MODULAR BUOYANT NOISE-INSULATING DEVICE FOR OFFSHORE PILE DRIVING

Abstract

A modular noise-insulating device for offshore pile driving, comprising interconnected noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other, wherein the noise-insulating modules are substantially homogeneous or comprise a noise-insulating portion providing a buoyant force and a ballast portion providing a gravitational force, wherein in a surrounding liquid in the operating position, each noise-insulating module arranged above the bottom module provides a ratio of a total buoyant force versus a total gravitational force provided by said noise-insulating module, said ratio being in a first range of ratio between 1 and 5, the bottom module provides a second ratio of a total buoyant force of said bottom module versus a total gravitational force of said bottom module, said second ratio being below a maximum ratio of said noise-insulating modules.

Description

CROSS-REFERENCE TO FOREIGN PRIORITY APPLICATION

The present application claims the benefit under 35 U.S.C. §§ 119(b), 119(e), 120, and/or 365(c) of PCT/EP2021/067568 filed Jun. 25, 2021, which claims priority to Application No. EP20182686.4 filed Jun. 26, 2020.

FIELD OF THE INVENTION

The invention relates to a modular noise-insulating device for offshore pile driving, comprising a holding device and tubular noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other from the holding device, a use of said modular noise-insulating device and a method for installing a modular noise-insulating device.

BACKGROUND OF THE INVENTION

Various sounds from different sources create natural, permanent background sounds in the underwater world, e.g., sounds made by wind, waves, currents, and rain, as well as sounds created by the communication of many underwater species. In addition, there are the man-made sounds, e.g., generated during activities below the water level of a water body. Anthropogenic underwater sound is usually undesired and is called noise as soon as it reaches a volume that many species find disturbing. It is known that noise generated under water spreads about 4.5 times faster than in the air due to physical properties of water. Furthermore, noises with lower frequencies can be heard over long distances because the damping effect of water can vary depending on the frequency. Anthropogenic underwater noise is seen as one of the main environmental burdens on the marine environment and marine life. In particular, underwater noise poses a serious threat for marine mammals that use sound to communicate, navigate and search for prey.

There are many sources of man-made noise that affect impulse noise or continuous noise, each of which has different effects on marine life. For example, when installing offshore plants, such as offshore wind turbines, oil drilling platforms, research platforms, etc., foundations are commonly installed by impact pile driving, leading to high sound pressure levels. In foundation work, piles of all kinds, such as concrete piles, iron girders, sheet pile elements and the like, are driven into a ground surface of a water body by means of a pile-driving device located in or above water with a pile hammer, in particular, an impulse hammer. For example, when installing a large-scale wind farm, a pile hammer is used to drive several meter thick steel piles about 50 meters into the ground surface of the water body to create a stable foundation on which the wind turbine can be installed. This requires thousands of hammer blows for each turbine. The underwater noise generated during such construction phases is tremendous and can spread over many kilometres. In addition, the noise is generated underwater and the noise therefore spreads over a larger distance from the noise source than would be the case if the noise source were placed above water.

Noise mitigation is needed to protect the marine environment and marine life from injury and severe disturbance. Technical measures are thus indispensable in the construction of wind farms, drilling platforms, and the like in order to minimize the spread of noise, in particular, impulse noise. Therefore, legislation is in place to regulate the occurrence of noise, in particular impulse noise.

Various noise mitigation and noise insulation devices are known in the state of the art, such as a bubble curtain, a cofferdam, or resonators close to the pile.

A bubble curtain, for example, is a system of perforated hoses or pipes arranged in a circle on the ground surface of a water body around the pile. Further, resonators close to the pile can comprise air-filled balloons or foam elements attached to a net surrounding the pile, the quantity and the size of the balloons or elements being selected according to the sound frequency to be damped. For sound insulation by the bubble curtain or the resonators close to the pile, the air rising from holes creates a curtain of rising bubbles in the water that reflects or dampens the noise.

A cofferdam, for example, is a structure such as a steel cylinder placed surrounding the pile during pile driving. The space between the pile and the structure can be pumped dry or a space between an inner wall and an outer wall of the structure can be filled with air. The resulting air gap damps the noise generated during pile driving.

Furthermore, elongated pipes for surrounding a noise source for noise insulation are known. For the transport, lowering into the water body, positioning around the noise source, and securing these elongated pipes with a relatively long pipe length on the ground surface of the water body, a correspondingly large floating crane is required. Therefore, transporting the pipe, lowering it into the water, arranging it around the sound source, and securing it to the ground surface is a rather costly and time-consuming operation.

WO 2011/046430 relates to a device for reducing the noise vibrations in a liquid, comprising a noise-insulating pipe with a number of telescopically extendable and retractable pipe sections, fastening means for attaching at least one first and one second pipe section to one another in extended and/or retracted position, wherein the fastening means are designed to keep the first and second pipe sections substantially acoustically disconnected in the fastening position. The fastening means ensure a rigid interconnection of the pipe sections. A drawback of said device is that arranging the pipe around the sound source and fixing the pipe sections to each other is quite time-consuming. This device also requires a high maintenance effort, in particular, with regard to the fastening means and the high loads experience by the element joints, limits its practical application in the presence of currents.

Therefore, it is an object of the present invention to provide an improved, inexpensive, and easy-to-install noise-insulating device, which provides effective noise insulation when driving piles into the ground surface of a water body at a high operability.

SUMMARY OF THE INVENTION

According to a first aspect, it is provided a modular noise-insulating device for offshore pile driving, comprising a holding device and tubular noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other from the holding device, wherein at least one of the noise-insulating modules is connected to the holding device and the noise-insulating modules arranged next to each other are interconnected, wherein the noise-insulating modules comprise a bottom module to be lowered down to a ground surface of a water body for positioning on or hovering above said ground surface in an operating position and form a substantially tapered structure extending along a vertical axis in the operating position for surrounding a pile, characterized in that at least two, preferably each of the noise-insulating modules a. are formed by a substantially homogeneous body or b. comprise a noise-insulating portion and a ballast portion for buoyancy control, wherein the ballast portion comprises a ballast weight and provides a gravitational force, wherein the noise-insulating portion is constructed to provide a buoyant force, which is bigger than a gravitational force generated by its material weight, wherein the ballast portion is constructed to provide a buoyant force, which is smaller than a gravitational force generated by its material weight, wherein in a surrounding liquid in the operating position, each single noise-insulating module arranged above the bottom module provides a ratio of a total buoyant force versus a total gravitational force provided by said single noise-insulating module, said ratio being in a first range of ratio between 1 and 5, the bottom module provides a second ratio of a total buoyant force of said bottom module versus a total gravitational force of said bottom module, said second ratio being below a maximum ratio of said single noise-insulating modules, such that said bottom module is adapted to pull down the bottom module for unfolding the noise-insulating modules from the storage position to the operating position and to retain the bottom module in the operating position against a total buoyant force of said noise-insulating modules acting on the bottom module.

