Turret 17B (Horsley) was scheduled at the same time as Turret 17A.[10] 17B was located on 11 June 1931 and excavated later that year.[10] It was found to be similar to 17A with a door at the southwest and a ladder platform in the southeast and lies beneath the B3618, leaving no visible surface traces of its existence.[10]
Location: 55.009233°N 1.918507°W