A bottom trawl footrope device

Abstract

A footrope device (1-7) for assembly onto a footrope for a bottom trawl comprises a forward side (F) facing in the direction in which the trawl is being towed, and a rearward side (R) facing in the opposite direction. One or more towing connector structures (52a,b; 62a,b) are configured and arranged for connection to a main towing member (11) in the footrope, and one or more trimming connector structures (54) are connected to an upper portion of the footrope device body. At least one of the trimming connector structures (54) comprises a plurality of attachment portions (551-n) via which the footrope device can be connected to a steering chain or steering line 14 in the footrope. The towing connector structures allow a main towing member to be connected to one of several positions on the footrope device, and the multiple trimming connector attachment portions allow the steering chain to be connected to one of several positions, which provides the ability for an operator to control the angle of inclination of the footrope device and thus fine-tune the setting of the entire footrope towards the seafloor.

Description

[0001] A bottom trawl footrope device

[0002] Technical field of the invention

[0003] The present invention relates to a bottom trawl configured for catching fish and other marine organisms on or near a seafloor. More specifically, the present invention concerns a bottom trawl footrope device as defined by the preamble of claim 1.

[0004] Background of the invention

[0005] Bottom trawling is a fishing method that involves towing a net close to the seafloor in order to catch fish and other marine organisms. A typical bottom trawl comprises a cone-shaped net (trawl bag) in which the narrow end (the codend) is closed in order to hold the catch, while the opposite, wider, trawl mouth is maintained in an open position by oppositely arranged boards trawl-doors) that are connected by respective trawl wires to one or more towing vessels (trawlers). A so-called footrope extends across the lower edge of the trawl mouth and is intended for keeping the trawl mouth near or on the seafloor. The footrope can comprise one or more ropes, wires, or chains, with weights to generate an appropriate downward force, and is in many cases equipped with discs or spheres (so-called rockhoppers) to prevent the trawl mouth from getting damaged by the seafloor and also minimising seafloor damage.

[0006] So, while the footrope on the one hand is intended for being dragged along the seafloor in order to efficiently catch fish and other marine organisms on or near the seafloor, it should also be designed such that is does not easily gets stuck on objects on the seafloor or cause damage to marine life. Extensive research has therefore been dedicated to developing a footrope that balances trawling efficiency with mitigating seafloor damage.

[0007] The prior art includes Project MultiSEPT - Development of multirig semi-pelagic trawling, by Eduardo Grimaldo, Manu Sistiaga, Svein Helge Gjosund, Jorgen Jensen, Lasse Rindahi, Jorgen Vollstad, Karl Johan Reite, and published by SINTEF Fisheries and Aquaculture, Fisheries Technology, 2014-01-09 ("Status report 2013, A25817 Unrestricted"). This publication describes a so-called Semi-Circular Spreading Gear (SCSG), in which a plurality of semi-circular devices is arranged on a footrope, with the concave portion of the body facing forward, i.e., in the trawling direction.The prior art also includes DK202530044A1, which describes a footrope for a bottom trawl. The footrope comprises a plurality of semi-circular devices; various shapes are illustrated. Embodiments include a semi-circular device with uniform wall thickness and a closed, foil-shaped, device. Each device is connected to the footrope’s main tow chain via a fixed connection.

[0008] The prior art also includes a footrope device 10 as illustrated in figures 1 and 2, developed by the applicant of the present application. Figure 1 illustrates a portion of a footrope comprising a plurality of footrope devices 10 arranged on a main tow chain 11, separated by spacers (e.g., of rubber) 12 and washers 13. When in use, the footrope extends between trawl doors and is arranged near the lower edge of a trawl mouth, as described above.

[0009] Adjacent footrope devices 10 are interconnected via a steering chain (aka a false fishing line) 14 via pairs of rings 15. Referring to figures 2a and 2b, the prior art footrope device 10 comprises a plate member 16 which has been bent along a plurality of bend lines B to form an approximate semi-circular shaped body. The distance between adjacent bend lines determines the curvature smoothness. Support members 19 span the concave side in order to provide structural stiffness.

[0010] The above-mentioned rings 15 for connection to the steering chain 14 are connected to the footrope device 10 via respective holes (or cut-outs) 20 in the upper portion of the plate member 16. When in use in a bottom trawl, the footrope device’s body convex side is facing forward, i.e., in the direction in which the trawl is being moved (towed). The footrope device 10 comprises laterally extending (i.e., wider) and raised portions 17 in the lower region in order to stabilise the footrope device as it is being dragged along the seafloor. A replaceable wear plate 18 is arranged on the lower region of the footrope device 10. The footrope device’s 10 rear side - i.e., the concave side, facing in the opposite direction from the trawling direction - comprises attachment structures 22 via which the body 10 can be connected to the main tow chain 11.

