Anybody who can give standard illumination on the different zone in a tunnel either based on CIE or IESNA standards. Am now doing the electrical design for a 900 meter twin tube, two lanes per tube tunnel.
IESNA devotes 3 pages of its Handbook to tunnel lighting. The parameters they base their recommended minimum lighting levels for the entrance threshold is:
Tunnel length
Traffic speed (higher speed more light)
Traffic volume (higher volume more light)
The ambient light level surrounding the tunnel entrance (if it is bright around the tunnel opening or if one is traveling toward the sun, more light).
Worst case is 330 candelas per square meter in the threshold zone during the daytime. At night only 2.5 cd/sq-m is required for the full length of the tunnel.
Interior zone in daytime is 5 cd/sq-m.
The transition zone should gradually dim from the threshold level to the interior zone level over the length of the safe stopping distance (720 ft at 65 mph, 450 ft for 50 mph, 200 ft for 30 mph)
Tunnels with a width to height of 3 or less work well with a reflected lighting system. Wider tunnels require supplemental road surface lighting.
one thing you could consider is photovoltaic solar lighting in the tunnel. it is probably the best use for it, you need lighting day and night and solar could give you more power than needed during the days, and batteries would do the rest at night. the lights in a tunnel is needed especially for the lanes outlines, led (for example garden lighting) would do the job. we tried it for marinas and its perfect. low maintenance and low power needed. if you are near water, windmill power could be interesting. No matter what you will use, maintenance and electrical power wattage will be present as the major constraints. you will also need extra on demand lighting for emergencies.
the big dig in Boston is a remarkable piece and one should contact them for advice from good and bad experiences, they have a ... state of the art update. Montreal, Canada, has the Lafontaine tunnel, the Ville Marie tunnel and the Lachine tunnel. The city has a web site and they could help you. Salts and polution will probably be an issue in electrical too for corrosion protection. Pratcical sailor had a test many years ago and good old petrolium gelly was the best corrosion protection, we use it in lightbulbs screw caps in salty environments, works fine.
if under clean waters, a daring design would be to have a glass dome over the tunnel ...
good luck and keep us informed on your final design for critics ...
Tunnel Lighting
Re: Tunnel Lighting
