Ekaterinburg Speleo Club (SGS) (from Sverdlovskaja Gorodskaja Speleosekcija; Свердловская Городская Спелеосекция – СГС), founded in 1961, is a Russian, non-profit speleological organization dedicated to the exploration, research, and conservation of caves. It is based in Ekaterinburg (named Sverdlovsk from 1924 to 1991), the fourth largest city of Russia, in the Middle Urals and on the western edge of Siberia. SGS is most known for the exploration of caves in the northern Sverdlovsk Oblast and high-mountain karst areas of Surxondaryo Region in Uzbekistan, including Boybuloq, the deepest cave in Central Asia and one of the deepest caves in the world.
Early history In summer 1961 three hikers from Ekaterinburg, Jurij Lobanov, Nikolaj Lizunov, and Anatolij Vagapov wanted to cross the Ural Mountain ridge and to raft down the Višera river. On the way, they encountered, near Severouralsk, below a rock overhang, a shaft with a very narrow entrance. They managed to descend into the cave, full of stalactites, and climbed back to the surface with great difficulty. The whole experience persuaded them to turn from hikers to cavers. Soon the first own cave, Svetlaja, in the Northern Ural was discovered and explored. In the autumn of 1961, a team was formed, two substantial caves on the Serga river were discovered and SGS, speleo section of the Sverdlovsk city tourist club established. It was the third speleological organization in the Soviet Union, after cavers from Krasnojarsk and the Crimea.
In 1962 SGS organized a search expedition to the Southern Ural and participated in the first all-Union meeting of speleologists in the Crimea, on the Ai-Petri mountain. In 1964 SGS organized its first caving school, with 160 participants, and in 1965 SGS separated from the city tourist club, obtained its own premises. Till 1968 several expeditions followed every year, to the caves of the Urals and Caucasus, including the extensive Sumgan-Kutuk cave in Bashkiriya National Park. In the 1970s further advancement was hampered by increasingly outdated and cumbersome equipment. Wire ladders were unsuitable for the descent and ascent in vertical sections of ever deeper caves, and the application of the single rope technique lagged behind because of stagnant, slow communication with the West. Cavers had to rely on locally, often even handmade equipment. At the end of the decade, technical problems were solved, SGS teams participated in expeditions to the main focus of Soviet speleology of the time, to the deep caves in the Western Caucasus, in Russia, and in Abkhazia, on Alek and Arabika massifs. They carried equipment, rigged the vertical sections, made cave surveys, discovered new cave branches. But the credits went to the expedition leaders, caving organizations who were there before. It was time to look for new horizons, for new, more pristine caving areas.
Boybuloq After the discovery of the Kievskaja cave on the Kirk Tau plateau in Uzbekistan in 1972, 2340 m a. s. l., by cavers from Kyiv, they later explored it to the depth of 990 m and it was in the years 1977–1978 the deepest cave in the USSR, SGS cavers in the late 1970s started to search for new deep caves in the wider area. In 1980 6 small teams of 4 people were sent to different mountain karst areas of the USSR: to Kazakhstan, to Pamir in Tajikistan, to Turkmenistan, and to Uzbekistan, with modest results. Yet in the same year, Aleksandr Bikbaev from the Institute of Geology of the Ural Scientific Center discovered in geological literature a location with a much better predisposition for very deep caves: massif Ketmen-Chapty in the south-western spurs of Gissar Range in Uzbekistan. The ridges here have an unusual structure: an almost vertical northeastern side and a gentle southwestern one, made of several different rock strata, including a covered limestone layer, 200–350 meters thick. An expedition led by Aleksandr Ryžkov discovered the Zindan cave in May 1981, 3100 m a. s. l., with springs at an altitude of 1300 m. In January 1983 the final depth of 565 m was reached, in the siphon too narrow to dive. Search expeditions later in 1983 were fruitless, and SGS decided to refocus on Arabika massif, participating again in expeditions of other speleological organizations.
In 1985 they resumed the Uzbekistan expeditions, to explore caves the entrances of which were discovered in 1984 by a token SGS team dispatched to Hodja-Gur-Gur-Ata massif. A group of five expedition members was sent to Surkhan-Tau ridge to scout its surface for new caves. On the way, in the village Kurgancha, 1455 m a. s. l., they were told of a cave higher in the mountain, called Boybuloq where a villager from the highest settlement in Uzbekistan, the Dehibolo (boy buloq = rich spring in Uzbek and in Tajiki, the language of the people from the village), went in 1971 and never returned. They followed the stream bed, discovered the cave, with a small entrance at an altitude of 2647 m, and followed its narrow meander which slowly ascended 600 meters in a straight direction, to a height of 90 meters, where it turned down. Below the 27-meter shaft, they discovered human remains, of Mustafaqul Zakirov, a teacher from Dehibolo who visited the cave, four hours away on foot, several times before. In May 1971, in time of severe drought, he departed to the cave with his son and pack donkeys to fetch water. He entered the cave, and after a long crawl, he reached the point close to the first shaft, where his kerosene lamp went out. In the darkness, he missed the direction towards the outside and fell into the abyss. Not only Boybuloq but most other caves in the area are a long sequence of very narrow passages which are difficult to pass, due to the geological situation and the very meager quantities of water present during the cave formation. All the (tiny) streams flowing in different directions in Boybuloq are, apparently, of condensation origin, since the floods the cavers observed on the surface do not reach the lower horizons of the cave.