[0011] There is a need for a footrope that can be controlled more precisely than the prior art footrope devices.Summary of the invention

[0012] The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

[0013] It is thus provided a footrope device for assembly onto a footrope for a bottom trawl, comprising a forward side facing in the direction in which the trawl is being towed, and a rearward side facing in the opposite direction; characterized by:

[0014] - one or more towing connector structures configured and arranged for connection to a main towing member in the footrope, and

[0015] - one or more trimming connector structures connected to an upper portion of the footrope device body; wherein at least one of the trimming connector structures comprises a plurality of attachment portions via which the footrope device can be connected to a steering chain or steering line in the footrope.

[0016] In one embodiment, the trimming connector structures are arranged on an upper portion of the forward side.

[0017] In one embodiment, the footrope device comprises side panels and a central stiffener.

[0018] In one embodiment, at least one towing connector structure comprises a tubular extending transversely on the footrope device’s rearward side, wherein a main towing member can be extended through the tubular.

[0019] A first connector structure can be arranged above a second towing connector structure, along a vertical axis for the footrope device, or the towing connector structures can be arranged side by side along a horizontal axis for the footrope device.

[0020] In one embodiment, the footrope device further comprises side panels, and stiffeners and additional trimming connector structures in each stiffener. In one embodiment, a first pair of towing connector structures extends between a first side panel and a first stiffener, and a second pair of towing connector structures extends between a second side panel and a second stiffener.

[0021] In one embodiment, the footrope device further comprises one or more alternative trimming connector structures connected to an upper portion of the footrope device body; wherein at least one of the alternative trimming connector structures comprises aplurality of attachment portions via which the footrope device can be connected to a steering chain or steering line in the footrope.

[0022] In one embodiment, the footrope device further comprises a plurality of light sources arranged in a housing, and the light sources are arranged on the forward side of the footrope device. The housing can comprise a power source and a control device whereby the light sources can be operated and controlled, and the light sources can be controlled to emit light at wavelengths that are suitable for attracting fish and other marine organisms on or near the seafloor.

[0023] The invented footrope device makes it possible to control the downward force from the footrope onto the seafloor more precisely than what is possible with prior art footrope devices.

[0024] Brief description of the drawings

[0025] These and other characteristics of the invention will become clear from the following description of embodiments of the invention, given as non-restrictive examples, with reference to the attached schematic drawings, wherein:

[0026] Figure l is a view of a portion of a footrope comprising a plurality of prior art footrope devices, as described above;

[0027] Figures 2a and 2b are oblique perspective views from the rear and front, respectively, of a prior art footrope device, as described above;

[0028] Figures 3 and 4 are oblique perspective views from the rear and front, respectively, of a first embodiment of the footrope device according to the invention;

[0029] Figure 5 is a side view of the footrope device illustrated in figures 3 and 4;

[0030] Figure 6 is a front view of the footrope device illustrated in figures 3, 4, 5;

[0031] Figures 7 and 8 are oblique perspective views from the rear and front, respectively, of a second embodiment of the footrope device according to the invention;

[0032] Figure 9 is a side view of the footrope device illustrated in figures 7 and 8;Figure 10 is an oblique perspective view from the rear of a third embodiment of the footrope device according to the invention;

[0033] Figure 11 is a side view of the footrope device illustrated in figure 10;

[0034] Figure 12 is an oblique perspective view from the rear of a fourth embodiment of the footrope device according to the invention;

[0035] Figure 13 is a side view of the footrope device illustrated in figure 12;

[0036] Figure 14 is an oblique perspective view from the rear of a fifth embodiment of the footrope device according to the invention;

[0037] Figure 15 is a side view of the footrope device illustrated in figure 14;

[0038] Figure 16 is a side view a sixth embodiment of the footrope device according to the invention;

[0039] Figure 17 is an oblique perspective view from the rear of a seventh embodiment of the footrope device according to the invention;

[0040] Figure 18 is a partly transparent side view of the footrope device illustrated in figure 17; and

[0041] Figure 19 is an oblique perspective view from the front of the footrope device illustrated in figures 17 and 18.

[0042] Detailed description of embodiments of the invention

[0043] The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, “upper”, “lower”, “inner”, “outer”, “forward”, “rear”, “underneath”, “above”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

[0044] Referring to figures 3-6, a first embodiment of the footrope device 1 according to the invention comprises a body 50 which in the illustrated embodiment comprises a plate member which has been bent along a plurality of bend lines B to form an approximate semi-circular shaped body. The distance between adjacent bend lines determines thecurvature smoothness. It should be understood that the footrope device 1 body can be formed by other methods or means and is not necessarily formed from a plate member. For example, the body 50 can be formed from a tubular body, such as a pipe, thus having a semi-circular cross-section. The body is made of a material suited for bottom trawling, such as steel.

