Endurance trapped in pack ice during the Imperial Trans-Antarctic Expedition
|Builder:||Framnæs shipyards, Sandefjord, Norway|
|Out of service:||1915|
|Fate:||Sank in the Weddell Sea, 1915|
|Length:||144 ft (44 m)|
|Beam:||25 ft (7.6 m)|
|Propulsion:||350 hp (260 kW) Coal fired steam and sail|
|Speed:||10.2 knots (18.9 km/h; 11.7 mph)|
Endurance was the three-masted barquentine in which Sir Ernest Shackleton sailed for the Antarctic on the 1914 Imperial Trans-Antarctic Expedition. She was launched in 1912 from Sandefjord in Norway; three years later, she was crushed by ice and sank in the Weddell Sea off Antarctica.
Design and construction
Designed by Ole Aanderud Larsen, Endurance was built at the Framnæs shipyard in Sandefjord, Norway and fully completed on 17 December 1912. She was built under the supervision of master wood shipbuilder Christian Jacobsen, who was renowned for insisting that all men in his employment were not just skilled shipwrights but also be experienced in seafaring aboard whaling or sealing ships. Every detail of her construction had been scrupulously planned to ensure maximum durability: for example, every joint and fitting was cross-braced for maximum strength.
The ship was launched on 17 December 1912 and was initially christened Polaris (eponymous with Polaris, the North Star). She was 144 feet (44 m) long, with a 25 feet (7.6 m) beam and measured 348 tons gross. Her original purpose was as an ice-capable steam yacht, to provide luxurious accommodation for small tourist and hunting parties in the Arctic. As launched she had 10 passenger cabins, a spacious dining saloon and galley (with accommodation for two cooks), a smoking room, a darkroom to allow passengers to develop photographs, electric lighting and even a small bathroom.
Though her hull looked from the outside like that of any other vessel of a comparable size, it was not. She was designed for polar conditions with a very sturdy construction. Her keel members were four pieces of solid oak, one above the other, adding up to a thickness of 85 inches (2,200 mm), while its sides were between 30 inches (760 mm) and 18 inches (460 mm) thick, with twice as many frames as normal and the frames being of double thickness. She was built of planks of oak and Norwegian fir up to 30 inches (760 mm) thick, sheathed in greenheart, a notably strong and heavy wood. The bow, which would meet the ice head-on, had been given special attention. Each timber had been made from a single oak tree chosen for its shape so that its natural shape followed the curve of the ship's design. When put together, these pieces had a thickness of 52 inches (1,300 mm).
Of her three masts, the forward one was square-rigged, while the after two carried fore and aft sails, like a schooner. As well as sails, Endurance had a 350 horsepower (260 kW) coal-fired steam engine capable of speeds up to 10.2 knots (18.9 km/h; 11.7 mph).
By the time of launch on 17 December 1912, Endurance was perhaps the strongest wooden ship ever built, with the possible exception of Fram, the vessel used by Fridtjof Nansen and later by Roald Amundsen. There was one major difference between the ships. Fram was bowl-bottomed, which meant that if the ice closed in against her it would be squeezed up and out and not be subject to the pressure of the ice compressing around her; Endurance was designed with great inherent strength in her hull to resist collision with ice floes and to break through pack ice by ramming and crushing. Endurance was not intended to be frozen into heavy pack ice, and so was not designed to rise out of a crush. In such a situation she was dependent on the ultimate strength of her hull alone.
As Endurance was built for Adrien de Gerlache and Lars Christensen, they intended to use her for polar cruises for tourists to hunt polar bears. Financial problems led to de Gerlache pulling out of their partnership, leaving Christensen unable to pay the Framnaes yard the final amounts to hand over and fit out the ship. For over a year Christensen attempted to sell the ship as her unique design as an ice-capable passenger-carrying ship, with relatively little space for stores and no cargo hold made her useless to the whaling industry. Meanwhile she was too big, slow and uncomfortable to be a private steam yacht. In the event Christensen was happy to sell the ship to Ernest Shackleton for GB£11,600, which represented a significant loss to him as it barely covered the outstanding payments to Framnaes, let alone the ship's total build costs. He is reported to have said he was happy to take the loss in order to further the plans of an explorer of Shackleton's stature . After Shackleton purchased the ship, she was rechristened Endurance after the Shackleton family motto "Fortitudine vincimus" (By endurance we conquer).
