Hydraulic dredge having articulated ladder and swell compensator

Claim 2

A floating deep-digging ladder dredge, including in combination, a hull, a main pump within said hull, superstructure supported on said hull, an articulated ladder comprising a plurality of sections pivoted together for relative swinging movement in a vertical plan only and including an upper swingable ladder section having a main pivot adjacent its upper end supported by said hull, and a lower swingable ladder section pivoted to the section above it and having excavating means at its lower extremity, a pipeline supported by said ladder passing from said excavating means through said ladder to said main pump, a plurality of block-and-tackle suspensions supported by said superstructure, each suspension being connected to the lower end of a swingable ladder section for support thereof and having a cable, winch means for said cable supportEd by said hull, sounding means for determining instantaneously the height of the hull above the bottom of the water on which the hull is floating, depth signal means actuated by said sounding means, angle sensing means for determining, instantaneously, the angle which the true horizontal makes with the nominally horizontal centerline of said dredge hull, angle signal means actuated by said angle sensing means, control means receiving said depth signal and said angle signal means and controlling the suspension length of at least said lower ladder section and accommodating it to swells in the water level on which the hull floats.

Claim 3

The dredge of claim 1, having a stern line and two quarter lines, each extending from a sea bottom anchor to said dredge, three winches for varying the lengths of said stern line and said quarter line, and a control circuit actuated by said control means for controlling the instantaneous lengths of said stern line and quarter lines during swells.

Claim 4

A floating deep-digging ladder dredge, including in combination, a hull, a main pump within said hull, superstructure supported on said hull, an articulated ladder comprising a plurality of sections pivoted together for relative swining movement in a vertical plane only and including an upper swingable ladder section having a main pivot adjacent its upper end supported by said hull, and a lower swingable ladder section pivoted to the section above it and having excavating means at its lower extremity, a pipeline supported by said ladder passing from said excavating means through said ladder to said main pump, a plurality of block-and-tackle suspensions supported by said superstructure, each suspension being connected to the lower end of a swingable ladder section for support thereof and having a cable, winch means for said cable supported by said hull, sounding means for indicating instantaneously the height of the hull above the bottom of the water on which the hull is floating, first command means actuated by said sounding means, angle sensing means for indicating instantaneously the angle which the true horizontal makes with the nominally horizontal centerline of said hull, second command means actuated by said angle sensing means, said winch means comprising a separate luffline winch for each said suspension, a stern line and two quarter lines each extending from a respective sea bottom anchor to said dredge, a stern line winch and two quarter line winches, for varying the lengths of said stern line and quarter lines, third command means for setting a nominal position of said stern line and quarter line winches, additional command means, one for setting a nominal position for each said luffline winch, and control means connected to all of said command means and transmitting the settings of said third and additional command means to their said winches by a series of outputs, said control means having means for superimposing on said outputs the effects of said first and second command means, so that the nominal positions of said winches are kept changing to actual positions varying from said nominal positions by amounts such as are needed to keep the position of said excavating means substantially constant.

Claim 5

A floating deep-digging ladder dredge, including in combination, a hull, a main pump within said hull, superstructure supported on said hull, an articulated ladder comprising a plurality of sections pivoted together for relative swining movement in a vertical plane only and including an upper swingable ladder section having a main pivot adjacent its upper end supported by said hull, and a lower swingable ladder section pivoted to the section above it and having excavating means at its lower extremity, a pipeline supported by said ladder passing from said excavating means through said ladder to said main pump, a plurality of block-and-tackle suspensions supported by said superstructure, each suspension being connected to the lower end of a swingable ladder section for support thereof and having a cable, winch means for said cable supported by said hull, sounding means for indicating instantaneously the height of the hull above the bottom of the water on which the hull is floating, first command means actuated by said sounding means, angle sensing means for indicating instantaneously the angle which the true horizontal makes with the nominally horizontal centerline of said hull, second command means actuated by said angle sensing means, said winch means comprising a separate luffline winch for each said suspension, a stern line and two quarter lines each extending from a respective sea bottom anchor to said dredge, a stern line winch and two quarter line winches, for varying the lengths of said stern line and quarter lines, third command means for setting a nominal position of said stern line and quarter line winches, additional command means, one for setting a nominal position for each said luffline winch, and control means connected to all of said command means and transmitting the settings of said third and additional command means to their said winches by a series of outputs, said control means having means for superimposing on said outputs the effects of said first and second command means, so that the nominal positions of said winches are kept changing to actual positions varying from said nominal positions by amounts such as are needed to keep the position of said excavating means substantially constant.

