Andrew Comyn "Sandy" Irvine (8 April 1902 – 8 or 9 June 1924) was an English mountaineer who took part in the 1924 British Everest Expedition, the third British expedition to the world's highest (8,848 m) mountain, Mount Everest.

While attempting the first ascent of Mount Everest, he and his climbing partner George Mallory disappeared somewhere high on the mountain's northeast ridge. The pair were last seen alive a few hundred metres from the summit, and it is unknown whether one or both of them reached the summit before they perished. Mallory's body was found in 1999, but Irvine's body has never been found.

Irvine was born in Birkenhead, Cheshire, one of six children of historian William Fergusson Irvine (1869–1962) and Lilian Davies-Colley (1870–1950).^[1][2] His father's family had Scottish and Welsh roots, while his mother was from an old Cheshire family. He was a cousin of journalist and writer Lyn Irvine, and also of pioneering female surgeon Eleanor Davies Colley and of political activist Harriet Shaw Weaver.

He was educated at Birkenhead School and Shrewsbury School,^[3] where he demonstrated a natural engineering acumen, able to improvise fixes or improvements to almost anything mechanical. During the First World War, he created a small stir at the War Office by sending them a design for a synchronisation gear to allow a machine gun to fire from a propeller-driven aeroplane through the propeller without damaging its blades, and also a design for a gyroscopic stabiliser for aircraft.^[4]

He was also a keen sportsman and particularly excelled at rowing. His prodigious ability as a rower made him a star of the 1919 'Peace Regatta' at Henley with the Royal Shrewsbury School Boat Club,^[5] and propelled him to Merton College, Oxford, to study engineering. At Oxford, he joined the Oxford University Mountaineering Club, and was also a member of the Oxford crew for the Oxford and Cambridge Boat Race in 1922 and a member of the winning crew in 1923,^[3] the only time Oxford won between 1913 and 1937.

Irvine had an affair with a former chorus girl named Marjory Agnes Standish Summers (née Thompson). Marjory was married to the steel magnate Henry Hall Summers and was 33 years younger than her husband. Summers was one of the sons of founder John Summers, of John Summers & Sons, a steel company. While Irvine was on Everest, Henry began divorce proceedings against Marjory.^[6][7]

In 1923, Irvine took part in the Merton College Arctic Expedition to Spitsbergen,^[3] where he excelled on every front. The expedition's leader, Noel Odell, and he discovered that they had met before, in 1919 on Foel Grach, a 3,000-foot-high Welsh mountain, when Irvine had ridden his motorcycle to the top and surprised Odell and his wife Mona, who had climbed it on foot.^[8] Subsequently, on Odell's recommendation, Irvine was invited to join the forthcoming third British Mount Everest expedition on the grounds that he might be the "superman" that the expedition felt it needed. He was at the time still a 21-year-old undergraduate student.

Irvine set sail for the Himalaya from Liverpool on board SS California on 29 February 1924,^[9] along with three other members of the expedition, including George Mallory. Mallory later wrote home to his wife that Irvine "could be relied on for anything except perhaps conversation".

During the expedition, he made major and crucial innovations to the expedition's professionally designed oxygen sets, radically improving their functionality, lightness, and strength. He also maintained the expedition's cameras, camp beds, primus stoves, and many other devices. He was universally popular, and respected by his older colleagues for his ingenuity, companionability, and unstinting hard work.

The expedition made two unsuccessful attempts on the summit in early June, and time remained for one more before the heavy snowfall that came with the summer monsoon would make climbing too dangerous. This last chance fell to the expedition's most experienced climber, George Mallory. To the surprise of other expedition members, Mallory chose the 22-year-old inexperienced Irvine above the older, more seasoned climber, Noel Odell. Irvine's proficiency with the oxygen equipment was obviously a major factor in Mallory's decision, but some debate has occurred ever since about the precise reasons for his choice.^[10]

Mallory and Irvine began their ascent on 6 June, and by the end of the next day, the pair had established a final two-man camp at 8,168 m (26,800 ft), from which to make their final push on the summit. What time they departed on 8 June is unknown, but circumstantial evidence suggests that they did not have the smooth, early start that Mallory had hoped for.^[10]

Odell, who was acting in a supporting role, reported seeing them at 12:50 pm—much later than expected—ascending what he believed was the Second Step of the northeast ridge and "going strongly for the top",^[11] although in the years that followed, exactly which of the Three Steps Odell had sighted the pair climbing became extremely controversial.

