Peening trials in No. 1 Ship Shop, Portsmouth Dockyard, Hampshire.

Two men taking measurements of a sheet of steel after welding during peening trials held in No. 1 Ship Shop in Portsmouth Dockyard. The test piece is edge welded to a 40 lbs base plate which is welded to T bar stiffeners. The men are each using an instrument fitted with a gauge. The test piece has No. 5 complete written on it. Peening is the process of working a metal's surface to improve its material properties, especially after welding to help relieve the tensile stresses that develop on cooling in the welded metal (as well as the surrounding base metal).