A bucket (also called a scoop to qualify shallower designs of tools) is a specialized container attached to a machine, as compared to a bucket adapted for manual use by a human being. It is a bulk material handling component. The bucket has an inner volume as compared to other types of machine attachments like blades or shovels. The bucket could be attached to the lifting hook of a crane, at the end of the arm of an excavating machine, to the wires of a dragline excavator, to the arms of a power shovel or a tractor equipped with a backhoe loader or to a loader, or to a dredge. The name "bucket" may have been coined from buckets used in water wheels, or used in water turbines or in similar-looking devices. Purposes Buckets in mechanical engineering can have a distinct quality from the traditional bucket (pail) whose purpose is to contain things. Larger versions of this type of bucket equip bucket trucks to contain human beings, buckets in water-hauling systems in mines or, for instance, in helicopter buckets to hold water to combat fires. Two other types of mechanical buckets can be distinguished according to the final destination of the device they equip: energy-consumer systems like excavators or energy-capturer systems like water bucket wheels or turbines. Size and shape Buckets exist in a variety of sizes or shapes. They can be quite large like those equipping Hulett cranes, used to discharge ore out of cargo ships in harbours or very small such as those used by deep-sea exploration vehicles. The shape of the bucket can vary from the truncated conical shape of an actual bucket to more scoop-like or spoon-like shapes akin to water turbines. The cross section can be round or square. Designs Simple design This is the same shape of a domestic form, the one-piece-standing single element, but often with an augmented size. Mining In early developments of mining, a large simple bucket allowed easy insertion of both miners and construction materials such as pit props, and later extraction of miners and ore. Common terms used in various parts of the world include: Bowk; Kibble; Hoppit; Hoppet. Latterly they have been called sinking buckets, as they are now only used when sinking new mine shafts before insertion of the cage, or for emergency rescue. Concrete bucket A concrete bucket delivers concrete by means of a tower crane.