A noise-insulating device as described herein comprises telescopically extendable and retractable noise-insulating modules. Due to the total buoyancy forces and the total gravitational forces acting against each other, the noise-insulating modules remain stable in the operating position and the noise-insulating modules can unfold automatically by lowering the bottom module by the total gravitational force. The buoyant forces of the noise-insulating modules arranged above the bottom module can preferably retain the structure against a material weight of interconnected noise-insulating modules in the operating position.

According to a first alternative, at least two noise-insulating modules or all noise-insulating modules may be made from a homogenous body. Such a substantially homogenous noise-insulating module is to be understood in particular in the way that a material block forming a noise-insulating module is substantially homogeneous. Therefore, the material block has an average density to provide the desired ratio of the buoyant and gravitational forces. In particular, the homogenous material block is constructed to insulate noises.

According to a second alternative at least two noise-insulating modules or all noise insulating modules may be substantially inhomogeneous in that such noise-insulating module comprises a noise-insulating portion and a ballast portion separate but connected to each other. This is to be understood in particular in the way that the noise-insulating module comprise the noise-insulating portion providing the buoyancy force and the ballast portion providing the gravitational force acting against the buoyancy force. In particular, a material of the noise-insulating portion for insulating noises has a weight that can provide a gravitational force acting on the noise-insulating portion, which is less than the buoyancy force provided by and acting on the noise-insulating portion, such that the noise-insulating module has an overall buoyance. In particular, the buoyant force may be up to twice as high as the gravitational force.

Preferably, the bottom module is constructed that the ratio of the total buoyant force versus the total gravitational force of all modules is below 1.

The total ratio of the total buoyant force versus the total gravitational force of all modules is below 1. This ensures the modules being positioned in an extended configuration along a pile with low forces acting on any elements interconnecting the modules. In case that the top noise-insulating module is immersed into the liquid in the operating position, the total ratio will be below 1. In certain configurations, the top noise-insulating module may not be fully immersed into the liquid in the operating position.

The arrangement of the noise-insulating modules “next to each other” can preferably refer to the operating position. It can be understood that in the storage position said noise-insulating modules are arranged in particular within each other.

The holding device can be understood, in particular, as a mounting unit, which can be arranged at a frame, a vessel, a platform, or the like to position the noise-insulating device at an installation position. In particular, the holding device can be constructed to prevent telescopic movement of the noise-insulating modules relative to each other in the storage position and to allow telescopic movement of the noise-insulating modules relative to each other for unfolding the noise-insulating modules from the storage position to the operating position.

Preferably, a lower limit for the total buoyant force provided by the noise-insulating module arranged above the bottom module in the surrounding liquid in the operating position can be defined by a ratio of 1 or 1.1 or 1.15 or 1.2 or 1.3 or 1.4, or 1.5 or 1.6 or 1.8 or 2.0 or 2.5.

Preferably, an upper limit for the total buoyant force provided by the noise-insulating module arranged above the bottom module in the surrounding liquid in the operating position can be defined by a ratio of 1.2 or 1.3 or 1.4, or 1.5 or 1.6 or 1.8 or 2.0 or 2.5 or 3.0 or 3.5 or 4.0 or 4.5 or 5.

Generally, the ratio of the buoyant force versus the gravitational force of the noise-insulating modules may be different between the single noise-insulating modules or all noise-insulating modules may have an identical ratio.

The neutral or slightly positive buoyancy of some or each of the noise-insulating modules arranged above the bottom module in the surrounding liquid in the operating position enables the bottom module to be designed more lightweight to enable automatic unfolding. These balanced out ratios of the buoyancy versus the gravitational force allows the device, according to the invention, to be used in deep-water applications as well as in shallow water applications without the need to adapt the design and weight of the bottom module or the noise-insulating modules. This will in particular apply the closer the ratio of the noise-insulating modules is set to be slightly above 1.

Due to the total buoyancy forces and the total gravitational forces acting against each other, dimension and number of fastening means for attaching adjacent noise-insulating modules to each other in the operating position or the storage position can be minimized.

In particular, connection means for connecting the noise-insulating modules arranged next to each other can be designed in such a way that they do not prevent neutral or slightly positive buoyancy of the noise-insulating modules in the surrounding liquid in the operating position.

The gravitational forces and the buoyant forces as described herein, refer to gravitational forces and buoyant forces in the liquid, such as water, preferably of a sea, a river, or a lake. The gravitational force is determined by the weight of the module. The buoyant force can be determined by the volume of water displaced by the module multiplied by the density of said water. Fresh water can have a density of 1.000 kg/m³ whereas the density of seawater can be between 1.020 kg/m³ and 1.035 kg/m³ on average. When the noise-insulating modules are immersed in seawater, they have about 2% to 3.5% more buoyancy in seawater than in fresh water, because the displaced volume of seawater is between 2% and 3.5% heavier.

The surrounding liquid herein is to be understood in particular as a liquid in which the noise-insulating device is used, preferably as seawater and/or fresh water. Preferably, the surrounding liquid in the operation position is to be understood as the liquid at an approximate depth in which the noise-insulating module can be retained in the operating position. In particular, some or all factors that influence the buoyancy can be considered to construct the noise-insulating modules, such as salinity, a temperature, a density, and a depth of each noise-insulating module. In general, there is preferably no need for an exact balancing of the buoyant forces and the gravitational forces acting on the noise-insulating modules in a specific liquid with an exact salinity, an exact temperature, an exact density, and in an exact depth. Rather, a noise-insulating device can be provided that can be used in different liquids. In particular, the density of the liquid can refer to an average density of the liquid.

