Rolling Stock Units Research Articles

Main criteria of complex evaluation of subway train power facility technological productive potential

Maintaining the train safety and passenger transportation safety is regulated by the technical condition of rolling stock, which meets the requirements of regulatory documentation. Modern conditions of operation of traction rolling stock units (UTRS) are characterized by insufficient use of production and technological potential.One of the main reasons for this situation is the lack of necessary scientific and methodological developments that describe and improve system methods, models and criteria for the effectiveness of the production processes of UTRS.

ANALYSIS OF THE INFLUENCE OF THE HUMAN FACTOR ON THE PROCESS OF DETERMINING THE PARAMETERS OF ROLLING STOCK UNITS DURING TECHNICAL MAINTENANCE

The analysis of the technological process of determining the parameters of rolling stock units (using the example of wheel set bandages) has been carried out in the article. It has been determined that its implementation by a person using a contact measuring instrument and manual recording of the results can lead to the appearance of errors in perception, attention, memory and thinking. These human errors can occur throughout the entire technological process.

Stress-Strain State of Reinforced Concrete Overpass under Load

Beam spans are the most vulnerable elements ofthe bridge system, as they are exposed to directeffects of mobile load, environmental and climaticfactors (temperature and humidity effects, includingfreezing and thawing, shrinkage, humidity, etc.).Appearance of defects of the structure is inevitable;the refore civil engineers face a topical problem ofstrengthening of damaged structures of bridges. Thearticle discusses some results of calculated valuesand instrumental measurements of stress-strain state(SSS) of reinforced concrete beam span structuresof railway overpass under operational load caused bydifferent rolling stock units. The objective of this studyis to control stress-strain state of railway overpass foridentification and elimination of defects at earlystages. The calculation results obtained, carried outby finite-element method (FEM) in the programABAQUS/Standard correlate well with experimentaldata. These results can be used for monitoring thestate of artificial structures on main lines of JSC NCKTZ.

DEVELOPMENT OF A RELIABILITY MODEL THAT TAKES INTO ACCOUNT CHANGES IN THE STATE OF STRUCTURAL COMPONENTS OF ELECTRICAL MACHINES

Statistic data concerning the trolleybuses operations in Ukraine prove that reliability of traction electric engines has been reduced for subjective and objective reasons over the past 10-15 years. New developments and the use of technologies are therefore needed for more effective use of the known technical equipment, its modernization, reliability improvement and extending the service life. To determine the effectiveness of trolleybus operation on the route, the modern methods of reliability assessment of the traction electric engines are used, which allow to get adequate characteristics of the structure, functional links of parts and units. Improving public transport services is linked to the efficient operation of urban electric transport. It depends on the capabilities and quality of individual components and units of rolling stock. In addition, power supply and traffic control systems play an important role. An important technical and economic indicator of quality for each technical system of electric transport or product is the concept of reliability, which characterizes the level of operating conditions of the main elements and characteristics of traction electric motors. One of the main criteria for the reliability of traction motors is the reliability of operation during operation. The conditions of operation of electric machines of trolley buses are analyzed and the main directions of increasing their operational reliability are determined. The nature of the change in the state of structural units of an electric machine during operation has been established. A mathematical model of reliability has been developed that takes into account changes in the state of structural units of an electric machine.

Dynamic load of the carrying structure of an articulated wagon with new draft gear concepts

The article deals with a new draft gear concept proposed by the authors to reduce the dynamic load of wagons in operational modes. The peculiarity of the concept is transformation of the kinetic impact energy into the work of viscous resistance forces when the viscous fluid passes through the throttle openings of the piston. The concept can be introduced for the wagons, in which centre sills of the frames are of closed sections. The mathematic modelling was conducted for the dynamic load of articulated wagons with consideration of the draft gear concept. It was established that the use of the draft gear concept can lower the dynamic load of wagons by about 10 %. The research will encourage engineers to design modern structures of rolling stock units and increase their operational efficiency.

