GB2463262A

GB2463262A - Wave slap noise preventer

Info

Publication number: GB2463262A
Application number: GB0816199A
Authority: GB
Inventors: Jim Pirrie
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-09-05
Filing date: 2008-09-05
Publication date: 2010-03-10
Anticipated expiration: 2028-09-05
Also published as: GB2463262B; GB0816199D0

Abstract

A wave slap noise preventer comprises a floating flexible membrane, mat, mesh or blanket 1 which is attached by, to or within a tension-bearing arrangement 2 with attachment points 3, such that it can be held in place alongside a boat hull or other construction during use. The membrane, mat, mesh or blanket may be formed from a buoyant material, or may have buoyant elements attached to it. The membrane, mat, mesh or blanket may be made from a material with sufficient stiffness to ensure that it does not fold, bunch, roll or curl in use. The membrane, mat, mesh or blanket may be formed as a single piece or may be formed as a number of sections.

Description

Wave Slap Noise Preventer This invention relates to a device for preventing wave and ripple slap noise, for example on the hull of a boat whilst moored or at anchor or on the surface of any other construction where the elimination of such noise is desireable.

In many leisure craft, there are sleeping cabins in areas of the boat hull where ripples and waves slap and popple against the hull, making sleeping difficult even in light weather. When the wave size grows as the windspeed and/or surface turbulence increases (for example as another vessel passes by), then the noise can become intrusive even for those not trying to sleep, and for those attempting to rest sleep becomes impossible. The loud volume and sharp nature of the slap sounds and the random nature of the disturbance means that for many people even earplugs do not provide an effective solution.

Existing attempts to solve this problem rely on either wrapping a cushion around the part of the hull affected, or making a specially-shaped in-fill that must be held in place in precisely the right part of the hull. Both of these solutions address the symptoms of the problem by attempting to exclude surface waves from the problem area.

This invention addresses the root cause of the problem by modifying the surface dynamics of the water such that the conditions necessary to create the slapping and poppling noises can no longer exist, and when correctly installed will almost entirely eliminate the acoustic problem.

To achieve this, a membrane, mat, mesh or blanket is floated on the surface of the water in the region of the hull where the noise problem exists. To ensure that the water surface is covered even as wave size builds, the membrane, mat, mesh or blanket may be held against the hull some distance below the waterline, the distance depending on the size of the waves and the design of the boat hull, so that even during larger wave troughs large areas of the hull are not exposed to the water surface directly.

The result is that the wave shapes that cause the slapping and poppling noises are largely eliminated, for the most part leaving only the smoother underlying waveform that makes little or no sound as it meets the boat hull or other construction.

To ensure that the membrane, mat, mesh or blanket covers the water surface, it may either be made of a buoyant material or made of a non-buoyant material supported on the water surface by floats or flotation chambers. In the latter case, the membrane, mat, mesh or blanket may be pierced with holes to ensure that it is not sunk beneath the water surface by water slopping on to the top surface.

To ensure that the membrane, mat, mesh or blanket extends across a sufficient area of water, it may be prevented from folding, bunching or rolling by its own structural properties and/or by using stiffeners and/or by other means such as guy lines or ropes.

The membrane, mat, mesh or blanket may be held in place against a boat hull by means of a suitable arrangement of ropes or lines, or by some other attachment means, for example screws or bolts in permanent installations.

The invention therefore comprises a device combining a suitable floating membrane, mat, mesh or blanket with the structural elements necessary to achieve sufficient rigidity for the membrane, mat, mesh or blanket to cover the desired surface area reliably in the prevailing wind and water conditions, while giving sufficient flexibility to conform to the underlying surface wave form. The structural element(s) of the device also include(s) loops and/or eyes and/or fixtures that are used to make the device fast to the boat hull or other construction by means of ropes and/or lines and/or other means, and may incorporate pockets to contain and/or protect buoyant elements of the device. Since the device may come under significant tension from the securing lines, the structural element may be suitably reinforced.

The membrane, mat, mesh or blanket may be either rectangular or shaped, so long as it is able to make contact with a sufficient area of the boat hull or other construction beneath the waterline, and also able to cover a sufficient area of the water surface adjacent to the boat hull or other construction, and it may be made either in one piece or in sections.

Depending on the design of the boat hull or other construction, and the prevailing weather and water conditions, the device may be used either singly, in pairs or several devices together, for example to protect two sides of a boat hull or to protect a more exensive area.

An example of the device will now be described by referring to the accompanying drawings.

Figure 2 shows a schematic of an example of the device itself, in this case a rectangular example, the membrane, mat, mesh or blanket (1) being made from a flexible closed-cell foam, attached along one edge to a bolt-rope or line (2) to take the tension from the securing arrangement which will be made fast to some or all of the rope ioops (3) which are attached to the bolt rope (2).

Figure 2 shows the top view of a typical installation of a pair of devices similar to that shown in Figure 1 on the aft portion of a sailing boat. The devices (1) are attached using ropes or lines to the securing points (2) well forward on the boat, and to a third securing point (3) at the stern, allowing the devices to float on the surface of the water adjacent to the hull at the rear part of the boat.

Figure 3 shows the side view of a typical installation of a device similar to that shown in Figure 1, on the aft portion of a sailing boat. The device (1) is attached using ropes or lines (2) to the securing points (3) well forward on the boat, and to a third securing point (4) at the stern, allowing the devices to float on the surface of the water adjacent to the hull at the rear part of the boat. In the forward part of the protected area, the device is pulled below the waterline (5) by the securing line which, because of the shape of the hull, will tend to pull the forward end of the device forward and down if it is secured far forward on the boat and with sufficient tension. In this example, the aft end of the device is held above the water and the membrane, mat, mesh or blanket may be held clear (6) until a wave arrives that locally raises the water level against the boat hull, at which time the aft area (6) of the device will float on the water surface.

Figure 4 shows a cross-section of a device similar to that shown in Figure 1 in situ against the hull of a boat, illustrating the positioning of the membrane, mat, mesh or blanket against the boat hull and on the water surface. The membrane, mat, mesh or blanket (1) floats on the water surface (2) except where it is held against the hull (3) and below the surface (2) by the tension and position of the bolt-rope (4).

Claims

Claims 1. A wave slap noise preventer comprising a flexible membrane, mat, mesh or blanket that floats on the water surface adjacent to a boat hull or other construction, attachment points or other means for attaching the device to a boat or other construction by means of ropes, lines or otherwise, and load-bearing elements such that the device can withstand any tension and other loads it may be subject to in use.
2. A wave slap noise preventer according to claim 1, in which the membrane, mat, mesh or blanket is made from a buoyant material.
3. A wave slap noise preventer according to claim 1, in which the membrane, mat, mesh or blanket is made from a non-buoyant material and is made buoyant by means of floats or flotation chambers.
4. A wave slap noise preventer according to claims 1 to 3, in which the membrane, mat, mesh or blanket is made from a material with sufficient structural stiffness that it will not fold, bunch, roll or curl in use.
5. A wave slap noise preventer according to claims 1 to 3, in which the membrane, mat, mesh or blanket is secured to, by or within an arrangement that ensures it will not fold, bunch, roll or curl in use.
6. A wave slap noise preventer according to claims 1 to 5, in which the membrane, mat, mesh or blanket is fabricated in a single piece.
7. A wave slap noise preventer according to claims 1 to 5, in which the membrane, mat, mesh or blanket is fabricated in sections.