lifting devices

When people say 'lifting devices', many people immediately imagine a standard winch on a construction site or in a garage. In the mining industry, this idea is the first and most dangerous misconception. Here we are talking about systems on which people’s lives and the continuity of production at depths of hundreds of meters depend. This is not a separate unit, but a complex: drive, brake system, ropes, vessels, control and safety systems. And if you save money somewhere or show negligence, the consequences will be catastrophic. During my practice, I have seen different situations, and now I will try to present them not according to the textbook, but as it actually happens.

What is really hidden behind the term?

In theory, everything is clear: a mechanism for vertical or inclined movement of loads and people in a mine shaft. In practice, the fun begins. It is important to separate devices according to their purpose: main hoists for ore, auxiliary hoists for people and materials, as well as tunneling winches. Structurally, these can be drum lifting machines or with friction pulleys (cylindrical or bicylindrical). The choice depends on the depth, load, intensity of work. They often mistakenly choose “simpler and cheaper”, not taking into account that in a year or two the operating mode will change radically.

One of the key points that many people overlook is not the lifting mechanism itself, but its “brain” - the control system and, critically, braking. Electrodynamic braking, mechanical brakes - everything must be duplicated. I remember an incident at one of the mines in Kuzbass: the failure of the main control system while lowering a cage with people. The emergency brake system worked, everything worked out. But after analysis, it turned out that she was checked “according to schedule”, without a real simulation of an emergency situation. After this, the approach to maintenance changed radically.

It’s also worth mentioning ropes here. This is a separate big topic. Not just a 'cable', but multi-strand steel ropes, their condition, lubrication, regular flaw detection. The life of the rope directly affects the safety of the entire system. A common mistake is extending the service life “a little more,” which is absolutely unacceptable. Changing a rope is a complex operation that requires stopping the lift, but it is an operation on which neither time nor money can be saved.

Experience that comes with problems

There are no ideal projects. Everything is learned through comparison and, unfortunately, often through mistakes. Previously, we worked a lot with equipment where the emphasis was on maximum load capacity with minimum dimensions. It would seem logical for the cramped conditions of the turbine room of the shaft building. But in reality, such “optimization” often led to overheating of engines, increased wear of gearboxes and, as a result, unscheduled downtime. The reliability of the system as a whole was declining.

Gradually it became clear that forlifting devicesin mines, a margin is needed, a 'margin of safety' in all respects: drive power, heat transfer, and service life of brake linings. This is not redundancy, but economic feasibility. Downtime due to a breakdown of the main lift costs tens or even hundreds of times more than the initial savings on a more powerful engine or high-quality gearbox.

An interesting practical point is vibrations. Not those that are visible to the naked eye, but low-frequency ones that arise during the operation of multi-layer winding of a rope on a drum. They can have a destructive effect on the foundation and structure of the building. We encountered this problem at one of the coal mines. The solution was not to strengthen the foundation (although this had to be done), but to change the kinematic scheme and introduce active vibration damping systems. The work is painstaking, but necessary.

Modern trends and 'smart' systems

Nowadays there is more and more talk about digitalization and smart equipment. In the field of hoisting machines, these are primarily predictive monitoring systems. Vibration sensors, bearing temperatures, brake lining thickness, rope condition analysis - all data flows into a single center. This allows you to move from planned preventive maintenance to repair based on actual condition.

But there is a pitfall here. Such systems are often supplied as a 'boxed' solution from European or American manufacturers. They are good, but can poorly adapt to specific, sometimes very difficult, Russian operating conditions: temperature changes, dust, quality of power supply. Therefore, it is important not just to install the system, but to deeply adapt it and train local personnel not just to press buttons, but to understand the logic of its operation and analyze data.

Another trend is variable frequency drives (VFDs). They provide smooth starting and braking, which increases comfort and safety for people in the cage and reduces dynamic loads on the mechanical part. However, their implementation into existing mine electrical networks, which often have problems with voltage quality and higher harmonics, is a separate engineering task. Simply plugging in a VFD instead of the old rotary controller will not work; a comprehensive analysis of the network and, possibly, installation of filters are needed.

Domestic manufacturer: a look from the inside

When talking about equipment for the mining industry, we cannot ignore domestic manufacturers. Take, for example, the LONGI corporation. A company that has been operating in this field since 1993 and has grown into a large enterprise. Their website -https://www.ljmagnet.ru— gives an idea of the scale. Factory in Fushun, area 140,000 m2, more than 1,200 employees, most of whom have higher education. This is a serious base.

What is important is that Shenyang Longji Scientific Electromagnetic Co., Ltd. initially relied on development and production. This is not just an assembly shop. When a manufacturer develops equipment itself, he better understands its pain points and can quickly make changes to the design based on feedback from operating organizations. This is a valuable quality. The annual volume of 4,000 units of equipment indicates mass production, which, as a rule, has a positive effect on the maturity of the technology and quality control.

In contextlifting devicesI'm interested in their comprehensive approach. Mining equipment is often not individual machines, but technological chains. And when one manufacturer can offer not only a winch, but also, relatively speaking, crushers or conveyors, this simplifies the joining of systems and responsibility. Of course, this does not mean that their equipment is ideal for all tasks - this does not happen. But the presence of such a large player in the market, with its own scientific and production base, is a good factor for the industry as a whole.

Final considerations, not conclusions

So what is all this for?Lifting devices- This is the circulatory system of the mine. They cannot be treated as ordinary equipment. Selection, installation, operation and maintenance require not just following instructions, but a deep understanding of the physics of processes, mechanics, electrical systems and, no less important, the specifics of a particular mine.

Even the most advanced system will not work if the personnel are not trained or if saving on “little things” (for example, defectoscopy of ropes) jeopardizes the entire work. Technologies are moving forward, smart sensors and digital twins are appearing, but the basis is competent engineering calculations, high-quality materials and responsible human control at every stage.

Working with such systems is a constant process of learning, analyzing failures (your own and others) and finding a balance between technological necessity, reliability and economics. There are no ready-made solutions for all occasions. There are basic principles that cannot be violated, and there is experience that, alas, sometimes has to be obtained at the cost of great nerves and, fortunately, not always at the cost of accidents. The main thing is that this experience is useful and becomes knowledge for the entire industry.