Shackleton had the ship relocated from Norway to London. She arrived at the Millwall Dock in the spring of 1914 where she was refitted and modified for expedition purposes. She was stripped of most of her luxurious accommodation and fittings. This included removing many of the passenger cabins to make room for space for stores and equipment, while the crew cabins on the lower deck were removed and converted into a cargo hold - the reduced crew of sailors that Shackleton would take on the expedition would make their quarters in the cramped forecastle. The darkroom remained in its original location ahead of the boiler. The refit also saw the ship repainted from her original white paint to a more austere (and visible amongst ice) black, and features such as gilt scrollwork on the bow and stern, were painted over. Despite her change of name she retained a large badge in the shape of a five-pointed star on her stern, which originally symbolized her name after the pole star.
Her new equipment included four ship's boats. Two were 21-foot (6.4 metre) transom-built rowing cutters purchased secondhand from the whaling industry. The third was a larger 22.5-foot (6.85 meter) double-ended rowing whaleboat built for the expedition to specifications drawn up by Frank Worsley, Endurance's new captain. The fourth was a smaller motorboat.
After her refit she made the short coastal journey to Plymouth.
In the previous 16 years, nearly two dozen wooden vessels had sailed to the icy seas of the far south. All had returned home but Aurora. Lloyd's of London and the Indemnity Marine Assurance Company had underwritten her hull, machinery and equipment for £15,000. Just before she sailed, The Times had reported that "Hitherto the insurance of vessels taking part in Antarctic exploration has ceased at the last port touched, and Endurance will be the first vessel to be insured in the ice zone."
The Times had praised Endurance as "built specially for work in Polar seas," adding that "in an ice-coated sea there can be no turbulent waves which are the causes of so many disasters in warmer zones."
Endurance sailed from Plymouth, England on 6 August 1914 and set course for Buenos Aires, Argentina. Shackleton remained in Britain, finalising the expedition's organization and for some last-minute fundraising. This was Endurance's first major voyage following its completion and amounted to a shakedown voyage. The trip across the Atlantic took more than two months. Built for the ice, her hull was considered by many of her crew too rounded for the open ocean. Shackleton took a steamer to Buenos Aires and caught up with his expedition a few days after Endurance's arrival.
On 26 October 1914 Endurance sailed from Buenos Aires to what would be her last port of call, the whaling station at Grytviken on the island of South Georgia, arriving on 5 November. She left Grytviken on 5 December 1914 heading for the southern regions of the Weddell Sea.
Two days after leaving from South Georgia, Endurance encountered polar pack ice and progress slowed down. For weeks Endurance worked its way through the pack, averaging less than 30 miles (48 km) per day. By 15 January 1915 Endurance was within 200 miles (320 km) of her destination, Vahsel Bay. By the following day, heavy pack ice was sighted in the morning and in the afternoon a gale developed. Under these conditions it was soon evident progress could not be made, and Endurance took shelter under the lee of a large grounded berg. During the next two days, Endurance moved back and forth under the sheltering protection of the berg.
On 18 January the gale began to moderate and Endurance set the topsail with the engine at slow. The pack had blown away. Progress was made slowly until hours later Endurance encountered the pack once more. It was decided to move forward and work through the pack, and at 5:00 pm Endurance entered it. This ice was different from what had been encountered before, and the ship was soon amongst thick but soft brash ice, and became beset. The gale increased in intensity and kept blowing for another six days from a northerly direction towards land. By 24 January, the wind had completely compressed the ice in the whole Weddell Sea against the land. Endurance was icebound. All that could be done was to wait for a southerly gale that would start pushing, decompressing and opening the ice in the other direction.
In the early morning of 24 January, a wide crack appeared in the ice 50 yards (45 metres) ahead of the ship. Initially 15 feet (4.5 metres) across, by mid-morning the break was over a quarter of a mile (0.4km) wide, giving the men on the Endurance hope that the ice was breaking up. But the break never reached the ship itself, and despite three hours under full sail and full speed on the engine, the ship did not budge.
Over the next days, the crew waited for the southerly gale to release the pressure on the ice, but while the wind backed to the hoped-for south/southwest direction, it remained light and erratic. Occasional breaks in the ice were spotted, but none reached the ship and all closed up within a few hours. Trials were made on January 27 with cutting and breaking the ice around the ship by manual labour but this proved futile.
