CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   The embodiments of the present invention relate generally to amphibious vehicles and in particular to amphibious excavating equipment. More particularly, the embodiments provide a tracked, self-propelled platform from which equipment can operate on land or floating in a body of water. 
   Amphibious vehicles, known as marsh buggies, were first developed over 50 years ago to support oil and gas exploration operations conducted in marshy or swampy terrain. Marsh buggies typically include a pair of pontoons connected to a center platform. The pontoons are usually surrounded by a cleated track system which is capable of engaging ground, water, or swamp land to propel the vehicle. The track system uses one or more endless chains surrounding the periphery of each pontoon. The endless chains, supporting the cleated tracks, are driven about the periphery of the pontoons, by a sprocket or other means, in order to provide propulsion to the vehicle. By varying the track speed around each pontoon, the vehicle can be advanced, turned, or reversed. 
   Marsh buggies are ideal for operation in wetlands, marshlands, and other low-lying areas because of the relatively low pressures exerted on the ground through the large, tracked pontoons. Therefore, marsh buggies will not sink into the soft soil in low-lying or submerged areas and have minimal environmental impact while traveling to and from a remote job site. Marsh buggies have been adapted to haul personnel and cargo as well as serve as the operating platform for various types of equipment, such as excavators, draglines, and backhoes. 
   Over the last several years, the environmental impact of operations in marshlands, wetlands, and other low-lying areas is of increasing concern. Many marshland and wetland areas are deteriorating and significant effort is being expended to preserve, protect, and restore these areas. Marsh buggies are currently being used in these restorations and preservation efforts. Marsh buggies are used to provide heavy earth-moving equipment to these low-lying, soft terrain areas for operations such as wetland restoration, crust management (de-watering), dredging, levee building, coastal erosion, and other environmental remediation operations. 
   Marsh buggies have proved useful in performing earth moving operations in soft-terrain and are often capable of floating in order to navigate small bodies of water. Although marsh buggies are often capable of moving through any terrain, these vehicles aren&#39;t designed to operate while floating in water deeper than their pontoons. Thus, marsh buggies are limited in performing earth-moving operations to dry land or relatively shallow water where their pontoons are resting on the ground. 
   When water depths preclude the use of marsh buggies, other equipment must be used. One such piece of equipment, facilitating operation in deeper water, is a spud barge. Spud barges are essentially floating platforms fitted with pilings that are extended into the bottom of the body of water on which the barge is floating. These pilings, known as spuds, fix the horizontal location of the barge during operations. Heavy equipment, which has been mounted to or placed on the barge, can be operated once the barge is fixed in location. 
   One drawback to spud barges is that the barge&#39;s access to land-locked bodies of water is limited. In other words, the barge has to be floated to the location in which it is to operate. For example, if dredging operations were needed in a lake that had no deep water access, the barge would have difficulty gaining access to the lake. Where no access is provided, it has been one common practice in low-lying, marshlands to have the spud barge dig a channel of sufficient depth to allow the barge to float to the work site. Not only does this technique add to the duration and complexity of the project, it also increases the environmental impact of the project. 
   Thus, there remains a need in the art for providing a self-propelled, amphibious vehicle capable of supporting operations on land or while floating. Therefore, the embodiments of the present invention are directed to methods and apparatus for providing versatile excavating systems that seek to overcome the limitations of the prior art. 
   SUMMARY OF THE PREFERRED EMBODIMENTS 
   The preferred embodiments provide a vehicle adapted to operate on dry land, in soft terrain, and while floating. The vehicle includes a piece of equipment, such as a hydraulic excavator or a dragline, mounted on a chassis. The chassis is formed by two interconnected pontoon sections, which are sized such that the chassis and equipment will float and are fitted with an endless-chain track system having cleats that provide propulsion either on land or in the water. The chassis also has two or more spuds that are deployed in order to stabilize the vehicle for operations while floating. 
   In one embodiment, the vehicle includes a chassis supporting at least two pontoons providing sufficient buoyancy such that the vehicle can float on water. Each pontoon has a track system, formed from cleats attached to endless chains, that provides propulsion to the vehicle. A piece of earth excavating equipment, such as a hydraulic excavator or a dragline, maybe supported by the chassis. The vehicle also includes a plurality of spuds connected to the chassis, wherein the spuds have a deployed position extending below the bottom of the pontoons and a retracted position where the spuds are above the bottom of the pontoons. The spuds are integrated into spud assemblies that deploy and recover the spuds. 
   One embodiment of a spud assembly includes a winch secured to the chassis and connected to a spud by a winch cable. The spud is slidably engaged with a spud retainer that is attached to the side of the chassis. One preferred winch has a release mode, where the winch cable is spooled out by the spud moving downward under the influence of gravity, and a recovery mode, where the winch cable is spooled onto the winch as the spud moves upward. 
