The flank wear rate of cutting inserts grows in proportion as the force and cutting temperature in-crease which in their turn depend on the value of bevel edge wear. It is possible to reduce the influence of a tool contact area with the work piece upon processes accelerating wear by means of changing the flank form. The paper reports the methods for the estimation of wear resistance of flanks in cutters of different forms. There is offered a new design of replaceable tangential cutting inserts with a combined form of an end flank allowing the considerable increase of a tool life without decrease of work piece quality. The results of new cutting insert manufacturing testing in rail milling operations are presented

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With the introduction of polygon site technologies, the extension of locomotive circulation areas has increased the complexity of solving the problems of regulating the fleet of locomotives. Determination of the required rational size of the irreducible reserve of locomotives at the stations of its turnover is currently carried out in order to extinguish the influence on the export of the inaccuracies in the planning and inadequate depth of the forecast of the car traffic flows. Substantially this determination is made on the basis of expert assessments and does not have sufficient methodological justification. In order to exclude the loss of the traffic threads in the schedule, it is necessary to create a rational irreducible reserve of locomotives at the stations of its turnover. To solve this problem, a mathematical model of train operation has been developed on locomotive circulation areas, taking into account the daily fluctuations of train traffic, possible deviations in predicting composition formation and other factors. Performing mass calculations for various conditions will allow determining the rational size of the irreducible reserve of locomotives at the stations of its turnover and eliminate the losses associated with the cancellation of the schedule threads due to the lack of provision of finished trains by locomotives. Extensive full-scaled tests were made to determine the difference between actual and planned train traffic, which allowed determining regularities in the formation of planned values of train traffic for use in the simulation model. An algorithm for constructing a simulation model has been developed that provides for the amount of a irreducible reserve of locomotives for different conditions: changing values of the average daily train traffic in the even and odd directions of traffic, traffic incompatibility, the degree of uneven daily traffic, errors in planning (planning quality), etc. The software of the simulation model was developed and its debugging was made to perform mass calculations. The study of the problem of determining the rational size of the irreducible reserve of locomotives at the stations of its turnover was carried out with the support of the Russian Railways and the Russian Foundation for Basic Research. Project No. 17-20-01136.

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Problem statement. During the operation of purchased navigation systems for topographic geodetic referencing and orientation, many shortcomings are revealed, mainly associated with software implementation, the correction of which is not always possible. A way out of this situation is creating own navigation complex from ready-made purchased meters and developed functional software (FSW). In this case, the primary task is to determine the preferable meters as part of the topographic location and navigation system (TLNS).Objective. Conduct a study of strapdown inertial navigation systems (SINS) of various manufacturers for compliance with the declared technical characteristics to determine a suitable meter for TLNS.Results. Information on the practical testing of studies the numerical estimates of standard deviations (SD) of errors in the determination and drift of grid azimuth, roll, and pitch of strapdown inertial meters in various climatic conditions, as well as under the influence of sinusoidal and broadband random vibrations (BRV) is presented. The values deviations of motion parameters from the reference values in autonomous mode as part of the developed navigation complex of mobile land objects of a particular purpose are analyzed. The preferable inertial meter for use in the developed TLNS was determined based on the research carried out.Practical implications. Recommendations are given on the use of SINS as an integral part at the facilities of the proposed base.