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Wavebrake Frequently Asked Questions
How did the Wavebrake come about?
In 1990 the founder of Wavebrake purchased his first waterfront property on the shore of Lake Ontario. He and his neighbors initiated a project to protect their properties from erosion. In 1993 flood waters removed 40' of property during one storm. In 1994, after a 2.5 year wait, they received a permit for a 750' long porous rubble mound revetment. The group bonded with other shore associations and became advocates for good regulatory practices to mitigate storm erosion damage.
Since no contractors existed who followed recommended USACE practices, the group became contractors and installed armor stone revetments for over 120 individual properties on Lake Ontario.
It was during this time that the concept for an offshore wave attenuator, the "Wavebrake", came to mind to allow for natural forces to work on the beach thus restoring balance to the shoreline. The Wavebrake was patented in the early and mid '00s and field tested for the last few years.
How does the Wavebrake work?
The Wavebrake works by disrupting the laminar flow of the wave and the resulting turbulence extracts the energy from the wave by a “canceling” effect. The energy is absorbed by this action and the wave is attenuated. Energy is not directed in other directions to cause damage in another area. The multi faceted shape of the individual cubes, when connected, provides a porous face that accepts the wave, and channels the water into the porous cavities between the modules. This space contains the turbulence and extracts the wave forces by a “canceling effect”.
What are the details of the Wavebrake system?
Each cube weighs 14 to 15 lbs each with a 3/16" thickness. They are made of LLDPE. This material is extremely tough in cold or heat and is not brittle. It can be molded in 47 different colors. We chose blue for visibility and black is common for the marine industry. The cubes in the water do not get UV rays so there is long life. The blue cubes have a UV inhibitor added. The life is 20 to 25 years. The specific gravity of the LLDPE is 98% of water. Even though they may be full of water, they will still float.
How is the system interconnected?
The system uses a 30,000 lb tensile strength, braided, polyester line. This far exceeds the lateral load requirement and the cubes do not slide along the line.
How is the Wavebrake anchored?
Anchoring is site specific and several options exist. Any common method will work, as long as the breakout point of the anchor system selected exceeds the wind, current and wave loads of the site. Generally this system is determined with the customer at the site.
How can the Wavebrake system be used?
Wavebrake can serve as an offshore floating breakwater to mitigate storm damage to the beach front - this would displace the need to use armor stone and would bring balance to the shoreline. Another application includes the reduction of boat wake and wind driven waves to the protect docks and boats of Marinas and Homeowners as well as improve safety. Also, accretion of beach and shoreline can be achieved.
Will Wavebrake help with beach nourishment or impact negatively on adjacent properties?
The positioning of the system is crucial to the success of beach accretion applications and in support of beach nourishment projects. With the movement of sand during storm events, the reduction of the velocity of the water allows for the sand to drop or settle out of the water returning the shore to its natural state. This is similar to stone breakwaters that break the waves and accumulate sand behind the revetment. This design is commonly used in many states in USACE designed projects. The Wavebrake is tethered to the bottom allowing the natural littoral drift of sand between beaches. Because the Wavebrake is adjustable, we are able to eliminate any damage to adjacent properties.
What are the types of floating breakwaters?
According to literature from the journals of the American Society of Civil Engineers (ASCE) there are four groups of floating breakwaters - box, pontoon, mat and tethered float. We believe that Wavebrake establishes a fifth: A three (3) Dimensional porous space frame ( Wavebrake ). Wavebrake reduces the waves by transferring some energy via mooring system to the sea floor anchors. It also inherently reduces wave energy due to its three (3) dimensional grid structure. The anchoring is intended to restrict the movement of the structure so that it will constantly interrupt the laminar flow of the waves by the self cancellation process created by the turbulence generated. In a sense the Wavebrake acts as a resonator.
What are the environments for the Wavebrake ?
The ability to modify and adapt the configuration of the Wavebrake modules allows an almost unlimited system size. Furthermore, articles from the journals of the ASCE indicate that wave attenuation is scalable to the size of the Wavebrake structure. The more cavities the water passes through, the greater the wave attenuation. A study involving a box type system showed upper limits of 6 Ft waves and 4 - 6 second periods with a 50% reduction. Another project described in the journals involved a box with an extended porous fence deeper into the water and it realized an 85% reduction. The more width and depth of a Wavebrake system, the better the wave attenuation.
The Wavebrake could also be used in sand in place of a rubble mound type revetment. The modules could also be filled with sand and become a monolithic structure at the shore line. Wavebrake could also be used in an artificial reef system to create shoals or promote accretion.
How is the Wavebrake installed?
The components ship directly to the site for assembly into 25' sections. The sections are then launched and anchored. A PWC or small boat may be used to position the Wavebrake sections since the dry weight of a 25' section is only 900 lbs. There is no need for cranes or a barge. A boat ramp is sufficient for launching or retrieving the system.
What is the Maintenance involved for the Wavebrake ?
The 25' system sections allow for ease of handling and inspection. Connections and anchor lines are also easily inspected.
What about fouling?
The system typically remains in motion and washes itself. System performance increases with additional weight such as from algae. If needed, each 25' section may easily be removed, cleaned and returned to service.
What are the permitting requirements?
All structures in a regulated zone require a permit or a letter of non-jurisdiction. Usually there is a joint application for all the governmental agencies involved. Your local USACE Districts may have the forms and requirements on their web page. The Wavebrake is not a permanent structure in its floating configuration and can be moved or repositioned with ease. Permitting for structures that do not rest on the bottom should be easier to obtain than for rock breakwaters.
What about lighting?
If lighting is required, the Coast Guard through the USACE will specify any lighting that will show on navigation charts. Many applications may not require lights and local lighting regulations should prevail.
What depth of water is required for Wavebrake installation ?
As the modules may be deployed at various depths, almost any application or depth of water will support a system, shallow or deep. It may be possible to accrete sand and build a beach under the right conditions. The depth of the floating system configuration is determined by the depth from the surface required to get the desired wave reduction.
What about large storms and 20' wave heights?
As stated above, independent research indicates a possible 85% reduction in wave height for a porous floating breakwater. Stone breakwaters are designed to achieve an 80% reduction but are extremely expensive and impact the environment in a negative fashion. The major issue with ocean or high flow rate installations is the anchoring. Determining the proper loads and the type of anchor is crucial to success.
As most Wavebrake configurations are based on workings of a stone revetment or breakwater, we would expect the same results without the negative aspects of a large stone breakwater in deep water.
What are the competitive advantages of the Wavebrake ?
We have easy assembly and installation by hand without the requirement of heavy equipment. This feature lowers the total cost of the system and we believe we have the best price in the market for the most functionality. A typical system (2x3x2) to attenuate a 2' to 4' wave, plus the anchoring and shipping requirements will range from $450 to $480 per foot installed. Larger and smaller systems are proportionately priced. Configurations can adapt to specific and varied applications. This flexibility and modularity increase the value of the Wavebrake system.
How can I purchase a Wavebrake ?
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