The latch is drawn back to open the door by means of a line extending from it to a lever at a point near the fulcrum, and a second line from the end of the lever to the cranesman stationed at the heel of the boom. The bottom door or floor of the bucket is held closed by a latch, which locks automatically by virtue of its bevelled end when the door is forced upward and closed by the water pressure. Rear face of the bucket or to the dipper stick near the bucket. The bucket hoisting wire is made fast to the centre of the bail, and the backing chain, which draws bucket and dipper stick back toward the hull, is fastened either to the 9 is a picture of a Bucyrus Dipper Dredge, swinging a 6 cubic yard bucket. The Bucket.-The bucket is an open steel cylinder, provided with a hinged flap bottom, a handle or bail and a reinforced cutting edge or lip, to which teeth are attached. As a rule, the crew is quartered on the dredge. The dredge is held in position by three spuds, and advances by grounding her dipper and stressing the backing chain. The hull is stiffer and the spuds heavier than those of the grapple, because of the greater strains. The boom is spying in one of two ways either as in the grapple by means of two bucket wires, or by bull wheel and swinging engine, the latter being the more common.

The bucket obtains its load by digging into the bottom under the impetus of dipper stick and bucket wire, which runs over a sheave in the boom head and thence to the main engine. The boom is supported by “A” frame and back guys as in the grapple, except that, frequently, the “A” frame is tilted forward, when it is termed the “shear legs.” The boom is necessarily of heavier construction than that of the grapple and, with the “A” frame, is set well forward at the very bow of the hull. The bucket, which is essentially a scoop with heavy teeth and a flap bottom, is attached to the end of the dipper stick, which is carried by the boom at or near the centre of the latter. General Description.-As has been said, the Dipper Dredge “ digs ” like the familiar steam shovel.

Manual hand dredge with bucket