Development of dynamic integral evaluation method of technical state of one-section electric locomotive body

At present, one of the main problems arising from the long-term operation of one-section electric locomotives is the need to maintain their good technical condition. In this case, the determining aspect is often rapid identification of existing defects and damage to the main bearing structural elements of machine bodies, as well as preventing their development into more serious structural deviations.The aim of the study is to develop a specialized method that allows identifying defects of the main bearing structural elements of the bodies of one-section electric locomotives at the early stages of emergence and development. This method of dynamic integral evaluation is based on the analysis of partial dynamic spectrum of the electric locomotive. Based on the magnitude of the spectrum deviation relative to the theoretical one obtained from finite element modeling, it is possible to determine the approximate nature and location of damage, especially latent.The frequency spectrum of the main bearing structural elements of the bodies of one-section electric locomotives obtained in the course of the studies is rather dense and lies in the frequency range up to 20 Hz. The presence of damage reduces its value, and for the most common types of defects, this reduction is 25–30 %.The effectiveness of the practical application of the dynamic integral evaluation method is illustrated by the example of the DS3-008 machine. The method revealed hidden damage to one of the elements of the bearing frame of the front surface of the cab, which was not revealed during the standard maintenance procedure of the machine. The use of the method of dynamic integral evaluation of the technical condition of electric locomotives is quite versatile and can also be recommended for other units of railway rolling stock. In practice, the introduction of this approach will effectively prevent the development of emergencies

On the Development of a System of Indicators for Assessing Financial Condition of Freight Truck Transport Enterprises

The article is devoted to the relationship analysis indicators of economic effect and efficiency of the freight road transport enterprises in modern economic conditions. The main indicators characterizing the relationship between revenue and costs of a freight transportation company are financial stability and operating leverage. Using the liquidity ratio of the cash flow, the optimal criteria for these indicators were obtained, as well as the share of fixed costs in revenue, which determine the increase in solvency of freight road transport enterprises. At the same time, the optimal levels of the specified financial and economic indicators are considered in the context of seasonality and size of economic entities. The optimal levels of indicators are determined separately for large freight road transport enterprises with more than one hundred units of rolling stock and for medium cargo road transport enterprises with up to one hundred units of rolling stock. To assess the performance of freight trucking companies, profitability indicators are used, in particular cost-effectiveness. The indicator of profitability of costs allows you to set the marginal rate based on the market situation and the level of costs, as well as determine the revenue from sales, taking into account the established tariff. Using indicators that have an impact on the change in the value of cost-effectiveness, the minimum possible value of the indicator was obtained, which determines the lower limit of the sustainable functioning of freight road transport enterprises, determining the excess of income over expenditure.

ОСОБЛИВОСТІ ФУНКЦІОНУВАННЯ ЗАЛІЗНИЧНИХ НЕОЛОГІЗМІВ

Метою статті є дослідження особливостей функціонування нових залізничних номінацій двох останніх десятиліть у залізничному дискурсі, включаючи спеціалізовані форуми й блоги, а також у мові засобів масової інформації, передусім на транспортних і новинних порталах. Названо періоди активної появи залізничних неологізмів: перехід на нові види тяги – з парової на теплову й електричну; введення й розвиток швидкісного руху; поява нових видів перевезень. Перелічено об'єкти номінації залізничними неологізмами – одиниці інноваційного рухомого складу, об'єкти інфраструктури, їхні частини, нові спеціальності й виробничі процеси. Зафіксовано превалювання морфологічного й синтаксичного способів словотвору залізничних термінів. На прикладі функціонування синонімічних залізничних неологізмів виявлено залежність функціонального й словотвірного потенціалу нових номінацій від способу їх творення, прозорості семантики мотивованого слова, а для запозичених одиниць – від форми запозичення неологізму й активності обраної словотвірної моделі. Відзначено загальну для термінологічних систем тенденцію вибору більш компактних, більш благозвучних і зрозумілих номінацій. Розглянуто приклади незалежного й паралельного функціонування синонімічних нових номінацій залізничних об’єктів. Виявлено явище стилістичної диференціації окремих синонімічних неологізмів. Відзначено дію соціального чинника на появу цілої групи неологізмів, пов’язаних із популярним серед підлітків новим захопленням – їздою зовні потягів. Визначені стилістична приналежність одиниць цієї групи й семантичні відносини між ними, окреслено сферу їх вживання; зроблено висновки стосовно їхньої словотвірної активності; описано значення багатозначних одиниць; зафіксовано факт створення псевдотермінологічних окказіонализмів.

