Grapple dredger is the type of dredger that excavates mud and gravel under water with a grab bucket. It can be classified into steel cable grapple dredger, hydraulic backhoe dredger and hydraulic hard jib grapple dredger. There are both self-propelling and non-self propelling grapple dredgers where the self-propelling ones have mud tank so that it can dump the mud when it arrives at the dumping place; whereas the non-self propelling ones are equipped with dredger pontoon to hold the mud. The grapple dredger has a dredging depth of 3~60 meters and a production capability of 20~400 cubic meters per hour.