 The York-class cruisers lacked a full-length waterline armour belt. The sides of Exeter's boiler and engine rooms and the sides of the magazines were protected by 3 inches (76 mm) of armour. The transverse bulkheads at the end of her machinery rooms were 3.5 inches (89 mm) thick. The top of the magazines were protected by 5.5 inches (140 mm) of armour and their ends were 4.375 inches (111.1 mm) thick. The lower deck over the machinery spaces and steering gear had a thickness of 1.5 inches (38 mm).
