Patent Application
20210387701
Certain embodiments may generally relate to marine crafts. More specifically, certain embodiments may relate to shallow draft sampling rafts or vehicles which can also be used as a scientific bench for marine science surveys in various conditions, including shallow water.
There are many types of rafts, boats, barges, scientific benches, and boards. However, each fails to provide all of the functionality to perform marine science surveys in shallow subtidal zones. For example, boards (e.g., paddle boards, surf boards, etc. . . . ) are usually fragile and require balance and concentration to load and transport heavy material.
Small boats are sometimes used for marine science; however, most boats have V-bottom hulls and are not suitable for use in shallower depths. Conventional barges are also inadequate options because of their large size. Many sites in which marine science and research is conducted require a marine raft, craft, or vessel (hereinafter “raft”) to be transported in the back of a land vehicle such as a pickup truck or attached to the roof of a car. For example, intertidal zones that include mangroves, seagrass, oyster beds, algae beds, and coral reefs, may contain nurseries and ecosystems that may be important natural resources, and often these important ecosystems are almost inaccessible for scientists because of the long distances from the shoreline to the subtidal slope. Consequently, conventional small boats and barges are poor options because they may require a loading ramp that is usually not available, and/or they may not be able to move effectively through the different ecosystems.
Therefore, there is a need for a shallow draft marine raft that is lightweight, stable, inexpensive, and easily portable.
In accordance with some certain embodiments, a marine raft may include a bow, a stern, and a top surface, wherein the bow is an opposite end of the raft from the stern. The marine raft further includes plurality of longitudinal stringers, wherein the plurality of longitudinal stringers is attached to an upper inner face of the top surface and runs from the bow to the stern. The marine raft further includes a bottom surface, wherein a lower inner face of the bottom surface is attached to the plurality of longitudinal stringers. The marine raft further includes a plurality of hull sides, wherein the plurality of hull sides is attached to the upper inner face and the lower inner face, and the plurality of hull sides are curved toward a center of the raft.
In accordance with certain embodiments, a method of constructing a raft may include providing a top surface, a bottom surface, a plurality of longitudinal stringers, and hull sides. The method further includes attaching an upper inner face of the top surface to the plurality of longitudinal stringers, wherein the plurality of longitudinal stringers runs from a bow of the raft to a stern of the raft. The method may further include fixing an inner facing surface of the top bottom surface to the plurality of longitudinal stringers; and attaching a plurality of hull sides, wherein the plurality of hull sides is attached to the upper inner face and the lower inner face, and the plurality of hull sides are curved toward a center of the raft.
The accompanying drawings, which are included to provide a further understanding of example embodiments and are incorporated in and constitute a part of this specification, illustrate certain embodiments of the invention and together with the detailed description serve to explain the principles of certain embodiments. In the drawings:
In the following detailed description of certain embodiments, reference is made to the accompanying drawings that form a part hereof. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical or structural changes may be made without departing from the spirit or scope of this disclosure. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense.
The features, structures, or characteristics of the invention described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of the phrases “certain embodiments,” “some embodiments,” or other similar terminology throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention.
Certain embodiments of the raft sampling bench have been designed to be used as a scientific bench for marine science surveys. Certain embodiments provide a low cost floating equipment suitable for use in various environments, including shallow subtidal zones.
Certain embodiments may use conventional, readily available materials and can weigh approximately 40 kilograms (kg), can have a draft of approximately 25 centimeters (cm), and can be configured to carry a load up to about 400 kg. Additionally, certain embodiments of the raft sampling bench may be easily transported in or on land vehicles such as pickup trucks or on roof racks of automobiles. The transportability of certain embodiments allows for easy study of coastal marine areas that can be difficult to access using conventional craft.
The area on the sides of the longitudinal stringers 110 can, in certain embodiments, be filled with a buoyancy material such as open cell foam, closed cell foam, air cells, polyurethane, ping-pong balls, etc., to create a floating cell 115. The bow 125 and stern 120 may be hydro-dynamically designed to move through water easily, to reduce splashing, and to retain stability in waves or uneven surface conditions. For example, the hull sides 105 may be curved at the ends to reduce drag in the water, or for other purposes.
Raft 100 may also include securing points 210 and 215, which can be cleats, eyes, loops, “D” rings, or other suitable devices. Securing points 210 and 215 may allow for ease in securing raft 100, attaching objects to raft 100, or towing raft 100. In certain embodiment, perimeter edge 225 of top surface 230 is square, 90 degrees, to allow use as a scientific bench for studying surveyed material still in situ (e.g., material recently removed from water). In particular, the perimeter edge may include the joint between the top surface 230 and a side surface of the raft which may include hull sides 105 and vertical surfaces at the bow 125 and stern 120. The top surface 230 can be flat.
In this example, two longitudinal 110 stringers may be used. Other stringer configurations could also be used. The space on the sides of the longitudinal stringers 110 may be filled with buoyancy material. Each floating cell 115 can be isolated from each other by the longitudinal stringers 110. The bottom surface 220 is attached to the longitudinal stringers 110 and hull sides 105 to seal the structure of the raft 100. The top surface 230 and bottom surface 220 may be connected at the bow 125 and the stern 120 with brackets 111 (e.g. longitudinal light wood sticks).
Certain embodiments may be assembled using the hollow wooden method. The different structural pieces may be assembled with screws and wood glue. The wood glue may be used to seal the inner of the raft structure, and the external sealing may be performed using a suitable coating such as epoxy paint. The inner sealing may also be plastic, glue, epoxy, tar, resin, and/or sealing tapes to provide a waterproof coating and sealing to the joints. The external sealing may also include fiberglass, carbon fiber, epoxy, weld and further material that connect the embodiment's joints, which seals externally the inner floating cells. An antifouling coating might be considered in any embodiment to avoid the biofouling. The epoxy with sand may also be used to provide a non-slip surface on the top surface 230.
The height of the raft may be determined based on the target buoyancy and the Archimedes Principle. The Archimedes Principle states, Fb=ρ×g×V, where Fb is the buoyant force, ρ is the density of the fluid, V is the submerged volume, and g is the acceleration due to gravity. In this example, the target submergible volume is 0.45 to 0.6 m3, where 1 m3 displaces 1026 kg of salt water. Accordingly, the raft may be 21 cm tall. Therefore, with the target submergible volume and total raft weight of 42 kg, the buoyancy of the raft is able to carry a load of more than 400 kg in sea water as shallow as 25 cm.
Certain embodiments illustrated in
Although the foregoing description is directed to a certain embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention. Moreover, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.
