In 1990 I purchased my first waterfront property on the shore of Lake Ontario. My neighbors and I initiated a project to protect our properties from erosion. In 1993 flood waters came to the Lake and we lost 40' of property in one storm. After 2.5 years we were able to get a permit in 1994 for a porous rubble mound revetment 750' long. We then bonded with other shore associations and became advocates for the shore and good regulatory practices to mitigate storm erosion damage from regulated high water.
We educated ourselves on U.S. Army Corp of Engineers (USACE) recommended practices and state regulations. There were no contractors who followed these practices or who offered a reasonable price to install armor stone revetments. We became contractors and did over 120 individual properties on Lake Ontario.
It was during this time, seeing how the revetments worked, that the concept for an offshore wave attenuator came to mind. This would allow for natural forces to work on the beach area thus restoring balance to the system. The Wavebrake could be moved to the near shore and a plastic rock revetment could be installed. This would allow the beach to remain natural while damaging storm energy is absorbed in the Lake.
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�.
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.
The lines used for connection have a 30,000 lb tensile strength. This far exceeds any load requirement. The configuration of the line adds to the lateral holding ability of the structure. This line is designed not to stretch and will change diameter under stress to increase holding power.
Anchoring is a site specific issue. 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.
We originally intended Wavebrake as an offshore floating breakwater to mitigate storm damage to the shore and to replace the use of armor stone on a beach and to bring balance to the shoreline Other applications became apparent for marinas, to eliminate boat wake and wind driven waves, and homeowners creating a personal harbor for the protection of their boats and docks and the inherent safety of calm water.
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 there is 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 tends to act like a resonator.
The ability to configure the Wavebrake modules does not limit the size of the system. Further articles from the journals of the ASCE indicate the amount of wave attenuation is scalable to the size of the Wavebrake structure. The more cavities the water passes through, the more wave attenuation. A study involving a box system has 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.
Usually, the components are shipped to the site and then assembled in 25' sections. They are launched and then connected with the anchoring line. Tethers are installed to connect the anchoring system. A PWC or small boat may be used as the dry weight of a 25' section is only 900#'s. There is no need for cranes or a barge, a boat ramp is sufficient for launching or retrieving the system.
The system is built in 25' sections for ease of handling and it may be readily removed to inspect the connections, anchor lines and to clean any growth from the system.
Most of the time, the system is in constant motion and washes itself. The added weight of any growth (barnacles, algae, etc.) will only make the system work better. Provision is made to remove a section, clean it, and then put it back in service.
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.
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.
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.
If the site is located in an area that is not subject to flow ice and is the custom to leave floating docks in the water over the winter, the Wavebrake may be left in the water. It is recommended, however, to remove the system if in an area which experiences flow ice. If flow ice occurs in the spring, then the system should definitely be removed in the fall.
Aesthetics is in the eye of the beholder. We have made every effort to maintain a low profile while maintaining functionality. We feel that the colors selected alert boaters and do not degrade the view more than any other possible structure. Some communities ban all structures from their waters regardless of their merits.
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 sand accumulates 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.
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.
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. There is not just one design configuration, but rather there are many for the varied applications. This flexibility and modularity only increase the value of the Wavebrake system.
We are currently selling direct to the market and through installer distributors. We are always looking for more dealer candidates who can provide full service sales, installation and service in a serviceable area.