[0045] When arranged in a footrope for a bottom trawl, as described above with reference to figure 1, the footrope device’s 1 convex side is facing forward, i.e., in the direction in which the trawl is being moved (towed). The footrope device’s convex side is thus referred to as the forward side or front side F, and the footrope device’s concave side is referred to as the rear side. The footrope device 1 need not necessarily comprise a semi¬ circular body shape having convex and concave portions. The footrope device 1 comprises laterally extending (i.e., wider) and raised portions 51 in the lower region in order to stabilise the footrope device 1 as it is being dragged along the seafloor. A replaceable wear plate (not shown) can be arranged on the footrope device’s lower region, or the lower region can comprise a reinforced portion or material.

[0046] Arranged on the footrope device’s 1 rearward side R are towing connector structures 52, configured for connection to a footrope main tow chain or wire, for example a main tow chain 11 as described above with reference to figures 1 and 2. Although the embodiment illustrated in figures 3-6 comprises two towing connector structures 52, it should be understood that the footrope device 1 can comprise fewer or more such structures. In the illustrated embodiment, each towing connector structure 52 comprises two towing member interface portions 52a, 52b, through which the main towing member (e.g. chain) can be extended.

[0047] The footrope device 1 also comprises trimming connector structures 54 connected to, or integrated in, an upper portion of the footrope device body 50. Although the embodiment illustrated in figures 3-6 comprises two trimming connector structures 54, it should be understood that the footrope device can comprise fewer or more such structures. Each trimming connector structure 54 comprises a plurality of attachment portions 55 i-n, via which the footrope device 1 can be connected to a steering chain or steering line, for example a steering chain (aka a false fishing line) 14 as described above with reference to figures 1 and 2. In the illustrated embodiment, the trimmingconnector structure 54 comprises five attachments portions 551-5, but the invention shall not be limited to this number. In the illustrated embodiment, the trimming connector structures 54 are arranged on an upper portion of the forward side F, but the trimming connector structures can alternatively be arranged on the rearward side R.

[0048] Figures 7-9 illustrate a second embodiment of the footrope device 2 according to the invention. Unless specified below, this embodiment is similar to the footrope device 1 of the first embodiment. In particular, the towing connector structures in this second embodiment are different from the towing connector structures in the first embodiment. Furthermore, the footrope device 2 of the second embodiment comprises side panels 66a, 66b, and a central stiffener 67 arranged on the rearward side. Arranged on the footrope device’s 2 rearward side R are towing connector structures 62a, 62b, configured for connection to a footrope main tow chain or wire, for example a main tow chain 11 as described above with reference to figure 1. Although the embodiment illustrated in figures 7-9 comprises two towing connector structures 62a, 62b, it should be understood that the footrope device can comprise fewer or more such structures. In the illustrated embodiment, each towing connector structure 62a, 62b comprises a tubular extending transversely on the footrope device’s 2 rearward side R, wherein a main tow member (e.g. chain) can be extended through the tubular. In the illustrated embodiment, an upper towing connector structure 62a is arranged above a lower towing connector structure 62b, along a vertical (y) axis for the footrope device.

[0049] Figures 10 and 11 illustrate a third embodiment of the footrope device 3 according to the invention. This embodiment is similar to the footrope device 2 of the second embodiment with the exception that the towing connector structures 62a, 62b are arranged side by side along a horizontal (x) axis for the footrope device.

[0050] Figures 12 and 13 illustrate a fourth embodiment of the footrope device 4 according to the invention. This embodiment differs from the previously described embodiments in that the body comprises two stiffeners 67a, 67b, additional trimming connector structures 56 in each stiffener, and the towing connector structures are arranged in pairs. A first pair of towing connector structures 63 a, 63b extend between a first side panel 66a and a first stiffener 67a, and a second pair of towing connector structures 64a, 64b extend between a second side panel 66b and a second stiffener 67b. The additionaltrimming connector structures 56 comprises a plurality of attachment portions 57i-n, via which the footrope device 4 can be connected to a steering chain or steering line, for example a steering chain (aka a false fishing line) 14 as described above with reference to figures 1 and 2. In the illustrated embodiment, the additional trimming connector structure 56 comprises four attachments portions 57i-s, but the invention shall not be limited to this number. In the illustrated embodiment, the additional trimming connector structures 56 are arranged on an upper portion of each stiffener 67a,b.

[0051] Figures 14 and 15 illustrate a fifth embodiment of the footrope device 5 according to the invention. It corresponds to the fourth embodiment, but the distance between the towing connector structures 63a, 63b, 64a, 64b and the additional trimming connector structures 56 is greater.

