AUSZUG | eb - Elektrische Bahnen INT 2/2015

68 Contact Lines 113 (2015) INT 2 with minor technical modifications to accommodate higher speeds and thereby significantly delay its complete replacement. In order to meet this technical challenge, running under the N-FLOCL should first be simulated and the matching of the results with available measurements be checked. Then, technical modifications should be simulated and the modifications showing prom- ise should be derived. This report covers this initial step for the technical adaptation of the N-FLOCL for higher commercial speeds. 2 The type N-FL contact line of SBB 2.1 History The contact line type N-FL has been in use by the SBB since around 1930. It comprises an automati- cally tensioned contact wire and a fixed messenger wire and was designed for a commercial speed of 125 km/h. The design has been improved over the past 80 years such that there are two variants with partially different components currently in use. One version is a supported contact line and the other is a suspended contact line. The suspended N-FL version is predominantly installed in stations. 2.2 Technical data Table 1 contains important technical data of the N-FLOCL and Figure 1 shows the suspended N-FLOCL version which is used in new installations. 2.3 Importance of the N-FLOCL type in SBB’s OCL network The N-FL is found throughout the SBB railway net- work. It is of particular interest with respect to higher speeds of travel, particularly on open sections be- tween stations and sections passing through sta- tions. On the basis of positive measuring results, N-FL sections can be travelled at up to 150 km/s only by using one pantograph in operation. There are cur- rently 665 km of N-FL section in operation on which speeds higher than 125 km/h are adopted currently or planned for the future. The goal of a streamlined enhancement of the N-FLOCL for higher speeds with a limitation to no more than four pantographs in operation is to delay complete conversions and the investments involved for 10 to 15 years. 3 Simulation of different versions 3.1 Introduction Simulations of the dynamic interaction between overhead contact line OCL and pantograph, referred to hereinafter as simulations, have already been an established method for the development of new catenary designs for all speed ranges and generally recognised for at least two decades. They are used in- creasingly for the assessment of contact lines, panto- graphs, and subsystems according to TSI Energy and TSI Locomotives and Passenger wagons. The author are currently aware of twelve simulation programs from Italy, Portugal, Spain, South Korea, Germany, Japan, France, Sweden, and China which have been developed and are used by universities, research in- stitutions, railway infrastructure operators, manufac- turers of railway equipment and inspection bodies. 3.2 The TracFeed ® CATMOS ® simulation program The TracFeed ® CATMOS ® simulation program used by Balfour Beatty Rail GmbH and created by pre- decessor companies AEG Bahnfahrwegsysteme and Adtranz was used for the optimisation of SBB’s N-FLOCL type [1]. Mathematical models of contact line and panto- graph are used for the simulation. The waves cre- ated in the OCL by the compression force of the pantograph are described using the wave propaga- tion method based on D’Alembert’s principle. By using this method, excellent simulation results are obtained, in which non-linear characteristics of the contact line, such as buckling of the droppers, are taken into account. Figure 1: Contact line SBB N-FL. 1 Contact wire stagger on straight sections +/–0,15m, 2 Steady arm type D (pull-off) 3 Contact wire AC107 4 Messenger wire 50mm² 5 Dropper 6 Return conductor 95mm² 7 Steady arm type R (pull-off)