A shoring device is disclosed comprising a piston and a cylinder. The piston is axially expanded by compressed gas, whereby the shoring device engages two opposing surfaces. Removable swivel sideplates comprise detente sphere attachments by which the sideplates reversibly attach to the piston and cylinder. These attached removable swivel sideplates contain set screws which engage the sides of trenches and excavations which are lined with timbers or other materials.