Hailwood's type 01 miner's lamp, made by Ackroyd and Best Ltd, Leeds, c.1925. Adapted with blue glass for use as an air raid lamp by World War Two ARP Wardens.

This safety lamp was designed to illuminate the pitch black depths of a coal mine, but it was adapted for use above ground during the gloom of World War Two blackouts. When war broke out in 1939, manufacturer Ackroyd and Best Ltd adapted surplus miner's safety lamps with blue glass which made them harder for enemy bombers to spot from above. ARP air raid wardens carried the dim blue lamps as they patrolled Britain's blacked-out streets during air raids. It was their job to make sure no light was peeping through the curtains and shutters of homes and factories.