Saša Radulović: My plan is to become Mayor of Belgrade and use that platform to win Serbia’s next parliamentary election

Serbian opposition leader Saša Radulović, a former Minister of the Economy and leader of Dosta je Bilo (Enough is Enough), has ambitious plans. Speaking to EUROPP editor Tena Prelec, he elaborates on why he feels Serbia has lost its way under Aleksandar Vučić’s leadership, gives details of the media blackout he alleges his movement suffers from, and explains why he believes the image of Russia as an ally and protector of the Serbian people has been artificially created by Serbia’s political elites. As he reveals, his plan is to run in upcoming elections in Belgrade, from where he hopes to set a precedent in terms of good governance and to gain more visibility for himself and his movement, with a view to launching a strong campaign in the next parliamentary elections

Influence of Measurement Method and Data Processing on the Determining Brake Weight of Railway Vehicles Within Standard Test Method : master`s thesis

Aнализиран je поступак испитивања шинских возила у циљу одређивања кочних перфоманси возила. Због тенденције кретања возила већим брзинама и коришћења композитних материјала за израду кочних тарних елемената, за оцену кочних перформанси није довољан прорачун. Стога је потребно испитивање спровести што квалитетније, са што мањом мерном несигурношћу и прецизном обрадом добијених мерних величина како би се правилно дефинисале кочне перформансе возила. Спроведном анализом поступка мерења и обраде мерних сигнала, у раду су анализирани поступци мерења и обраде мерних сигнала у циљу побољшања поновљивости и упоредивости резултата.This master`s thesis analyses the test procedure for rail vehicles in order to determine the braking performances of vehicles. Due to tendency of moving vehicles at higher speeds and use of composite materials for the production of brake friction elements for assessment of the brake performance calculation is not sufficient. Therefore it is necessary to perform testing of the highest quality, with the lowest measurement uncertainty and precise processing of measured values obtained in order to properly define the braking performances of vehicles. Based on conducted analyses of the measurement and processing of measurement signals, in the master`s thesis were analyzed methods of measuring and measuring data processing signals in order to get better repeatability and comparability of results

Механика контакта точак/папуча железничких возила

Кретање и заустављање железничких возила омогућено је силама трења у контакту точак/шина и точак/папуча. Силе које се јављају у контакту точак/папуча зависе од бројних параметара. Због повећаних и строжијих захтева који се последњих година постављају пред железничка возила, са становишта заштите околине и смањења нивоа буке, предложена је замена папуча од сивог лива папучама од композитних материјала. Циљ рада је анализа сила у контакту точак/папуча и параметара који утичу на коефицијент трења, независно од типа и материјала папуча. Разматране су фазе приањања и клизања које се јављају у контакту точак/папуча. Анализирани су узроци појаве вибрација и њихов интензитет. У раду су приказане последице сила у контакту, као што су хабање и оштећења, на точковима и папучама реалних железничких возила, која су регистрована у експлоатацији

Breaking of coupling of trains on the Serbian Railways

This paper proposes an analysis of breaking of train coupling which occurred on the Serbian Railways (ŽS) in the period since 2007. by 2011. The problem of longitudinal dynamic forces, especially in freight trains, is most evident in the Serbian Railways, and for the reference period breaking of coupling of freight train occurred on a total of 201 cases (an average of 40.2 cases per year). Analysis of breaking of freight train coupling will be done based on number and place of breaks relative to the length of the freight trains, driving regime of trains, speed before breaking of coupling, damaged parts, causes of train breaks, etc. This analysis will identify the main factors that affect more frequent emerge of freight trains breaking of coupling, in order to prevent accidents and improve safety in freight railway traffic

Uncertainty of the wheel-rail angle of attack measurements using laser based wayside system

