grab dredge

A grab, or clamshell, dredge lowers, closes, and raises a single bucket by means of flexible cables. In operation the bucket is dropped to the bottom, where it bites because of its weight and the action of the bucket-closing mechanism. A grab dredge can work at…

…all the above is the grab dredge, either self-propelled or towed to the site. Grab dredges are especially suitable for dredging close up to existing quay walls or other structures with minimum risk of damage, and the grab equipment is often capable of lifting individual boulders. Not infrequently, grab dredges…

The clamshell dredge, another mechanical system, is characterized by a large single bucket operating at the end of cables. Although it can operate in deeper water than other systems and handles large particles and trash well, it has the disadvantage of being a discontinuous, batch-type system,…