A view from above of the Ust-Kamenogorsk hydroelectric power station can decorate the covers of the coolest glossy magazines. In the gorge, squeezed by rocks, there is a forty-meter dam with a dammed turbine hall building. In the upper pool – Ust-Kamenogorsk reservoir, repeating the historical channel of the Irtysh. The very fact that the man-made lintel holds a reservoir 71 km long and with a volume of 650 million cubic meters, you see, sounds impressive. The water mass presses on the concrete and, exactly according to the saying, looks for how to pave the way for itself. In turn, experts are looking for technology and applying knowledge to subordinate the power of the river exclusively to peaceful purposes. For this they have a special underground gallery – poterna. Figuratively speaking – the path in the depths «of the soul» of the dam.

If technogenic tourism operated at hydroelectric power stations, poterna would have long ago become a magnet for diggers and stalkers. However, station – sensitive facility. Therefore, the massive steel door to the dungeon was opened here only for the «Kazpravda» correspondent.

…A dark corridor with a path of lamps along the ceiling, booming sounds, the noise of the flow, as if a stream was running nearby… My guide – engineer of the group for the operation of buildings and structures of hydroelectric power stations Gleb Shalaev. He immediately provides data that journalists are usually interested in: the total length of the hydroelectric complex is 461 m, the dam is – 391 m, the surface is about 30 meters shorter due to indentations from the blind part. The turbine hall is located at level 311 according to the Baltic height system, below – mine premises for servicing hydraulic units – 307th and 300th marks.

–And we, – says Gleb, – are even lower. We are at the bottom of the Irtysh. You could say we are walking along the river bottom. Lowest mark – 286.

I take a closer look: the gallery really goes up and down a little. Archival information has been preserved about how in the war year of 1943 the GESstroy members carried out preparations for the future dam: they manually removed more than 67 thousand cubic meters of soil and rock, blew up and removed 6 thousand cubic meters of ice, prepared and lowered 12 thousand cubic meters of ripples to the bottom, loaded 20 thousand cubic meters of stone into the lintel. 80% of the GES construction team consisted of women. I would like to believe that someday in Ust-Kamenogorsk they will pay tribute to the memory of these great workers – they will erect a monument or obelisk.

The hum intensifies. The engineer points up: a pressure pipeline is laid directly above the heads, through which water is supplied to the turbine unit. Every second a stream of hundreds of cubic meters rushes over me! I can imagine what kind of selfie session diggers would have in this brutal setting. I notice a large black telephone on the wall – in old films the characters approached these people, picked up the phone and said importantly: «At the phone».

–Now these means of communication are – a rarity, a historical detail, – Gleb notes. – That’s why we don’t remove it. By the way, it is in working order and serves for operational communication with the duty officer.

Large, noticeable T and TS designations, for example, T50, TS 25, are applied on the walls throughout the entire posture. I look closely – I don’t notice anything, I touch it with my palm – the wall is wet. My guide explains: this way the gallery is marked with temperature seams, or, more simply put, cracks. If you talk to builders, they generally consider concrete to be a living material: it takes a hundred years to gain strength, produces sediment, «breathes» when weather conditions change. That is, it is a plastic material. Each concrete dam must have seams that allow it to relieve stress in the hydraulic structure. Their parameters are – hundredths of a millimeter, the maximum permissible value is – 0.1 mm. Where can you see such cobwebs with the naked eye!

All these T and TS – under the constant supervision of specialists and automation. Gleb shows a miniature device installed just to monitor the cracks. It is based on the principles of electrical measurement. Sensors can record changes of almost microns.

The further we go down the tunnel, the louder the sound of drops and murmurings. Water flows through the gutters along the walls, the air is humid. The atmosphere of a mysterious podze-melje. Gleb assures with a smile: this is how it should be, and leads to the device, as if from the magical class of teacher Stem in Hogwarts.

–This is a slot gauge drip, – explains the engineer. – All drips are indicated, for example, KP – this is a drip of a right-bank dam, KL – a drip of a left-bank dam. The water will always find a place where it can run, there are pockets where it is gradually filtered, and the instruments show them. We are watching them.

Equipment readings are regularly recorded in observation logs. Specialists have been running them since the station was launched in the 1950s; here you can find «ledgers» that are 50–60 years old. Such databases are invaluable in the implementation of artificial intelligence.

– Beware! – warns the specialist when I almost run into a strange pillar in the middle of the gallery.

It turned out that under my feet – a piezometer, expensive equipment that measures the pressure and water level in the foundation. According to Gleb, their readings can change for various reasons, for example, when there are temperature changes or a change in the number of operating hydraulic units. It’s normal.

Nearby is another device located in a special well to monitor the same parameters – level, pressure, temperature, flow. There are criterion values for them, including «green», which cannot be exceeded. Many drainage wells are 30–40 years old, they are already the history of hydroelectric power plants. In general, the equipment allows you to get a picture of how the dam resists the pressure of the river.

–If the numbers were rising, we would sound the alarm, – says the engineer. – But they are not growing.

I look at the numerous instruments and understand: there is no question of secrets in the underground tunnel. All the clothes are – under «the hood» for hydroelectric power station specialists. They see any changes, and in micro-shares. For example, tilt gauges can record a deviation of one to half a degree from the dam relative to the vertical.

–The monitor displays data on all the main criteria, – says Gleb. – It would seem that you don’t have to leave the office. But we have a service that, as before, continues to take measurements manually. They walk and check with a caliper and a stopwatch. Control is never superfluous.

The excursion into the depths «of the soul» of the gas dam ends. The engineer accompanies me to the checkpoint and invites me to come to the station, for example, in two or three years. Now they are starting a project to introduce an automated diagnostic and control system, or predictive diagnostics. Including using 3D models. The program will reflect parameters such as stress in concrete, temperature, deformation.

–Perhaps we will be the first in Kazakhstan where such a system will be introduced, – the specialist promises. – Now everyone is interested in seeing historical mechanisms, but in thirty years the same rarity will become machines and our programs.

Galina Vologodskaya («Kazakhstanskaya Pravda»)