Displacement compensators for the skylines of timber transportation cableways

Abstract

Cableways for timber transportation are quite effective in terms of manufacturability, specific energy consumption, material capacity and the negative impact level on the environment in difficult natural operating conditions, compared to similar types of machines. Since non-stationary cableways are usually used in forestry production, which are characterized by a light construction with relatively small safety margins of cable equipment elements, then for this type of roads, the reliability and safety of the skylines work are important factors for their effective operation. In order to reduce the cost and duration of installation and dismantling operations, the skylines are usually rigidly fixed to trees, stumps or artificial supports. Such a cable fastening scheme is technically convenient, but it does not allow for constant tension of the skylines when the carriage with the load is moving along the span, under wind load, possible temperature fluctuations, icing of structural elements, and emergency situations. As a result, intensive changes in cable tension during their operation cause dynamic loads and vibrations in the cable rigging, as well as uneven and accelerated wear of the skylines, and a decrease in their durability. Under such conditions, in order to increase the reliability of the cable rigging of timber transportation cableways (both individual existing models of equipment and the latest ones), it is proposed to equip them with displacement compensators for the skylines. After analyzing a number of prototype devices that are effectively used in related industries, it was concluded that pneumatic, mechanical, and hydraulic compensator designs can be considered rational for timber production. Therefore, in view of the above, we performed a detailed calculation and designed the main technical elements of the compensating device, developed a control scheme for its working body, and analyzed its stress-strain state using the Autodesk Inventor software package. The use of rational compensator designs and appropriate control schemes for their working bodies will create the prerequisites for reliable and safe operation of timber transportation cableways in various operating modes and terrain and climatic conditions, and minimize the likelihood of emergencies