Whether Mallory and Irvine reached the summit before they died has been the subject of debate. Upon hearing of Irvine and Mallory's disappearance, a family friend wrote: "One cannot imagine Sandy content to float placidly in some quiet back-water, he was the sort that must struggle against the current and, if need be, go down foaming in full body over the precipice".^[12] Arnold Lunn, one of Irvine's friends, wrote: "Irvine did not live long, but he lived well. Into his short life he crowded an overflowing measure of activity which found its climax in his last wonderful year, a year during which he rowed in the winning Oxford boat, explored Spitsbergen, fell in love with skiing, and – perhaps – conquered Everest. The English love rather to live well than to live long".^{[citation needed]}

In May 1999, Mallory's body was found at 8,155 metres (26,755 ft) by the Mallory and Irvine Research Expedition, in a funnel-shaped basin on the "8,200 m Snow Terrace", some 300 metres (980 ft) below and about 100 metres (330 ft) horizontal to the location of the ice axe found in 1933.^[19][20][21] The remains of a rope still encircled his waist, which exhibited serious haemorrhaging, indicative of a strong rope-jerk injury, and strongly suggesting that at some point either Mallory or Irvine fell while they were still roped together. Mallory was found with relatively few major injuries, compared to a number of modern climbers who had fallen the full distance from the northeast ridge and who were found to have sustained numerous fractures, suggesting he had survived this initial fall, and suffered a further accident. A golf ball-sized puncture wound in his forehead seemed to be the likely cause of death,^[22] and could have been inflicted by an ice axe. It has subsequently been speculated that an injured Mallory was descending in a self-arrest "glissade", sliding down the slope while dragging his ice axe in the snow to control the speed of his descent, and that his ice axe may have struck a rock and bounced off, striking him fatally.

A search of the body revealed two pieces of circumstantial evidence that suggested that Mallory might have possibly reached the summit:

• Firstly, Mallory's daughter had always said that Mallory carried a photograph of his wife on his person with the intention of leaving it on the summit when he reached it,^[23] and no such photograph was found on the body. Given the excellent state of preservation of the body and the artifacts recovered from it, the absence of the photograph suggests that he may have reached the summit and deposited it there.
• Secondly, Mallory's snow goggles were in his pocket when the body was found, indicating that he died at night, that he and Irvine had made a push for the summit and were descending very late in the day. Given their known departure time and movements, had they not made the summit, it is unlikely that they would have still been out by nightfall.

The search revealed no trace of the two Vest Pocket Kodak cameras^[23] that Irvine's diaries said he and Mallory were carrying, leading to speculation that one or more of the cameras might yet be found with Irvine's body. Experts from Kodak have said that there is a good chance that the cameras' black-and-white film could be developed to produce "printable images", due to its chemical nature and its likely preservation in subzero temperatures.^[24] Such images could illuminate the fate of Mallory and Irvine. Irvine's body has never been found.

In 2010, a team informally dubbed the Andrew Irvine Search Committee and led by Holzel searched for Irvine in a computer-assembled montage of aerial photographs taken in 1984 by Brad Washburn and the National Geographic Society. They identified a possible object at about 8,425 metres (27,641 ft), less than 100 metres (330 ft) from the ice-axe location, consistent with a body lying in a slot of rock, feet pointing toward the summit, just as Xu described his sighting.^[32]

A new expedition organised by Holzel was due to explore the upper slopes of Everest in December 2011, presumably with a view to determining the nature of this possible object.^[32] By conducting the expedition in winter, it was hoped that there would be much less snow on the upper slopes, increasing the chances of finding Irvine, as well as the camera that it is hoped will be with him.^[33]

In 2019, Mark Synnott led a party that investigated the 'crevice' identified by Holzel as the potential resting place of Irvine, but discovered that it was merely an optical illusion.^[34] Synnott later reported on the possibility that the 1975 Chinese expedition may have found both Irvine and the camera.^[35]

The deaths of Mallory and Irvine inspired Baku Yumemakura to author the 1998 novel The Summit of the Gods, which in turn inspired a manga series of the same name published from 2000-2003, which was adapted into a French-made anime-influenced animation film, Le Sommet des Dieux, that was released in 2021.

• List of Oxford University Boat Race crews
• List of people who died climbing Mount Everest
• List of people who disappeared
• The Wildest Dream