Ugao naletanja točka na šinu je značajan parametar dodira točak-šina. Zajedno sa silama koje nastaju pri tom dodiru, služi za ocenu dinamičkog ponašanja šinskog vozila pri prolasku kroz krivinu. U ovom radu je analizirana merna nesigurnost rezultata merenja specijalnim laserskim sistemom konstruisanim za merenje ugla naletanja točka na šinu, ističući značaj teorijskog pristupa pri izboru odgovarajućeg mernog principa i pri identifikaciji svih uticajnih parametara. Razmatran je i uticaj pravilnog postavljanja i pozicioniranja sistema na koloseku na rezultate merenja. Kako bi se ocenio kvalitet sprovedene analize, u radu su prikazani neki od rezultata merenja ovim uređajem i njihovo poređenje sa rezultatima dobijenim simulacijom, primenom specijalizovanog softverskog paketa VAMPIRE Pro. PR Projekat Ministarstva nauke Republike Srbije, br. TR 35006 i br. TR 35045.The angle of attack is an important wheel-rail contact parameter. Together with wheel-rail contact forces it serves for estimation of the rail vehicle curving performances. This paper analyses measurement uncertainty of the specially designed laser system for measurements of the wheel-rail angle of attack, with emphasis on the importance of the theoretical approach for selection of the appropriate measuring principle and for identifying all influential factors. The influence of the correct installation of the system on results is also considered. In order to evaluate quality of the analysis, some measurement results are presented and compared with the results of multibody system (MBS) simulation using specialized computer package VAMPIRE Pro

Осврт на испитивања кочнице Божић – 9 деценија касније

У току 1927. и 1928. године, под надзором Међународне железничке уније обављена су испитивања у циљу одобравања кочнице Божић за примену на возилима у међународном железничком саобраћају. Она су довела до светских патената, производње и коришћења те кочнице на великom броjу шинских возила, од којих су нека са Божић кочницом у саобраћају и данас. У раду су приказани најзанимљивији делови из извештаја о испитивањима. Оцењени су постигнути резултати и јединствени домет у историји железничког машинства Србије

Specific aspects of the rail vehicle pass-by noise measurement

Actual European legislative (NOI TSI) urges for quitter rail vehicles requiring obligatory assessment of noise emitted by rail vehicles within vehicle approval procedure. After survey of different rail vehicle noise emission scenarios, this paper discusses more in detail specifics of the pass-by noise measurement. The requirements of the measurement procedure from applicable standards are presented and discussed on the example of the tank wagon pass-by tests. Under several parameters that can influence measurement, for vehicle approval is important to measure and check if the most influencing parameters related to track lies in specified limits. If so, the measured noise emission level mainly represents the vehicle contribution and allows comparability to noise emission measurement of other vehicles. Two main track characteristics have to be measured and assessed: acoustical rail roughness and track decay rate. In the paper are presented both measurements that are more demanding than the noise emission measurement itself

Influence of head wind on the braking distance of single railway vehicle

Train stopping distance during brake application is influenced by the brake system performance, longitudinal running resistance and presence of wind and its direction. This paper deals with influence of the wind conditions on the results of slip brake tests. The influence is more expressed in the case of single vehicles tests and less expressed for the trains. The tests with and without presence of head wind were performed on the tank car type Zacns. Depending on wind speed, measured stopping distances may differ significantly. Opposite from head wind, tail wind increases stopping distance and should be considered when calculating safety margin and setting service train speed depending on the wind conditions. The results may also serve for further analyses of aerodynamic characteristics of railway vehicles and for verification of numerical simulations

Influence of measurement method and data processing on the results of brake performance test

In order to determine the brake weight of rail vehicles, brake perfomance test has to be perfomed. This test shall be conducted in accordance with the UIC 544-1. This regulation defines the necessary conditions and required quantities that shall be measured (speed, stopping distances, pressure etc.), but does not specify measuring method and all details about data processing. This paper presents possible influences on the results when using different speed measurement techniques or data processing details

Design specificity of Eams-z self-propelled wagon

Self-propelled wagon Eams-Z inteded for bulk material transportation provides enhancement in railway infrastructure construction and maintenance. Its main advantage is possibility of manipulation along tracks and construction material discharging without use of locomotive. Thus this car saves energy, human resources, and shortens the time of transportation and unloading. The car has two crates with the possibility of side and frontal inclining using hydraulic cylinders. These cylinders provide controlled and precise unloading of cargo on 3 sides without need of any extra man or machine power. Power pack, consisting of Iveco engine, hydro transmission and two small wheels without flange is positioned in the middle of the car between the bogies. In the self-propelled regime wheels lower down to rails providing traction force needed for wagon manipulation. This car type requires special attention during design and calculations in order to achieve safe manipulation in all regimes