Sheet piles are made by employing planks, thick boards or other wood pieces that fit together. They are usually wedge shaped and often tongued at the bottom and grooved at the other end and pounded into the ground as gauged piles close together. This creates the effect of a wall which is similar to a cofferdam. Rolled steel can also be utilized in this manner. Each pile is designed in a similar way so as to interlock around each edge to bond with adjacent piles.