In 1942, the US Navy decided to commission a special helmet for sailors posted on decks and tasked with transmitting orders by sound-powered telephone. The new helmet was to protect "exposed deck personnel" and accommodate a telephone headset; furthermore, it had to be usable while wearing a gas mask and binoculars.[2]
The helmet was made of non-magnetic Hadefield manganese steel.[3] Designated "USN MK-2",[4] was at the time the largest helmet ever used in US service. [2]
Gallery
The US Navy Mk II talker helmet, worn by the sailor in the rear-center of the image; The two sailors in the foreground wear the M1 helmet