Roald Amundsen and the 1925 North Pole Expedition

6/12/2006 • Aviation History

To the six aviators stranded on the Arctic ice, the future looked bleak but not hopeless. Engine trouble had forced their pair of Dornier-Wal flying boats to put down on the shifting ice. With makeshift tools and grim determination, the men not only had to fix the engines but also had to stave off the drifting ice floes that threatened to crush their frail craft, and prepare a runway across the rough pack.

The 1925 expedition to fly over the North Pole was led by renowned Norwegian polar explorer Roald Amundsen. Amundsen had gained international fame two decades earlier when he had searched for the elusive Northwest Passage from Baffin Bay and Lancaster Sound through the maze of islands and straits of the Canadian Arctic aboard the ship Gjöa.

In December 1911, Amundsen and his party became the first to trek to the South Pole. Always on the prowl for more adventure; Amundsen purchased a Farman biplane in 1914, intending to mount skis on the craft and use it to fly over polar obstacles. World War I ended that endeavor, but the explorer continued to dream of flying over the great ice cap.

Amundsen purchased a Junkers J-13 monoplane in 1922, satisfied that the craft’s aluminum shell would withstand the rigors of the Arctic clime. Unfortunately, the airplane crashed during a practice flight over Pennsylvania. Amundsen scraped together enough cash to purchase another just in time for his expedition across the Arctic coasts of Europe and Asia to reach Nome, Alaska, aboard the sailing ship Maud. Neither the Junkers nor a small Curtiss Oriole biplane loaned by the Curtiss factory survived much beyond the opening leg of the journey.

Still convinced that the airplane was the best machine for polar exploration, Amundsen sought help from the Norsk Luftseiladsforeningen, a Norwegian air club. The club enthusiastically promised what aid it could, but Amundsen was still sorely lacking funds. He traveled to New York in 1924, hoping a lecture tour would provide some of the necessary monies. but he was unprepared for the chance phone call he received. Lincoln Ellsworth, the son of a multimillionaire, promised him $85,400 for a joint flight over the North Pole.

Ellsworth had attended both Columbia and Yale universities and had been trained as an aviator during World War 1. Illness kept him out of combat, but Ellsworth had met Amundsen while stationed in France and briefly discussed polar exploration by air with him. The Norwegian quickly forgot the encounter, but the seed of an idea had been planted in the American’s mind. After the war, Ellsworth led a geological survey to the Peruvian Andes for Johns Hopkins University. When he returned to New York in 1923 and discovered that Amundsen was in the city, Ellsworth immediately telephoned the famous explorer. ‘I met you several years ago in France, during the war,’ Ellsworth said. ‘I am an amateur interested in exploration, and I might be able to supply some money for another expedition.’ An excited Amundsen immediately invited him to his room.

With Ellsworth’s money in hand, Amundsen telegraphed his pilot, Norwegian naval Lieutenant Hjalmar Riiser-Larsen, with instructions to purchase a pair of Dornier-Wal flying boats. Both men had decided on the Dorniers for several reasons. The aircraft sported twin Rolls-Royce 365-hp water-cooled Eagle engines mounted on top of the wing structure, one facing forward, the other aft. The location and power produced by the engines ‘make it possible for a weight equal to that of the machine to be lifted,’ noted Riiser-Larsen. The Dorniers also featured a duralumin flat-bottomed fuselage with projecting sponsons, or flynders to the Norwegians, which helped to stabilize the craft in the water. The flynders would tend to be less fragile in icy seas than wingmounted stabilizer floats.

The Dornier-Wals were being built in Pisa, Italy, by the firm of S.A.I di Construzioni Mecchaniche i Marina di Pisa because German manufacture of such aircraft was prohibited by the Versailles Treaty. Rather than ship the flying boats halfway around the world to an Alaskan starting point, Amundsen planned to begin his expedition from King’s Bay on Spitsbergen, only 750 miles from the North Pole.

Amundsen and Ellsworth quickly began to make preparations for their flight. The Dorniers, simply named N24 and N25 after Amundsen and Lincoln Ellsworth in 1924. Ellsworth first met the Norwegian explorer in 1918. Five years later, he offered to finance a joint polar expedition.

their registry numbers, were being crated and shipped to Tromso, Norway. The two men assembled their support staff and aircrews. N24 was to be piloted by Norwegian naval Lieutenant Lief Dietrichson, with Ellsworth and mechanic Oskar Omdal aboard. Riiser-Larsen would fly N25, with Amundsen and a German mechanic, Ludwig (named Karl in some sources) Feucht, as crewmen.

