Repairs to cracks in steel rails along a $1.4-billion, 20-mile Phoenix-area light-rail project are nearly complete. The 33-station, at-grade METRO line, which runs through Phoenix, Tempe and Mesa, is still on track for a Dec. 27 debut.

Officials found fissures up to 7.5 in. long in three of the five segments during routine inspections. In January, METRO hired consultant Zeta-Tech Associates, Cherry Hill, N.J., for $60,000 to conduct a three-month investigation to determine the cause and recommend repairs. It found that high heat from handheld plasma welding torches used to cut drainage openings changed the steel’s structural properties, resulting in brittleness and microscopic cracks that worsened with expansion and contraction during seasonal weather changes.

Thirty-one flaws were found along line section 3, built by Archer Western Contractors, Atlanta; and line sections 4 and 5, both done by a joint venture of Sundt Inc., Tempe and /Stacy & Witbeck Inc., Alameda, Ca. The contractors are responsible for $600,000 in repairs, including grinding away damaged portions and replacing 12-ft to 16-ft-long line sections.

“Anything failing a magnetic particle test used to find microscopic cracks is being replaced,” says Marty McNeil, a METRO spokesperson. “Two of the three line-section repairs are done. The third line-section repairs will finish in May.”

The project is still within budget, thanks to a $177.2-million contingency fund that is now 85% exhausted. Parsons Brinkerhoff, New York City, is the general designer and engineer. A joint-venture of PBS&J Inc., Orlando, and PGH Wong Engineering Inc., San Francisco, is overseeing contract administration.

“There is no fault being assigned,” McNeil says. “Discussions are still under way with our contractors, consultants and designers. Those talks are going well.” Valley Metro Rail Inc., the owner of the project, will ask the party responsible for the use of torches to pay for the repair costs.