It is preferred, that each noise-insulating module arranged above the bottom module in the operating position can have a lower average density than a surrounding liquid in the operating position to generate a positive or neutral buoyancy in the operating position. In particular, the bottom module can have a higher average density than a surrounding liquid in the operating position and provides a gravitational force to pull down the bottom module from a water level for unfolding the noise-insulating modules from the storage position to the operating position and to retain the bottom module in the operating position against a buoyant force acting on the bottom module. In particular, the average density of the bottom module can be at least, in particular close above, 1.035 kg/m³ and/or the average density of the noise-insulating modules arranged above the bottom module can be less than, in particular close below, 1.000 kg/m³, preferably less than 1.035 kg/m³.

Preferably, gravitational force provided by and acting on the bottom module has a higher or an equal magnitude than the buoyant force acting on the bottom module, in particular, the sum of buoyant forces provided by the interconnected noise-insulating modules arranged above the bottom module, so that the bottom module is retained in the operating position by said gravitational force.

It is preferred that the bottom module comprises an additional ballast weight to provide a gravitational force to pull down the bottom module from the water level under the effect of gravitational force. In particular, said ballast weight can be attached at a lower end of the bottom module.

The noise-insulating modules arranged above the bottom module can preferably be adjusted by design with respect to self-buoyancy. Preferably, the ballast weight of said noise-insulating modules can be adjusted with respect to self-buoyancy. It is further preferred that a ballast weight can be additionally attached if it is needed for buoyancy control. In particular, said noise-insulating modules can be adjusted to be slightly self-buoyant to unfold to the operating position automatically.

In particular, the noise-insulating modules can comprise at least two noise-insulating modules. In particular, a total height can be reduced by partially moving the noise-insulating modules into each other. The telescopic arrangement of separate modules generates a modular noise-insulating device with a variable height adjustment. Thereby, the system can surround piles of any length and diameter and thus adjust to project specific water depth requirements.

In the storage position, the noise-insulating device can be set into the water body as a compact package by means of a relatively small crane, positioned, lowered, and unfolded in the final desired tubular position of use. Therefore, the costs and effort for transporting the noise-insulating device, lowering it into the water, and arranging it around the sound source can be reduced.

It is particularly preferred that the noise-insulating modules are ring-shaped with, e.g., a circular shape or a polygon shape. In a preferred embodiment rotational is provided by said shape. The tubular noise-insulating modules are designed in particular as pipe sections with an outer diameter and an inner diameter, a height and a wall thickness. The inner diameter is preferably designed for passing through of a pile element to be driven into the ground surface.

It is further preferred that the diameter of the substantially tapered structure can decrease in an upwards direction starting from the bottom module. Therefore, upper noise-insulating modules can be smaller than lower noise-insulating modules. Thus, the upper noise-insulating modules can have a lower weight than the lower noise-insulating modules.

Preferably, the lower noise-insulating modules can have a bigger weight than the upper noise-insulating module, which are arranged above the lower noise-insulating modules in the operating position. It is particularly preferred that a ballast weight of a ballast portion of the lower noise-insulating module can be bigger than a ballast weight of a ballast portion of the upper noise-insulating module. Thus, the noise-insulating modules can be constructed to enable easy and efficient unfolding of the noise-insulating modules into the operating position. Due to the bigger weight of the lower noise-insulating modules, which are to be placed at deeper depths in the operating position, they can be stabilized in the operating position.

Preferably, the noise-insulating modules can be interconnected by its geometry. In particular, each noise-insulating module can be tapered at a lower end. Thus, the noise-insulating modules can be fitted into each other.

It is particularly preferred that an outer circumference of at least one noise-insulating module arranged above another noise-insulating module in the operating position is shaped with a taper at an end adjacent to the other noise-insulating module. The tapered shape allows for smooth folding of the noise-insulating modules whilst the bottom module is lifted upwards and/or for smooth unfolding of the noise-insulating modules whilst the bottom module is lowered down.

In particular, if reference is made to an arrangement of the noise-insulating modules or the bottom module or the modular noise-insulating device or the holding device, the information can refer to the operating position. Preferably, information such as horizontal, vertical, lower, upper, etc. can refer to the operating position.

According to a preferred embodiment, the ballast portion extends from a lower end to the noise-insulating portion, wherein the noise-insulating portion extends from the ballast portion to an upper end, which is arranged above the lower end in the operating position.

In particular, the ballast portion can be a ballast ring attached at the lower end of the noise-insulating portion.

In general, when a module is immersed in a fluid, an upward force on the bottom of a homogenous object is bigger than a downward force on the top of the object. Therefore, the ballast portion can stabilize the noise-insulating modules in the operating position and has a positive effect to the buoyancy control.

Alternatively or additionally, the ballast portion can be attached at any other position, such as at an upper end of the noise-insulating portion or in the middle of the noise-insulating portion.

In a preferred embodiment, the gravitational force provided by and acting on the bottom module is higher than the sum of the buoyant forces in the surrounding liquid, preferably seawater, of all noise-insulating modules arranged above the bottom module minus the sum of the gravitational forces of all noise-insulating modules arranged above the bottom module. Preferably, the buoyant forces and the gravitational forces described herein can refer to the forces provided by and acting on the noise-insulating modules in the operating position. Therefore, all influencing factors, in particular, a salinity, a temperature, a density, and a depth of each noise-insulating module can be considered. The embodiment described herein, ensures that the bottom module is retained firmly in the operating position.

Due to the fact that fresh water has a lower density than seawater and therefore less buoyancy forces act on each noise-insulating module in freshwater, the noise-insulating device can be installed equivalently in fresh water. Preferably, the gravitational force provided by and acting on the bottom module can be higher or equal than the sum of the buoyant forces in fresh water of all noise-insulating modules arranged above the bottom module minus the sum of the gravitational forces of all noise-insulating modules arranged above the bottom module.

Further, preferably, the noise-insulating modules, in particular, the noise-insulating portions of each noise-insulating module, comprise a support structure and a noise-insulating element attached to the support structure. Preferably, the noise-insulating element comprises polyethylene terephthalate and/or plastic and/or steel and/or concrete and/or aluminum and/or foam glass. In this way, it can be ensured that the modules insulate noise and prevent spreading of the noise. In addition, the modules can be manufactured very easily and cost-effectively.

