A clamp assembly comprising a pair of clamps may couple to an assembly body. The clamps may pivot to receive material beneath the assembly body. The clamps may include opposing surfaces that define a scoop space beneath the assembly body. Each of the clamps may include a cutting plate. The cutting plate may include a perforating edge configured to extend into the scoop space relative to a corresponding one of the opposing surfaces. The clamp may further include a retention plate. The retention plate may include an inner surface that faces the cutting plate. The cutting plate and the retention plate further define the scoop space between the clamps. The clamp assembly may couple to a lift assembly. The lift assembly may include a hydraulic actuator configured to raise and lower the clamp assembly.

A clamshell bucket assembly including first and second pivotally connected steel bucket halves rotating between open and closed positions and including sediment retention bars secured between the overlapping sides define a scoop for permitting outflow of water while retaining a volume of a dredged material. Weld rivets provide reinforced securing of the side and bottom steel portions of each bucket half and extend a thickness of the bucket halves to prevent fracturing at the welded interface. Upper and lower sheave assemblies provide increased durability and wear resistance during repetitive opening and closing of the mechanical bucket halves. The sheaves each include a central pin supporting hub collar formed from a plurality of progressively inwardly stepped and stacked disc shaped plates, these being initially sectioned from a hardened steel sheet and welded to form the hub at the highest zone or area of stress exerted upon the sheave during operation of the bucket.

A clamshell bucket assembly including first and second pivotally connected steel bucket halves rotating between open and closed positions and including sediment retention bars secured between the overlapping sides define a scoop for permitting outflow of water while retaining a volume of a dredged material. Weld rivets provide reinforced securing of the side and bottom steel portions of each bucket half and extend a thickness of the bucket halves to prevent fracturing at the welded interface. Upper and lower sheave assemblies provide increased durability and wear resistance during repetitive opening and closing of the mechanical bucket halves. The sheaves each include a central pin supporting hub collar formed from a plurality of progressively inwardly stepped and stacked disc shaped plates, these being initially sectioned from a hardened steel sheet and welded to form the hub at the highest zone or area of stress exerted upon the sheave during operation of the bucket.