In the following years further expeditions took place: in 1986 the cave was deepened to −400 m, in 1987 to −500 m and the remains of Zokirov were returned to his family, in 1988 a siphon at −600 m was free-dived and also the barrier on the other side lowered so that the lake could be waded through, and a new branch of the cave was discovered – it continued to −900 m. In 1989 a combined Soviet-Italian team reached the terminal siphon at −1158 m and managed to climb upwards to the point at an elevation of +156 m which gave the total cave depth of 1310 m. In 1990 a Soviet-British team managed to extend the New branch in the cave upwards to +222 m (total depth 1376 m), in 1991 lower levels of the New branch were discovered, and in 1992 an additional chimney upwards was climbed, to +257 m which gave the final cave depth of 1415 m. In 1995 a major collapse in the cave was dug through and in 1998 the diving of the siphon at −560 m was unsuccessful, and the spring Holtan-Čašma, where the water from the terminal cave siphon comes to light, was also dived. The spring is situated 130 m below the terminal cave siphon while the horizontal distance is 7 km, so the connecting passages are most likely submerged. The turmoil which followed the dissolution of the Soviet Union was unfavorable for caving expeditions. SGS cavers returned to Boybuloq only in 2007, and expeditions followed almost every year. New passages in Boybuloq were discovered and explored, yet the cave depth remained the same. Diving in the Holtan-Čašma spring was resumed in 2014, 2015, and 2016, when, at a horizontal distance of 170 m and depth of 18 m, a lenticular grotto was reached, with impassable downwards extending slots.
Hodja-Gur-Gur-Ata There are three ridges in the south-western spurs of the Gissar Range, part of the Tian Shan mountain chain, to the west of Baysun: Ketmen-Chapty, Hodja-Gur-Gur-Ata, and Chul-Bair. They all include limestone strata. When the Zindan cave on Ketmen-Chapty, explored from 1981, ended with an impassable siphon in 1983, SGS refocused on Arabika massif in Abkhazia. In the summer of 1984 a small expedition of 9 people, led by Viktor Dianov, nevertheless departed to Uzbekistan, to try to open up new caves in the sinkholes near Zindan. After several days without success two members of the team, Sergej Matrënin and Igor' Belokrys, asked Dianov to depart to the Hodja-Gur-Gur-Ata ridge on the northeastern horizon, topped at 3700 m by very distinctive precipitous mountain wall, with a karst baseline defined by the Machai spring at an altitude of 1400 m. Just for a few days to check the stories about "terribly deep caves" there, heard on the Baysun bazaar. They got four days. While hitch-hiking from Baysun to Kurgancha, the village below the ridge, fellow travelers who gave them the ride, learned that they are looking for caves. One of them showed with the hand towards the mountain wall: Why to look for them, here they are! Indeed, in the wall, there was a dark hole, which the locals called the Sacred Grotto, and next to it – either the shadows of the rock outcrops or cave entrances. Another villager recounted that somewhere behind the village of Alachapan, on the Chul-Bair ridge, there is a cave, into which a local resident ventured a few years ago and never returned. The two left the second option, which next year led to the discovery of Boybuloq, for later and the next day found the first cave of the Hodja-Gur-Gur-Ata ridge, Sifonnaja (Siphon cave). After the rendezvous with Dianov, the whole team continued to explore the surrounding caves, Berloga (Den cave) and Jubilejnaja (Jubilee cave) till the end of the expedition. In 1985 an SGS expedition led by Aleksander Babanin discovered the largest of the Southern caves on this ridge, Festival'naja. During the expeditions from 1986 to 1988 Emma Lobanova was marking the cave entrances in the up to 400 m high wall below the crest of the ridge, labeling them as R (for a reference point) and a number, for the distance in meters from Katataš, the towering rock outcrop at the far south, divided by 100. Examples are R-10, R-19, and R-21: 1000 (10 times 100) meters from Katataš to the northeast, 1900 and 2100. Marking ended 2400 m from Katataš (R-24). All the Southern caves of the ridge were included, and a few of the Northern group. Unlike many caves in the southern group, those caves required a long climbing route to access, entrances were in the middle of a 400-meter high near-vertical wall. In 1988 cavers from Iževsk managed to explore R-10 (renamed Isetskaja, 1600 m long, 220 m deep), R-19, and R-21. In 1986 Vladimir Čudinov discovered several entrances of the Northern cave group, beyond R 24. Towards the end of the 1980s Soviet Union began to open up, under the leadership of Mihail Gorbačev movements such as perestrojka and especially glasnost led to the establishment of contacts with Western cavers. One such instance involved Tullio Bernabei, a councilor of the Italian Speleological Society and Aleksandr Višnevskij, a senior member of SGS and expedition organizer. SGS expedition in 1989 included 11 Italian cavers and in the summer of 1990, Čudinov led British cavers to the main cave in the Northern group, 160 m above the wall base, which they named Dark Star and explored 2 km far and about 100 m deep. Unlike previous caves in the area, mainly composed of very tight meanders, Dark Star was wider, a large tunnel with lakes. The temperature in the cave was −3 °C and −5 °C deeper inside, so the lakes were frozen and allowed easy advancing. They stopped at a T junction with a large shaft, due to lack of equipment and time.