US3535801A - Dredge construction - Google Patents

Description

Oct. 27, 1970 J. E. RICHTER DREDGE CONSTRUCTION Filed May 5, 1969 5 Sheets-Sheet 1 Oct. 27, 1970 J. E. RICHTER DREDGE CONSTRUCTION 5 Sheets-Sheet 2 Filed May 5, 1969 INVENTOR.

BY John E. Richter 5%, W, M Mwms Oct. 27, 1970 J. E. RICHTER DREDGE CONSTRUCTION 5 Sheets-Sheet 5 Filed May 5, 1969 n gym ,m mn. A E. .mf nl .m Y; B

Oct. 27, 1970 J. E. RICHTER 3,535,801

DREDGE CONSTRUCTION Filed May 5. 1969 5 Sheets-Sheet 4 mi@ #d Ff g. /4

INVENTOR.

John E. Richter f orneys Oct. 27, 1970 J. E. RICHTER 3,535,801

DREDGE CONSTRUCTION Filed May 5, 1969 5 Sheets-Sheet 5 INVENTOR.

John E. Richter BY if ,mw M? MAMA frneys United States Patent Office Patented Oct. 27, 1970 U.S. Cl. 37-61 3 Claims ABSTRACT F THE DISCLOSURE An improved dredge construction for dredging solids from the bed of a body of water. The dredge employs an open ended conduit mounted on a pair of spaced pontoons in conjunction with uid jet means opening into an intermediate section of the conduit so as to project uid under pressure in the said intermediate section to create suction and draw solids into the conduit for movement from an inlet section to an outlet section of the same. A flexible portion of the conduit between said intermediate and inlet section also enables substantially universal movements of the inlet section in response to hydraulically actuated means for moving the inlet section. The dredge further employs a high capacity pump in conjunction with a power source mounted in spaced relation on the pontoons so that the pontoons will remain substantially level during dredging operations.

Background of invention Heretofore, dredges for the removal of silt and debris, such as rocks, cans, bottles and refuse from harbors, canals, etc., and for deepening and widening channels, have been cumbersome, extremely costly, relatively inefficient, and difficult, if not impossible, to move from one site to another without disassembling them.

A dredge of the present invention is capable of moving a substantially greater number of yards of solids per hour, for its size, than heretofore, and which dredge may be quickly and easily loaded onto a trailer for movement over the highway, without disassembly, and can normally be launched at the desired site and ready for operation in less than an hour.

The unit and discharge conduit, including suction-jet means therebetween, provide an open, through bore free from moving parts, through which the materials hereinbefore mentioned are adapted to fully pass without clogging the conduit or injuring the latter, and the jet means is iluid actuated for water to carry and to propel the dredged material, and for air to assist in the elevation of said material at one or more points along the conduit.

The center of gravity of the portion of the suction conduit in the dredge is low, said conduit being at the water level and preferably partly submerged, thereby materially reducing the height the dredged material is to be lifted. Also, the draft of the hull is materially reduced due to the position of the conduit on the hull and relative to the water level, and the pontoons providing the hull are so constructed and connected as to insure against distortion or injury thereto during loading, launching, and use with the minimum of material, and the means for connecting the pontoons provides for watertight bulkheads thereon and a support for the conduit.

Other objects and advantages will appear in the description and drawings.

FIG. 1 is a side elevational view of the dredge with air and water pressure lines indicated in dot-dash lines, and with end portions broken in length to accommodate the view to the sheet;

FIG. 2 is a top plan view of the dredge, with end portions broken away;

FIG. 3 is a cross-sectional view along line 3-3 of FIG. 1;

FIG. 4 is an enlarged elevational view of one of the bulkhead plates;

FIG. 5 is an enlarged top plan view of the intake end of the suction conduit, and the supporting means therefor including the control means, several positions of one of the control means being shown in dot-dash lines;

FIG. 6 is a side elevational view of the portion shown in FIG. 5 with one of the control means indicated in several positions in dot-dash lines;

FIG. 7 is an end view of the intake end of the main suction conduit;

