DEVELOPMENT OF MINING SYSTEMS FOR THICK SEAMS IN KUZBASS OVER THE PAST 40 YEARS

STRELNIKOV D. A.

Professor, Doctor of Technical Sciences

1. In a number of decrees in recent years, the Party and the government have noted the special importance of the rational mining of thick coal seams in Kuzbass as a major national-economic and, at the same time, political task. This can be seen in a number of orders of the People’s Commissariat of Heavy Industry: 1) of February 5, 1937, No. 119; 2) of October 3 and 4, 1937, for each of the Kuzbass trusts; 3) of January 21, 1938, No. 20; as well as in the resolution of the Central Committee of the VKP(b) and the Council of People’s Commissars of the USSR of October 20, 1938, etc.

2. This is due to the fact that thick seams occur not only in Kuzbass, but also in all the coal basins of the Union except the Donets Basin. With each year the number of thick seams being mined, and with them the share of coal output from thick seams in total coal production, increases; this is especially true of the Prokopyevsk and Kiselevsk districts of Kuzbass, which are richest in thick seams, and, at the same time, coal output in these districts by 1942 was to amount to 46% of the output of all Kuzbass. Of especially important and decisive significance is the fact that the mining systems for thick seams, as well as the methods for a number of the basic processes of coal extraction, support of stoping faces, stowing of the worked-out space in them, etc., remain unsatisfactory to this day.

3. The need to mine thick seams in Kuzbass had to be faced already in the period before the October Socialist Revolution.

In 1913 and in the following years, at the Kemerovo mine it was first of all necessary to ensure the mining of two thick seams: the Volkovsky and the Kemerovsky. The heads of the enterprise, represented by engineering and technical workers, had previously traveled abroad, mainly to France, where they studied achievements in the field of mining systems for thick seams; upon arriving in Kuzbass they made use of this foreign experience, as a result of which, in the mining systems applied at that time, especially for the Volkovsky seam, one could see a number of variants, chiefly of the system of horizontal slices so characteristic of such coal districts of France as Saint-Étienne and others; among these variants there were used variants with stowing, with caving, and with an ascending and descending order of extracting the slices. These trials up to 1917 did not, and could not, yield final conclusions, since the conduct of the work was primitive, and the stowing material—clay—especially in winter, was clearly unsatisfactory. The mining of the Tenth seam at Mine No. 10 in Sudzhenka, a seam of typically great thickness, with soft, unstable coal and weak side rocks, with variable elements of occurrence, was instructive in the sense that in fact only preparatory workings were being driven in this seam.

and, on the whole, no more than 25% of the coal was extracted from the seam; consequently, its working was of an evidently predatory character. There was little that was instructive, either, in the working of the Zhurinsky seam at the Leninsky (formerly Kolchuginsky) mine of Kuzbass: extraction of coal here was far from complete. The same may be said of the working of the Kemerovo seam at the Kemerovo mine of Kuzbass: its lower bench remained unextracted because it was considered so ashy that it was not worth mining; undoubtedly, such an explanation did not correctly reflect the true cause: they did not know how to work coal seams of such thickness.

