Generally speaking, the word sluice (German Schleuse, Dutch sluiz, Spanish esclusa, Italian chiusa, French écluse) denotes a controlled outlet; in medieval usage, it could also mean a mill stream, dam, or weir. In hydraulic engineering (“hydrotechnology”), a shipping sluice (more commonly called a lock) is a connecting link between two stretches of water with different levels (see Canal). By raising and lowering floating ships, the ef…