FIG. 8 is an enlarged cross-sectional view along line 8-8 of FIG. 2 taken through one form of a jet that is in the suction conduit;

FIG. 9 is an enlarged part sectional and part elevational view of two other forms of jets that may be employed;

FIG. l0 is a side elevational view of one of the mooring spuds, with part of the dredge hull shown in crosssection, and dot-dash lines indicating the position of the spud in its elevated position `before lowering;

FIG. 11 is an elevational view of the mooring Spud of FIG. l() as seen at a right angle to the position shown in FIG. 10;

FIG. 12 is a top elevational view of the spud of FIG. 10;

FIG. 13 is an end view of a loat for the discharge end portion of the conduit positioned away from the dredge, the conduit being shown in cross-section;

FIG. 14 is a top plan view of the float of FIG. 12, broken in length;

FIG. 15 is a semidiagrammatic view of the portion of the conduit on the dredge showing a preferred form of arrangement in which air and water is employed for elevating and propelling material;

FIG. 16 is a semidiagrammatic view of the conduit on the dredge, where air may be employed for elevating and propelling the material;

FIG. 17 is a semidiagrammatic view showing an arrangement employing water only.

Referring to FIG. 1, the symbol W/ L designates substantially the normal water level of the body of water in which the dredge is oated, and which water level may be even higher `when the dredge is in operation.

A pair of horizontally elongated hollow pontoons of sheet metal, designated 1 (FIGS. 2, 3) are in parallel, spaced, side-by-side relation, leaving a space 2 (FIG. 2) between them. These pontoons provide a hull transversely divided by bulkheads, generally designated 3, which bulkheads extend transversely across the pontoons and the sapce between them.

Bulkheads 3 divide each pontoon into a row of sections extending longitudinally of the pontoons, each section having top, bottom and side walls welded at their edges to the bulkheads. Said sections may be generally square in cross-sectional contour (FIG. 3) except that the oppositely outwardly lateral facing side walls 4 of the pair of pontoons (FIG. 3) preferably extend slightly slantingly outwardly form each other in an upward direction. The upper wall 5 of each section, except those hereafter identified as being for fuel and for hydraulic fluid, may be provided with a valved air inlet tting 6 and a valved water outlet tting 7, said air inlet fitting being adapted to be connected by a conventional air line with a source of air pressure under pressure, and the water inlet tting being adapted to be connected with a source of water under pressure.

An engine unit 8 includes a compressor 9 adapted to provide air under pressure and said engine unit is also connected with a water pump 10 for providing water under pressure. The lines connecting the inlet fittings with the compressor and pump are conventional, and by their manipulation the hull may be trimmed. A water outlet 11 in each section extends from a point adjacent to but spaced from the bottoms of each section to and outwardly of the upper portion of the latter for exhausting water from each section under the influence of air through the air inlet fitting. Normally the hull remains substantially level both before and during operation of the dredge, due to the parts thereon being substantially balanced with the main suction and discharge conduit centrally between the pontoons and intermediate the upper and lower sides so as to provide a low center of gravity.

Each bulkhead 3 (FIG. 4) comprises a single plate having end portions 13 (FIGS. 3, 4) that are between adjacent sections of the respective pontoons. The central portion 14 of each plate 3 extends transversely across the space 2 between the pontoons and is cut away from the upper edge to provide a centrally, upwardly opening recess 15 of less width than the distance between the f pontoons forming the hull of the dredge. The opposite lateral edges 16 of the lower portion of each recess are vertically extending, and the lower edge 17 of each recess is horizontal (FIG. 4), and the upper portion of the recess is enlarged to provide a pair of upwardly facing shoulders 18. A saddle-like or generally U-shaped strap 19 is secured over the edges 16, 17 of each recess 15 and extensions 20 of each strap extend over and are secured to shoulders 18.

The sections designated 21 (FIG. 2) and 22 are respectively for engine fuel and for hydraulic fluid and have capped inlets therefor.

