Rerouting Boston's Utilities

During construction of the Central Artery/Tunnel project in downtown Boston, engineers had to move utility lines over and under both new and existing infrastructure and maintain utility service to customers. One of the challenges was to install a 72-inch-diameter concrete sewer through the basement of an existing six-story brick building; another involved relocating utilities into long corridors, adjacent to future excavations for the tunnel. susceptible to corrosion by the soil that surrounds them, but there are numerous ways that these surfaces may be protected. The most effective are barrier coatings, which vary widely in their makeup and application depending on the type and quality of protection needed. Common types are epoxy polymers, coal tar enamels, tape coatings, and multilayer systems combining several different types. The author stresses the need to handle coated pipes carefully to avoid coating damage that would compromise the protection. Other protective methods include cathodic protection (which reverses a damaging electric current), corrosion inhibitors, and altering concrete's mix to make it resistant to attack.