Western Bypass for Zurich

Location: Zurich/Switzerland
Products: , TALEXXstrip

The Western Bypass for Zurich with its large number of special structures places enormous demands on the lighting and safety systems. In the tunnels Tridonic components demonstrate their excellent qualities day after day in operating the various light sources.

The stretches of motorway that provide a link between the A1 from Zurich to Berne and the A3 from Zurich to Chur, and the A4 motorway to central Switzerland, are of major importance because they relieve the city of Zurich from transit traffic. 79 % of the 10.6 km long West Bypass passes through tunnels. 

An intelligent approach

To ensure a smooth flow of traffic and high levels of safety, the tunnel lighting has to take account of the ability of the eye to adjust to different lighting levels. An abrupt change from bright to dark therefore has to be avoided. The luminance at the tunnel entrance depends on the brightness of the ambient natural daylight, and this luminance is automatically reduced continuously the further into the tunnel you drive.

The entrance zones of each of the tunnels are illuminated by RNH300S luminaires from Officine Rigamonti, Contone/Switzerland. The prime considerations for choosing the right control gear were durability and low power losses. The high-pressure sodium lamps of various wattages are operated in accordance with their specifications on Tridonic OMBS 150/100 A603W, OGLS 250/150 C043W and OGLS 400/250 C043W magnetic ballasts with power tapping and thermal protectors. Superimposed-pulse ignitors ZRM 6-ES/C and power changeover switches ZRM U6L for adaptive control are perfect additions.

The superimposed-pulse ignitors and the ballasts are characterised by their compact design and low self-heating. Perfectly matched ignition combined with exceptional reliability ensure that discharge lamps are reliably started and achieve their maximum life.

Exceptional continuity

Inside the tunnels, more than 25,000 Travalux R Hexal tubular luminaires from Siteco Switzerland provide high levels of safety and glare-free illumination. The continuous strip lighting acts as an excellent visual guide for drivers.

The tunnel lighting comprises long-life fluorescent lamps LL-58W from Aura and dimmable PCA ECO 58 W hp ECGs from Tridonic and meets the tough requirements in terms of durability and energy efficiency. The ECGs have a dimming range from 100 % to 1 % and have been developed specifically for use in harsh tunnel environments. Their digital control system ensures trouble-free operation. Thanks to the addition of DSI-V/T repeaters the control lines were extended along the entire length of the tunnel.

The result is one of the most cost-effective solutions as PCA ECO 58 W hp units can be operated perfectly in the long tunnels and require almost no maintenance at all. The emergency lighting system provides the necessary safe lighting levels in the event of a fire. All the tunnel sections are fitted with around 500 Brasyt A4 LED luminaires from BSBT GmbH of Oberentfelden in Switzerland – mounted at 50 m spacings. The TALEXXstrip P105 LED modules in white offer adequate brightness. These strip modules each have six light points with beam characteristics that provide excellent orientation even in dense smoke.

This perfectly matched lighting solution with innovative ballasts, lighting control components and LED modules from Tridonic gives drivers not only a sense of well-being but also safety. 

Project Data
Owner: City of Zurich (CH) 
Lighting: Officine Rigamonti, Contone (CH),
Siteco Schweiz AG, Belp (CH),
BSBT GmbH, Oberentfelden (CH)
Used equipment: