The Vierarmen Tunnel on the Brussels ring road - one of the busiest in the country - is now also one of the safest and most sustainable.
Well known to Belgians due to the high numbers of commuters travelling through each day on their way in and out of the capital city, the tunnel was fitted with a smart lighting solution in 2019.
The Flemish Ministry of Transport and Mobility (AWV) had decided to replace the 20-year old fluorescent and sodium fixtures in this two-lane, dual-tunnel system with LED luminaires to save energy, money and time.
More than 1,400 LED luminaires managed by the ATS control system were installed to light this 540m long tunnel.
Lighting to improve visibility with less energy
The AWV chose the TAG and ContiLED luminaires to upgrade the tunnel lighting.
They were chosen for their high-performance and light weight.
For these energy-efficient fixtures guarantee the right lighting levels with excellent uniformity (Uo > 40% and UL > 70%) and high visual comfort.
Just over 600 TAG luminaires light the critical entrance zone, providing the 300cd/m² required by European regulations to reduce the contrast with the sun outside and guarantee safety.
The interior zone is lit by 840 ContiLED luminaires, that deliver the necessary 12cd/m². During the night, the levels are reduced to 3cd/m².
They have improved visibility in the tunnel, ensuring a safer and more comfortable driving experience with less energy consumption.
Due to the low ceiling in this tunnel, the luminaires could only be installed on the side of the walls so they are equipped with special lenses to direct the light on to the road. This guarantees the required lighting levels and brightness in the tunnel with minimal energy consumption.
For this tunnel, the architects opted for so called optical units in combination with separate driver boxes that incorporate the electronic drivers and local luminaire controllers. This provides 2 main advantages:
- the luminaires will not have to be opened if any maintenance is required on the electronics at a later date
- the LEDs are not affected by the heat generated by the electronics, ensuring their long lifespan.
Control to streamline operations
All of the luminaires are controlled by the Advanced Tunnel Control System (ATS), a co-development between Schréder and Phoenix Contact, which can switch each fixture on/off individually (and even part of the fixture), as well as adapt the light level to the exact requirements.
An RS422 closed loop network runs through the tunnel, connecting all the driver boxes to the central controller. The system controls the lighting levels in the tunnel based on the measurement of the luminance meter and the pre-configured scenarios.
During the night, when the lighting can be dimmed significantly, the control system switches off certain luminaires or parts of them, as this is more energy-efficient and better for the lifespan of the luminaires.
The system integrates the AWV’s IRIS platform, which manages the entire road network so that it can be controlled and monitored from its control room. At any time, the AWV can adapt the lighting levels or get real-time diagnostics of the lighting solution.
Operators at their desks have access via the IRIS platform to all status and diagnostic data. The lighting can also be operated from here. This is done by means of predefined scenarios. If, for example, an accident occurs in the tunnel, all of the luminaires automatically switch to 100% when the emergency button is pressed by the emergency services in situ.
The installation operations were all carried out during the night, with minimum lane closures and little commuter interruption.
Meticulous planning from all the parties involved and the easy “plug and play” installation of the power and controls cables equipped with their ‘Quick-on’ connectors ensured all went smoothly and efficiently.
We wanted, of course, to limit the number of nights that the tunnel had to close. A comprehensive work schedule, which had to be strictly adhered to, was set-up. Every morning, the tunnel was inspected to determine if it was safe to open again.
Schréder is delighted to have provided the lighting for this tunnel. The high-efficiency and long lifespan of the luminaires will enable the AWV to reduce its operating costs while delivering a much better service for commuters.
Indeed, the new lighting has not only improved the driving experience for motorists but will also ensure less closures and hold-ups due to maintenance for a more pleasant commute.