The service tunnel of the La Mancha tunnel, more than 50 kilometers long, has electrical and safety systems. In this gallery a lamp has been placed every 9 meters in height at 2.5 m. To this number of lamps are added the existing in the corridors of connection with railway tunnels, resulting a total of 6,700 lamps.
These lamps must withstand the heat released by them, the corrosion and pressure exerted by the trains that circulate through the tunnels. This was intended to dismantle 10,000 polycarbonate lamps from a quarry for reuse in the tunnel, but the International Safety Commission banned the use of plastics inside the tunnel.
The solution was offered by a special glass tube manufacturer. The glass used was borosilicate, used in both optical and kitchen appliances. A semi-anal lamp module has been completed to achieve good reflectance and adequate light distribution inside the glass.