Waiting at Tromsö, about 300 miles to the southeast, was the Norwegian naval transport Fram and the motor ship Hobby, which would transport survival gear, including a light sled and a canvas boat as well as spare parts. The Dorniers, crated in sections, were carefully lifted and lashed to the deck of Hobby. ‘Hobby had already given up trying to be a boat,’ Amundsen wrote later. ‘She looked like a mass of gigantic cases which was wandering along over the sea.’

When the ships departed in early April, high winds and ice squalls battered them on the four-day voyage from Tromso to King’s Bay. The vessels became separated, and Amundsen feared that the heavily burdened Hobby would founder in the crashing waves. Seasickness took its toll, even though many of the crew were experienced sailors. Fram steamed into frozen King’s Bay on April 12, 1925, anchoring at the rim of the ice sheet covering the bay. A short time later, to the cheers of all, Hobby hove into view. A Norwegian ship preceded them and broke a passage through the ice for Fram and Hobby to eventually tie up at quayside. Booms began to lower gear and airplane parts to the icy surface of the bay.

Amundsen, Ellsworth and the pilots believed that the flying boats were capable of taking off fully loaded from the ice-covered bay. Snow and ice would actually offer less resistance than a takeoff from open water. Once the planes were airborne, they would proceed to the North Pole, verify their location, then return to Spitsbergen. Although the planes carried extra fuel, they would not both be able to make the round trip. There was little doubt that on the return trip the Dorniers would have to set down on the ice, where the tanks of one plane would be emptied into the other, and the emptied flying boat would then have to be left behind.

The aviators chose their gear carefully because of weight limitations. A lightweight sled would provide some movement of equipment if they were forced down onto the ice. A canvas boat would allow the crews to cross patches of open water in the ice pack. There was the usual assortment of guns, tents and compact stoves. Food consisted of salted beef, chocolate, biscuits, dried milk and malted-milk tablets. A camera was brought along to verify the expedition’s findings and record events.

As the planes were assembled, the polar summer crept ever closer. Although the bay’s ice sheet remained relatively solid, the weight of the Dorniers caused the surface to sag and buckle, forcing water up around the hulls, which could cause additional drag on takeoff. The Rolls-Royce engines functioned perfectly, but Amundsen resisted any attempt to take the planes skyward on a practice flight. He reasoned that a single takeoff from the ice was perilous enough, and he did not want to jeopardize his frail planes with a practice effort. Instead, trial runs consisted only of taxiing.

Several weeks passed with storms or gusty winds prohibiting the flight. Finally, on May 21, the expedition’s meteorologist proclaimed the weather would clear for takeoff. The engines were warmed up and last-minute adjustments were made. Since the Dorniers had open cockpits, the fliers wore heavy flying clothes, thick underwear of wool and leather and capacious canvas boots padded with senna grass.

At 5:10 p.m., N25 with Riiser-Larsen at the controls roared across ice-covered King’s Bay. The additional weight of extra fuel drums and equipment caused the icy sheet to bend, and water surged up, increasing the drag on the plane. As the Dornier clawed slowly skyward, the hulk of King’s Bay Glacier loomed in its path. An emotionless Riiser-Larsen had a firm hand on the stick. ‘Had he been seated at the breakfast table he could scarcely have looked less concerned,’ noted Amundsen. With its engines roaring at 2,000 rpm, N25 climbed above the glacier.

N24, meanwhile, swerved along the path N25 had created on the ice and eased into position to start its run. The crew had to manhandle the flying boat for proper positioning, and they had to strip off some of their outer clothing as their bodies heated from exertion. Just as the Dornier was about to start its takeoff run, pilot Dietrichson detected a problem. ‘Above the humming of the engine I suddenly heard a noise which sounded to me as if a row of rivets in the bottom had sprung,’ he later wrote. As the crew hastened to put on their heavy flight suits, the ice began to sink under the plane’s weight. A foot of water closed in against the hull and began to stream into the fuselage through a broken seam in the metal skin. Dietrichson chose to continue the flight, thinking that the ruptured seam would not prove a problem when landing on the solid ice of the pole and that immediate repairs would have meant an aborted mission. In moments, N24, with its unwanted cargo of water, sped across the ice and soared into the cold air.

