British Rail Class 315 alternating current (AC) electric multiple units (EMU) were built by BREL York works from 1980 to 1981. They were the fifth and final variant of British Rail's then-standard 1972 design for suburban EMUs, which eventually encompassed 755 vehicles and five Classes (Class 313/314/315/507/508). Like the Glasgow-based Class 314 units, they are only able to operate from the 25 kV overhead line. The fleet works inner-suburban TfL-run services on the Shenfield Metro for TfL Rail and the Lea Valley Lines for London Overground out of London Liverpool Street.