1. Already in the first years of work in Kuzbass under Soviet power, the question of working thick seams had to be resolved in earnest; it was no longer possible to postpone its solution. By 1924 so much material had accumulated in this field that Kuzbassugol of that time was given the task of describing the methods and procedures of mining developed in Kuzbass and of providing a critical analysis of them. The fulfillment of this task was entrusted by Kuzbassugol to the author of the present article and ultimately found expression in a printed work, in a separate monographic edition: “The Working of Thick Seams in the Kuznetsk Coal Basin” (submitted for publication in December 1924). In this period of mastering and seeking the best systems for working thick seams, we find approaches that were in principle correctly applied: for example, variants of inclined slices with caving, with their extraction in descending order, on seams with a typically gentle dip (at Sudzhenka, on the Tenth seam), or with nearly horizontal occurrence (at the Leninsky, formerly Kolchuginsky, mine, on the Zhurinsky seam). Already at that time the question was being closely approached of the possibility of applying inclined slices also on seams with an inclined dip, as could then be seen in the example of working the Vnutrenny I seam at the Prokopyevsk mine of Kuzbass, with a dip angle of 45°. Horizontal slices at that time had a number of variants. A typical variant of horizontal slices along the strike, with their extraction in ascending order and with stowing, was the one used, in particular, on the Moshchny seam of the Prokopyevsk and Kiselevsk mines. Of great interest were the attempts in that period to apply a variant of horizontal slices in descending order with caving on the Lutuginsky seam of the Prokopyevsk mine; unfortunately, the trials with this variant at that time gave negative results. By 1924 the variant of horizontal slices in the form of so-called zones had received great development and variety, and was later used for a long time and widely at the Prokopyevsk, Kiselevsk, and Kemerovo mines of Kuzbass. Already at that time there were zones with stowing and with caving, with the use of frame supports (square sets) and with the ordinary “main support” used in Kuzbass; with alternation of zones with stowing and with caving (the Kiselevsk variant). An original variant was that of zones at the Kemerovo mine, where, as the final result of the search, there had already by that time been developed a variant of zones with simultaneous extraction of coal in the horizontal slices of several sublevels, with stowing and with the use of simple (“main”) support. Another original and relatively successful variant should be considered the horizontal slices along the strike with stowing, with extraction of the slices in ascending order, used on the Tenth seam of the Sudzhenka mine in areas of typical steep dip (a more detailed description of all the preceding variants is given in our work published in 1926—see above). It is of interest to note the experience of applying, in the period before 1924, the room-and-pillar system at the Kemerovo mine of Kuzbass, which gave negative results.

2. The rapid increase in coal output in Kuzbass already in the years preceding the First Stalin Five-Year Plan and in its first years revealed the negative aspects of most of the methods applied in the preceding period.

the use in Kuzbass of systems for developing thick seams: a short front of stoping operations, low productivity of extraction districts and fields, low productivity of workers, and a high cost of coal. All this led to a number of attempts and searches to eliminate these shortcomings. In the subsequent years, in the period up to 1931, much initiative was shown with respect, in particular, to modifying the zones: extracting them through one zone; through two zones, with subsequent extraction of the interzonal pillars; extraction with pillars left between the zones—the variant of the Yungor adits at the Prokopyevsk mine; extraction by zones with the creation of a bench face in the roof—the variant of the American engineer Paul; extraction by zones with the same roof-bench face, but moving along the strike—the so-called zone-lavas, etc. It is likewise necessary to note the attempts, during the same period, to develop a thick seam in five inclined slices with caving, extracting them in descending order at a dip angle of \(60^\circ\); this attempt proved unsuccessful, and extraction by inclined slices did not go beyond the second slice.

In this same period of time, work in zones with storage of coal instead of packing was put into practice experimentally—at mine No. 2-bis on the Moshchnyi seam, zone No. 28. Of some interest is the attempt to organize simultaneous extraction in horizontal slices of several “panels” of a zone at once—on the example of zones at the Central mine of the Prokopyevsk mine. Characteristic of this period must be considered the proposal, in designs, of variants of zones with simultaneous extraction of coal in a large number of zones along the strike, leaving interzonal pillars for their development in a second stage—similar to the chamber-and-pillar system—or leaving interzonal pillars permanently, i.e., in the form of a variant analogous to the chamber system of development, but with the use of supports and packing; or with simultaneous extraction of zones in several sublevels, and moreover with two-sided extraction of zones in each extraction field. There was even a proposal to use in the zones inclined slices set normal to the sides of the seam. Almost all these designs did not find even experimental application, since the shortcomings inherent in many of them were obvious. During this period of time—from 1924 to 1931—there was again a return to the variant of horizontal slices in descending order, with caving and with packing, with extraction along the strike and across the strike; but in this period as well, in the absence of any forms of mechanization of work in horizontal slices, positive results were not achieved.

