Copper/fibre-optic cable is approved for Germany

Edited by the Engineeringtalk editorial team Jan 30, 2007

DuoTrack, the innovative duplex copper/fibre-optic lineside cabling solution for regional railways from Nexans, has just received type approval from the German Federal Railway Authority (EBA).

DuoTrack, the innovative duplex copper/fibre-optic lineside cabling solution for regional railways from Nexans, has just received type approval from the German Federal Railway Authority (EBA).

DB Deutsche Bahn (the German National Railways) will now use the cable for the first time in a pilot project for the modernisation of the Odenwaldbahn line in Hesse, in central Germany.

Nexans has developed DuoTrack to provide an all-in-one solution that combines all the copper and fibre-optic lineside cable services required for regional railway communications and control functions within a single cable.

Typically, these services include communication between electronic interlocks via fibre-optic cables or the control of signals and level crossings via copper cables, as well as the new ETCS (European Train Control System).

DuoTrack 's high strength and durability makes it exceptionally easy to install, as the single cable can be clamped directly to the track.

This method avoids time-consuming and costly civil engineering work compared with the traditional approach, in which several individual cables are laid in a concrete trough.

Furthermore, DuoTrack is designed to offer significant reductions in TCO (total cost of ownership), with anticipated savings of over 50%.

This makes DuoTrack an attractive option for equipping nonelectrified regional lines with modern control and communication technology.

DuoTrack is designed to offer the optimum combination of stability, flexibility and functionality.

It features the figure-eight cross-section that is well-proven in Nexans' aerial cables, with the joint insulation of copper and fibre-optic cables, which are connected to each other via a strong web, facilitating low cost installation in a single step.

The larger lower part accommodates a variable number of copper quads, while the upper part comprises a tiny high-grade steel pipe with single-mode fibres inside.

Special Nexans hybrid joints allow for separate splicing of the DuoTrack copper and fibre-optic cable in a waterproof joint, which is housed in a lockable high-grade steel housing and allows up to four cables to be used without additional cable cabinets.

Direct installation of the DuoTrack cable to the rail avoids time-consuming and costly civil works.

This can be carried out using a special DuoTrack laying device developed by Contec in partnership with Nexans.

It consists of a laying vehicle, cable chains with minimised tension and a laying arm which places the cable in the correct position.

The system also includes a special tool for fastening the DuoTrack clamps which are individually tested at a bearing pressure of 200N.

The DuoTrack cable insulation and sheathing is designed to meet the high mechanical and thermal requirements of rail base installation, and both copper and fibre-optic elements have individual anti-rodent protection.

The DuoTrack system has already proved its capability in long-term tests and interference evaluation on a test track in Northern Germany, as well as in numerous laboratory tests.

Nexans and Contec are now fitting the DuoTrack system to approximately 100km of track as part of the "Odenwald railway modernisation project" and this pilot project will promote the acceptance of this innovative technology for standard use by the German Railways network (DB Netz).