In a further preferred embodiment, the noise-insulating modules, in particular, the noise-insulating portions of each noise-insulating module comprise a chamber filled with a noise-insulating medium. Preferably, the noise-insulating medium is a gaseous substance, in particular, air, and/or a noise-insulating material, preferably a foam, in particular, polyurethane foam, or glass wool or foam glass. In particular, a pressure of the gaseous substance can be lower as 0.5 bar or there can be a vacuum or an overpressure in the chamber.

The noise-insulating modules, in particular, the noise-insulating portions of each noise-insulating module, can preferably comprise an outer wall, an inner wall, and an intermediate space between the outer wall and the inner wall creating the chamber.

This embodiment has several advantages. By constructing noise-insulating modules, in particular, noise-insulating portion, with a chamber, the weight and thus the density can be reduced. This ensures that the noise-insulating modules has a lower density than the surrounding liquid in the operating position.

According to a preferred embodiment, the noise-insulating modules arranged next to each other are constructed to have an overlap in the direction of the vertical axis in the operating position, wherein a first noise-insulating module of the noise-insulating modules is arranged next to a second noise-insulating module and overlaps this second noise-insulating module, wherein said first noise insulating module has an inner diameter which is larger than an outer diameter of said second noise-insulating module to form a circumferential gap between said first and said second noise-insulating module in a region of the overlap, said gap having a gap width in a radial direction with respect to the vertical axis, preferably wherein an extension of the vertical overlap in the direction of the vertical axis is larger than said gap width, preferably the extension of the vertical overlap is at least twice as large or at least three times as large than the gap width.

The overlap of the noise-insulating modules can be sufficiently large, relative to the maximum gap between these noise-insulating modules, such that the noise escaping through the gaps will be deflected upwards with a sufficiently steep angle. Thereby, the sound can be reflected multiple times between the air-water interface and the ground surface of the water body very close to the pile. Therefore, the noise insulation can be comparable to a closed system at a couple of water depths distance, while sophisticated and error-prone seals between the noise-insulating modules are not needed.

Preferably, the overlapping section can be at least 10% of the total height of the noise-insulating modules. The individual noise-insulating modules can preferably have a vertical overlap of about 0.50 m, preferably at least 0.30 m, 0.40 m or 0.50 m. This creates a screen that surrounds the pile and acts as a noise barrier around the pile.

Preferably, the overlap of the single modules should be at least three times a maximum horizontal gap between the noise-insulating modules, to allow for sufficient upward noise deflection.

This construction can prevent canting due to drifting of the modules caused by currents when the modules are pulled down from the water level for unfolding the noise-insulating modules from the storage position to the operating position by gravitational force. Furthermore, no guiding means between adjacent noise-insulating modules for guiding the noise-insulating modules during displacement with respect to one another are required. The gap between adjacent modules resulting from this construction is not significant with regard to the effectiveness of noise insulation, as it merely allows noise to be emitted upwards at an acute and steep angle.

The noise-insulating device preferably does not have to be watertight against water flowing through it. In particular, the height of the overlap can reduce or preferably avoid noise spreading. Residual flows are possible in the gap so that drifting of the noise-insulating modules can be avoided. With the device according to the invention, an effective sound insulation can therefore be achieved with a reduced effort.

Preferably, the gap between the adjacent noise-insulating modules can disconnect said adjacent noise-insulating modules acoustically in the operating position.

According to a further preferred embodiment, the bottom module comprises a plate at a lower end for positioning on or hovering above the ground surface of the water body, wherein the plate comprises a central opening for passing through of a pile element to be rammed into the ground surface, preferably wherein a lower edge of at least one, preferably all noise-insulating modules arranged above the bottom module in the operating position is configured to be supported by the plate in the storage position and/or while telescoping the noise-insulating modules to the storage position.

The main noise source is the pile or its bulge caused by the hammer. In known sound insulation systems, noise also penetrates into the ground. By constructing the bottom module with the plate at the lower end, the noise can be reduced or prevented from penetrating the ground.

The central opening preferably has dimensions that ensure that the pile can be driven into the ground without damaging the bottom module. In particular, a diameter of the central opening may be larger than a diameter, preferably up to or at least one and a half times or twice or three times the diameter of the pile.

Preferably, the central opening can have a diameter that is smaller than an inner diameter of an uppermost noise-insulating module.

In particular, the bottom module with the plate at the lower end can serve as a depot for upper noise-insulating modules. Preferably, the plate can serve as the basis of the noise-insulating device that can be lowered down to the ground surface and the geometry of the plate can reduce the self-weight penetration into the ground of the water body due to the increased bearing area. In addition, the bottom module can serve as a support for the upper noise-insulating modules during a transport or a storage of the noise-insulating device.

It is further preferred, that the plate comprises a ballast weight to provide the gravitational force to pull down the bottom module from the water level under the effect of gravitational force.

This embodiment provides a particularly straightforward retrieval and lowering system. In this way, there is no need for an additional retrieval system, thus enabling further weight reductions.

Preferably, the noise-insulating modules arranged next to each other are interconnected by connection means, in particular, by flexible connection means like straps, chains, or ropes. In particular, the connection means can be arranged at an outer circumference of the noise-insulating modules.

The noise-insulating modules are, therefore, particularly easy and securely connected to each other. Due to the flexible connections, the modules can slightly drift against each other caused by currents without being damaged. Preferably, the connection means can be designed in such a way that they do not prevent neutral or positive buoyancy of the noise-insulating modules in the operating position.

Preferably, the noise-insulating modules are free from guiding means for guiding the noise-insulating modules during displacement with respect to one another. This enables a particularly simple design of the noise-insulating modules.

In particular, it is preferred that the bottom module is connected to the holding device, wherein the noise-insulating modules are constructed to extend telescopically to the operating position upon lowering the bottom module and to telescope to the storage position upon retrieving the bottom module. In this way, the telescopic arrangement can be unfolded to the operating position by lowering the bottom module and folded by retrieving the bottom module. Thereby a very simple lowering and retrieving system is provided which reduces the susceptibility to errors.