Likewise, the search continued in the direction of applying inclined slices with caving and with packing on seams with dip angles of \(45^\circ\) and more; in a number of cases these experiments were successful—for example, on the Vnutrennii II seam of mine No. 2, on the Lutuginskii seam at the same mine—and definitely unsuccessful in others—for example, on the Moshchnyi seam of mine No. 2-bis, see above. The results obtained with the use of inclined slices on the Vnutrennii IV seam of mine No. 2 were uncertain: in a section with a dip of \(52^\circ\) and a thickness of \(8\ \text{m}\), they were relatively satisfactory, while in a section with a seam dip of \(23\text{–}40^\circ\) they proved unsuccessful. There were proposals to use inclined slices with packing and to extract them in descending order on typically steeply dipping seams—with a dip angle of \(60^\circ\)—and a thickness of \(13.9\ \text{m}\), the Moshchnyi seam; and also a variant of transverse-inclined slices, with their dip in the opposite direction relative to the dip direction of the seam being developed. And finally, in this same period of time, designs were proposed with storage of coal—the future variants of the chamber-and-pillar system. As an experiment at the mines, initially of the Aralichevsk mine, only one variant by the group of engineers of Design and Construction Bureau No. 14 was applied at that time. This system was designed for seams II, IV, and V of the Aralichevsk de-

deposits of Kuzbass with a normal thickness of 4.5 to 5 m. This variant reflected what was most characteristic of this type of mining system, which found wide application in Pennsylvania (USA) in the mining of steeply dipping anthracite seams. The authors of this design used literary sources, as well as what they themselves had had the opportunity to see in the USA. It is absolutely necessary to emphasize here that the design provided for mining by this system such seams whose thickness varied within the limited range from 4.5 to 5 m; that is, in making the proposal the authors envisaged a limited sphere of application for this system, all the more so because it was proposed for the secondary, especially at that time, Aralichevsky mine, with its ashy and relatively low-value coals. The authors regarded as advantages of the proposed system: 1) the absence of stowing, 2) low consumption of timber for supports, 3) the absence of coal raking in the stoping faces and haulage along intermediate drifts, 4) high productivity not only of the main group of miners at the face, but also per face, and 5) a reduction in the cost of coal. Alongside these merits, losses, calculated by the authors themselves at 37%, were noted among the shortcomings.

Finally, it cannot be ignored that this system was put forward at a time when Kuzbass was faced with the difficult task (in 1931) of a further sharp increase in coal output, with considerable difficulties in supplying the coal mines with labor, housing, and support timber, and with the necessity of achieving a significant improvement in its technical and economic indicators and, first and foremost, labor productivity and reduction of cost.

1. The room-and-pillar system proposed in 1931 was, as an experiment, applied in that same year and in the following year first at the Aralichevsky mine, and later at the Prokopyevsky and Osinovsky mines¹. Having found supporters among local engineering and technical personnel in the first stages of its application, it rather quickly came into widespread use in Kuzbass. These attitudes in the engineering and technical milieu, and especially the conditions of that time, which required more coal, a reduction in timber consumption, and an increase in workers’ productivity, were taken advantage of by enemies, who for the most part brought matters to the point that losses in its application reached not only 40–50 percent, but in some cases even 60–70%, i.e., the system was transformed from predatory into plainly harmful, since in addition to the impermissible increase in losses it became necessary, at the mines and pits where this system was used, to confront a new calamity for Kuzbass—numerous underground fires.

In this same period—1931–36–37—attention to stowing work weakened, and the zone system likewise more and more often began to appear in variants with caving; a considerable number of other variants also appeared, likewise with caving, which were applied under conditions far from favorable for them.

Thus, mainly the room-and-pillar system, or more precisely the room system, in the period from 1931 to 1937, having been put forward and having found in Kuz—

basin, especially in its southern mines; its widespread use, owing to its exploitation by wreckers for their criminal purposes, not only led to great losses of the most valuable coals and to the occurrence of a considerable number of underground fires, but also sharply impeded the correct search for the most rational systems for working thick seams in Kuzbass.