   An alternative spud assembly includes a spud retainer attached to the chassis and slidably engaging one of the spuds. A hydraulic cylinder is attached between the spud retainer, or the chassis, and a link that is releasably connected to the spud. The spud is deployed and recovered using the hydraulic cylinder to provide the linear movement where the pin and link are used to change the position of the attachment between the cylinder and the spud. 
   In another embodiment, the vehicle includes an amphibious chassis having pontoons fitted with powered track systems and a plurality of spud assemblies. The track systems are adapted to provide propulsion to the vehicle on both land and in the water. Various pieces of equipment, including hydraulic excavators and draglines, can be mounted to the amphibious chassis. The mounted equipment has a first operating mode, wherein the vehicle is resting on the ground, and a second operating mode, wherein the vehicle is floating in water and the plurality of spud assemblies laterally support the vehicle. 
   In another embodiment, a method for performing earth moving operations includes providing earth excavating equipment disposed on a vehicle adapted to move over land or through the water, floating the vehicle carrying the earth excavating equipment in a body of water, deploying a plurality of spuds from the vehicle into the bottom of the body of water in order to secure the lateral location of the vehicle, and performing earth excavating operations. The method may also include retracting the plurality of spuds from the bottom of the body of water, moving the vehicle to a position where the vehicle is not floating but is resting at the bottom of a body of water, and performing earth excavating operations. The vehicle may also perform earth moving operations after being moved to a position not in a body of water where the vehicle is resting on land. In order to move to each position, the vehicle can move over land or through water under its own power. 
   Thus, the present invention comprises a combination of features and advantages that enable it to provide for an amphibious excavating system. These and various other characteristics and advantages of the preferred embodiments will be readily apparent to those skilled in the art upon reading the following detailed description and by referring to the accompanying drawings. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more detailed understanding of the preferred embodiments, reference is made to the accompanying Figures, wherein: 
       FIG. 1  is an isometric view of an amphibious vehicle; 
       FIG. 2  is a top down, partial view of one embodiment of an amphibious vehicle; 
       FIG. 3  is a schematic view of the operation modes of an amphibious vehicle; 
       FIG. 4  is a schematic view of one embodiment of a spud assembly; and 
       FIG. 5  is a schematic view of a second embodiment of a spud assembly. 
   


   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results. 
   In particular, various embodiments of the present invention provide a number of different methods and apparatus for providing an amphibious platform supporting heavy excavating equipment. The concepts of the invention are discussed in the context of heavy excavating equipment, such as a hydraulic excavator, but the use of the concepts of the present invention is not limited to this particular application and may be applied to any amphibious equipment application. The concepts disclosed herein may find application with other equipment types, such as backhoes, shovels, or loaders, as well as other mobile, amphibious applications. 
   Referring now to  FIG. 1 , an amphibious spud barge  10  is shown including a chassis  12  and a hydraulic excavator  14 . Hydraulic excavator  14  is preferably mounted to a chassis cross member  15 . Chassis  12  includes two pontoons  16 , which are connected by chassis cross member  15  and equipped with endless-chain track systems  18  having a plurality of cleats  20 . Track systems  18  are driven so as to provide forward motion to barge  10  by the moving cleats  20  pushing on the land or in the water . Pontoons  16  are preferably constructed so as to provide adequate buoyancy to enable barge  10  to float in water. Thus, spud barge  10  can traverse dry land, soft soils, and water using the propulsion provided by the cleats  20  on track systems  18 . 
   Pontoons  16  are also equipped with spud assemblies  22  located on the sides of the pontoons. The spud assemblies  22  include elongated spuds  23  that can be extended below the bottom of the pontoons  16 . The spuds  23  can take many forms, but are essentially an elongated column that reaches from the barge to the bottom of the body of water in which the barge is floating. The spuds  23  are of sufficient strength to provide lateral support to the floating barge  10  to keep the barge in one position by resisting the forces both from water motion (e.g. current, tides, waves) and from the operations of the equipment on the barge  10 . The spud assemblies  22  may be permanently mounted to the barge or be removable such that they can be installed when required and stored, either on or off the barge, when not in use. 
     FIG. 1  depicts a spud barge  10  having four spud assemblies  22 , with two assemblies  22  located near the outside corners of each pontoon  16 .  FIG. 2  depicts an alternative arrangement of a spud barge  24  having three spud assemblies  22 , with two assemblies  22  on one pontoon  16  and one assembly  22  on the other pontoon  16 . Although using less than three spud assemblies may result in less than desired stability, any number of spud assemblies  22  may be used in any arrangement desired. Certain embodiments may include adjustable spud assembly arrangements so that individual spud assemblies can be repositioned depending on the needs of the work being performed. 