Preferably, the holding device comprises winches, in particular, synchronized winches, with lifting means, in particular, flexible lifting means like straps, chains, or ropes, connected to the bottom module and configured to lower and to retrieve the bottom module. Winches can be attached particularly easily to existing systems, such as frames, vessels, or platforms. This means that existing systems can be easily re-equipped. Furthermore, the modules can be easily lowered and retrieved by means of the winches.

Preferably, the lifting means are arranged at an outer circumference of the bottom module. Thus, the risk of damaging the lifting means can be mitigated.

According to a further preferred embodiment, the holding device is constructed and/or arranged to compensate the excess gravitational force of the noise-insulating modules for retaining the holding device at or above a water level. Thus, the holding device can preferably be or comprise a floating body.

Preferably, the holding device comprises a gripper frame and/or a vessel and/or a pile gripper and/or a platform for a pile driver, preferably wherein the gripper frame and/or the vessel and/or the platform for a pile driver is equipped with the winches. In particular, the holding device can comprise other floating units to be equipped with the winches. In this way, the noise-insulating modules can be deployed from the gripper frame and/or a vessel and/or a pile gripper and/or a platform for a pile driver by means of the winches.

It is preferred that the holding device can be a frame equipped with the winches and can be designed to be suspended below a deck level or the vessel.

Preferably, the gripper frame is designed as a stand-alone frame tailored for individual vessel requirement to be attached to the specific vessel or to a gripper frame and integrated into said gripper frame.

In a further preferred embodiment each noise-insulating module comprises at least two segments forming partial shells constructed to form a part of a circumference of said noise-insulating module for creating its tubular form, wherein the at least two segments are constructed to be pivoted relative to each other for opening and closing said noise-insulating module, preferably wherein the segments are interconnected by a hinge. In this way, the noise-insulating device is very easy to install and more flexible with respect to operational requirements. In addition, this opening mechanism allows the noise-insulating device to be opened, if it is needed or desired.

Preferably each noise-insulating module comprises at least three segments forming partial shells constructed to form a part of a circumference of said noise-insulating module for creating its tubular form, wherein the at least three segments are constructed to be pivoted relative to each other for opening and closing said noise-insulating module, preferably wherein the segments are interconnected by a hinge.

In particular, it is preferred that the noise-insulating modules comprise protection spacers and/or guides attached to an inner circumference of some, preferably each of the noise-insulating modules for maintaining a distance between the noise-insulating modules and a pile inserted through said noise-insulating modules while piling. Preferably, the protection spacers and/or guides can be constructed as rollers or gliders, in particular PE-gliders. Thus, the risk of damaging the noise-insulating modules in case the pile hits the modules can be mitigated.

Preferably, the noise-insulating device as described herein can be additionally equipped with a bubble curtain and/or additional nozzles at the bottom module. In particular, the nozzles can be protected by the protecting spacers to mitigate the risk of damaging the nozzles.

According to a further aspect, it is provided a modular noise-insulating device for offshore pile driving, comprising a holding device and tubular noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other from the holding device, wherein at least one of the noise-insulating modules is connected to the holding device and the noise-insulating modules arranged next to each other are interconnected, wherein the noise-insulating modules comprise a bottom module to be lowered down to a ground surface of a water body for positioning on or hovering above said ground surface in an operating position and form a substantially tapered structure extending along a vertical axis in the operating position for surrounding a pile, wherein the noise-insulating modules arranged next to each other are constructed to have an overlap in the direction of the vertical axis in the operating position, wherein a first noise-insulating module of the noise-insulating modules is arranged next to a second noise-insulating module and overlaps this second noise-insulating module, wherein said first noise insulation module has an inner diameter which is larger than an outer diameter of said second noise-insulating module to form a circumferential gap between said first and said second noise-insulating module in a region of the overlap, said gap having a gap width in a radial direction with respect to the vertical axis, preferably wherein an extension of the vertical overlap in the direction of the vertical axis is larger than said gap width, preferably the extension of the vertical overlap is at least twice as large or at least three times as large than the gap width.

According to a further aspect, it is provided a modular noise-insulating device for offshore pile driving, comprising a holding device and tubular noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other from the holding device, wherein at least one of the noise-insulating modules is connected to the holding device and the noise-insulating modules arranged next to each other are interconnected, wherein the noise-insulating modules comprise a bottom module to be lowered down to a ground surface of a water body for positioning on or hovering above said ground surface in an operating position and form a substantially tapered structure extending along a vertical axis in the operating position for surrounding a pile, wherein the bottom module comprises a plate at a lower end for positioning on or hovering above the ground surface of the water body, wherein the plate comprises a central opening for passing through of a pile element to be rammed into the ground surface, preferably wherein a lower edge of at least one, preferably all noise-insulating modules arranged above the bottom module in the operating position is configured to be supported by the plate in the storage position and/or while telescoping the noise-insulating modules to the storage position.

According to a further aspect, it is provided a method for installing a modular noise-insulating device in a water body, comprising the steps providing a noise-insulating device, in particular as described herein, positioning the noise-insulating device close to a pile driving device for surrounding a pile, moving noise-insulating modules of the noise-insulating device telescopically relative to each other from a holding device in order to increase a length of a tapered structure formed by the noise-insulating modules by lowering down the bottom module to a ground surface of the water body by a total gravitational force provided by the bottom module for positioning on or hovering above said ground surface in an operating position and unfolding the noise-insulating modules arranged above the bottom module from a storage position to an operating position by lowering down the bottom module, retaining the noise-insulating modules in the operating position by the opposing total gravitational force provided by and acting on the bottom module and total buoyant forces provided by and acting on the noise-insulating modules arranged above the bottom module.

Thereby a very simple lowering and retrieving system is provided which reduces the susceptibility to errors. Preferably, there is no need to fix the noise-insulating modules arranged next to each other in extended and/or retracted position with additional fastening means.

According to a further preferred embodiment, the method of installing a modular noise-insulating device in a water body, comprising the steps positioning the noise-insulating modules, in particular, as described herein, with at least two segments forming partial shells constructed to form a part of a circumference of said noise-insulating modules near to a pile in an open position, pivoting the at least two segments relative to each other and closing the at least two segments to create a tubular form of said noise-insulating modules for surrounding the pile.