The two airplanes of the Amundsen-Ellsworth expedition cruised at 2,000 feet. They passed over the west coast of Spitsbergen, leaving behind Cape Mitre and the Amsterdam Islands. Fog boiled above the sea, forcing the planes up to 3,000 feet. A little after 8 p.m., the fog thinned. ‘And there below us and in front of us lay the great shining plain of the notorious pack ice. How many misfortunes have you been responsible for during the passage of years, you vast `Whiteness’?’ mused Amundsen.

After several hours’ flying above the frozen mass, the dazzling whiteness forced the fliers not only to don snow goggles but also to fit special blinders over their windscreens. To escape the glare, the planes climbed to their maximum ceiling of 10,000 feet. The aviators could discern nothing from that altitude. To conserve fuel, the Dorniers returned to 3,000 feet, where the engines ran more smoothly.

Things seemed to be fine aboard N25, but pilot Dietrichson on N24 was concerned. The temperature indicator for his engines had begun to rise while they were still over the fog bank, and nothing he tried seemed to improve the situation.

The gauge soared to 229 degrees Fahrenheit and burst. Incredibly, the Rolls-Royce engines continued to hum without a hitch.

At about 5 a.m. on May 22, Feucht informed Amundsen that that N25‘s fuel level had dropped below half capacity. The Norwegian determined that it would be a good time to set down on the ice, fill the tanks of both planes from the reserve drums, then abandon the empty barrels and continue on to the Pole. Once their goal had been achieved, the planes would return on the fuel remaining in their tanks. If they ran short of fuel, they would land on the ice, pool the remaining fuel in one plane and abandon the other. Then, with extra human cargo, a single Dornier would continue to Spitsbergen.

Riiser-Larsen began to descend in slow spirals toward the ice pack, hoping to find a smooth landing area. The trio debated setting down on the water but were concerned that ice freezing around the plane could crush the hull. The ice pack appeared deceptively smooth from their altitude. Once they began descending, however, they realized the surface was a tortuous maze of pressure ridges piled into mountain-like ice walls. As the Dornier continued to descend, the aft engine suddenly sputtered and died.

Amundsen spotted a distant ice dam that promised a relatively smooth landing, but with the loss of power and the extra weight aboard the machine, he knew it would be impossible to reach. The crew decided on a slush-choked arm of water dotted with icebergs leading toward the dam. The arm was wide enough to accommodate the Dorniers wingspan, but with icebergs flanking the passage there was no room for error.

The Dornier slapped down into the slush and began to zigzag. ‘We were passing a small iceberg on the right,’ recalled Amundsen. ‘The machine turned to the left with the result that the wings stroked the top of the iceberg and loose snow was whirled in the air.’ With thick slush spraying about, N25 eased to a stop at the end of the arm, its nose pushing up against yet another iceberg.

Dietrichson, aboard N24, saw the after engine of N25 quit and watched the plane descend to the slush. He circled as the crew of N25 jumped out of their plane and began kicking and hacking at the ice to keep it from freezing around the hull. Dietrichson realized there was not enough room for both machines in the arm, so he slowly descended to a watery lake that appeared to be near N25. As he throttled back, N24‘s aft engine also quit. Fortunately, the landing was smooth, and he taxied across the surface and anchored his plane to a large ice floe.

Ellsworth and Dietrichson searched for N25 while mechanic Omdahl examined the engines. Compression in the aft engine had weakened considerably, and part of the exhaust system had burned out. Repairs, if possible, would take a long time. To make matters worse, sea water was leaking into the hull where the rivets had torn loose during takeoff.

It was noon before Dietrichson and Ellsworth finally spotted N25 from atop a high ice hummock. The plane lay about three-quarters of a mile away with her nose sticking into the air at a 45-degree angle. Ellsworth took meteorological readings and found they were about 150 miles short of the Pole and had drifted off course to 22 degrees west.

