Rail fasteners for urban tramway tracks must, in addition to the usual requirements for rail traffic, meet additional criteria to ensure smooth operation.

In curve radii of < 25 m, extreme lateral forces act on tramways. For this reason, grooved rails should be equipped with adjustment possibilities of several millimeters, especially for rail replacement required after a few years of operation. High, largely freely selectable elasticities and low, electrically dissipative coatings must also meet today's standard requirements.

The NV-1 system was developed specifically for these applications. It uses wedge-shaped angular guide plates made of high-strength polyamide for track adjustment and secure lateral guidance. The tension clamp has a flat design and thus requires only a small amount of installation space of the track cover - without losing any of the stability of the rail bearing. The double insulation at the rail foot and center loop as well as the Nirotec coating ensure particularly high corrosion resistance and electrical insulation. The system is tested in accordance with the latest specifications of the standards for rail tracks and rail fasteners (EN 13481) - also for radii R < 25 m.