Fourteen months after a 110-lb light fixture fell from the ceiling of Boston's O'Brien tunnel, Massachusetts Dept. of Transportation highway officials have announced a $54-million plan to replace all of the tunnel's 25,000 lighting units with new light-emitting diode fixtures to assure long-term safety in the Central Artery system.The fixture recommended by the Boston-based office of engineering consultant HNTB is an 8-ft-long sealed unit that has a fiberglass housing, an acrylic lens cover and a three-row LED array board."We will replace the [existing] aluminum fixture with a single fabricated piece firmly bolted to the wireway, so there is no risk of falling," says Frank DePaola, MassDOT highway administrator.
The fluorescent lights, now safely secured with plastic strapping, are attached with two-part stainless-steel buckles that accelerate corrosion when in contact with the aluminum housing, heightening the risk of the light separating, DePaola says.