Abstract:
An amphibious dredging vehicle includes a base including a pair of floatable pontoons linked together in essentially parallel relation; a cutterhead dredge system that is mounted on the base and that includes a cutterhead mounted on the front end portion of the base, a first directable discharge mounted to the rear end portion of the base, and a dredge pump in operative connection with the cutterhead and the directable discharge so as to develop suction at the cutterhead and to propel material from the cutterhead to the directable discharge. The directable discharge is configured so that the operator can aim the directable discharge in order to use the dredge pump to propel the amphibious dredging vehicle through water. The amphibious dredging vehicle may be used as part of a system and may be used with a method for building up land in a water-covered or water-surrounded area.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of applicant&#39;s U.S. patent application Ser. No. 10/349,599, filed Jan. 23, 2003, now U.S. Pat. No. 6,827,525 B2. 

   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   REFERENCE TO SEQUENCE LISTING, TABLE, OR COMPUTER PROGRAM LISTING SUBMITTED ON COMPACT DISK 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The invention relates to amphibious vehicles, particularly to amphibious vehicles for use in dredging, and more particularly to restoring wetlands using amphibious dredging vehicles. 
   (2) Description of the Related Art 
   Amphibious vehicles, sometimes called marsh buggies, were first developed about fifty years ago. The early vehicles were often used to transport persons and equipment through marshes for oil-and-gas exploration. 
   First-generation amphibious vehicles have two engines powering four large hollow wheels. The wheels are made of lightweight steel to provide both buoyancy and durability. Each wheel has deep, lugged cleats for traction. 
   Second-generation amphibious vehicles incorporate pontoons and track-drive systems. These second-generation amphibious vehicles include two longitudinal pontoons for buoyancy and at least one continuous drive track surrounding each pontoon for drive power. Each drive track includes an endless chain driven by a hydraulic motor through a sprocket, and each chain carries channel-type cleats for traction. These conventional vehicles are common in the art of amphibious vehicles. For example, see U.S. Pat. No. 5,984,032 to Gremillion et al. 
   Both first-generation and second-generation amphibious vehicles move in shallow water by gripping the water bottom with their cleats and rolling or tracking forward. (In this patent application “shallow water” means water in which the cleats of a conventional amphibious vehicle can grip the water bottom; and “deeper water” means water in which the cleats of a conventional amphibious vehicle float above the water bottom and cannot grip it.) In deeper water, conventional amphibious vehicles move by paddling the water with their cleated wheels or cleated tracks. The wheels or tracks are driven just as they are on land or in shallow water, and the vehicle moves by the force created by moving the wheels or tracks through the water. These vehicles move through deeper water inefficiently and slowly. 
   Cutterhead dredges are useful for restoring degraded wetlands. In restoring wetlands, cutterhead dredges can be used to rebuild land in water-covered areas where erosion has occurred. Applicant&#39;s U.S. patent application Ser. No. 10/349,599, which is incorporated herein by reference, discloses a system and method for restoring degraded wetlands using a cutterhead dredge and other devices. 
   Cutterhead dredges intended for use in wetlands are commonly mounted either on a floating vessel—typically a boat or a barge—or on a conventional amphibious vehicle. Whether mounted on a floating vessel or on an amphibious vehicle, cutterhead dredges work well in the areas that they can reach. But both floating vessels and conventional amphibious vehicles cause problems when one dredging task is complete and the operator needs to move the dredge to a new location. Floating vessels cannot travel over land; conventional amphibious vehicles travel across water inefficiently and slowly. 
   Floating vessels are limited to areas where there is enough water to float the particular vessel—preferably without undue risk of running aground. Because wetlands restoration often takes place in a degraded marsh—a combination of land, water too shallow for most vessels, and deeper water—floating vessels simply cannot reach many areas that need to be restored. Further, in many wetlands that need to be restored, cutting a channel for a floating vessel would be expensive and counterproductive. 
   Unlike floating vessels, conventional amphibious vehicles can travel on land or in shallow water. But in deeper water, where their cleats cannot grip the bottom, conventional amphibious vehicles move so slowly that driving them a substantial distance across deeper water becomes impractical. The user must choose between driving the conventional amphibious vehicle slowly across the deeper water or finding another way—usually transport by vessel or truck—to move the vehicle where it needs to be. When a vessel or truck can be used to transport a conventional amphibious dredging vehicle, the transportation requires substantial additional equipment (and thus substantial additional cost) when compared to the applicant&#39;s amphibious dredging vehicle. 
