Bucket Dredge


Also found in: Dictionary.
Related to Bucket Dredge: dredging

bucket dredge

[′bək·ət ‚drej]
(mechanical engineering)
A floating mechanical excavator equipped with a bucket elevator.

Bucket Dredge

 

a floating excavation machine with a bucket device for scooping up soil from under the water; one of the ships of the technical fleet. Bucket dredges are used mainly for dredging operations, the creation of submerged trenches, and the extraction of minerals. The bucket dredges used for mining are equipped with concentrators and are called drags. Modern bucket dredge types include single-bucket dipper dredges, grab dredges, and chain-and-bucket dredges. Grab (grapple) dredges (equipped with a hold for the soil) and seagoing chain-and-bucket dredges are usually self-propelled.

A single-bucket dipper dredge is a floating mechanical shovel with a bucket capacity of 12 cu m; it is sometimes equipped with a rock-crushing device. It is intended primarily for rocky (heavy) and debris-littered bottoms. It is moved by means of lifting piles. The dredged soil is dumped directly onto the waste pile or loaded into a hopper barge (dump scow).

Grab (grapple) dredges have one to four slewing bucket cranes. Double-hinged (clamshell) or four-hinge grab buckets with a capacity of 1–4 cu m are used depending on the properties of the bottom to be dredged and on the load-lifting capacity of the cranes. Grab dredges are suited mainly for dredging work in moorages; they move along cables by means of boat hoists. The dredged soil is dumped into the grab dredge’s own hold or into a hopper barge.

A chain-and-bucket dredge is a continuous-operation machine that excavates the bottom with buckets with a capacity of 1.2 cu m, connected in a closed loop; the loop passes around two drums, the upper of which has the drive. The dredge is moved by means of boat hoists. Modern chain-and-bucket dredges have capacities of up to 1,500 cu m per hour for light bottom work and up to 750 cu m per hour for heavy bottom work. The dredged soil is transported by hopper barges, soil pumps, or conveyers.

REFERENCE

Krakovskii, I.I . Suda tekhnicheskogoflota. Leningrad, 1968.

V. N. PESOCHINSKII

References in periodicals archive ?
The bucket dredge was a "large barge unit with a crane" that was located off-shore near the U.S.
Observations Bid (%) Deviation Pooled Yes 204 83.6 24.2 No 308 86.2 20.5 Bucket Dredges Only Yes 43 81.2 19.5 No 44 83.9 21.1 Pipeline Dredges Only Yes 156 84.1 25.1 No 155 89.7 19.7 Emerging Small Yes 115 82.0 23.7 Businesses Only No 13 84.0 25.1 Small Businesses Only Yes 89 85.8 24.7 No 27 87.5 16.7 Emerging and Yes 204 83.6 24.2 Small Businesses Only No 40 86.4 19.6 Maintenance Yes 195 83.7 24.4 Dredging Only No 265 85.9 20.3 New Material Yes 8 84.2 19.3 Dredging Only No 32 90.3 21.6 t-statistic Significant Pooled 1.24 No Bucket Dredges Only 0.62 No Pipeline Dredges Only 2.17 Yes Emerging Small 0.29 No Businesses Only Small Businesses Only 0.41 No Emerging and 0.67 No Small Businesses Only Maintenance 1.03 No Dredging Only Material 0.72 No Dredging Only
Bidders Pooled Yes 204 3.6 No 308 1.3 Bucket Dredges Only Yes 43 4.0 No 44 3.7 Pipeline Dredges Only Yes 156 3.5 No 155 3.0 Emerging Small Yes 115 3.7 Businesses Only No 13 3.4 Small Businesses Only Yes 89 3.5 No 27 3.6 Emerging and Yes 204 3.6 Small Businesses Only No 40 3.6 Maintenance Yes 195 3.6 Dredging Only No 265 3.0 New Material Yes 8 5.0 Dredging Only No 32 4.0 Discription Standard of Data Deviation t-statistic Significant Pooled 1.6 -3.63 Yes 1.3 Bucket Dredges Only 2.1 -0.85 No 1.2 Pipeline Dredges Only 1.4 -3.30 Yes 1.4 Emerging Small 1.6 -0.73 No Businesses Only 1.6 Small Businesses Only 1.7 0.27 No 1.7 Emerging and 1.6 -0.31 No Small Businesses Only 1.7 Maintenance 1.5 -3.95 Yes Dredging Only 1.2 New Material 3.3 -0.87 No Dredging Only 1.5
Traditional types of dredging, such as the bucket dredge, would cost $85,000 for the same project.
Unfortunately, the project had to be shelved in 1991 but Sierra Rutile continued to look for a way to obtain another bucket dredge.
FWP and OCI have also been active in promoting the small, demountable bucket dredge. These are seen as the way to meet the increasing need for low cost, easily transported dredges that are quick to bring into production and efficient in operation, being specifically designed for alluvial mining.
Many of its applications are on a massive scale, such as a 100 t helical gearbox for driving twin 5.5 in diameter heads on one of the world's deepest digging bucket dredges, or slew drives for giant draglines.
Dredged using two bucket dredges, excavated earth was used to form a levee on each side of the channel.