   Amphibious spud barge  10  provides three distinct operating modes as can be seen in FIG.  3 . In a land-based mode  26 , barge  10  sits on land  34  and pontoons  16  distribute the weight of barge  10  so that the barge can operate in soft soil or mud. In an amphibious mode  28 , barge is in shallow water where pontoons  16  sit on the bottom  36  but waterline  32  is below the top of the pontoons  16  and the depth is not sufficient to float the barge. In a full-floatation mode  30 , barge  16  is floating on pontoons  16 . Spud assemblies  22  are extended into the bottom  38  to stabilize barge  22  against lateral movement. 
   Thus, barge  10  can operate in a fixed-pontoon mode (e.g. either land-based mode  26  or amphibious mode  28 ), where the pontoons  16  are sitting firmly on the ground, and in a floating-pontoon mode (e.g. full-flotation mode  30 ), where the pontoons  16  provide the buoyancy to float the barge  10 . Spud assemblies  22  provide the resistance to lateral motion that is needed to stabilize barge  10  in full-flotation mode  30  and can also be used in either fixed-pontoon mode to further stabilize barge  10  as desired. 
   In some embodiments, spud assemblies  22  may be manually deployed and recovered, but in the preferred embodiments the spud assemblies  22  are mechanized, at least to the extent needed for efficient deployment and recovery of the spuds. One embodiment, as shown in  FIG. 4 , involves a spud assembly  40  that is partially mechanized by being gravity deployed and recovered using a powered winch. Another embodiment, as shown in  FIG. 5 , spud assembly  50  is fully mechanized with a hydraulic cylinder being used to deploy and recover the spud. 
   Referring now to  FIG. 4 , spud assembly  40  is shown including spud  42 , spud retainer  43 , pulleys  44 , winch  46 , and winch cable  48 . Spud  42  is an elongated body having a pointed lower end  41 . Spud  42  is disposed slidably within, and laterally restrained by, spud retainer  43 , which is attached to a stable surface, such as the side of a pontoon. Winch cable  48  is attached to the upper end  45  of spud  42  and run over pulleys  44  to winch  46 . Winch  46  is preferably a gravity spooled-out winch so that when the winch releases, the weight of spud  42  will spool line from winch  46 . Winch  46  is activated to take-up cable  48  to retrieve spud  42 . 
   Alternately, the winch cable could be wound around one or more stationary pulleys and around one or more pulleys integrated into the spud and then the end of the cable, known as the deadline, fixed to the vehicle. The stationary and spud-mounted pulleys would work like the block assembly of a hoist, giving mechanical advantage to the cable, effectively multiplying the load able to be lifted by a single strand of cable and enabling the use of lower power winches. There are many pulley configurations that would work, including those that would allow a single winch to control the deployment and recovery of multiple spuds. 
   Referring now to  FIG. 5 , spud assembly  50  is shown including spud  52 , spud retainer  53 , and hydraulic cylinder  58 . Spud  52  is an elongated body having a pointed lower end  51  and a plurality of slots  57  along its body. Spud  52  is disposed slidably within, and laterally restrained by, spud retainer  53 , which is attached to a stable surface, such as the side of a pontoon. Hydraulic cylinder  58  is attached to spud retainer  53  at lower connection  54 . The rod  59  of cylinder  58  is attached to link  56 . Pin  55  connects link  56  to a slot  57  on spud  52 . 
   To deploy spud  52 , cylinder  58  is retracted, pulling spud  52  downward. Pin  55  is removed and cylinder  58  is extended while the position of spud  52  is maintained. Pin  55  is then reinserted, connecting spud  52  and cylinder  58 , and cylinder  58  is retracted again, moving spud  52  lower. This procedure is repeated until spud  52  reaches the desired depth. Pin  55  may be removed or left installed during operations of the barge. Spud  52  is retrieved by reversing the process and leaving pin  55  engaged as cylinder  58  extends. Pin  55  is then removed to disconnect spud  52  as cylinder  58  is retracted and the pin  55  re-engaged. 
   The embodiments set forth herein are merely illustrative and do not limit the scope of the invention or the details therein. It will be appreciated that many other modifications and improvements to the disclosure herein may be made without departing from the scope of the invention or the inventive concepts herein disclosed. Because many varying and different embodiments may be made within the scope of the present inventive concept, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.
A vehicle adapted to operate on dry land, in soft terrain, and while floating. The vehicle includes a chassis formed by two interconnected pontoon sections sized such that the chassis and equipment will float. The pontoons are fitted with a track system providing propulsion to the vehicle. The chassis a plurality of spuds that are deployed to a position extending below the bottom of the pontoons so as to stabilize the vehicle for operations while floating.