Claim 6

A floating deep-digging dredge having a hull and a superstructure with a ladder pivotally supported by said hull and a main pump within said hull connected by a pipeline to excavating means on the lower end of the ladder, characterized by the ladder comprising a plurality of articulated sections of substantially equal length pivoted together for relative swining movement in a vertical plane only, a plurality of block-and-tackle suspensions supported by said superstructure, each suspension being connected to the lower end of a swingable ladder section for support thereof and having a cable with winch means for said cable supported by said Hull, said pipeline comprising a plurality of pipe sections, one supported by each ladder section and connected by a flexible connection at each ladder articulation, sounding means for determining instantaneously the height of the hull above the bottom of the water on which the hull is floating, depth signal means actuated by said sounding means, angle sensing means for determining, instantaneously, the angle which the true horizontal makes with the nominally horizontal centerline of said dredge hull, angle signal means actuated by said angle sensing means, control means receiving said depth signal and said angle signal means and controlling the suspension length of at least said lower ladder section and accommodating it to swells in the water level on which the hull floats.

Claim 7

A floating deep-digging dredge having a hull and a superstructure with a ladder pivotally supported by said hull and a main pump within said hull connected by a pipeline to excavating means on the lower end of the ladder, characterized by the ladder comprising a plurality of articulated sections of substantially equal length pivoted together for relative swining movement in a vertical plane only, a plurality of block-and-tackle suspensions supported by said superstructure, each suspension being connected to the lower end of a swingable ladder section for support thereof and having a cable with winch means for said cable supported by said Hull, said pipeline comprising a plurality of pipe sections, one supported by each ladder section and connected by a flexible connection at each ladder articulation, sounding means for determining instantaneously the height of the hull above the bottom of the water on which the hull is floating, depth signal means actuated by said sounding means, angle sensing means for determining, instantaneously, the angle which the true horizontal makes with the nominally horizontal centerline of said dredge hull, angle signal means actuated by said angle sensing means, control means receiving said depth signal and said angle signal means and controlling the suspension length of at least said lower ladder section and accommodating it to swells in the water level on which the hull floats.

Claim 8

The dredge of claim 4 having a stern line and two quarter lines extending from respective sea bottom anchors to said dredge, a stern line winch and two quarter line winches for varying the length of said stern line and quarter lines, and means actuated by said control means for controlling the instantaneous length of said stern line and quarter lines during swells.

Claim 9

A floating deep-digging dredge having a hull and a superstructure with a ladder pivotally supported for relative swinging movement in a vertical plane only, by said hull and excavating means on the lower end of the ladder, characterized by block-and-tackle suspension means for the ladder supported by said superstructure and connected to the lower end of at least one swingable ladder section for support thereof and having a cable, winch means for said cable supported by said hull, sounding means for determining instantaneously the height of the hull above the bottom of the water on which the hull is floating, depth signal means actuated by said sounding means, angle sensing means for determining, instantaneously, the angle which the true horizontal makes with the nominally horizontal centerline of said hull, angle signal means actuated by said angle sensing means, control means receiving said depth signal and said angle signal means and controlling the suspension lengths of said ladder and accommodating it to swells in the water level on which the hull floats, a stern line and two quarter lines extending from respective sea bottom anchors to said dredge, a stern line winch and two quarter line winches for varying the length of said stern line and quarter lines, and means actuated by said control means for controlling the instantaneous length of said stern line and quarter lines during swells.

Claim 10

A floating deep-digging dredge having a hull and a superstructure with a ladder pivotally supported for relative swinging movement in a vertical plane only, by said hull and excavating means on the lower end of the ladder, characterized by block-and-tackle suspension means for the ladder supported by said superstructure and connected to the lower end of at least one swingable ladder section for support thereof and having a cable, winch means for said cable supported by said hull, sounding means for determining instantaneously the height of the hull above the bottom of the water on which the hull is floating, depth signal means actuated by said sounding means, angle sensing means for determining, instantaneously, the angle which the true horizontal makes with the nominally horizontal centerline of said hull, angle signal means actuated by said angle sensing means, control means receiving said depth signal and said angle signal means and controlling the suspension lengths of said ladder and accommodating it to swells in the water level on which the hull floats, a stern line and two quarter lines extending from respective sea bottom anchors to said dredge, a stern line winch and two quarter line winches for varying the length of said stern line and quarter lines, and means actuated by said control means for controlling the instantaneous length of said stern line and quarter lines during swells.

Claim 11

The dredge of claim 6, wherein said depth signal means comprises first command means actuated by said sounding means, said angle signal means comprises second command means actuated by said angle sensing means, said winch means comprising a separate luffline winch for each said suspension, a stern line and two quarter lines each extending from a respective sea bottom anchor to said dredge, a stern line winch and two quarter line winches, for varying the lengths of said stern line and quarter lines, third command means for setting a nominal position of said stern line and quarter line winches, additional command means, one for setting a nominal position for each said luffline winch, control means connected to all of said command means and transmitting the settings of said third and additional command means to their said winches by a series of outputs, said control means having means for superimposing on said outputs the effects of said first and second command means, so that the nominal positions of said winches are kept changing to actual positions varying from said nominal positions by amounts such as are needed to keep the position of said excavating means substantially constant.