In this way, the noise-insulating device is very easy to install and more flexible with respect to operational requirements. In addition, this opening mechanism allows the noise-insulating device to be opened, if it is needed or desired.

According to a further aspect, it is provided a use of a modular noise-insulating device as described herein as an underwater noise insulator to insulate noise generated during offshore pile driving, in particular, to surround a pile while driving the pile into a ground surface of a water body and to insulate noise generated during offshore pile driving.

According to an exemplary aspect, it is provided a method for manufacturing a modular noise-insulating device, in particular as described herein, comprising the steps: providing noise-insulating modules, preferably wherein at least two, preferably each of the noise-insulating modules are manufactured by connecting a ballast portion and a noise-insulating portion, telescopic arranging the noise-insulating modules, preferably wherein the ballast portion of each of the noise-insulating module is turned towards a next larger noise-insulating module, if provided for in the telescopic arrangement, and/or the noise-insulating portion of each of the noise-insulating module is turned towards a next smaller noise-insulating module, if provided for in the telescopic arrangement, interconnecting noise-insulating modules arranged next to each other, providing an holding device and connecting at least one of the noise-insulating modules to the holding device.

According to an exemplary aspect, it is provided a method for installing a modular noise-insulating device in a water body, comprising the steps providing a noise-insulating device, in particular, as described herein, positioning the noise-insulating device close to a pile driving device for surrounding a pile, moving noise-insulating modules of the noise-insulating device telescopically relative to each other from a holding device in order to increase a length of a tapered structure formed by the noise-insulating modules by lowering down the bottom module in a direction of a ground surface of the water body by a gravitational force for positioning on or hovering above said ground surface in an operating position and unfolding the noise-insulating modules arranged above the bottom module from a storage position to an operating position by lowering down the bottom module, compensating a misalignment, in particular, caused by a current, by displacing the noise-insulating modules relative to each other in a direction with a direction component orthogonal to the vertical axis within a gap width of an overlap of two noise-insulating modules arranged next to each other.

According to an exemplary aspect, it is provided a method for installing a modular noise-insulating device in a water body, comprising the steps providing a noise-insulating device, in particular as described herein, positioning the noise-insulating device close to a pile driving device for surrounding a pile, moving noise-insulating modules of the noise-insulating device telescopically relative to each other from a holding device in order to increase a length of a tapered structure formed by the noise-insulating modules by lowering down the bottom module in a direction of a ground surface of the water body by a gravitational force for positioning on or hovering above said ground surface in an operating position and unfolding the noise-insulating modules arranged above the bottom module which have lower edges supported by a plate of the bottom module arranged at a lower end of the bottom module in the storage position and/or while telescoping the noise-insulating modules to the storage position from a storage position to an operating position by lowering down the bottom module, positioning the plate of the bottom module so that a central opening of the plate is positioned for passing through of a pile element to be rammed into the ground surface.

As to the advantages, preferred embodiments, and details of these further and exemplary aspects and their preferred embodiments, reference is made to the corresponding advantages, preferred embodiments and details described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments shall now be described with reference to the attached drawings, in which:

FIG. 1 shows an example sectional view of a noise-insulating device in the operating position;

FIG. 2 shows an example sectional view of a noise-insulating device in the operating position;

FIG. 3 shows an example sectional view of a noise-insulating device in the operating position.

In the figures, elements with the same or comparable functions are indicated with the same reference numerals.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIGS. 1-3 depict an example of a modular noise-insulating device 1 in the operating position. The modular noise-insulating device 1 comprises exemplarily three tubular noise-insulating modules 2, 3, 4 with one bottom module 2 and two upper noise-insulating modules 3, 4 arranged above the bottom module 2. The noise-insulating modules 2, 3, 4 arranged next to each other in this operating position are interconnected by flexible connection means 5 arranged at an outer circumference of said noise-insulating modules 2, 3, 4. Further, the noise-insulating modules 2, 3, 4 are interconnected by its geometry to limit the relative movement to each other.

The noise-insulating modules 2, 3, 4 form a substantially tapered structure extending along a vertical axis in the operating position and surrounding a pile 10. The diameter of said tapered structure decreases in an upwards direction starting from the bottom module 2 which is positioned on a ground surface 6 of a water body 7. In the exemplary shown, the uppermost noise-insulating module 4 is partially positioned above the water surface by a buoyant force acting on said uppermost noise-insulating module 4. Alternatively, it is also possible that the uppermost module can end at the level of the water surface. Thus, the spreading of noise can be safely prevented.

In the exemplary shown, the noise-insulating modules 2, 3, 4 comprise a noise-insulating portion 8 and a ballast portion 9. Alternatively, it is possible to provide a noise-insulating device with substantially homogeneous noise-insulating modules.

The ballast portion 9 comprises a ballast weight extending from a lower end to the noise-insulating portion 8, and the noise-insulating 8 portion extends from the ballast portion 9 to an upper end, which is arranged above the lower end in the operating position. The ballast portion 9 provides a gravitational force. Therefore, the ballast portion 9 can stabilize the noise-insulating modules 2, 3, 4 in the operating position and has a positive effect to the buoyancy control.

The noise-insulating portion 8 comprises an inner wall 81, an outer wall 82, and an intermediate space 83 between the inner wall 81 and the outer wall 82. Said intermediate space 83 forms a chamber filled with a noise-insulating medium. The chamber can be filled with air. This has the advantages that air is an excellent noise insulator and reduces the weight of the noise-insulating portion 8. Further, the noise-insulating portion 8 has a reduced density. Thus, the noise-insulating portion 8 provides a buoyant force, which is bigger than a gravitational force generated by its material weight, in particular of the inner wall 81 and the outer wall 82. In this way, the noise-insulating portion 8 is positive buoyant.

Due to the buoyant force provided by the noise-insulating portion 8 and the gravitational force provided by the ballast portion 9, the noise insulating module arranged above the bottom modules 3, 4 is neutral or slightly positive buoyant.