Peculiarities of determining the residual resource of weight-test wagons with a service life that exceeds the appointed

At present, a significant number of units of 1520 mm track calibration wagons in Ukraine have a life span that exceeds that specified by the factory. At the same time, the long-term experience of diagnosing the technical condition of freight and weighing wagons after long-term operation by the specialists of the Scientific and Production Center of Ukrtzaliznytsia branch of JSC Ukrzaliznytsia shows that in most cases the service life specified in the technical conditions is far from the limit. In many ways, this is due both to the substantial safety margin inherent in the design and to the particularities of operating a particular type of wagon. Ensuring safe and timely freight transportation is one of the main tasks of rail transport. In this regard, when at the end of the last century, a shortage of freight rolling stock, including specialized, and taking into account the technical and economic difficulties of its updating after the expiration of the appointed term, it was decided to partially abandon the prescribed scheduled service life for units of rolling stock whose individual resource allowed them to be resolved without further accident-free operation. In recent years, there has been a significant aging of the specialized car fleet. The fleet of weighing wagons has more than 50% of wagons that have served one and a half years or more.

Method of identification of the ranges of (non)acceptable factor values to reduce the risk of freight car derailment due to broken bogie solebar

Aim. According to the Russian freight car crash/derailment investigation records for the period between 2013 and 2016., derailments and crashes during train operations were mostly caused by rolling stock malfunctions, while about a third of such derailments were due to bogie solebar fracture. The average number of derailed units of rolling stock is 4.16 in case of derailment due to solebar fracture against 1.73 in case of derailments due to other rolling stock malfunctions. Previously, a method was developed that allows making decisions to discard a batch of solebars. On the other hand, solebars from batches exempt from discarding can be subject to fractures over time. In this context, it appears to be of relevance to develop a method that would enable timely uncoupling of a car for its submission to depot/full repairs in order to avoid solebar fracture. For this purpose, factor models of fracture hazard estimation should be considered. Such factors may include the number of kilometers travelled from the last maintenance depot (MD), as well as the number of kilometers and days until the next scheduled full/depot repairs. The probability of solebar fracture can be used as the quantitative characteristic of the hazard of solebar fracture. However, probability estimation in the form of, for instance, the frequency of solebar fracture is only possible when observation data is available on when fracture or critical defect of solebar did not occur, yet such data is not collected. Therefore, the hazard index of solebar fracture should be developed. As it is difficult to manage the frequency of car submission to MD, the hazard index must depend only on the number of days and kilometers to repairs. Using the constructed index, the ranges of (non) acceptable factor values must be defined in order to enable decision-making regarding car uncoupling and submission to repairs, should the MD car inspector have doubts regarding the necessity of uncoupling. Methods. Methods of mathematical programming were used in this paper. Results. Conclusions. An impact index was built that characterizes the probability of freight car solebar fracture depending on the number of days and kilometers until the next scheduled repairs of such car. Based on that index, two methods of definition of ranges of (non)acceptable factor values were proposed. The first method was based on the values of the impact index. The second one was based on the identification of some parameters of ranges of (non)acceptable factor values and selection – out of all ranges – of the best ones in terms the lowest hazard of solebar fracture. Such selection was made by solving problems of mixed integer programming with quadratic constraint.

Comprehensive method for evaluating results of ultrasonic testing of parts and components of rolling stock when adjusting the sensitivity for different reflectors

Operation of railway rolling stock is accompanied by high costs of maintaining its operating condition throughout the entire period of operation. To improve the operation efficiency of rolling stock, methods and diagnostics tools have been developed, which are used both in its manufacture and in carrying out maintenance and repairs, and as an independent technological process. Diagnostics allows to increase the availability factor and the probability of uptime of the rolling stock, reduce the complexity and cost of periodic maintenance of its nodes. The article proposes a new integrated method for estimating discontinuities in parts and units of railway rolling stock according to the amplitude — distance — diameter diagrams by the standardless method with the possibility of determining the type of discontinuity by the dual-frequency method of flaw-detection with a manual ultrasonic testing with a single-channel ultrasonic flaw detector. Developed method is most relevant in the control of cast parts of railway rolling stock, since castings can be equally likely to contain bulk (pores, shells, nonmetallic inclusions, etc.) and planar discontinuities (cracks of different origin; flocks; segregations that lead to violation continuity, etc.). Proposed method allows estimating the discontinuity by comparing the amplitude of the echo signal from it with the corresponding type of tuning reflector: if the discontinuity is planar as a result of using the two-frequency flaw-detection method, the comparison is carried out with the amplitude of the flat-bottomed cylindrical reflector; if the discontinuity is volumetric, then the comparison is made with the amplitude from the spherical reflector. The article describes the algorithm that was developed to automate the calculation of the parameters of the amplitude — distance — diameter diagram, the parameters of the use of the two-frequency method, and also the estimation of the detected discontinuities, and, based on it, the NDTRT-25 software that allows ensuring the convenience of the operator-diagnostician.

