Abstract: A trench shield has a pair of upright shields laterally spaced from each other with spreaders. Each shield has a frame supporting side walls and a horizontal earth penetrating blade. A pounding rail is releasably mounted on a channel top member of the frame. The pounding rail is an inverted channel member located in the channel of the top member. Rods secured to opposite sides of the pounding rail cooperate with the top member to retain the pounding rail on the top member and allow removal of the pounding unit from the top member. Collars secured to opposite ends of the frame accommodate the spreaders.