Rear Admiral Peter Gerald Hammersley CB OBE (nicknamed Spam, 18 May 1928 – 16 January 2020) was an English Royal Navy officer who served from 1946 to 1982. Hammersley won a scholarship to Britannia Royal Naval College to train as a deck officer but his eyesight was too poor. Instead, he chose to become an engineer and studied at the Royal Naval Engineering College from 1946 to 1950. He trained onboard HMS Frobisher and HMS Duke of York and served on HMS Ocean during the Korean War. Hammersley specialised in submarines from 1954 and in 1959 served on secondment to the US Navy on the nuclear submarine Nautilus. In 1960 he became the first marine engineering officer to serve aboard the Royal Navy's first nuclear-powered submarine, HMS Dreadnought. Hammersley helped design the Swiftsure-class