On February 14 an open channel of water opened up a quarter of a mile (0.4km) ahead of the ship and dawn showed the Endurance was afloat in a pool of soft, young ice no more than two feet (0.6 metres) thick but the pool was surrounded by solid pack ice of 12-18 feet (3.6-5.4 metres) in thickness, blocking the path to the open lead. A day's continual work by the crew saw them hack a clear channel 150 yards (137 metres) long. This work continued through the following day (February 15) and, with steam raised, the Endurance was backed up within her pool as far as possible to allow the ship to ram her way through the channel. As the ship went astern for successive attempts, lines were attached from the bow to loosened blocks of ice, estimated to weigh 20 tons (18 tonnes) to clear the path. The pool proved too small for the ship to gain enough momentum to successfully ram her way clear and by the end of the day the ice began to freeze up again. By 3pm the Endurance had made 200 yards (180 metres) of distance through the ice, with 400 yards (365 metres) still to go to clear water. Shackleton decided that the consumption of coal and manpower, and the risk of damage to the ship, was too great and called a halt.
After this frustration, Endurance's boilers were extinguished, committing the ship to drift with the ice until released naturally. On 17 February the sun dipped below the horizon at midnight, showing the end of the Antarctic summer. On February 24 regular watches on the ship were cancelled, with the Endurance now functioning as a shore station. The ship had slowly drifted south and at this point was within 60 miles (96km) of the intended landing point at Vahsel Bay. But the terrain between the ship and the shore was too arduous to cover over the ice while carrying the materials and supplies needed for the overland expedition.
By March, navigational observation showed that the ship (and the mass of pack ice that contained it) was still moving, but now swinging towards the west-northwest and increasing in the speed of its drift, moving 130 miles between the start of March and May 2, when the sun disappeared below the horizon and the dark Antarctic winter began. Still the men on the ship hoped for either a change in the weather which would break up the pack or that, by the spring, the warmer weather and the ship's northward drift would mean it was released.
On 14 July 1915 Endurance was swept by a southwest gale, with wind speeds of 112 km/h (31 m/s; 70 mph), a barometer reading of 28.88 inHg (975 hPa) and temperatures falling to -36 °C (-34 °F). The blizzard continued until 16 July. This broke up the pack ice into smaller, individual floes, each of which began to move semi-independently under the force of the weather, while also clearing water in the north of the Weddell Sea. This provided a long fetch for the south-setting wind to blow over and then for the broken ice to pile up against itself while individual parts moved in different directions. This caused regions of intense localised pressure in the ice field. The ice began 'working', with sounds of breaking and colliding ice audible to those on the ship through the next day. Breaks in the ice were spotted but none approached the ice holding the Endurance.
During July the ship drifted a further 160 miles to the north. On the morning of 1 August, a pressure wave passed through the floe holding the ship, lifting the 400-ton Endurance bodily upwards, heeling the ship sharply to its port side before it dropped into a pool of water, afloat again for the first time in nearly six months. The broken sections of floe closed in around the ship on all sides, jarring the Endurance forward, backwards and sideways in violent fashion against the other slabs of ice. After over a quarter of an hour, a force from astern pushed the ship's bow up onto the floe, lifting the hull out of the pressure and with a list of five degrees to her port side.
A gale overnight further disturbed the floe, driving it against the starboard side of the hull and forcing a sheet of ice upwards at a 45-degree angle until it reached the level of the scuppers. Despite the ordeal of the past few days the ship remained undamaged.
Two pressure waves struck the ship on 29 August without incident. On the evening of 31 August, a slow-building pressure gripped the Endurance, causing her hull and timbers to creak and shudder continuously. The ice around the ship moved and broke throughout the night, battering the port side of the hull.
All was quiet again until the afternoon September 30, by which time there were signs of spring with ten hours of sunlight per day and occasional temperature readings above freezing point. A large floe was swept against the Endurance's port bow and then gripped that side of the ship against the built-up ice and snow on her starboard beam. The ship's structure groaned and wracked under the strain. Carpenter Harry McNish noted that the solid oak beams supporting the upper deck were being visibly bent "like a piece of cane." On deck the ship's masts were whipping back and forth as their stepping points on the keel were distorted. Despite these disconcerting signs, Captain Frank Worsley noted that the strength of the ship's structure was causing the ice itself to break up as it piled against the hull - "...just as it appears she can stand no more, the huge floe weighing possibly a million tons or more yields to our little ship by cracking across...and so relieves the pressure. The behaviour of our ship in the ice has been magnificent. Undoubtedly she is the finest little wooden vessel ever built...." Despite this, the ship's decks were permanently buckled following this ordeal.
