tides required can be reduced, lowering the installation cost
- Extends lifting capacity of cranes, can lift from 20kg to 2000Te
- Significantly reduces the cost of launch and recovery of large, shallow water objects
Environmental issues
Environmental issues in using GLS
- There are no environmental issues in using GLS.
- All the components of GLS are considered PLONOR
(Poses Little or NO Risk to the environment) - All the chemicals used pose no risk to human health.
Orkney trials testing of GLS
At the trials in Orkney the concept of the GLS was proven. The trials involved the testing of the GLS in sheltered waters supported by Leask Marine's vessel Eskmoor.
The trial involved using a three tonne sea flex bag as the silo, which was partially filled with GLS. The bag was attached to a one tonne clump weight and released in to the sea. The bag filled with GLS was seen to float at the water surface with a small area of the bag above the water.
The controlled decent was the next stage, this involved pumping an adequate amount of GLS out of the bag until sinking began. The bag was observed by the diver and was seen to slowly sink to the seabed in a controlled manner.
Pumping carefully a small but sufficient amount of GLS back in to the bag meant that the clump rose approximately two meters where it remained stationery, demonstrating giving an object "neutral balance". This proved that the GLS could hold an object at a given position between seabed and surface.
When more GLS was added to the bag it rose in a controlled fashion to the sea surface.
Please see here for a full report of the trial Orkney report.
If you are unable to view the video. Please, download the SCAR Demo Video