“Clamshell” dredges are floating platforms that house a heavy duty cycle crane that uses a wire rope suspended bucket to excavate the sea bottom. The dredge locates itself in position during dredging operations by lowering retractable “spud” poles to the sea bottom. Excavated material is loaded into barges (scows) for transportation by tugs to a disposal area.
This method is most suited to the excavation of loose materials in restrictive areas, working around obstacles and where disposal is beyond normal direct pumping distances. Generally dredged material will be disposed of in an ocean site being released from the barges through opening in the bottom of the hull. If the material is required to be disposed of in an upland site then a “barge unloader” may be used to pump material out of the barges.
| NEW YORK |
| Dimensions |
| | Length: | 200 ft (61.0 m) |
| | Breadth: | 57 ft (17.4 m) |
| | Depth: | 15 ft (4.6 m) |
| | Draft: | 7 ft (2.1 m) |
| | Bucket Size: | 12 to 24 yd³
(9 to 18 m³) |
|
| |
| Operating Parameters |
| | Dig Depth Range: | 60 to 83 ft
(18.3 to 25.3 m) |
|
| |
| Machinery & Power |
| | Fuel Capacity: | 60,000 gal (227,124 l) |
| | Total Installed Power: | 3,434 hp (2,561 kW) |
|
| |
Associated Documents
New York |
|  |
|
| NO. 54 |
| Dimensions |
| | Length: | 185 ft (56.4 m) |
| | Breadth: | 60 ft (18.3 m) |
| | Depth: | 11 ft (3.4 m) |
| | Draft: | 6.1 ft (1.9 m) |
| | Bucket Size: | 12 to 50 yd³
(9 to 38 m³) |
|
| |
| Operating Parameters |
| | Dig Depth Range: | 74 to 150 ft
(22.6 to 45.7 m) |
| | Linepull: | 107,000 lb (476 kN) |
| | Linepull @ Param: | 360 fpm (110 mpm) |
| | Stallpull: | 175,000 lb (779 kN) |
|
| |
| Machinery & Power |
| | Fuel Capacity: | 39,400 gal (148,145 l) |
| | Total Installed Power: | 2,340 hp (1,745 kW) |
|
| |
Associated Documents
No. 54 |
|  |
|
| NO. 53 |
| Dimensions |
| | Length: | 160 ft (48.8 m) |
| | Breadth: | 60 ft (18.3 m) |
| | Depth: | 10.3 ft (3.1 m) |
| | Draft: | 6.0 ft (1.8 m) |
| | Bucket Size: | 10 to 26 yd³
(8 to 20 m³) |
|
| |
| Operating Parameters |
| | Dig Depth Range: | 60 to 150 ft
(18.3 to 45.7 m) |
| | Linepull: | 100,000 lb (445kN) |
| | Linepull @ Param: | 318 fpm (97 mpm) |
|
| |
| Machinery & Power |
| | Fuel Capacity: | 100,500 gal (380,433 l) |
| | Total Installed Power: | 2,550 hp (1,902 kW) |
|
| |
Associated Documents
No. 53 |
|  |
|
| NO. 55 |
| Dimensions |
| | Length: | 165 ft (50.3 m) |
| | Breadth: | 50 ft (15.2 m) |
| | Depth: | 10.5 ft (3.2 m) |
| | Draft: | 6.8 ft (2.1 m) |
| | Bucket Size: | 12 to 40 yd³
(9 to 30 m³) |
|
| |
| Operating Parameters |
| | Dig Depth Range: | 65 to 150 ft
(19.8 to 45.7 m) |
| | Linepull: | 96,000 lb (427 kN) |
| | Linepull @ Param: | 290 fpm (88 mpm) |
| | Stallpull: | 150,000 lb (668 kN) |
|
| |
| Machinery & Power |
| | Fuel Capacity: | 25,400 gal (96,149 l) |
| | Total Installed Power: | 1,745 hp (1,301 kW) |
|
|  |
|
| NO. 51 |
| Dimensions |
| | Length: | 155 ft (47.2 m) |
| | Breadth: | 44 ft (13.4 m) |
| | Depth: | 9 ft (2.7 m) |
| | Draft: | 6.3 ft (1.9 m) |
| | Bucket Size: | 7 to 26 yd³
(5 to 20 m³) |
|
| |
| Operating Parameters |
| | Dig Depth Range: | 58 to 120 ft
(17.7 to 36.6 m) |
| | Linepull: | 80,000 lb (356 kN) |
| | Linepull @ Param: | 360 fpm (110 mpm) |
| | Stallpull: | 140,000 lb (623 kN) |
|
| |
| Machinery & Power |
| | Fuel Capacity: | 13,500 gal (51,103 l) |
| | Total Installed Power: | 1,890 hp (1,409 kW) |
|
| |
Associated Documents
No. 51 |
|  |