Rolling stock scheduling with maintenance requirements at the Chinese High-Speed Railway

Efficient rolling stock schedules have always been the focus of railway companies. At the Chinese High-Speed Railway, rolling stock scheduling is usually done manually by dispatchers. Such an approach often makes it difficult to quickly obtain an optimal rolling stock schedule that can be used to operate the proposed timetable and which is also feasible with respect to the rolling stock maintenance requirements. In this paper, we consider the problem of rolling stock scheduling with maintenance requirements and propose a heuristic approach that decomposes the problem into two main stages. In the first stage, the maintenance restrictions are ignored and a conventional Mixed Integer Programming model is used to generate multiple candidate rolling stock schedules. In the second stage, we check to see whether any of the candidate rolling stock schedules are feasible when maintenance restrictions for the individual rolling stock units are also considered. Checking a candidate rolling stock schedule can be performed using an assignment problem. To provide some structure to the search, candidate rolling stock schedules generated in the first stage are sorted in descending order according to their objective values. The two stages can be iteratively performed to avoid generating all schedules in the first stage before proceeding to the second stage. We analyze the performance of the proposed approach on real-life instances provided by the Chinese High-Speed Railway. These instances focus on the railway network within the Zhengzhou Group, which is one of the busiest transportation networks in China. Comparisons with the manual approach that is currently used in practice show that the proposed approach yields far superior schedules. The optimized schedules improve rolling stock efficiency and lead to a reduction in operating cost of approximately 10.5%.

Risk-based automated system for prediction of fire safety in railway facilities

Aim.The development of the Russian railway industry is associated with the growing number of operated buildings, rolling stock, more complex business processes of infrastructure maintenance and client service. In this context, JSC Russian Railways (JSC RZD) needs to manage the fire safety of more than ten thousand units of traction rolling stock and hundreds of buildings, where potential fires may cause harm to passengers or interruption of service. Fire safety management of both fixed and mobile railway facilities is performed at all lifecycle stages from design to disposal. Implementing the processes of fire safety diagnostics and prediction requires the development of a man-machine system whose core would be an automated fire risk control system (ACS) that allows – basedon the fire risk prediction – makingdecisions regarding the requirement for the repairs, replacement or maintenance of railway facilities and fire safety systems. Methods.The methods of the automatic control theory, expert assessment were used. The study aimed to develop an algorithm of automated auditing of railway facilities fire safety. Results.It is established that the majority fire safety control systems use gas concentration sensors to detect symptoms of hazard before flame development. This approach is hardly effective in terms of fire safety of railway facilities. For railway facilities whose actual state has an effect on the probability of fire a fire audit algorithm was developed that is based on the existing service and repair system, as well as statistical data on the states of railway facilities that precede fire. In order to enable systematic risk management measures in a large number of railway facilities, the paper proposes the structure of an automated fire risks management system that includes a fire safety management center and a mobile hardware and software system for fire safety auditing. Conclusions. It shows the importance of developing a proactive fire safety management system based on fire risk assessment. It was identified that information on the states preceding fires in railway facilities can be obtained from both the existing automated failure reporting and risk assessment systems and the diagnostic results of the actual state of objects as part of scheduled preventive maintenance. A method of automated assessment of fire hazard is proposed for systematic management of fire risks in many railway facilities.

