Titanic crewman Samuel Hemming followed his orders to the letter - even if it risked certain death.
When the cruise liner struck an iceberg in the North Atlantic on the night of April 14 1912, the lamp-trimmer received a personal order from the ship’s captain, Edward J Smith, to ensure all 15 lifeboats had lit oil lamps - making them easier for both survivors in the water and rescue ships to see.
Despite being told the Titanic would sink in just 30 minutes the dedicated crewman made five trips below deck to bring the lamps - four at a time - to the top deck.
After his job was done Mr Hemming, then aged 43, plunged into the freezing water and swam 200 yards to a collapsible lifeboat which he was heaved into.
A short time later, the same boat saved about 30 men who were standing on the upturned hull of one of the main lifeboats.
The fascinating story of Mr Hemming and his heroism has emerged on the eve of the centenary of the Titanic disaster.
The set of keys he used to unlock the door to where the stock of lifeboat lanterns were kept below deck will go under the hammer later this month.
Mr Hemming survived the 1912 disaster in which 1,522 people perished and kept the set of three keys for the rest of his life.
They were passed down through his family who sold them to a private collector more than 20 years ago.
The private collector is now selling them at auction with a pre-sale estimate of between £50,000 and £60,000.
The sale is being held on March 31st - the 100th anniversary of the completion of the Titanic at ship builder Harland and Wolff — at Henry Aldridge & Son in Devizes, Wiltshire.
Auctioneer Andrew Aldridge said: “The keys themselves played a part in the story as they were actually used in those last desperate hours.
“This is because Mr Hemming received a personal order from Captain Edward J Smith as the ship was sinking and it became apparent all was lost to ensure all of the lifeboats were provided with lamps.
“In detailed evidence that he gave to the United States Titanic Inquiry to Senator Smith he confirmed he was given a direct order by the Captain to stop what he was doing and ensure all of the lifeboats had lamps onboard.
“Mr Hemming would have travelled down several flights of stairs into the bowels of the ship to the Third Class area to gather the lamps.
“The keys bear a brass tag bearing the words Lamp-trimmer and Storekeeper.
“Keys from the Titanic are exceptionally rare but the examples being offered for auction are among the most desirable.”