dolphin

At each end of the piers in the water, in cases where several rows of pile are driven, a sort of cutwater should be formed, in order to ward off heavy bodies, such as floating trees, ice, etc. and prevent them from injuring the superstructure (called in German constructions, "Eisbrecher," or ice-breaker). This is usually done by driving one pile by itself in advance of the rest, or by forming what is called a "dolphin" at each end of the pier.