A tub boat lift is a type of boat lift designed to lift tub boats between different elevations of a canal. Tub boats are small boats used to transport coal and other minerals, sometimes working singly, sometimes in long trains. A tub boat lift (German: Kahnhebehaus) lifts the boat out of the water. Most other types of boat lift such as locks or inclined planes are designed to move the boat afloat in some kind of water-filled tank, and, apart from maximum dimensions, are not restricted in the type of craft transported. Tub boat lifts and tub boats are designed to work together as a system. A given lift will only be able to lift boats designed for the lift.