   Further, many wetlands that need restoring simply cannot be reached conveniently by vessel or by truck. Accessing these areas forces the user of a conventional amphibious vehicle to endure the long, slow, unproductive trip to the dredging area from the closest point of access. 
   Applicant&#39;s invention improves on the prior art by using the pumping capacity of a cutterhead dredge to increase a conventional amphibious vehicle&#39;s speed and maneuverability in deeper water. The applicant&#39;s amphibious dredging vehicle provides greater speed and maneuverability in deeper water than a conventional amphibious vehicle provides. And using applicant&#39;s invention, a cutterhead dredge can be moved across land or shallow water as if mounted on a conventional amphibious vehicle. In sum, when compared to dredges mounted on conventional amphibious vehicles, applicants&#39; amphibious dredging vehicle provides equal performance on land or in shallow water and superior performance in deeper water. 
   In a degraded marsh that includes land, shallow water, and deeper water that must all be crossed for the dredge to do its work, applicant&#39;s invention allows for faster, more efficient, and more convenient restoration than is possible using a dredge mounted on a floatable vessel or on a conventional amphibious vehicle. 
   Applicant&#39;s invention provides an amphibious dredging vehicle with improved mobility in deeper water. In embodiments of applicant&#39;s invention in which only a single directable discharge is present, the amphibious dredging vehicle has this advantage when the vehicle is being moved from one dredging area to a second dredging area—with no dredging performed during the trip from the first dredging area to the second. When a single-directable-discharge embodiment of the amphibious dredging vehicle is dredging (actually removing material), the directable discharge normally will be unavailable for propulsion. The directable discharge cannot normally be used for propulsion during material removal because normally the dredging plan will require the dredged material to be deposited in a particular area by means of piping connected to the dredge discharge. When piping is connected to the directable discharge of an amphibious dredging vehicle that has a single directable discharge, the directable discharge cannot provide propulsion to the amphibious dredging vehicle. 
   On the other hand, if the amphibious dredging vehicle is equipped with a second directable discharge that is not connected to the dredge cutterhead so as to discharge dredged material, then the second directable discharge may be used for propulsion while the cutterhead is being used to remove and deposit dredged material. 
   BRIEF SUMMARY OF THE INVENTION 
   It is an object of this invention to provide an amphibious dredging vessel that includes one or more of the following: a directable discharge connected to the dredge pump and controlled by a directable-discharge-control means for aiming the directable discharge; a water discharge connected to a water pump and controlled by a water-discharge-control means for aiming the water discharge. 
   It is an object of some embodiments of this invention to provide a method for restoring wetlands using the amphibious dredging vehicle disclosed herein and optionally using, along with the amphibious dredging vehicle, a system for building up land in a water-covered area as described in applicant&#39;s U.S. application Ser. No. 10/349,599, which is incorporated herein by reference. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial side view of an amphibious dredging vehicle according to the invention. 
       FIG. 2  is a partial top view of an amphibious dredging vehicle according to the invention. 
       FIG. 3  is a partial rear view of an amphibious dredging vehicle according to the invention. 
       FIG. 4  is a schematic diagram showing a hydraulic circuit according to the invention. 
   

   The invention will be better understood in view of the following description presented with reference to the accompanying drawings: 
   Both the foregoing general description and the following detailed description are exemplary and explanatory only and do not restrict the invention as claimed. 
   DETAILED DESCRIPTION OF THE INVENTION 
   The inventor now moves to a detailed description of an embodiment of an amphibious dredging vehicle  100  according to the invention. 
