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The first of these systems used mechanical clutches between luffing and hoist drums, giving simplicity and a "near level" result. [5] Later systems have used modern electronic controls and quickly reversible motors with good slow-speed control to the hoist winch motors, so as to give a positioning accuracy of inches.
A hoist controller is the controller for a hoist. The term is used primarily in the context of electrically operated hoists, but it is apparent that the control systems of many 20th century steam hoists also incorporated controllers of significant complexity. Consider the control system of the Quincy Mine No. 2 Hoist. [1] This control system ...
Fugacity and BCF relate to each other in the following equation: = [6] where Z Fish is equal to the Fugacity capacity of a chemical in the fish, P Fish is equal to the density of the fish (mass/length 3), BCF is the partition coefficient between the fish and the water (length 3 /mass) and H is equal to the Henry's law constant (Length 2 /Time 2) [6]
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. [1] Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects. Shaft sinking is one of the most difficult of all ...
A system context diagram in engineering is a diagram that defines the boundary between the system, or part of a system, and its environment, showing the entities that interact with it. [2] This diagram is a high level view of a system. It is similar to a block diagram.
Dragline excavator. Built by Bucyrus-Erie in 1969, Big Muskie was the world's largest ever dragline, being 487 ft (148 m) in length, weighing some 13,500 short tons (12,247 t), and hoisting a 220 cu yd (168.2 m 3) bucket that could move 325 short tons (295 t) of material at a pass. A dragline excavator is a heavy-duty excavator used in civil ...
Proportional–integral–derivative controller. A proportional–integral–derivative controller (PID controller or three-term controller) is a control loop mechanism employing feedback that is widely used in industrial control systems and a variety of other applications requiring continuously modulated control.
Manual crane from the late 19th century used for unloading small loads from ships at the Port of Barcelona, Spain. A crane is a machine used to move materials both vertically and horizontally, utilizing a system of a boom, hoist, wire ropes or chains, and sheaves for lifting and relocating heavy objects within the swing of its boom.