By October temperatures of nearly 42° F (5° C) were recorded and the ice showed further signs of opening up. The floe which had been jammed against the ship's starboard side since July broke up on October 14, casting the Endurance afloat in a pool of open water for the first time in nine months.
On 16 October, Shackleton ordered steam to be raised so the ship could take advantage of any openings in the ice. It took nearly four hours for the boilers to be filled with freshwater melted from ice, and then a leak was discovered in one of the fittings and they had to be pumped out, repaired and then refilled. The following day a lead of open water was seen ahead of the ship. Only one boiler had just been lit and there was insufficient steam to use the engine, so all the sails were set to try and force the ship into the loosening pack ice but without success.
In the late afternoon of 18 October, the ice closed in around the Endurance once again. In just five seconds the ship was canted over to port by 20 degrees, and the list continued until she rested at 30 degrees, with the port bulwark resting on the pack and the boats on that side nearly touching the ice as they hung in their davits. This put the ship in a seemingly safe position - instead of being pinched between two opposing masses of ice the Endurance had been pushed from starboard to port and further pressure from starboard would push her bodily upwards over the top of the port-side floe, which had actually collided with its counterpart under the ship's bilge. In any case, after four hours in this position, the ice drew apart and the ship returned to a level keel.
The ice was relatively still for the rest of the month. On October 20 steam was raised again and the engines tested. On October 22 the temperature dropped sharply from 42° F (5° C) to -14° F (-25° C) and the wind veered from southwest to northeast. This caused the loosening pack to compress against the Antarctic coast once again. On October 23 pressure ridges could be seen forming in the ice and moving near the ship. The next day a series of pressure waves struck the Endurance, causing the ice around the ship to fracture into separate large pieces which were then tumbled and turned in all directions. The ship was shunted back and forth before being pinched against two floes on her starboard side, one at her bow and one at her stern, while on the port side a floe impacted amidships, setting up a huge bending force on the hull. Parts of the rigging were snapped under the strain.
A large mass of ice slammed into the stern, tearing the sternpost away from the hull planking. Around the same time the bow planking was stove in, causing simultaneous flooding in the engine room and the forward hold. Despite using both the portable manual pumps and getting up steam to drive the main bilge pumps, the water level continued to rise. The main man-powered deck pumps did not work as their intakes had frozen and could only be restored by pouring buckets of hot water onto the pump pipes from inside the coal bunkers and then playing a blowtorch over the intake valve. McNish constructed a cofferdam in the shaft tunnel to seal off the damaged stern area while the crew were arranged in spells of 15 minutes on/15 minutes off on the main pump. After 28 hours of continual work the inflow of water had only been arrested - the ship was still badly flooded.
On October 24 the damaged ship was wracked by further pressure waves. The port-side floe was pressed more heavily against the side, warping the keel along its length and causing near-continual creaks, groans, cracks and 'screams' from the ship's timbers. The footplates in the engine room were pushed up and would no longer sit in place as the compartment was compressed. The planking of the ship's port side was bowing inwards by up to six inches (15cm). At 10pm Shackleton ordered the ship's boats, stores and essential equipment to be moved onto the ice.
In the afternoon of 25 October, the pressure of the ice increased further. The main deck of the Endurance buckled upwards amidships and the beams sheared. As the ice moved against her stern, the aft part of the ship was lifted up and the damaged sternpost and the rudder were torn away. This angle caused all the water in the ship to run forward, collecting in the bow where it then began to freeze. The action of the ice in the stern and the excessive weight in the bow caused the ship to sink into the ice bow first. Under its own pressure, the ice then broke over the forecastle and piled up onto the deck in the forward part of the ship, further weighing this end of the ship down. Through all of this, the pumping operations had continued but by the end of the day Shackleton ordered this to stop and for the men to take to the ice.
During the course of the next day, parties were sent back to the ship to recover more supplies and stores. They found that the entire port side of the Endurance had been driven inwards and compressed, and the ice had entirely filled the bow and stern sections. The ship's Blue Ensign was hoisted up her mizzen mast so that she would, in Shackleton's word's "go down with colours flying."
After a failed attempt to man-haul the boats and stores overland on sledges, Shackleton realised that this could not be done and the party would have to camp on the ice until it carried them to the north and broke up. More parties were sent back to the Endurance, still with her masts and rigging intact and all but her bow above the ice, to salvage any remaining items. A large portion of provisions had been left on the submerged lower deck. The only way to retrieve them was to cut through the main deck (more than a foot (30cm) thick in places and itself under three feet (1 metre) of water). Some crates and boxes floated up once a hole had been cut, while others were retrieved with a grapple. In total, nearly 3.5 tons of stores were recovered from the wrecked ship.