Tendencies in the field of application of metal-powder materials for repair and maintenance of railway equipment

Logistics strategy in railway transport provides for a comprehensive solution of four tasks: technical, technological, economic and management. At the same time the technical task is one of the most important, because it ensures reliability of the equipment, an uninterrupted delivery of goods, a reduction of the idle time of locomotives and wagons, which in turn depends on the quality of the repair and the parts used. In the article the main tendencies in field of application of modern metal-ceramic materials for production, repair and operation of railway transport equipment are considered, modern directions in powder technologies and applied materials are shown, as well as possibilities of increasing reliability and safety of used powder parts. The basic properties and advantages of parts from powder materials are estimated. The possibilities of using powder details in various units of rolling stock are shown, as more reliable, safe and economically profitable. Among them: metal-powder slide bearings based on iron-copper, the main advantage of which is the presence of residual porosity, which contributes to the formation of a stable oil film in the bearing; bushings of valves of diesel motors, gears of oil and water pumps possessing high wear resistance; friction discs and brake pads designed to work in brakes and friction clutches in conditions of dry and liquid friction.

Skid adjuster for humps

The paper based on the analysis of the working conditions of railway transport shows that, ceteris paribus, an increase in actual durability and mean time before failure of rolling stock units is obtained through maintenance of wheelsets, especially during logistic processes on nonmechanized humps. One of the main causes for the service life decrease of wheelsets is brake damage. To eliminate such brake damage on highways, on-board braking dis-tance regulators mounted on the locomotive are used. In the hump yards, using such systems is not possible, since under marshalling, cars are detached from the locomotive. In this regard, an industrial challenge turns up to design a similar in purpose braking distance regulator for humps through skidding. To solve this problem, we developed a method of controlling the speed of cars to be sorted, which complements the widely used technology of the shoe braking and avoids the formation of one-way sliders. The paper presents a skid adjuster, which excludes brake damage to the rolling stock wheels by the slides on the humps using the shoe braking techniques. The motion equation of the rolling stock equipped with a skid adjuster on the hump tracks is developed. In the result of this study, an equation of car motion in the system of “rolling stock Hughes regulator way” allowing to enter the working elements of Hughes controller to an existing and debugged algorithm of any slides with minimal change it.

RESEARCH OF LOCOMOTIVE MECHANICS BEHAVIOR

Purpose. The main purpose of the study is to compare and confirm the results of theoretical studies of locomotive motion along the straight and curved track sections in the set range of operating speeds, which is essential for determining their dynamic qualities. The conducted research complex is one of the prerequisites for improving the reliability of the rolling stock mechanics, in particular the bogie parameters. Methodology. The research was carried out by numerical integration of the dynamic loading of a railway vehicle using one of the modern software complexes. In this study we used the mathematical model of locomotive spatial oscillations obtained using Lagrangian equations of the second kind. Findings. Authors carried out theoretical research and performed the analysis of the vehicle behavior during the motion along the track section, which in the vertical plane has no geometric defects, and taking into account the inequalities on the example of the main locomotive. The researches were carried out both analytically and with the help of the modern software complex. Comparison of the graphs shows that the results obtained by different methods coincide with sufficient accuracy. Originality. Based on the results of many years of work, the authors present the General Classification of Locomotive Mechanics, which may be useful to researchers, who are involved in the assessment of the dynamic qualities of new and upgraded types of rolling stock. Practical value. A new licensed modern software complex has been applied, which makes it possible to use it in the design, modeling of units of rolling stock and their elements; during theoretical and experimental studies, comparison of their results. The results of theoretical research can be taken into account for the preliminary research during creating the reliable constructions of a new vehicle, further improvement of the mechanics, modernization of the existing units of rolling stock during field tests.

Improvement of the Organizational Technological Model of the Route Made Up of the Groups of Cars of Different Owners

A route made up of the groups of cars of different owners can be formed in accordance with the technological processes of the station operation by the transport operator, by the operator that owns the rolling stock, by structural or production units of the railways on the access tracks or on the station tracks which are leased by the branch railway lines to cargo owners. Route optimisation uses an estimation function that determines the routing cost based on the automatic operating system data bases and enables to control routing efficiency and other characteristics used further in making a route table with defining function costs. The technology of cargo transport logistic services with the operation sequence starting from the moment of arrival of empty and loaded cars is proposed. A model for determining cost savings in transportation of the route with bulk cargoes from a consignor as a two-stage model of stochastic programming with recursion and random right-hand sides of the restrictions at the Ukrainian railways is proposed.

