# Reducing Oscillations in Suspension of Mine Monorail Track
## 1 Introduction  
Suspended monorails are increasingly being used in mining operations around the world. Currently, they are used for the prompt delivery of various goods weighing up to 32 tons, as well as transportation of people as close as possible to their workplaces. The main advantage of suspended monorails is their efficient operation on tracks with slopes of up to 25\({}^{\circ}\), while the speed can reach up to 3.5 m/s. They include monorail track and rolling stock. For underground conditions, there is a single-term path, consisting of segments of an I-profile, a fixed direction of transport route to support of a mine working on chain suspensions (Figure 1). At the same time, the installation step of the suspensions is not higher than 3 m.  
A rolling stock is suspended from the monorail track, transporting auxiliary cargo in pallets, containers or trolleys. As guides for movement, the inclined surfaces of lower shelves of the I-beam are more often used, although in underground conditions it is possible to ride on the top of the monorail. Movement of composition is provided by locomotive traction or a flexible rope traction body. A number of companies are engaged in development and production of such funds, among which the following should be highlighted: BECKER MINING SYSTEMS AG (Friedrichsthal, Germany), BECORIT GmbH (Recklinghausen, Germany), GTA MASCHI-NENSYSTEME GmbH (Hamminkelen, Germany), NEUHAUSER GmbH (Lunen, Germany), SMT SCHARF AG (Hamm, Germany), BEVEX-BANSKY VYSKUM spol. s.r.o. (Prievidza, Slovakia), Grupa FAMUR (Katowice, Poland), SIGMA S.A (Barak, Poland), FITE a.s. (Ostrava, Czech Republic), FERRIT s.r.o. (Stare Mesto, Czech Republic), STAVUS (Pribram, Czech Republic). Most of these companies have subsidiaries in Australia, Canada, China, Poland, USA, France, Chile and South Africa. Since the monorail track is suspended from the roof of excavation, rolling stock and cargo moving along the monorail additionally load support of excavation. The emerging static and dynamic loads [1; 2] cause deformation of monorail suspension and vibration. All this leads to displacement of blood rocks and reduces the life of the mine working. Typical for mine suspended monorails is location of rolling stock under monorail, which is suspended from roof of mine working. In addition, the one advantage of the monorail is the possibility to avoid the need for some infrastructure such as the overhead contact line [3] erected along the conventional track. The difference between a mine monorail and a passenger monorail [4] also deserves to be described. The operation of the mine suspended monorail tracks necessarily involves additional loads affecting the mine timbering. While moving the rolling stock along the suspended monorail, not only static gravity forces of the indicated elements of the tracks but also dynamic forces are applied to the beams of the mine working supports. These forces cause oscillations of the rolling stock, monorail track and mine timbering. The timbering oscillations cause displacement of rocks cutting their stability and leading to reduction in roadway cross-section. This, in its turn, increases accident rates and reduces efficiency and operational safety of the suspended monorail tracks. That is why this problem is of topical importance for mining enterprises. Figure 1: General view of the mine suspended monorail road: 1—support of the mine working; 2—monorail track; 3—monorail suspension. Problems of development of mine underground transport using suspended monorail roads are described in [5; 6]. It has been established that it is necessary to consider possible aspects: geologic conditions of current and future transport workings; parameters of transported loads; safety level required for conducting transport operations; competitiveness of predicted new means of transport; minimization of effects to the environment. The authors in [7; 8] studied the effect of rolling stock speed on dynamic loads in suspension of a mine suspended monorail road.