A plate 11a, 11b arranged at a lower end of the bottom module 2 forms the ballast portion of the bottom module 2. The plate 11a, 11b has a ballast weight, which is preferably higher than a ballast weight of the ballast portions 9 of the noise-insulating modules 3, 4 arranged above the bottom module 2. Therefore, the bottom module 2, in particular its ballast weight, provides a total gravitational force in the surrounding liquid to pull down the bottom module 2 from the water level and to retain the bottom module in the operating position under the effect of gravitational force. Therefore, the gravitational force provided by and acting on the bottom module 2 has a higher magnitude than the buoyant force acting on the bottom module 2, which is the sum of buoyant forces provided by the interconnected noise-insulating modules 3, 4 arranged above the bottom module 2, so that the bottom module 2 is retained in the operating position by said gravitational force.

The bottom module 2 is connected to winches 12 via flexible lifting means 13. The lifting means 13 are arranged at an outer circumference of the bottom module 2 to reduce the risk of damaging the lifting means 13.

The winches 12, in particular, brakes of the winches, can prevent telescopic movement of the noise-insulating modules 2, 3, 4 relative to each other in the storage position and allow telescopic movement of the noise-insulating modules 2, 3, 4 relative to each other for unfolding the noise-insulating modules from the storage position to the operating position, in particular, by releasing brakes on the winches 12.

By releasing brakes on the winches 12, the total gravitational force acting on the bottom module 2 pulls down the bottom module 2 from the storage position to the operating position. By lowering down the bottom module 2, the noise insulating modules 3, 4 arranged above the bottom module 2 also pull down. The noise-insulating modules 2, 3, 4 can also be retrieved from the operating position to the storage position in which the noise-insulating modules 2, 3, 4 are movably nested in a telescopic arrangement using the winches.

The neutral or slightly positive buoyancy of the noise-insulating modules 3, 4 arranged above the bottom module 2 in the operating position retain said noise-insulating modules 3, 4 in the operating position.

FIG. 1 shows a plate 11a with a central opening for passing through of the pile 11 to be rammed into the ground surface 6. A lower edge of the noise-insulating module 3 arranged above the bottom module 2 in the operating position is configured to be supported by the plate 11a in the storage position and/or while telescoping the noise-insulating modules to the storage position.

FIGS. 2 and 3 show a plate 11b with a central opening for passing through of the pile 10 to be rammed into the ground surface 6. Lower edges of the noise-insulating modules 3, 4 arranged above the bottom module 2 in the operating position are configured to be supported by the plate 11b in the storage position and/or while telescoping the noise-insulating modules to the storage position.

Therefore, the bottom module 2 with the plate 11a, 11b at the lower end can serve as a depot for upper noise-insulating modules 3, 4. In addition, the plate 11a, 11b is positioned on the ground surface 6 of the water body 7 to reduce the self-weight penetration into the ground of the water body due to the increased bearing area and to reduce or to prevent the noise from penetrating the ground.

The noise-insulating modules 3, 4 arranged above the bottom module are shaped with a taper at the lower end for smooth folding and unfolding.

The noise-insulating modules arranged next to each other 2 and 3 as well as 3 and 4 has an overlap 20 and a circumferential gap 21 between these noise-insulating modules 2 and 3 as well as 3 and 4 in a region of the overlap 20. The vertical overlap 20 in the direction of a vertical axis is larger than a gap width of the gap 21. Thus, the noise escaping through the gaps will be deflected upwards with a sufficiently steep angle.

In FIG. 1, the winches 12 are attached to a platform 14 of a pile driver 15. In this way, existing systems can be easily re-equipped.

In FIG. 2, the winches 12 are attached to a frame 16, which is attached to the platform 14 of the pile driver 15. In this way, existing systems can be easily re-equipped. Further, the noise-insulating modules 2, 3, 4 comprise rollers or gliders as protection spacers 18 attached to an inner circumference. Thus, the risk of damaging the noise-insulating modules 2, 3, 4 in case the pile hits the modules can be mitigated.

In FIG. 3, the winches 12 are attached to a frame 16, which is attached to a vessel 17. In this way, the vessel 17 can be easily re-equipped. Further, the noise-insulating modules 2, 3, 4 comprise rollers or gliders as protection spacers 18 attached to an inner circumference. Thus, the risk of damaging the noise-insulating modules 2, 3, 4 in case the pile hits the modules can be mitigated.

Claims

1.-15. (canceled)

16. A modular noise-insulating device for offshore pile driving, comprising a holding device and tubular noise-insulating modules movably nested in a telescopic arrangement in a storage position and constructed to move telescopically relative to each other from the holding device:

wherein at least one of the noise-insulating modules is connected to the holding device and the noise-insulating modules arranged next to each other are interconnected;

wherein the noise-insulating modules comprise a bottom module to be lowered down to a ground surface of a water body for positioning on or hovering above said ground surface in an operating position and form a substantially tapered structure extending along a vertical axis in the operating position for surrounding a pile;

wherein the bottom module is connected to the holding device, wherein the noise-insulating modules are constructed to extend telescopically to the operating position upon lowering the bottom module and to telescope to the storage position upon retrieving the bottom module; and/or

wherein the holding device comprises winches with lifting means connected to the bottom module and configured to lower and to retrieve the bottom module, further comprising:

at least two of the noise-insulating modules: are formed by a substantially homogeneous body; or comprise a noise-insulating portion and a ballast portion for buoyancy control; and wherein the ballast portion comprises a ballast weight and provides a gravitational force; wherein the noise-insulating portion is constructed to provide a buoyant force, which is bigger than a gravitational force generated by its material weight; wherein the ballast portion is constructed to provide a buoyant force, which is smaller than a gravitational force generated by its material weight;

wherein in a surrounding liquid in the operating position: each single noise-insulating module arranged above the bottom module provides a ratio of a total buoyant force versus a total gravitational force provided by said single noise-insulating module, said ratio being in a first range of ratio between 1 and 5; the bottom module provides a second ratio of a total buoyant force of said bottom module versus a total gravitational force of said bottom module, said second ratio being below a maximum ratio of said single noise-insulating modules; such that said bottom module is adapted to pull down the bottom module for unfolding the noise-insulating modules from the storage position to the operating position and to retain the bottom module in the operating position against a total buoyant force of said noise-insulating modules acting on the bottom module.