The suction and discharge conduit 23 is seated in the U-shaped strap 19 and a hold-down or clamping strap 24 extends across said conduit at each bulkhead plate and is i bolted to extensions 20 of the saddle strap to hold the conduit rigid with the hull of the dredge.

Said conduit 23 includes a jet unit 2S adjacent to the front end of the dredge, which front end is the left end, as viewed in FIGS. l, 2, while the opposite end may be designated the rear end. The said conduit 23 extends horizontally from end-to-end of the dredge, and is fully closed.

Said jet unit includes another open-ended cylindrical inner tube 26 (FIG. 8), and an outer cylinder 27 coaxial with and spaced outwardly of said tube 26, the latter having a radially inwardly projecting rear flange 28 in sealing engagement with the outer surface of portion 27, while the forward end portion of said outer cylinder extends convergently to but in relatively close spaced relation to the forward end of the inner tube 26, providing an annular jet opening 29 directed convergently generally toward the axis of the tube 26 in a rearward direction. A radially inwardly extending flange 30 on cylinder 27 spaced between flange 28 and the forward end of tube 26 is in sealing engagement with the outer surface of utbe 26 and defines the rear end of a water pressure chamber 31 around tube 26 communicating with the jet opening 29.

The convergent forward end of the cylinder 27 is approximately the same diameter as conduit 23, and the rear end of the inner tube 26 also is approximately the same diameter as the conduit 23, although preferably slightly smaller, and connects with the latter. Thus, the jet unit is virtually part of the conduit.

A pair of water inlets 34, 35 (FIGS. 1, 2) open substantially tangentially into the water chamber 31 at opposite sides of the latter, and in the same direction circumferentially of the outer cylinder 27 to provide a swirling flow of water in said chamber for similar swirling ejection into the conduit toward the forward end of the latter, creating a suction within the inlet or front end of the suction unit, and a spiral propelling ow in a forward direction forwardly of the ejection orifice 29.

The front end of the portion of the conduit 23 that is on the dredge 1 connects with a flexible section 36 (FIGS. l, 5, 6) that is of approximately the same diameter as that of portion 23, and which section 36 extends forwardly from the rear end of hulls 1. The rear end of section 36 is supported on a ladder, generally designated '37 (FIGS. 5, 6), which ladder comprises elongated parallel horizontally spaced members 38, the forward ends of which are respectively pivotally supported by coaxial horizontal pivots 39 (FIGS. 5, 6) to the lower rear ends of the pontoons 1 for vertical swinging of the rear ends 0f said members 38. The rear ends are connected by a head 40.

The rear end of flexible section 36 connects with a rigid tube 41 that, in turn, is rigidly supported on a supporting frame 42, the forward end of which is pivotally suprorted on a pivot 43 for horizontal swinging of the tube 41.

Double-acting hydraulic cylinders 45 connect members 48 with the upper rear ends of pontoons 1 for vertical swinging of the rear end of ladder 37 vertically from a downwardly extending dot-dash line position 46 (FIG. 6) to above the horizontal full line position of FIG. 6, as indicated by dot-dash lines 47.

A double-acting hydraulic cylinder 48 (FIGS. 5, 6) connects the frame 42 on which tube 40 is supported and rearward extension 49 (FIG. 5) of said tube, for horizontal swinging of said tube 41 and extension 49 laterally between dot-dash line positions 50, 51 of the cylinders, thus enabling the intake end of the extension 49 to be moved downwardly to different depths and to sweep laterally at any of the different depths.

Preferably, an annular row of radially inwardly directed equally spaced projections 53 (FIGS. 5, 7) in the intake end of extension 49 is provided to prevent rocks or other objects from blocking the intake end and from entering the conduit if too large to pass therethrough.

As seen in FIGS. 5, 6, cylinder rod 54 of each cylinder 45 is pivotally connected to a member 38, and cach cylinder 4S is pivotally connected to the upper end of a pontoon. Cylinder rod 55 of cylinder 48 is pivotally connected to the rear end of frame 42 while the forward end of the cylinder 48 is pivotally connected to the head 40 that connects the forward ends of members 38.