The party was still camped under two miles (3km) from the remains of the Endurance on 8 November, when Shackleton returned to the ship to consider further salvage. But by now the ship had sunk a further 18 inches (45cm) into the ice and the upper deck was now almost level with the ice. The interior of the ship was almost full of compacted ice and snow, making further work impossible. The damage to the bow and stern, and the force of the ice against the port side, had caused a large portion of the hull on that side of the ship to break free of the rest of the ship and, under the force of the ice, be moved bodily inwards in a telescoping effect. In some places, the outer hull planks were now in line with the keel. A stash of empty fuel oil cans placed against the port side wall of the deckhouse had been pushed through the wall and then the cans and the wall had come to rest against its counterpart on the starboard side of the deckhouse. The row of five cabins that had been on the port side of the main deck above the engine room and their contents had been compressed into the space of a single cabin.
|The end of Endurance, 1915, YouTube video|
On 13 November a new pressure wave swept through the pack ice. The forward topgallant mast and topmasts collapsed as the bow was finally crushed - these moments being recorded on film by Frank Hurley. The mainmast was split near its base and shortly afterwards the mainmast and the mizzen mast broke and collapsed together (this also being filmed by Hurley). The ensign was re-rigged on the tip of one of the foremast yardarms which, constrained by the rigging, was now hanging vertically from the remains of the foremast and was the highest point of the wreck.
In the late afternoon of 21 November movement of the remaining wreckage was noticed as another pressure wave hit. Within the space of a minute the stern of the Endurance was lifted clear of the ice as the floes moved together and then, as the pressure passed and they moved apart, the entire wreck fell into the ocean. By daylight the following day the ice had moved together again obliterating any trace of the wreck. Worsley fixed the position as 68° 38.5'S, 52° 58'W.
The crew of Endurance in her final voyage was made up of the 28 men listed below:
- Sir Ernest Shackleton, Leader
- Frank Wild, Second-in-Command
- Frank Worsley, Captain
- Lionel Greenstreet, First Officer
- Tom Crean, Second Officer
- Alfred Cheetham, Third Officer
- Hubert Hudson, Navigator
- Lewis Rickinson, Engineer
- Alexander Kerr, Engineer
- Alexander Macklin, Surgeon
- James McIlroy, Surgeon
- Sir James Wordie, Geologist
- Leonard Hussey, Meteorologist
- Reginald James, Physicist
- Robert Clark, Biologist
- Frank Hurley, Photographer
- George Marston, Artist
- Thomas Orde-Lees, Motor Expert and Storekeeper
- Harry "Chippy" McNish, Carpenter
- Charles Green, Cook
- Walter How, Able Seaman
- William Bakewell, Able Seaman
- Timothy McCarthy, Able Seaman
- Thomas McLeod, Able Seaman
- John Vincent, Boatswain
- Ernest Holness, Stoker
- William Stephenson, Stoker
- Perce Blackborow, Steward
Nationalities. All the crew were born and resident in England before the expedition, except for the following:
- Shackleton. Irish
- Worsley. New Zealander.
- Greenstreet. New Zealander.
- Crean. Irish.
- Macklin. Indian
- McIlroy. Irish
- Wordie. Scottish.
- Hurley. Australian.
- Clark. Scottish.
- McNish. Scottish.
- Bakewell. American, may have claimed to be Canadian when he applied to join the Imperial expedition in Buenos Aires.
- McCarthy. Irish.
- Blackborrow. Welsh.
- Edgar Smith. Irish.
- McCarthy. Irish.
- Green. British
Blackborrow was originally refused a post aboard the vessel due to his young age and inexperience and decided to stow away, helped to sneak aboard by William Bakewell, a friend of his, and Walter How. When he was found Shackleton decided to make him a steward rather than leave him ashore at South Georgia. Blackborrow eventually proved his worth, earning the Bronze Polar Medal, and the honour of becoming the first human being ever to set foot on Elephant Island. His name is also the matter of some debate—it is sometimes spelled Percy, or Blackboro, or in other ways.