Scientific Substantiation of Thermal Leveling for Deformations in the Car Structure

Railway transport is the foundation of the transport complex and part of the transport network of logistics chains. However, significant deterioration of rolling stock units (especially freight cars accounting for the greater part of all transportation) is an urgent problem of the rail industry. Therefore, the problems of renovation of the existing freight car fleet by developing and introducing domestic models which can effectively compete in terms of the technical and economic and operational indexes are of crucial importance. But the car structure suffers from various deformations at all service stages (production, maintenance and operation). The main type of these deformations is residual ones developing during the welding procedure, due to the thermal effect. Therefore, the issues concerning elimination of these deformations in production and maintenance are becoming ever more urgent. In particular, the most recognized and economy-oriented approach in the field is the one based on the thermal leveling of welded structures. The implementation of this approach requires some research aimed at scientific substantiation of the thermal leveling, as well as, specification of forms and heating temperatures, determination of heating form sizes, thermal leveling simulation and experimental verification of the results, optical microscopy and determination of mechanical characteristics.

On traffic safety incidents caused by intrusion of derailed freight cars into the operational space of an adjacent track

Aim.Derailments of rolling stock units (cars, locomotive units) of freight trains cause damage to roadbed and rolling stock, as well as possible loss of transported cargo. Of special interest are cases when derailed rolling stock units intrude into the operational space ofan adjacent track. This, for instance, happened in the case of the Moscow – Chișinșu train at the Bekasovo I – Nara line on May 20, 2014, when as a result of the derailment of freight cars with subsequent intrusion into the operational space of an adjacent track 6 people were killed as the result of collision with an opposing train. In some cases intruding units may collide with an opposing freight train, which may cause the death of that train’s crew and derailment of its cars, which in case of transportation of hazardous loads (e.g. oil and gasoline) may have catastrophic consequences. Intrusion into the operational space ofan adjacent track also interrupts the traffic in both directions. In this context, evaluating the probability of derailed cars intruding into the operational space of an adjacent track is extremely important in order to maintain the tolerable level of risk in railway transportation, while the aim of this paper is to construct functional dependences between the probability of derailed cars intruding into the operational space of an adjacent track and various factors.Methods. Probability theory and mathematical statistics methods were used: maximum likelihood method, logistic regression, probit regression, Cauchy regression.Results.For each of the groups of incidents: derailments due to faulty cars/locomotive units, derailments due to faulty track, using the classic binary choice model an estimation was constructed of the probability of at least one derailed freight car intruding into the operational space of an adjacent track. This estimation turned out to be dependent upon the train loading and number of derailed units. As the number of derailed units is a priori (before the derailment) unknown, it was suggested to construct the probability of intrusion by at least one derailed freight car into the operational space of an adjacent track using a parametric model of dependence between the average number of derailed units and various traffic factors. The resulting dependences were compared. A numerical example was examined.Conclusions.There is a significant direct correlation between the random values that characterize intrusion by at least one unit into the operational space of an adjacent track and the number of derailed freight train units. A direct dependence between the train loading and intrusion by derailed units into an adjacent track was established. In case of derailment due to faulty track, for loaded trains the probability of at least one derailed unit intruding into the operational space of an adjacent track is extremely high.

Increase of informativity of two-frequency method of defectometry at ultrasonic control of details and units of railway rolling stock

When forecasting the technical state of the parts and units of railway rolling stock in operation, an important task is to determine the shape of the discontinuity in ultrasonic non-destructive testing in order to predict its behavior in further operation (this is especially important if the discontinuity in the results of such control is acceptable). Author proposed a solution for the improvement of the two-frequency defectometry method. A mathematical apparatus was developed and a method for determining the coefficient of the discontinuity shape was elaborate on its basis. The method makes it possible to determine the shape of both a point and an extended discontinuity. The software product NDTRT-07.03.01.18 was developed to automate calculations in determining the shape of discontinuity by a two-frequency method. The article gives a description of the experimental studies carried out to evaluate the reliability of the proposed method. This method can be used in determining the shape of the discontinuity in the details of the rolling stock, in which the defect can have a different shape, for example: cast wheel centers; various shaped castings used in the manufacture of rolling stock units (brackets for locomotive bogies, cast sidewalls for cars), as well as in parts manufactured by the method of plastic deformation, including wheel treads, axles, all-rolled wheels, rolled wheel centers, etc. In these details discontinuities are predominantly planar in nature, but voluminous discontinuities are also encountered - non-deformable nonmetallic inclusions, therefore the developed method can be applied to such objects of rolling stock railways.