The dredge itself is moored in position by mooring spuds, generally designated 57, disposed at each corner, or at least at diagonally opposite corners (FIGS. l, 10- l2). Each spud comprises a vertical cylindrical guide member 58 (FIG. l0) rigidly secured to the forward end of one pontoon and to the rear end of the other pontoon, where only two spuds are used, or to the forward and rear ends of each pontoon where four are used.

A vertical post 59 is vertically reciprocable in each guide 58 and a vertically disposed hydraulic cylinder 60 is secured to the lower end of each guide at its lower end while the plunger rod 61 of said cylinder projects from the upper end of each cylinder and is connected to a collar 62 around said post above said guide.

A vertical strip 63 (FIGS. l0, l2) is secured to one side of the post 59 which strip is slidable in a rvertical slot formed in one side of guide 57, and collar 62 above guide 58 includes a recess 64 (FIG. 12) formed in said one side in which said strip 63 is positioned. A vertical web 65 (FIG. 10) is on the side of guide 58 from which the strip 63 projects. Said web 65 is formed with openings 66 adapted to register with openings 67 formed in strip `63 and coaxial openings 68 in sides 69 of recess gg are also adapted to register with openings 67 in strip To elevate the post, a pin 72 is positioned on registering openings 63, 68 in collar 62 and strip 63 and pin 71 is removed, after which the plunger rod 61 is extended to elevate the post 59. If more than one stroke of the plunger rod 61 is required, the pin 71 is replaced and the plunger rod 61 is lowered to again be engaged with the post. The same procedure is followed to lower the post, although it may move downward under the iniluence of gravity, if released.

As seen in FIGS. 13-14, drum oats 73 may support the discharge extension 74 of conduit 23 that are forwardly of the dredge, where such extensions extend over a body of water, said floats being connected by horizontal strips 75 at their ends, between which the conduit extension is secured.

All controls for the engine 8, compressor 9, and pump 10, may be in the operators cab 76, which controls are conventional, and the cab 716 is positioned adja cent to the front end of the dredge where he can observe the dredging operation.

The jet unit is part of the conduit 23, and as seen in FIG. 1, it is positioned between the pontoons 1 adjacent to the front end of the hull. The position of the conduit extending forwardly from the hull and downwardly, during a dredging operation includes the flexible portion 36 and the rigid terminal extension 49 and the latter includes a jet unit 77 (FIG. l) that corresponds to A the unit 25.

The portion of conduit 23 that extends rearwardly of the rearward end of the dredge, and which may be called the discharge end, may extend upwardly to elevate the material that has been dredged over a bank or onto land that borders the body of water that floats the dredge, and this may include a flexible section similar to section 36, or it may be rigid sections of tubing, rigidly or flexibly coupled together to vary the degree of incline.

Where the rise is substantial at the discharge end a jet 78 corresponding in structure to jet 25 may be in the conduit at the lower end of the rise.

The provision of two twater inlets, such as 34, 35, to each of the jets 25, 77, 78 enables varying the water delivery to the jets to meet varying conditions, llexible water pressure lines 79 connecting the pump 10 with jet 25.

The jet 77 is connected by exible air lines 80 with the source of compressed air 79, and flexible air lines 81 also connecting jet 78 with said source of compressed air 9.

Preferably, a check valve 82 is provided at each of the fluid inlets to each of the jet units 25, 77, 78.

A valve 83 is adapted to be actuated to open air lines 80, 181 to the jets 77, 78 or to close either lines 77 or 78 to air, according to the degree of lift required to efficiently move the dredged material. Also, valves 84, 85 in one o fthe lines 80, 81 of each pair thereof may cut out such line, and a valve 86 in one of the lines 79 may discontinue the movement of water therethrough. Obviously, any of valves 84, 815, 86 may also regulate the ow of lluid through the lines in which each valve is located.

