He achieved worldwide recognition in the climbing world in 1992 when he climbed the East Face of Great Trango Tower in Karakoram, Pakistan, with Xaver Bongard. As a lightweight, two man team, they were the first to climb the largest rock face involving big wall climbing of Great Trango Tower to its summit and make it down alive. The Grand Voyage ascends the 1350 metre vertical and overhanging rock wall of Great Trango to the East Summit of Great Trango Tower at 6231 metres. Over 2000 metres of climbing is involved from the Dungee Glacier. Along with the Norwegian Pillar on the same face, the routes have been noted as "perhaps the hardest big-wall climbs in the world". The 1992 new route required 15 days and nights to climb and three days to descend, using portaledges designed and constructed by Middendorf in his outdoor equipment company
Equipment maker
Middendorf, a Stanford-trained mechanical engineer, founded a company, A5 Adventures Inc., in 1986 to design and manufacture portaledges. A portaledge failure during a climb of Half Dome nearly led to the death of Middendorf and his companions Steve Bosque and Mike Corbett, and Middendorf was interested in better designs. A5 portaledges were made of highly weatherproof fabrics and were engineered to be structurally strong and stable; they were the first ones that could withstand the severe weather of high alpine regions, including the Himalayas and Karakoram. A5 went on to design and manufacture a variety of big-wall climbing gear, including aiders, slings, haul bags and packs, climbing protection hardware, and other items. A5 Adventures Inc. was acquired by The North Face in 1996, where he worked as a Senior Product Manager for several years and continued manufacturing the equipment under its "A5" brand. His A5 portaledge designs were universally copied by other manufacturers and became the standard portaledge design for the next 20 years. In 2017, Middendorf, while working as a high school teacher in Tasmania, began tinkering with portaledge designs again, and between 2017-2020, designed significant advances and a whole new standard of portaledge technology with the advent of his D4 designs. See bigwallgear.com for details.