The pair unlimbered their canvas boat and had a light lunch before setting out for N25. Three-foot-deep snowdrifts slowed their progress on the ice, as did patches of slushy water that had to be negotiated with the boat. Even worse were the jagged ice ridges that had been thrust upward when shifting sheets of ice collided. Dietrichson and Ellsworth searched for an easier route but only found more ice ridges. After several hours of incredible exertion, they gave up and returned to N24 thoroughly exhausted. They hoisted a Norwegian flag atop the highest hummock, pitched their light tent next to their plane and crawled inside to rest.

Amundsen and his crew, meanwhile, were busy trying to stave off ice closing in around N25‘s hull. Extra room in the plane had been devoted to drums of fuel, so ice tools and even radio equipment had had to be left behind. Using knives, an ax and an ice anchor, the trio finally managed to chip enough ice away so their plane could float freely for several hours. Though exhausted, the men fruitlessly scanned their surroundings for N24 before finally taking refuge in the Dorniers compartments.

Snow squalls buffeted the area during the night, and movement of the ice sheets brought the two planes closer together. The morning of May 23 was clear and bright. Amundsen climbed to a wing of the Dornier and scrutinized the monotonous horizon. Suddenly he noticed the flag, tent and N24 itself. He called for Riiser-Larsen to start waving their own Norwegian flag, and within moments contact was established with Ellsworth and crew. It was decided, via Morse code signals with the flags, that each crew would work on their own plane for the rest of the day.

Omdahl poured buckets of warm oil on the valves and placed camp stoves under the engine gondola in a vain attempt to start N-24’s aft Rolls-Royce. Amundsen, Riiser-Larsen and Feucht chopped and slashed at the ice encroaching on N25. Slowly they began to fashion a ramp onto which they hoped to maneuver N25 away from the clutches of the slushy pool. For the next two days, both crews tried to prepare their respective planes for takeoff.

May 26 brought startling changes to the ice pack. Shifting had occurred throughout the night, so by morning the two Dorniers had drifted within easy visual contact with each other. At 3 p.m., with temperatures at 14 F, Ellsworth signaled that he, Dietrichson and Omdahl would try to cross to N25. Within 20 minutes, the trio had worked their way to within 200 yards of a mundsen. Riiser-Larsen took N25‘s canvas boat to meet them.

Ellsworth’s crew had marched too close to a patch of thin ice. Suddenly, Dietrichson crashed through into the freezing water. Fortunately, the men were carrying their skis rather than wearing them, but the pilot’s 80-pound backpack was pulling him down. At Dietrichson’s cry, Omdahl turned and also plunged through the ice. Both men scrambled at the surface, only to have the thin ice break under their hands. Dietrichson managed to get his rifle on top of the flimsy sheet.

When the two men crashed through the ice, Ellsworth managed to jump sideways as the sheet sagged beneath him. Finding a solid spot on some old ice, he reached his ski toward Dietrichson and managed to pull him partially onto the firmer ice. Omdahl cried out, ‘I’m gone! I’m gone!’ as his head began to submerge. The American managed to hook the strap of the mechanic’s backpack and hold on until Dietrichson could crawl over to help. ‘It took all the remaining strength of the two of us to drag Omdahl up onto the old ice,’ Ellsworth later wrote. The three managed to struggle to Riiser-Larsen’s boat, and he quickly transported them to the relative comfort and warmth of N25.

The six men decided their best chance of escape from the Arctic ice was to abandon N24 with its disabled engine and work to get N25 aloft. Amundsen’s Dornier, however, was still threatened by the icy slush freezing around the fuselage. Working with their makeshift tools, the party succeeded in freeing N25 and cutting a shallow ramp onto the ice pack. With a nearly superhuman effort, they hauled the Dornier onto the surface of the floe.

Fuel was drained from N24 to N25 while Amundsen and Ellsworth worked on a list of necessities. Any item not needed would be left on the ice. To make sure the food supply would last until they could get airborne, the rations were cut from two pounds per day to three-quarters of a pound.

Even allowing for abandoned equipment, N25 would have to take off with the added weight of more fuel and three more men. Amundsen and Riiser-Larsen reckoned that because there was no open water nearby, they would need at least 500 yards of relatively smooth, hard ice as a runway-and there was nothing smooth about the ice surrounding them. The only alternative was to use their makeshift tools and fashion a path for their plane.