17. The modular noise-insulating device according to claim 16, wherein at least two of the noise-insulating modules comprise the noise-insulating portion and the ballast portion;

wherein the ballast portion extends from a lower end to the noise-insulating portion, wherein the noise-insulating portion extends from the ballast portion to an upper end, which is arranged above the lower end in the operating position.

18. The modular noise-insulating device according to claim 16, wherein the gravitational force provided by and acting on the bottom module is higher than the sum of the buoyant forces in the surrounding liquid, preferably seawater, of all noise-insulating modules arranged above the bottom module minus the sum of the gravitational forces of all noise-insulating modules arranged above the bottom module.

19. The modular noise-insulating device according to claim 16, wherein the noise-insulating portions of each noise-insulating module comprise a support structure and a noise-insulating module attached to the support structure.

20. The modular noise-insulating device according to claim 16, wherein the noise-insulating portions of each noise-insulating module, comprise a chamber filled with a noise-insulating medium; and

wherein the noise-insulating medium is a gaseous substance and/or a noise-insulating material.

21. The modular noise-insulating device according to claim 20, wherein the noise-insulating medium is a foam.

22. The modular noise-insulating device according to claim 20, wherein the noise-insulating medium is a glass wool.

23. The modular noise-insulating device according to claim 16, wherein the noise-insulating modules arranged next to each other are constructed to have an overlap in the direction of the vertical axis in the operating position;

wherein a first noise-insulating module of the noise-insulating modules is arranged next to a second noise-insulating module and overlaps this second noise-insulating module;

wherein said first noise insulation module has an inner diameter which is larger than an outer diameter of said second noise-insulating module to form a circumferential gap between said first and said second noise-insulating module in a region of the overlap, said gap having a gap width in a radial direction with respect to the vertical axis;

wherein an extension of the vertical overlap in the direction of the vertical axis is larger than said gap width, preferably the extension of the vertical overlap is at least twice as large or at least three times as large than the gap width.

24. The modular noise-insulating device according to claim 16, wherein the bottom module comprises a plate at a lower end for positioning on or hovering above the ground surface of the water body, wherein the plate comprises a central opening for passing through of a pile element to be rammed into the ground surface;

wherein a lower edge of at least one, preferably all noise-insulating modules arranged above the bottom module in the operating position is configured to be supported by the plate in the storage position and/or while telescoping the noise-insulating modules to the storage position.

25. The modular noise-insulating device according to claim 16, wherein the noise-insulating modules arranged next to each other are interconnected by connection means, in particular by flexible connections.

26. The modular noise-insulating device according to claim 16, wherein the bottom module is connected to the holding device, wherein the noise-insulating modules are constructed to extend telescopically to the operating position upon lowering the bottom module and to telescope to the storage position upon retrieving the bottom module, and/or

wherein the holding device comprises synchronized winches, with flexible lifting means connected to the bottom module and configured to lower and to retrieve the bottom module;

wherein the lifting means are arranged at an outer circumference of the bottom module.

27. The modular noise-insulating device according to claim 26, wherein the holding device is constructed and/or arranged to compensate the excess gravitational force of the noise-insulating modules for retaining the holding device at or above a water level and/or wherein the holding device comprises a gripper frame and/or a vessel and/or a pile gripper and/or a platform for a pile driver, wherein the gripper frame and/or the vessel and/or the platform for a pile driver is equipped with the winches.

28. The modular noise-insulating device according to claim 16, wherein each noise-insulating module comprises at least two segments forming partial shells constructed to form a part of a circumference of said noise-insulating module for creating its tubular form;

wherein the at least two segments are constructed to be pivoted relative to each other for opening and closing said noise-insulating module; and

wherein the segments are interconnected by a hinge.

29. The modular noise-insulating device according to claim 16, wherein the noise-insulating modules comprise protection spacers and/or guides attached to an inner circumference of some;

wherein each of the noise-insulating modules for maintaining a distance between the noise-insulating modules and a pile inserted through said noise-insulating modules while piling.

30. A method for installing a modular noise-insulating device in a water body, comprising the steps:

providing a noise-insulating device, according to claim 16;

positioning the noise-insulating device close to a pile driving device for surrounding a pile;

moving noise-insulating modules of the noise-insulating device telescopically relative to each other from a holding device in order to increase a length of a tapered structure formed by the noise-insulating modules by: lowering down the bottom module to a ground surface of the water body by a total gravitational force provided by the bottom module for positioning on or hovering above said ground surface in an operating position; and unfolding the noise-insulating modules arranged above the bottom module from a storage position to an operating position by lowering down the bottom module;

retaining the noise-insulating modules in the operating position by the opposing total gravitational force provided by and acting on the bottom module and total buoyant forces provided by and acting on the noise-insulating modules arranged above the bottom module.

31. A method for installing a modular noise-insulating device in a water body, comprising the steps:

providing a noise-insulating device, according to claim 28;

positioning the noise-insulating device close to a pile driving device for surrounding a pile;

moving noise-insulating modules of the noise-insulating device telescopically relative to each other from a holding device in order to increase a length of a tapered structure formed by the noise-insulating modules by: lowering down the bottom module to a ground surface of the water body by a total gravitational force provided by the bottom module for positioning on or hovering above said ground surface in an operating position; and unfolding the noise-insulating modules arranged above the bottom module from a storage position to an operating position by lowering down the bottom module;

retaining the noise-insulating modules in the operating position by the opposing total gravitational force provided by and acting on the bottom module and total buoyant forces provided by and acting on the noise-insulating modules arranged above the bottom module.

32. The method according to claim 31, comprising the steps:

positioning the noise-insulating modules, with at least two segments forming partial shells constructed to form a part of a circumference of said noise-insulating modules near to a pile in an open position;

pivoting the at least two segments relative to each other; and

closing the at least two segments to create a tubular form of said noise-insulating modules for surrounding the pile.

33. A method of using of a modular noise-insulating device according to claim 16, as an underwater noise insulator to insulate noise generated during offshore pile driving, in particular to surround a pile while driving the pile into a ground surface of a water body and to insulate noise generated during offshore pile driving.

34. The modular noise-insulating device according to claim 25, wherein said flexible connections are straps.

35. The modular noise-insulating device according to claim 25, wherein said flexible connections are chains.