A Search Begins for Shackleton’s Endurance, the ‘Most Unreachable Wreck’

A century after Ernest Shackleton’s ship Endurance sank in the waters of Antarctica, resulting in one of the greatest survival stories in the history of exploration, a team of modern adventurers, technicians and scientists is setting sail to find the wreck.

With a crew of 46 and a 64-member expedition team aboard, a South African icebreaker is set to leave Cape Town on Saturday, bound for the Weddell Sea. Once there, the team hopes to find the wreck and explore it with two underwater drones.

Getting there won’t be easy. Crushed by pack ice in 1915, the 144-foot-long Endurance is sitting in 10,000 feet of water. And this isn’t just any water: In the Weddell, a swirling current sustains a mass of thick, nasty sea ice that can be a match even for modern icebreakers.

Shackleton himself, whose plans to be the first to cross Antarctica were derailed by the loss of his ship, described the site of the sinking as “the worst portion of the worst sea in the world.”

“It’s the most unreachable wreck ever,” said Mensun Bound, a marine archaeologist and director of exploration of the expedition, Endurance22. “Which makes this the greatest wreck hunt of all time.”

Endurance is also one of the most famous shipwrecks, perhaps on par with the Titanic. It’s a relic of the heroic age of Antarctic exploration, when adventurers undertook elaborate, risky and wildly popular expeditions to the continent and the pole. Some, like Roald Amundsen, succeeded. Others, like Robert Falcon Scott, died in the process.

Shackleton failed to achieve his goal, but when he returned to Britain having saved all his crew after an epic open-boat journey across treacherous seas, he was hailed as a hero. He’s still lionized today, in books, films and even business school courses, where the expedition is considered a case study in effective leadership.

“I’m as much under the spell of Shackleton and Endurance as anybody,” said Caroline Alexander, an author and co-curator of a 1999 exhibition about the Endurance expedition at the American Museum of Natural History in New York City. Of the wreck, she said, “it’s significance almost is emotional rather than, say, strictly historical.”

The expedition to find it, financed at a cost of more than $10 million by an anonymous donor, will have less than two weeks to locate the wreck once the icebreaker reaches the Weddell Sea. If Endurance is found, the drones will take photographs and videos and make precise laser scans of the wreckage. But the site won’t be disturbed, as it has been declared a historic monument under the terms of the Antarctic Treaty, an international agreement signed in 1959 intended to preserve the continent for peaceful purposes.

The wreck is expected to be in relatively good shape because of the cold water and the absence of wood-eating organisms in Antarctic seas.

Thanks to the work of Endurance’s captain and navigator, Frank Worsley, who with basic navigational tools was able to determine the ship’s location around the time it sank, the expedition is confident the wreck is in a 7-mile by 14-mile zone in the western Weddell.

“We know pretty much where we need to go,” said John Shears, leader of Endurance22, who is making his 25th expedition to Antarctica. And so far this season (it is the Antarctic summer) satellite imagery shows the pack ice has not been too bad. “We’re very optimistic that we’ll get over the wreck site with the ship,” Mr. Shears said.

But a shift in winds or a sudden drop in temperature can change things in a hurry, as Shackleton learned the hard way. Should the ice make reaching the wreck site impossible, the expedition has an audacious Plan B. It involves using two helicopters to dispatch equipment and technicians to a drifting ice floe, where they will drill a three-foot-wide hole and launch the submersibles from there.

Lasse Rabenstein, the expedition’s chief scientist, and other sea-ice experts on board would have to choose a floe that can safely support the crew and equipment. But there is another wrinkle, Dr. Rabenstein said. Because it would take a few days to set up a camp on the floe, the task for him and others would be to choose one “so that two days later we are over the wreck site,” Dr. Rabenstein said. “And that’s a most delicate question.”

A previous expedition three years ago ended in failure when an older-technology submersible was lost before technicians could determine whether it had located the wreck. The newer ones will be connected to the surface by a fiber-optic cable that can deliver images and data in real time.

Built in Norway of massive timbers, powered by both steam and sail, Endurance was designed to withstand the extreme pressures of maneuvering through pack ice.

Shackleton set sail in late 1914 with a crew of 27 men, bound for Vahsel Bay on the eastern side of the Weddell Sea. The plan was for Shackleton and a small party to journey across the vast Antarctic ice sheet to the South Pole, as Amundsen had been the first to do in 1911, but then keep going, to the Ross Sea on the other side of the continent.

They never made it to the starting point. In early 1915, about 100 miles from the bay, the Endurance became stuck in the Weddell’s drifting pack ice. Shackleton and his crew watched for months as the ship suffered from the pressure of the ice building up around it. The crew eventually decamped to the ice and emptied Endurance of food and stores and almost everything else, including three open lifeboats, before it sank in November.

The rest of the story is the stuff of legend. The following April, as the ice broke up, all 28 men sailed in the lifeboats to Elephant Island, little more than a rocky outcropping north of the Antarctic Peninsula. From there Shackleton, Worsley and four others, enduring freezing weather and rough seas, sailed one of the 22-foot boats 800 miles to the nearest inhabited island, South Georgia.

It was an extraordinary feat of sailing, one that was immediately followed by an extraordinary feat of mountaineering, in which Shackleton and two others made the first crossing of the island’s peaks and glaciers to reach a whaling station on the opposite side. From there he organized rescues of the other men, who were picked up, alive, within months.

“There are a lot of people for whom the story is familiar,” said Donald Lamont, chairman of the Falklands Maritime Heritage Trust, which organized the expedition. “But also a lot of people globally who don’t know the story at all.” So the expedition team includes digital media specialists who will chronicle the search via online streaming, and if the wreck is found, the images and data gathered from the site could become the basis of museum exhibitions.

“It’s a springboard to the human stories of the people who went down there,” Mr. Lamont said. (A former governor of the Falkland Islands, he won’t be on the ship. “I very happily sit in the warmth and comfort of the United Kingdom and say, ‘Farewell and good luck.’”)

Even if the wreck isn’t found, the expedition should help scientists better understand the ice of the Weddell Sea, and how it is changing as the planet warms because of emissions of greenhouse gases.

Among the scientists on board will be Stefanie Arndt, a sea-ice researcher from the Alfred Wegener Institute in Germany. Dr. Arndt took part in the Mosaic scientific expedition of 2019-20, in which an icebreaker drifted with the ice across the Arctic Ocean. But her specialty is actually Antarctic ice, so she jumped at the chance to join this one.

Dr. Arndt will be taking samples and studying the properties of the sea ice, which are affected in part by the snow that falls on it. Unlike Arctic sea ice, which has declined in seasonal extent over decades as the Earth has warmed, sea ice extent around Antarctica has remained relatively constant. Dr. Arndt will be looking for signs that possible long-term changes are beginning.

But she is also looking forward to the search for the Endurance. “This is a really huge thing,” she said. “And for me, it’s really special. The first book I read about Antarctica was one about Shackleton’s expedition. This was for me the kickoff into polar science.”