On June 1, after the men had chipped and scraped ice for days to form a firm runway, N25 was ready to fly. The air intake on the aft engine had been repaired, and both Rolls-Royce engines ran smoothly. After manhandling the Dornier through deep, soft snow, the men clambered aboard. No sooner had they begun their takeoff run than the ice path they had so laboriously cut began to sag under the plane, and slushy water splashed against the duralumin skin. Worse still, fog suddenly blanketed the ice floe, forcing them to cancel their takeoff attempt.

For two days, the explorers battled ice threatening to crush the Dornier as they worked to chisel a new runway. On June 2, a second liftoff was aborted when the flying boat broke through the ice of the new runway. By June 4, heavy fog enveloped them and brought a new onslaught of ice pressure. ‘There were pipings and singings all round us as the ice jammed against the machine,’ Amundsen later recalled. To make matters worse, the shifting ice was inexorably heaving a forbidding iceberg which they nicknamed ‘the Sphinx’-in their direction.

Riiser-Larsen reconnoitered the area and discovered a patch of ice roughly 600 square yards that could be leveled as a runway. Unfortunately, it was nearly 1,000 feet from N25. The men began shaping an icy ramp over which they could maneuver their plane toward the patch for a takeoff run. After hours of backbreaking labor, they pushed the Dornier into place between two icebergs that would have to be partially leveled to permit takeoff. But the short Arctic summer was approaching, and daylight hours were becoming warmer. If N25 did not get airborne soon, the drag from the sticky snow on top of the ice would be too great.

Amundsen knew there was nothing to do except shovel the snow aside. He calculated the men would have to create a track more than 1,500 feet long and 40 feet wide. The snow was nearly three feet deep and would have to be shoveled about six yards away from each side of the runway so it would not interfere with the takeoff. Such a task was beyond what the crews could produce on less than half rations, but they knew an effort had to be made before they became progressively weaker.

June 9 through June 11 found the men struggling to level the surface. Suddenly Omdahl shouted, ‘See, this is what we can do instead of shoveling.’ Stupefied, the other crew members watched as the mechanic began to stomp the wet snow into solid patches. Following suit, they began to trample the area into a useable runway. Ice ridges still had to be chipped and removed by hand.

‘On the 14th of June as we laid down our tools I don’t think I exaggerate when I say that, all in all, we had removed 500 tons of ice and snow,’ noted Amundsen. Unfortunately, thawing conditions prevented two more attempts to get airborne. Amundsen worried that the continuing spate of warm, foggy weather would frustrate every takeoff attempt. As their supply of food dwindled, he wrestled with the notion of heading southward on foot; perhaps they could reach solid land in a few weeks. But in their weakened state, they might not be able to cross the broken snow ridges or open leads in the ice in their canvas boat. He finally decided they must wait for proper conditions and attempt another takeoff.

On June 15, with the temperature hovering around 28 F, the Norwegian explorer inspected the runway they had chipped, shoveled and stamped into the snow and ice. The 1,500-foot expanse was relatively smooth and had seemed to firm up a bit in the chill air, but small cracks had developed just in front of N25. And 250 yards down the track, a 7-foot-wide crack threatened to expand and ruin their runway. Beyond that, a 10-foot-wide open lead of water led to another 45-yard plain of stable, flat ice. Amundsen and his crew felt the time to fly was now or never.

By 9:30 p.m., the engines on N25 had been sufficiently warmed up to attempt a liftoff. The six men had unloaded all cargo except for a few bare necessities lest they be forced back onto the ice and, of course, the extra barrels of fuel. With rueful glances at the crippled N24, perched awkwardly on the ice in the distance, they clambered aboard the remaining Dornier.

Riiser-Larsen, in the pilot’s seat, opened the throttle and N25 began to move across the icy plain. With engines roaring at 2,000 rpm, the big Dornier shook and rattled as it scraped over the runway. The ice sheet held firm. Dashing over the 10-foot-wide crack, N25 rushed along the last flat piece of ice. ‘The scraping noise stopped; only the humming of the motor could be heard,’ recalled Amundsen. ‘At last we were in flight.’

Navigator Dietrichson plotted his course southward using magnetic compasses. Within two hours the sun broke through the fog, and the solar compass showed they were exactly on course. Below them, a twisted mass of ice ridges flanked basins of open water choked with icebergs. If engine trouble developed now, there would be no safe place to land.

