Already in November 2022, Jastrzębskie Zakłady Remontowe fulfilled an order from the Knurów-Szczygłowice mine for the delivery of a set of 143 sections of JZR-14/38-POz (/S) WI; WII type longwall roof supports. These were the first sections entirely designed and built by JZR employees. Since then, in addition to ongoing overhauls and modernization of other sections (in 2022-2023 a total of about 5,500 units), Jastrzębskie Zakłady Remontowe undertook to design and manufacture more new sections, this time for the KWK Borynia-Zofiówka-Bzie Borynia Section mine - 110 sections JZR-17/41-POz and JZR-17/41-POz/S with delivery by the end of 2023, and for the KWK Pniówek mine - 165 sections JZR-11/33-POZ WI; WII, and JZR-11/33-POz/S WI; WII with delivery by the end of April 2024.
During the implementation of the aforementioned projects, JZR's technical departments, together with JSW's Production Department and representatives of the mines, began activities aimed at unifying the powered support sections manufactured by JZR.
- All of us, i.e. both JSW, the mines and us as the manufacturer, see the need to standardize the design of powered support sections. We plan to divide the sections into three groups: low, medium and high, and to develop solutions that make the maximum number of elements that make up the support structure is a repeatable element in a given series. We believe that this can be done with close cooperation with both JSW's substantive departments and the mines, which have invaluable knowledge of typical operations and the possibilities for improving the designs already in use. The unification will make it possible to introduce serial production of selected elements, which will translate directly into shorter lead times and provide the possibility, if necessary, of moving these elements between mines - says Rafał Rychter, President of the Management Board of Jastrzębskie Zakłady Remontowe.
In order to carry out the unification process efficiently, at the initiative of JZR and the JSW Production Department, at the end of April 2023 a task force was established, which, in addition to employees of the JSW Management Board Office, JZR and all mines, among others, included an expert group consisting of employees of GIG Katowice and ITG KOMAG. The final outcome of the task force's work is the technical assumptions for all three series of powered supports. These assumptions, after being presented to JSW's management board and mine directors, were adopted as binding in the assumed unification process.
- Thanks to the intensification of the task force's work, we plan to produce the first unified sections of the so-called "high" group as early as in 2024. These will be type JZR-21/54-POz WI; WII sections and outermost JZR-21/54-POz/S sections with a gauge of 1.75. The first 109 sections will go to the Budryk mine as early as the middle of next year. A few months later, 120 supports will be delivered to the Pniówek mine - adds President Rychter.
The new unified sections will be adapted for the assembly of both rigid, rigid-retractable and tiltable-retractable roof canopies and, in addition, they can work with foot piece extensions, which (without changing the kinematics of the section) increase the working range of the sections by H=600mm.
The structure uses two double-telescopic hydraulic legs with an inner cylinder diameter of ø400 mm, where the capacity at yield, at an operating pressure of 36 MPa, is 4524 kN. Active support of the ceiling in the linear and outermost sections was ensured by appropriate placement of the leg seat in relation to the overall length of the roof canopy. In addition, the roof canopy of the linear section uses an upward bend (about 2°) in its front part (about ¼ of its length), so that the straight line of action of the resultant pressure force of the roof canopy on the ceiling moves toward the face of the longwall, which is advantageous in terms of preventing roof fall. The support is designed for mining in horizontal and inclined (longitudinal inclination up to ±35º, transverse inclination up to ±20°) longwall workings using the full caving system.
- The new support sections were designed and constructed in accordance with current regulations, recommendations and guidelines for mining machinery, as well as based on expert analyses of both structural solutions and safety aspects, which were developed, among others, by the Central Mining Institute in Katowice. This is mainly to ensure safety during their transportation, installation and operation itself - stresses Waldemar Stachura, director of JSW's Production Department.
The project to unify powered supports is another project related to the unification of mining machinery and equipment used at JSW. Earlier on, the production of scraper conveyors was unified.