Where the dredged material is to be elevated a distance of say approximately 04 to 20 feet to the forward or inlet end of the portion of the conduit 23 that is on the hull, and is required to lift the material only approximately two and one-half feet above the forward or discharge end of said portion of the conduit, the operation of the jet 25 may be adequate. However, if the dredged material is to be elevated approximately ten feet or more at each of the opposite ends of the horizontal portion of conduit 23 that is on the hull, then it is preferable that all three jets 25, 77 and 78 be actuated at the same time. Or, if the material is to be lifted over twenty feet to the portion of the conduit 23 that is on the hull, the jets 25, 77 are actuated, and also jet 78 where the material at the discharge end of the aforesaid portion of conduit 23 is to be elevated more than several feet.

FIGS. 15 to 17 semidiagrammatically illustrate different arrangements, and FIG. 9 shows different type jets that are more economical to make than the jet unit of FIG. 8 but that are satisfactory.

In FIG. 9 the main conduit is generally designated 87, and corresponds generally to conduit 23. Instead of lll n.. nl)

the jet unit 25, a section of said main conduit may be formed with a plurality of annular rows of relatively small openings 88 that are drilled at an angle of approximately 45 degrees relative to the axis of the conduit, provide passageways directed angularly inward the rearward end of the hull of the dredge, so as to generate a suction at the inlet end of the conduit and to propel said material in the same direction as the jet unit 25 in FIG. 8. Openings 88 may be approximately %2 inch in diameter and equally spaced apart in the annular rows, the latter extending circumferentially of the conduit.

A pressure chamber 89 is formed around the section having holes 88 therein by a tubular sleeve 90, coaxial with and spaced around conduit 87, and joined at its ends to the latter by heads 91. Water to the chamber is provided by a line 92 opening into chamber `89 having a check valve 93 thereon adjacent to and outside sleeve 90.

Also, in FIG. 9, a jet unit 97 is shown along the lower side of the horizontal run of conduit 87 opening into the latter. This unit includes a nozzle 97 having a restricted discharge opening `99 outside but adjacent to the inner surface of the conduit 87l and directed at an angle of approximately 45 degrees relative to the axis of said conduit and generally toward the discharge end of the portion of the conduit that is on the hull, as indicated by the arrow. A check valve 100 is adjacent to said nozzle in the uid line 101 that connects the nozzle with a source of air under pressure.

A second jet nozzle 102 corresponding to nozzle 97 may be at the bend or elbow 103 that is at the lower end of an upwardly extending end portion of the conduit 87 at its discharge end, and said nozzle 102 is directed upwardly into said upwardly extending end portion, and it also has a check valve 104 therein, and line 105 connects said nozzle 102 with a source of air under pressure.

In FIG. 15, a source of water under pressure, which may he the same as pump 10 in FIG. 1, is diagrammatically indicated at 106, and a compressor unit or source of air under pressure is indicated at 107.

Main conduit 108 on the dredge hull may be provided with a jet 109 thereon adjacent to the intake end of the conduit, which jet may correspond to jet 25 and is connected with the source of water 106 through flexible lines 110, one of which has a valve 111 thereon.

A jet unit 114 is adjacent to the terminal lower end of the portion of conduit 108 extending to the inlet end of the conduit, and this unit may correspond to the jet unit 87 of FIG. 9. A check valve 115 is adjacent to the inlet to the unit 114 and a line 116 connects said unit with the source of compressed air 107.

Along the underside of the horizontal portion of conduit 108 that is on the dredge hull, are a plurality of spaced jet units 117 that corresponds to the jet unit 97, one of said jet units being designated 118 is at the elbow 119 where the conduit extends upwardly beyond the discharge or forward end of the dredge hull. All of the jet units 117 and jet 119 are connected with the source of air 107 and each has a check valve 120 at the inlet end of each unit.

This arrangement basically corresponds generally to the arrangement shown in FIG. 1 in that provision is made for the employment of air and water in the dredging operation. However, the provision of jets 117 along the horizontal length of the main conduit not only contributes to movement of the dredged material toward the discharge end of the main conduit, but being injected into the material at the lower side of the horizontal length of the conduit the upward force of the air against the material that may tend to settle, plus the inherent upward movement of the air in the conduit prevents the settling of the dredged material and expedites its How through the conduit.