   As best seen in  FIG. 2 , amphibious dredging vehicle  100  has first floatable pontoon  10  and second floatable pontoon  20  with a link disposed therebetween and fixed thereto in conventional fashion, such as by welding or bolting the link to floatable pontoons  10  and  20 . In this embodiment, floatable pontoons  10  and  20  are constructed of lightweight and sturdy metal and are equipped with conventional internal baffles, which increase the strength of the pontoons and render the pontoons less likely to lose their buoyancy due to a leak or puncture. The link between the floatable pontoons  10  and  20  may take any convenient and sufficiently sturdy form. In the embodiment depicted, the link takes the form of a conventional metal frame  31  having a generally flat deck  30  mounted thereon. The deck  30  allows for a convenient mounting point for other components of the invention and for other components of the amphibious dredging vehicle  100 . The total width and length of the amphibious dredging vehicle  100  may preferably be selected to allow the amphibious dredging vehicle  100  to be transported by truck. 
   The front end portions of first floatable pontoon  10  and second floatable pontoon  20  are aligned with the front end portion of deck  30 . First floatable pontoon  10  has conventional drive track  12  mounted thereon. Second floatable pontoon  20  has conventional drive track  22  mounted thereon. The pontoons may be constructed of any material that is sufficiently light and durable to allow construction of a sturdy and floatable pontoon; examples include aluminum and steel. 
   Mounted to the front end portion of the deck  30  is cutterhead  40 . Cutterhead  40  may be of any convenient design, including cylindrical or disk-shaped rotating devices or arrays of high-pressure water jets; a cylindrical rotating design is shown here. Also mounted to the deck  30  is dredge pump  50 , which is operatively connected to cutterhead  40  in conventional fashion. Dredge pump  50  includes both impeller housing  51  and ten-inch hydraulic pump  52 . 
   Also mounted near the front end portion of deck  30  is control house  32 . Control house  32  provides a convenient location for operating the amphibious dredging vehicle. Tank housing  38  includes therein tanks for both diesel fuel and hydraulic fluid. A powerplant in the form of diesel engine  36  provides power to the amphibious dredging vehicle  100  through three separate paths. The powerplant also may take the form of other fuel-air engines, electric motors, or other power-providing mechanisms. Diesel engine  36  powers pump  37 A that pressurizes hydraulic fluid in a conventional hydraulic circuit  137 , which includes conventional tubing linking the hydraulic pump  37 A to all devices that are powered by the hydraulic circuit  137 .  FIG. 4  is a schematic diagram showing that the hydraulic circuit  137  links hydraulic pump  37 A to first hydraulic drive motor  14 , second hydraulic drive motor  24 , hydraulic drive motor  53  mounted adjacent to dredge pump  50 , hydraulic drive motor  91  mounted adjacent to water pump  90 , hydraulic ram  63 , and hydraulic ram  99 ; the devices are linked in conventional fashion by pairs of hydraulic lines. 
   In one path, the hydraulic circuit  137  powers the drive tracks, which allow the amphibious dredging vehicle to track forward across land or shallow water. The hydraulic circuit  137  powers a first track-driving means in the form of a first hydraulic drive motor  14  and second track-driving means in the form of second hydraulic drive motor  24 . The first hydraulic drive motor  14  drives first drive track  12  through a chain and sprocket  16 . The second hydraulic drive motor  24  likewise drives second hydraulic drive motor  24  drives second drive track  22  through a chain and sprocket  26 . The claimed first track-driving means and the claimed second track-driving means do not have to be hydraulic drive motors. Instead, the claimed first track-driving means and the claimed second track-driving means may take the form of any device capable of providing sufficient motive power, including electric motors and mechanical transmissions driven either by a central powerplant or by individual powerplants for each track. 
   In the second path, the hydraulic circuit  137  provides power to a dredge-pump-driving means in the form of hydraulic drive motor  53  that drives dredge pump  50 . When the dredge is being moved across deeper water from one dredging site to another, dredge pump  50  may be used to pump water through directable discharge  60  to move the amphibious dredging vehicle  100 . By controlling the aim or orientation of directable discharge  60 , the operator may control the direction of the amphibious dredging  100  vehicle when the dredge pump  50  is being used to move the amphibious dredging vehicle  100  through water. The claimed dredge-pump-driving means does not have to be a hydraulic drive motor. Instead, the claimed dredge-pump-driving means may take the form of any device capable of providing sufficient motive power, including electric motors and mechanical transmissions driven either by a central powerplant or a powerplant dedicated to driving the dredge pump  50 . 