[0052] Figure 16 illustrates a sixth embodiment of the footrope device 6 according to the invention. It corresponds to the fifth embodiment, but the towing connector structures 63a, 63b, 64a, 64b are arranged horizontally.

[0053] Figures 17, 18, and 19 illustrate a seventh embodiment of the footrope device 7 according to the invention, which comprises a plurality of light sources 31 arranged in a housing 30. In the illustrated embodiment, a sealed housing 30 is arranged on the rearward side of, or inside of, the footrope device body, and light sources are arranged on the forward side F of the footrope device 7. The sealed housing 30 comprises a power source and a control device, whereby the light sources 31 can be operated and controlled. The light sources can be remotely controlled, via a cable (not shown) or wirelessly, in a manner known in the art. The light sources can be controlled to emit light at wavelengths that are suitable for attracting fish and other marine organisms on or near the seafloor. It should be understood that any of the embodiments described above can comprise the light sources of the seventh embodiment of the invention.

[0054] Common to all of the embodiments of the footrope device 1-7 is that the towing connector structures 52a, b; 62a, b; 63a, b, 64a, b allow the main tow chain 11 to be connected to one of several positions on the footrope device, and the multiple trimming connector attachment portions 55 i-n, 57i-nallow the steering chain 14 to be connected to one of several positions. This provides the ability for an operator to control the angleof inclination of the footrope device and thus fine-tune the setting (i.e., the downward force) of the entire footrope towards the seafloor. The angle of inclination can thus be controlled by choosing connector structures and attachment portions to achieve the desired distance d between towing connector structure and attachment portion.

[0055] In the embodiments described above, various features and details are shown in combination. The fact that several features are described with respect to a particular example should not be construed as implying that those features by necessity have to be included together in all embodiments of the invention. Conversely, features that are described with reference to different embodiments should not be construed as mutually exclusive. As a person skilled in the art readily will understand, embodiments that incorporate any subset of features described herein and that are not expressly interdependent have been contemplated by the inventor and are part of the intended disclosure. However, explicit description of all such embodiments would not contribute to the understanding of the principles of the invention, and consequently some permutations of features have been omitted for the sake of simplicity or brevity.

Claims

Claims1. A footrope device (1-7) for assembly onto a footrope for a bottom trawl, comprising a forward side (F) facing in the direction in which the trawl is being towed, and a rearward side (R) facing in the opposite direction; characterized by:- one or more towing connector structures (52a, b; 62a, b) configured and arranged for connection to a main towing member (11) in the footrope, and- one or more trimming connector structures (54) connected to an upper portion of the footrope device body; wherein at least one of the trimming connector structures (54) comprises a plurality of attachment portions (55 i-n) via which the footrope device can be connected to a steering chain or steering line (14) in the footrope.

2. The footrope device of claim 1, wherein the trimming connector structures (54) are arranged on an upper portion of the forward side (F).

3. The footrope device of claim 1 or claim 2, further comprising side panels (66a, 66b), and a central stiffener (67).

4. The footrope device of any one of claims 1-3, wherein at least one towing connector structure (62a, 62b) comprises a tubular extending transversely on the footrope device’s rearward side (R), wherein a main towing member can be extended through the tubular.

5. The footrope device of claim 4, wherein a first connector structure (62a) is arranged above a second towing connector structure (62b), along a vertical (y) axis for the footrope device, or the towing connector structures (62a, 62b) are arranged side by side along a horizontal (x) axis for the footrope device.

6. The footrope device of any one of claims 1-3, further comprising side panels (66a, 66b), and stiffeners (67a, 67b) and additional trimming connector structures (56) in each stiffener7. The footrope device of claim 6, wherein a first pair of towing connector structures (63a, 63b) extends between a first side panel (66a) and a first stiffener (67a), and a second pair of towing connector structures (64a, 64b) extends between a second side panel (66b) and a second stiffener (67b).

8. The footrope device of any one of claims 1-7, further comprising one or more alternative trimming connector structures (56) connected to an upper portion of the footrope device body; wherein at least one of the alternative trimming connector structures (56) comprises a plurality of attachment portions (57i-n) via which the footrope device can be connected to a steering chain or steering line (14) in the footrope.

9. The footrope device of any one of claims 1-8, further comprising a plurality of light sources (31) arranged in a housing (30), and the light sources are arranged on the forward side (F) of the footrope device.

10. The footrope device of claim 9, wherein the housing (30) comprises a power source and a control device whereby the light sources (31) can be operated and controlled, and the light sources can be controlled to emit light at wavelengths that are suitable for attracting fish and other marine organisms on or near the seafloor.

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