Air Bubble Curtains with Bubble Tubing®

Air Bubble Curtains also known as Bubble Barriers
Air bubble curtains made with Bubble Tubing® have an enormous potential that warrants further research, toward the protection of marine mammals, maritime environments, and those who work or find recreation in the ocean.
Air Bubble Curtains are also known under several other names: Air barrier, air curtain, bubble barrier, bubble curtain, pneumatic barrier, pneumatic boom, barrier of air bubbles, curtain of air bubbles, air bubble curtains, bubble wall, bubble screen.
How do Bubble Curtains function?
The interest in bubble curtains and the effect of air bubbles in water was studied in detail during the Second World War in order to block sound waves created by submarines. It has also been demonstrated that air bubbles in water reduce the rate of sound wave dispersion and disrupt the propagation of energy densities that would normally be observed. The effectiveness of bubble curtains depends mainly on the frequency of the waves, the volume of air injected, the size of the bubbles, the number of air diffuser lines used and the distance between the bubbles emanating from the air diffuser lines.
The operating principle of a curtain of bubbles consists in creating a wall more or less dense, a flexible bubble barrier that rises continuously from the bottom of the water to the surface.
This wall of air bubbles is created using a properly adapted compressor and capable of operating continuously according to the estimated air volume. These bubble curtains serve as a buffer zone to reduce the impact of shock waves, sound waves and frequencies of these shock events dispersing in water from a source (e.g. sea bed pile driving). The injected air flow must be large enough to form a very dense and efficient bubble curtain. Depending on the project, we regularly suggest the installation of double or triple bubble curtains to maximize the amount of bubbles present. In the case of a double or triple curtain, the lines of Bubble Tubing® diffusers are installed parallel to one another at a distance specific to each project. The reasoning is that each layer of bubble tubing contributes to the reduction of the total impact, so by incorporating several layers it is possible to increase protection in the aquatic environment.
Independent studies are underway to determine the specific capacity of the Bubble Tubing®. The market for noise attenuation and environmental protection by two-phase barriers is certainly evolving.

What are the various applications of Bubble Curtains?
Fish guiding and containment systems in waterways such as rivers
There is an increasing demand for marine life conservation worldwide. Submerged air bubble curtains not only reduce the sound, but create a linear screen that can protect, deflect, herd & guide specific fish species away from the pile, water intakes, hydroelectric dams or contaminated areas.
In Denmark, RS Coast Care has tested Air Bubble Curtains with our Bubble Tubing® to protect beaches, harbors and coastlines against seaweed, algae, jellyfish and other floating debris.
More and more companies specialize in the development of barrier protection systems for small fish such as salmon smelts that migrate between rivers and the sea.
These companies contact us to obtain our Bubble Tubing® to integrate in their existing guiding systems that function with various components. Bubble Tubing® creates a bubble curtain deterring fish from swimming past the bubble wall. By installing Bubble Tubing® in a strategic location of a dam, a hydrant or other engineering structure, we can redirect fish to ladders specially designed for them. Other components such as strobe lights and sounds at low frequencies can be added to redirect the fish to safe places or prevent them from passing into water intakes that can be fatal to the fish.
As seen in the video, air bubble curtains made of Bubble Tubing® are already in use as fish screening systems to stop jellyfish from entering and blocking water intake pipes in the United Kingdom.


Motion control and direction of floating debris
Hotel chains and other tourism businesses living along coastal regions are faced with a growing problem of seaweed called Sargassum. The seaweed is pushed by waves on the beaches and accumulates sometimes up to 9 feet thick! The daily costs associated to the machinery and the employees required for to the collection of these seaweeds is staggering. The growing presence of Sargassum (and indeed many other species of aquatic plants or algae) in the sea is due to the increase of nutrients in the water, increase in temperature and sea currents and winds. The tourism industry is affected by this problem in areas such as the island of Saint-Martin, Guadeloupe, Mexico and Martinique. Other debris may be found floating on the water surface such as bottles, plastic bags and micro plastics. Installing bubble curtains can be a solution to contain these floating debris and algae for easier retrieval before they arrive on the coasts. Bubble curtains can prevent floating debris from entering channels or create a current that can repel algae and debris to a less sensitive area.
Silt barrier and turbidity curtains to contain sediments in suspension
Bubble curtains also meet the requirement for containing silt and turbidity for in-situ work where sediment containment barriers are mandatory. When working in a stream, river or lake, marine construction and dredging companies are required to install a physical curtain called a floating turbidity barrier.
These barriers do not allow free passage for boats and work equipment. Whereas a bubble curtain does both: it allows movement of boats and equipment over the barrier while retaining sediment and other suspended matter. In this case, a bubble curtain installed from the stream, river or lake bed will mitigate the migration of silt and other suspended sediments through the water column.
Our Bubble Tubing® has proven to be very effective as a silt barrier and turbidity curtain during these applications. Also, in this article, research is currently underway to validate the effectiveness of bubble curtains in altering stream dynamics. Water currents in the outer curves of riverbeds are slower allowing for sediment deposition and accumulation. Over time, a sand bank can be created, making shipping impossible without dredging under certain circumstances. By installing a bubble curtain in this outer curve, this creates a sufficient current to prevent sediment buildup.
These are a few of the applications for Bubble Curtains. We look forward to working closely with engineers, scientists and water managers to find bubble curtain applications to protect wildlife and the environment so projects can move forward in an environmentally responsible manner.

Who may need to create a bubble barrier?
Demand for bubble curtains is booming. Who are our customers:
- Port authorities
- Shipbuilding companies
- Acoustic reduction specialists
- Environmental firms
- Hotel chains
- Oil platform managers
- Companies specializing in dredging
- Marine construction companies
- Hydroelectric dam managers
- Companies specializing in fish barriers
- Naval bases
- Environmental engineering firms
- Cities to recover waste in canals and rivers
- Floating waste recovery companies
- Environmental groups and citizen associations
Bubble Tubing® is available in 1/2, 3/4, 1 and 1 1/4” I.D., in weighted or non-weighted formats. It is also available with 100’ already mounted on a stainless steel diffuser, the OctoAir-10 industrial grade diffuser.