Officially, Fraser-Smith was a temporary civil servant for the Ministry of Supply's Clothing and Textile Department (Dept. CT6). In reality, he developed and supplied gadgets and other equipment for section XV of Britain's World War II intelligence organisation, the
Special Operations Executive. Travelling by train from his home in
Hertfordshire to a small office in the clothing department of the Ministry of Supply, near
St. James's Park in London, Fraser-Smith was actually working at the direction of
MI6 in the nearby Minimax House. Performing a job so secret that neither his secretary nor his boss knew what he was doing, Fraser-Smith invented numerous ingenious gadgets intended to help
prisoners of war to escape and to aid SOE agents gathering information on
Nazi activities in
occupied Europe. His first order was to counterfeit Spanish Army uniforms for a proposed SOE plan to infiltrate agents into neutral Spain to prevent it from entering the war on the side of Germany. He dealt directly with the textile suppliers; ultimately using more than 300 firms in and around London: many of them had no idea what they were making or why, to make equipment for secret operations. Directed to make copies of a new type of
Luftwaffe life jacket, he made discoveries that were subsequently incorporated as standard in
RAF "
Mae Wests", including the use of a
compressed air cylinder for inflating the jacket and a pouch filled with a powerful
fluorescent dye for spotting of a downed airman at sea. In an example of lateral thinking, Fraser-Smith used a special left-hand thread for the disguised screw-off top of a hidden-document container; he suggested this would prevent discovery by the "unswerving logic of the German mind", as no German would ever think of trying to unscrew something the wrong way. which was designed to drop a body, carrying false papers to mislead the Nazis, off the Spanish coast. He was tasked with designing a trunk, 6' 2" long and 3' wide, to carry a "deadweight" of 200 lb that would be preserved in
dry ice. When the dry ice evaporated, it filled the canister with carbon dioxide and drove out any oxygen, thus preserving the body without refrigeration. The plot was the basis of the book (and later film)
The Man Who Never Was and the 2021 film
Operation Mincemeat. ==Later life==