1. The last years of the second Stalin five-year plan and the first years of the third were characterized by intensive searches for the most rational systems for working thick seams in Kuzbass. The main impetus for the manifestation of creative initiative was the repeated indication by the Party and the government of the special importance of this task, which was of great national-economic and political significance; local competitions for the best system of working thick seams also played a certain favorable role. In particular, many variants of a typical system for working thick seams by inclined slices were submitted to the competition for thick-seam working systems announced by Kuzbassugol in 1937: these included proposals to work steeply dipping seams: 1) by inclined slices from bottom to top and from top to bottom (the proposal of mining engineer T. F. Gorbachev) with stowing (a variant of inclined slices proper); 2) by diagonal slices; 3) by transverse-inclined slices in two variants, when these slices had a dip the same as the dip of the seam being worked or the reverse of the latter (the variant of mining engineer B. M. Skorogo); 4) by the “herringbone” method (the proposal of mining engineer V. F. Parusimov) with a double-slope diagonal face; 5) by the “half-herringbone” method with a single-slope diagonal face, with extraction of the slices in ascending order with stowing, in short sections along the strike; 6) Ivanov’s variant, providing for the separation, in space, on thick steeply dipping seams, of inclined slices, taking into account the directions of the cleavage planes in the seam being worked. At this same competition variants of horizontal slices were presented with mechanization of undercutting, breaking, haulage, stowing, with extraction of the slices from top to bottom with caving and with stowing—full and partial—with a proposal to carry out undercutting—breaking of the underlying slice from above (the proposal of mining engineer P. M. Kovachevich), and to use in the slices special metal props of the design of mining engineer B. M. Skorogo. An original proposal at this same competition was that of mining engineer N. A. Chinakal: to apply a variant with shield support for steeply dipping seams—a variant of long pillars with their extraction along the dip.

In the period from 1937 through 1940 inclusive, at the mines of Kuzbass—chiefly at Prokopyevsk, and partly at the Kiselevsk, Sudzhenka, Kemerovo, and Aralichevo mines—experiments were carried out on the application of most of the above-proposed systems for working thick seams. From the experience of the last three years, it is already possible to draw a number of guiding conclusions, which by the present time have received the approval of the All-Kuzbass Conference on systems for working thick seams in Kuzbass, held in Novosibirsk in January 1941. This conference noted the extensive work done in Kuzbass in recent years to identify the most rational systems for working thick seams under the conditions of the Kuznetsk Basin. Of all the above-mentioned variety of proposals and searches, there remains for subsequent time a limited number of systems approved by the conference: 1) long pillars along the strike, 2) inclined slices for seams with a dip from 0 to 60° and with a thickness of up to 9 m, 3) horizontal slices with their extraction in descending and ascending order, with caving and with stowing, and 4) long pillars with their extraction along the dip and with the use of the movable support of mining engineer N. A. Chinakal. With respect to each of these systems

the conference established certain conditions for their use and a number of basic elements and rules of technical operation; on the second mining level, as a rule, systems with stowing should be used.

At the same time it has been established that, with respect to all the tested conferences of systems for working thick seams, there remains a considerable number of questions requiring resolution. Thus, in the most recent period—since 1937—much work has been done to reduce the number of thick-seam mining systems used in Kuzbass: 1) the room-and-pillar system has been completely eliminated, thereby largely eliminating the consequences of harmful practice that had taken place mainly in the period from 1931 to 1937; 2) zones have almost disappeared as well, as a low-productivity system and, in a number of its variants, differing little in the percentage of losses, especially with caving, from the room-and-pillar system; 3) diagonal slices, the “herringbone,” “half-herringbone,” and transverse-inclined slices have not justified the hopes placed upon them. The exchange of opinions at the January conference established that positive results have not yet been achieved in Kuzbass with mechanization and with the performance of work in horizontal slices with stowing and with caving. Gravity stowing does not fully solve the tasks of filling the worked-out space with waste rock and controlling the roof. Experiments with pneumatic stowing (in particular, with the stowing machine of the Torkret firm, Karaganda), carried out by the Leningrad Mining Institute in 1934, and later, in 1935 and 1936, by the Mining Faculty of the Tomsk Industrial Institute—by the brigade of Associate Professor V. G. Mikhailov—did not reveal all the possibilities that these stowing machines may provide. The use of the same machines from case to case likewise does not provide grounds for definite conclusions. The stowing throwing machine designed by the Kuznetsk Scientific-Research Coal Institute requires reconstruction, taking into account the shortcomings that have been revealed in it.