To find crew for the Endurance, Shackleton reportedly placed an advertisement in the London Times newspaper reading:
When discussing the advertisement in the 1944 book Quit You like Men, Carl Hopkins Elmore quoted Shackleton as saying that "so overwhelming was the response to his appeal that it seemed as though all the men of Great Britain were determined to accompany him." Although the advertisement was listed in Julian Watkins' The 100 Greatest Advertisements: 1852-1958, no trace has been found to date. Many sources have concluded that the story of Shackleton's advertisement is likely apocryphal.  The crew did receive the recognition the advertisement promised; Time Magazine has deemed their voyage "the most storied epic of survival." 
Two Antarctic patrol ships of the British Royal Navy have been named Endurance in honour of Shackleton's ship. The first HMS Endurance, launched in May 1956 and awarded pennant number A171 sometime later, acted as an ice patrol and hydrographic survey ship until 1986. The second HMS Endurance was bought from Norway in 1992 where she was named MV Polar Circle. She suffered severe flooding in 2008 due to procedural errors during maintenance and despite being returned to the UK was not repaired prior to being scrapped in 2016.
In 1998, wreckage found at Stinker Point on the south western side of Elephant Island was incorrectly identified as flotsam from the ship. It instead was from the 1877 wreck of the Connecticut sealing ship Charles Shearer. In 2001, wreck hunter David Mearns unsuccessfully planned an expedition to find the wreck of Endurance. By 2003, two rival groups were making plans for an expedition to find the wreck; but no expedition was actually mounted. In 2010, Mearns announced a new plan to search for the wreck. The plan is sponsored by the National Geographic Society but is subject to finding sponsorship for the balance of the US$10 million estimated cost. A 2013 study by Dr Adrian Glover of the Natural History Museum, London suggests the Antarctic Circumpolar Current could preserve the wreck on the seabed by keeping wood-boring "ship worms" away. A Weddell Sea Expedition to locate and possibly photograph the wreck using long-range Autonomous Underwater Vehicles (AUV) was underway in the Antarctic summer of 2018–19. That expedition failed when the researchers' AUV was lost to the ice as well.
- Voyage of the James Caird, for what happened after Endurance broke up
- List of Antarctic exploration ships from the Heroic Age, 1897–1922
- Endurance (Shackleton)
- Heacox, Kim (1999). The Antarctic Challenge. Washington, D.C.: National Geographic. p. 82. ISBN 978-0792275367.
- Endurance's crew
- "Shackleton's Ad – Men Wanted for Hazardous Journey". Discerning History. 2013-05-05. Retrieved 2018-12-26.
- "The Greatest Adventures of All Time — The Great Survivor". TIME. 2003-09-12. Retrieved 2011-03-27.
- Elmore, Carl Hopkins (1944-01-01). Quit You like Men. New York: Charles Scribner’s Sons. p. 53. OCLC 903946983.
- "Shackleton's Ad – Men Wanted for Hazardous Journey". Discerning History. 2013-05-05. Retrieved 2018-12-26.
- "Shackleton Probably Never Took Out an Ad Seeking Men for a Hazardous Journey". Smithsonian.com. 2013-09-10. Retrieved 2018-12-26.
- "The Greatest Adventures of All Time — The Great Survivor". TIME. 2003-09-12. Retrieved 2011-03-27.
- "Archived copy" (PDF). Archived from the original (PDF) on 2012-10-11. Retrieved 2010-04-10.CS1 maint: archived copy as title (link)
- "Endurance Rush". OutsideOnline.com. 1915-11-21. Archived from the original on 2010-09-20. Retrieved 2011-03-27.
- "Endurance, Ships of the Antarctic explorers". Coolantarctica.com. Retrieved 2011-03-27.
- "Shackleton's ship 'ultimate challenge'". Sydney Morning Herald. January 16, 2010. Retrieved 2011-03-27.
- "Blue Water Recoveries are a deep sea shipwreck recovery company". Bluewater.uk.com. Retrieved 2011-03-27.
- Jonathan Amos (14 August 2013). "Antarctic: Where 'zombies' thrive and shipwrecks are preserved". =BBC News. Retrieved 14 August 2013.
- "Weddell Sea Expedition". Retrieved 27 January 2019.
- "Antarctic expedition to find Shackleton's lost Endurance loses its own submarine to the ice". Retrieved 17 December 2019.
- ^ Lansing, Alfred. (1999) 2nd ed. Endurance: Shackleton's Incredible Voyage. Carroll & Graf Publishers. ISBN 0-7867-0621-X
- Shackleton, Ernest (1982) . South: The story of Shackleton's 1914–17 expedition. London: Century Publishing. ISBN 0-7126-0111-2.
- Media related to Endurance at Wikimedia Commons