AUSZUG | eb - Elektrische Bahnen INT 2/2015

67 Contact Lines 113 (2015) INT 2 Overhead contact line type N-FL of Swiss Rail – Extension of application Kurt Bader, Bern (CH), Jörg Mohrich, Leipzig (DE) Older contact line designs, like the Swiss contact line type N-FL, exist in conventional railway net- works to a great extent. Their low maximum permissible speed conflicts with the goal of increasing the maximum line speed. The high effort for a replacement of the complete contact line requires looking for a reasonable alternative for the increase of the running speed. By means of simulation, modifications of the existing contact line type N-FL in view of increasing the running speed were in- vestigated. Higher tensile forces of the contact wire and the installation of stitch wires have proven to be promising adjustments. OBERLEITUNG BAUART N-FL DER SBB – ERWEITERUNG DER ANWENDUNG Ältere Oberleitungsbauarten, wie die Bauart N-FL der SBB, sind häufig auf vielen Streckenkilome- tern in Bestandsnetzen zu finden. Häufig begrenzt die geringe maximale Befahrgeschwindigkeit dieser Bauarten die Streckengeschwindigkeit, die damit nicht erhöht werden kann. Der hohe Aufwand für einen Ersatzneubau der Oberleitung veranlasst die Suche nach preisgünstigeren Alternativen zur Erhöhung der Befahrgeschwindigkeit. Mit Hilfe von Simulationen wurden Än- derungen der N-Fahrleitung höhere Befahrgeschwindigkeit untersucht. Höhere Zugspannungen im Fahrdraht und der Einbau von Y-Beiseilen an den Stützpunkten ergaben sich als vielverspre- chende Anpassungen. SYSTÈME DE FIL DE CONTACT DU TYPE N-FL DES CHEMINS DE FER FÉDÉRAUX SUISSES (CFF) – EXTENSION DE SON APPLICATION Souvent on rencontre des systèmes de fil de contact plus anciens, comme le type N-FL des CFF, sur beaucoup de kilomètres des lignes des réseaux existants. Souvent les vitesses maximales de circu- lation permises sur ces lignes sont déterminées par les vitesses limites imposées par le système de fil de contact. Une augmentation des vitesses de circulation demanderait donc le renouvellement couteux du système de fil de contact. Pour éviter cela, on a étudié à l’aide de simulations des modi- fications du type N-FL qui permettraient une augmentation des vitesses de circulation. Comme pre- mières mesures prometteuses se sont révélés l’augmentation de l’effort de tension du fil de contact ainsi que le montage de suspensions en Y aux points de support. 1 Introduction Swiss Federal Railways (SBB) operate a railway net- work with around 8000km of overhead contact lines. These contact lines can essentially be classified under two types: Contact line type N-FL and contact line type R-FL. The type N-FL is an old design which has been in use since the 1930s. It can still be found frequently on old line sections and especially in sta- tions. The type R-FL is the current standard design on tracks outside stations and on main-tracks in stations. The number of trains in the timetable is constantly expanding. In addition, there is also the requirement of shortening travel times by increasing the commer- cial line speeds so that adherence to timetables can be improved. In order to satisfy this requirement on lines equipped with the N-FL contact lines, this con- tact line type is often replaced with the R-FLOCL. This requires major financial resources, which are currently limited. For this reason, consideration has been given to how the N-FLOCL can be updated TABLE 1 Technical data between supports of SBB‘s N-FL OCL type. Remarks Messenger wire mm 2 50 Copper-clad steel wire Tensile force, fixed by terminated messenger wire kN 8 oder 6 at – 20 °C, depending on system height 1,9m or 2,4m Contact wire mm 2 107 Cu-ETP Tensile force kN 8,5 System height m 1,9 oder 2,4 Maximum distance between supports m 58 new 52 Number of droppers - 6 Mean contact force N 75 Ampacity A 490