   The rear end portion of the deck  30  is disposed opposite the front end portion of the deck  30 . Mounted near the rear end portion of the deck  30  is directable discharge  60 , which is more easily seen in FIG.  3 . Directable discharge  60  is made from conventional sturdy, flexible tubing such as reinforced rubber or flexible PVC pipe and is joined to discharge plumbing  70  by flange  72  or by another conventional joint. Directable discharge  60  is operatively connected to cutterhead  40  and dredge pump  50  by conventional discharge plumbing  70 , which preferably is aluminum pipe with a diameter between 4 inches and 10 inches. Directable discharge  60  is made from flexible material that allows the directable discharge  60  to be aimed as needed to provide the desired propulsion to the amphibious dredging vehicle  100 . The directable-discharge-control means takes the form of ring  62  secured to directable discharge  60  and operatively connected to hydraulic ram  63 , which is in turn attached to second floatable pontoon  20 . The hydraulic ram  63  may be controlled to select and maintain the desired aim of the directable discharge  60 . The directable-discharge-control means also may take the form of any of several known devices capable of aiming directable discharge  60 —for example, hydraulic cylinders, cables, links, electric motors, solenoids, and other devices operatively connected to directable discharge  60  and capable of changing and maintaining the aim of the directable discharge  60  in the desired orientation. 
   In the third path, the hydraulic circuit  137  provides power to a water-pump-driving means in the form of a hydraulic drive motor  91  that drives water pump  90 . Water pump  90  may be used to pump water from water intake  94  through water discharge  92  to move the amphibious dredging vehicle  100 . By controlling the aim or orientation of water discharge  92 , the operator may control the direction of the amphibious dredging  100  vehicle when the water pump  90  is being used to move the amphibious dredging vehicle  100  through water. The claimed water-pump-driving means does not have to be a hydraulic drive motor. Instead, the claimed water-pump-driving means may take the form of any device capable of providing sufficient motive power, including electric motors and mechanical transmissions driven either by a central powerplant or a powerplant dedicated to driving the water pump  90 . 
   The rear end portion of the deck  30  is disposed opposite the front end portion of the deck  30 . Mounted near the rear end portion of the deck  30  is water discharge  92 , which is more easily seen in FIG.  3 . Water discharge  92  is operatively connected to water intake  94  and water pump  90  by conventional water-discharge plumbing  96 , which preferably is aluminum pipe with a diameter between 4 inches and 10 inches. Water discharge  92  may be made from conventional sturdy, flexible tubing such as reinforced rubber or flexible PVC pipe and is joined to water-discharge plumbing  96  by flange  98  or by another conventional joint. Water discharge  92  is made from flexible tubular material that allows the water discharge  92  to be aimed as needed to provide the desired propulsion to the amphibious dredging vehicle  100 . The water-discharge-control means is operatively connected to water discharge  92 . The water-discharge-control means may take the form of ring  97  secured to water discharge  92  and operatively connected to hydraulic ram  99 , which is operatively connected to ring  97  and attached to second floatable pontoon  20 . Ring  97  and hydraulic ram  99  operate in the same manner as ring  62  and hydraulic ram  63  described above. Likewise the water-discharge-control means may take the same forms as the directable-discharge-control means described above. Note that in  FIG. 1  water pump  90 , water discharge  92 , and water intake  94  are shown, but associated hardware such as ring  97 , flange  98 , and hydraulic ram  99  are omitted from  FIG. 1  for clarity; these items appear in FIG.  2  and FIG.  3 . 
     FIG. 1  shows several optional components not previously discussed. Winch  34  is attached to deck  30 . Cable  35  is wound onto winch  34 . Cable  35  then passes through dredge pulley  37  and is attached to cutterhead  40 . Winch  34  thus can raise and lower cutterhead  40  as desired. Overhead frame  80  provides a mounting point for dredge pulley  37 . Overhead frame  80  also provides guide-wire pulleys  82  and  84 , which attached to guide wire  86 . Guide wires sometimes are used in dredging to provide a reference grid for dredging operations. Dredge pulley  37 , overhead frame  80 , guide-wire pulleys  82  and  84 , and guide wire  86  are omitted from the other figures for clarity. 
   The amphibious dredging vehicle can be used for building up land in a water-covered area in combination with the system and method that the applicant described in his application Ser. No. 10/349,599, filed Jan. 23, 2003, of which this application is a continuation-in-part.