The air injected into the conduit at the lower ends of the riser of the latter positioned at the intake and discharge ends of the conduit 23 will rapidly rise to assist in the upward movement of the water and dredged material into and away from the inlet and discharge ends of the horizontal length of the conduit that is on the hull. The elbow 119 may be adjacent to the hull or it may be remote from the latter where there is a substantial horizontal length of conduit in extension of the portion on the hull, and which extension may be supported by tloats 73 shown in FIGS. 13, 14 at approximately the same level as the portion of the conduit that is on the hull.

With the arrangement shown in FIGS. 1 and 15, the dredged material will be carried in a substantially horizontal extension of the portion of the conduit on the hull several hundred yards and more without booster jets along such extensions, but with such booster jet where the conduit may extend upwardly for either discharging the dredged material over a bank or onto a barge, or onto an elevated area of ground.

In FIG. 16 only a source of air at 122 is provided, which source is connected by flexible hose lines 123 to a jet unit 124 that may correspond to the jet unit 114 of FIG. or 87 of FIG. 9, and jet units 125 and unit 126 corresponding to jet units 117 and unit 118 are along the underside of the lower horizontal length of the horizontal length of the main conduit 127, with check valves associated with or adjacent to each jet unit. These units 124-126 correspond in position to the units 114, 117-118 of FIG. 15.

This arrangement is more restricted in its scope of use than the arrangement in FIGS. 1 and l5, but the air jet 124 in combination with jets 12S-126 will function to elevate the water and certain types of dredged material a minimum of 10 feet to the horizontal length of conduit 127 and to and through the latter and the discharge portion of the conduit.

In FIG. 17, water only is used, the source 128 being fr a pump or the like, such as 10 of FIG. I, connected by flexible hose lines 129 to jet units 130, 131 that structurally correspond to jet unit 97 of FIG. 8, the former being at the terminal lower intake end of the downward extension of the horizontal hull supported portion of conduit 132 that is on the hull, and which jet unit 130 is directed diagonally upwardly into the lower end of said extension, while jet unit 131 is at the upper end of said extension for discharging into the intake end of the aforesaid horizontal portion of the conduit. A jet unit 134, corresponding to the jet unit of FIG. 8, is positioned in said horizontal portion of conduit 132.

By the arrangement shown in FIG. 17, the use of water alone will elevate the dredged material approximately feet to the horizontal portion of the conduit 132 that is on the hull and will propel it, with no more than a use of approximately 21/2 feet, to the discharge end of the conduit including an extension thereof in a direction away from the hull forwardly of the latter.

In the event the conduit is blocked at the inlet end by some obstruction, a gate valve 136 is provided, which gate may be closed, thereby reversing the ilow of water in the conduit to dislodge whatever blocks the inlet.

It is pertinent to note that nowhere in the conduit is there any obstruction to the tlow of dredged material therethrough.

In the event the pump 10 should stop or slow down to the extent that the dredged material within the conduit should cease to move to the discharge end, or in the event any back pressure within the conduit should develop at any of the jet units, the check valve adjacent to any such jet unit will close to prevent any of the dredged material from entering the pump line or jet unit to impair its operation of the latter when such back pressure is removed.

It is to be understood that either of the jet units 87 or 97 shown in FIG. 9 may be employed wherever a jet unit is shown, but the type shown at 97 in FIG. 9 is preferable where used along the horizontally extending length of the conduit, as indicated at 117 and 125 in 8 FIGS. l5, 16, inasmuch as the fluid enters the conduit at the lower side to keep the dredged material from tending to settle to the bottom along this length.

Also, where booster jet units may be used along a horizontal length of the conduit leading away from the hull of the dredge, such units may be used and would both function to propel the dredged material toward the discharge end, and to prevent settling. As already described, air employed in connection with these jet unils, would automatically rise in the conduit from each such jet unit to keep the dredged material and water thoroughly mixed within the conduit as the dredged material is moved along the horizontally extending run.