Heavy, low-lying clouds developed as N25 approached 82 degrees north latitude. Riiser-Larsen hoped to fly below the haze to conserve fuel. At 120 mph, the plane threaded a course through what seemed a forest of icebergs laced with wisps of fog. Clouds, fog and ice blended into a treacherous and indiscernible expanse. The pilot was finally forced to climb above the thick quilting to avoid the ice outcrops.

Hour after hour sped by as N25 clawed its way to safety. Amundsen continuously checked the fuel reserves, noting that the gasoline supply would soon run dangerously low. ‘Suddenly,’ the Norwegian recalled, ‘a big, heavy fog-cloud tore itself away and rose slowly, disclosing a high glittering hilltop. There was scarcely any doubt. It must be Spitsbergen.’

Although N25 was buffeted by strong winds, Riiser-Larsen eased the flying boat toward the choppy waters of Hinlopen Strait. The rest of the crew retreated toward the tail of N25 to allow the nose to lift as high as possible. Waves slammed against the duralumin hull as the plane set down. The pilot, drenched in his open cockpit, fought the controls in the heavy sea. By 8 p.m. on June 16, N25 finally cruised into the relatively calm waters of a small shoal bay.

Like children, the aviators leapt onto the rocks after securing their plane. After a brief meal, they began to gather driftwood for a fire. Riiser-Larsen suddenly straightened as he scanned the horizon.

‘There is a ship!’ he cried.

A small Norwegian seal-hunting cutter sailed across the face of the bay, seemingly oblivious to the anchored plane. With barely a word, the explorers scrambled back aboard N25 and restarted the engines. In moments, they had taxied across the water and eased close to the sealer Sjoliv. Startled sailors gazed in disbelief at the Dornier-Wal bobbing on the waves. The famished men boarded the vessel and were greeted with coffee, cooked seal meat and egg pancakes.

Nils Wollen, Sjoliv‘s captain, reported that rescue ships had plied the seas for weeks in a vain attempt to find the missing aviators. He agreed to tow N25 to King’s Bay. At first the towing went smoothly, but as the night wore on the winds increased and Wollen was forced to anchor in a protected cove. By 11 a.m. on June 17, gale force winds aborted any further attempt at towing the Dornier-Wal. A safe anchorage for the plane was found in Brandy Bay, and by 8 p.m., Sjoliv and its cargo of survivors was finally on the two-day journey to King’s Bay.

The ice in the bay had long since melted, and tiny blue flowers now colored the surrounding hills. Hobby was anchored at quayside, but Amundsen and his companions were surprised to see the Norwegian Coast Guard vessel Heimdahl also secured there. A pair of Hansa-Brandenburg W33 seaplanes rode the bay’s calm waters as well. The ship and the planes had been scouring the polar regions in search of them.

The population of King’s Bay poured onto the docks to welcome the lost aviators. A band struck up the Norwegian national anthem amidst a flurry of toasts and handshakes. Telegraphers at the coaling station and aboard Heimdahl began to tap out the joyful news, and photographs were snapped. The explorers found the clothing they had left behind at the beginning of their expedition was now too large for their emaciated frames.

By June 25, N25 was safely recovered and stored aboard a transport ship for the voyage to Norway. Amundsen, Ellsworth and crew boarded Heimdahl. Four days later they neared Tromso Sound, where they were welcomed by Norwegian cruise ships packed with jubilant crowds. Outside Kristians and, four naval Hansa-Brandenburgs circled overhead in salute. At the Norwegian naval base at Horten they received another ovation.

A reassembled N25 rode the waters near Oslo on July 5. Roald Amundsen, Lincoln Ellsworth and their crew once more clambered aboard the Dornier-Wal to fly the final few miles to the Norwegian capital. ‘Good old N25!’ recalled a tearful Ellsworth. ‘We dropped down into the fjord amid a pandemonium of frantically shrieking river craft and taxied on through the wildly waving and cheering throngs.’ King Haakon of Norway feted the explorers, whom he described as being ‘once dead and returned to life.’

This article was written by Kenneth P. Czech and originally published in Aviation History magazine. For more great articles subscribe to Aviation History magazine today!

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