This is one of many attempts to create a set of shapes that the sculpture visitor can move around.
In this case each shape sits on a base that has the same outer shape, but slightly larger, so no matter how the shapes are moved, only the bases will collide, like bumper cars.
Each shape has a pulley on top with a cable attached to the shape. The pulley goes down into the column with a counter weight attached, so the shape slides up and down with no effort.
Each of the bumper car bases has transfer balls for feet, so they can move around easily (on a smooth surface, on grass this would not work…)