The system with shield support of engineer N. A. Chinakal, over the time it has been in use, has recommended itself so well that, in accordance with point 7 of Order No. 220 of 28.IX.1940 of the People’s Commissar of the Coal Industry, V. V. Vakhrushev, work by this method was organized by November 15, 1940, in 50 sections of the Prokopyevsk-Kiselevsk district. At present one may regard as resolved, in a positive sense, the question of mining, by shields of this design, steeply dipping seams with an angle of dip of not less than 50° and a thickness of up to 9 m, with relatively constant elements of occurrence. In terms of the principal indicators, this method—new for Kuzbass—of working thick steeply dipping seams, in productivity, consumption of support timber, and cost, ranks among the best, and more often occupies first place.

1. Among the tasks requiring resolution in the coming period in the field of mining thick seams in Kuzbass, the following must be noted.

a) The individual stages of work in all the systems for mining thick seams planned for further use in Kuzbass must find a better solution than at present, each separately and especially in their integrated combination with one another; this must be expressed in precise work plans and schedules, with strict observance of a definite cyclicity and with the achievement of better technical-economic indicators than at present.

b) Greater attention is required by questions connected with the mechanization of undercutting, breaking, supporting, and the delivery of coal and timber in stoping faces. Undoubtedly, the necessary machines must urgently be designed, manufactured, tested, and mastered for the distinctive conditions of occurrence of coal seams and their mining in Kuzbass. At the same time, the operation of all these mechanisms must be coordinated with one another.

c) The stowing operations on the seams of Kuzbass require exceptional attention. Here there is a vast field of work, beginning with the additional excavation of the existing central quarries, the organization and performance of all work in them, and ending with the streamlining of all stowing processes in general, starting from the faces where stowing material is extracted at the surface, when it passes through crushing plants, is moved along the surface, lowered underground, and moved underground all the way to the actual stoping face.

In conclusion, looking back over the past 40 years, which coincide with the forty-year period of work of our institute, now awarded an order, we must say to ourselves: 1) nothing remains of old Kuzbass, apart from the former names of mines that continue to operate to this day; 2) on the site of old Kuzbass a new Kuzbass has been created; instead of a primitive artisanal enterprise that produced less than one million tons of coal per year, we now have a Kuzbass that stands on the eve of achieving an output of 25 million tons per year, i.e., it will be capable of producing as much as the pre-revolutionary Donbass produced in its best years. It may be said that the new Kuzbass is completing the first stage of the task set by the Party and the Government: “To turn Kuzbass into a second Donbass.”

1. We pointed out a number of substantial shortcomings inherent in the room-and-pillar system in our 1931 work, “Systems of Mining Thick Seams of the Prokopyevsky Mine in Kuzbass,” when this system was known to us only as a design; later, at the beginning of 1932, we had the opportunity to see the first experiments in the application of this system at the Prokopyevsky, Aralichevsky, and Osinovsky mines, and in our conclusions we not only confirmed our previous negative conclusions about it, but also clarified and expanded them (see our article in Nos. 7–8 of the journal Coal of the East, May 1932: “Experience in Applying the Room-and-Pillar System with Magazinage in Kuzbass”); the same assessment was reflected in our later articles. (Author). ↩