From the foregoing description, it is apparent that, both in the method and apparatus, an important feature of the invention is the fact that the material being dredged is elevated to approximately the level of the water, instead of being elevated to a height above the pontoons, therefore the center of gravity of the load on the dredge itself is quite low and the pontoons have a very low draft enabling the dredge to operate in relatively shallow water. More important, is the economy in power effected by elevating the dredged material only sutliciently to raise it to the level of the water before moving it horizontally out of said body of water.

Where the head of the fluid and material in the conduit is substantial, and the pressure of the injection fluid drops, it is important that the reverse flow of lluid and dredged material into the fluid injection units would choke the latter. The check valves preclude failure due to such reverse flow.

I claim:

1. A dredge for dredging solids from the bed of a body of water comprising:

(a) an open ended conduit of substantially uniform unobstructed inside diameter from end to end thereof including a horizontally extending intermediate section, and an inlet section and an outlet section, respectively extending outwardly from the ends of said intermediate section, one open end of said conduit being an inlet at the outer end of said inlet section remote from said intermediate section and the opposite open end of said conduit being an outlet at the outer end of said discharge section relative to said intermediate section,

(b) a pair of corresponding, horizontally extending,

elongated, hollow pontoons in parallel, spaced sideby-side relation at opposite sides of said intermediate section,

(c) water-tight vertical bulkheads within said pontoons spaced apart longitudinally of said pontoons and extending at right angles to the axes of said pontoons dividing each of said pontoons into separate compartments,

(d) said bulkheads comprising plates extending from said pontoons across the space between them supporting said intermediate section of said conduit centrally between said pontoons parallel therewith, and at approximately the level of the body of water in which said pontoons are tloated when the latter are on said body,

(e) power means supported on said pair of pontoons over the space between said pair of pontoons at the ends of the latter to said inlet section whereby said pontoons will be substantially level in the water oating them,

(f) said conduit including a tlexible portion between said inlet section and said intermediate section for substantially universal swinging of the inlet end of said inlet section relative to vertical and horizontal,

(g) hydraulically actuated means connected with said inlet section for moving the latter for so swinging its inlet end,

(h) a pump connected with said power means for actuation by the latter for pumping water from said body under pressure when said pontoons are floated on said body,

(i) fluid jet means opening into said intermediate section including a jet outlet directed into said conduit in a direction generally toward said discharge section for projecting uid under pressure into said intermediate section in said one direction to create a suction in said inlet section to draw solids into said conduit for movement from said inlet to said outlet, and a uid pressure line connecting said pump with said jet means for providing water under pressure to the latter,

(j) manually actuatable means on said pontoon posi tioned over said space between the latter at the ends of said pontoons adjacent to said inlet section and connected with said hydraulic means for actuating the latter for moving said inlet section,

(k) and one of the corresponding compartments in each of said pontoons adjacent to said power means being adapted to hold hydraulic tluid for said hydraulically actuated means, and another of the corresponding compartments in each of said pontoons being adapted to contain fuel for said power means, said power means being an internal combustion engine.

2. ln a dredge as defined in claim l;

(l) each of said pontoons being approximately rectangular in vertical cross-sectional contour transversely thereof with horizontal upper sides providing shallow draft pontoons each with the upper wall of each pontoon being a horizontal deck for workmen and equipment,

(rn) and a vertically reciprocable vertically elongated hydraulically actuated spud at two diagonally opposite corners of said pair of pontoons for mooring said pontoons to the bed of said body of water upon said spuds being moved downwardly lo said bed.

3. In a dredge as defined in claim 2:

(n) a second jet means adjacent on said inlet section adjacent to said inlet for injecting air under pressure into said inlet section in a direction generally toward said intermediate section,

(o) an air compressor connected to said power means for actuation by the latter, and means operatively connecting said air compressor with said Second jet means for supplying said air under pressure to said second jet means.

References Cited UNITED STATES PATENTS ROBERT F. PULFREY, Primary Examiner C. D. CROWDER, Assistant Examiner U.S. Cl. XR.

37-72, 57; ll4-l25; 103-262, 263

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