CABLE'S OUT: Cables, like the one burned here, can be worn out by decades of wear and tear under New York sidewalks or even damaged by rats snacking on them.
PHOTOGRAPHS BY MIKE FALCO FOR CON EDISON

BRONX, N.Y.—They arrive in wooden coffins and body bags, with yellow "toe tags." The evidence is carefully protected. A team of highly skilled scientists quickly starts the "autopsy" with a visual examination, sampling, and dissection.

But these "bodies" are not murder victims. They're defective electric cables sent by large municipal utilities all over America. The "forensic" experts are engineers from New York City's Consolidated Edison (Con Ed) power utility at the one-of-a kind Cable & Splice Center for Excellence, a $10-million facility in the Bronx, N.Y., dedicated to sussing out the source of the nation's cable breakdowns.

The center opened in July 2003. It was established by members of the Electric Power Research Institute (EPRI), a national consortium of utilities that conducts research on electric power issues, which was eager to avoid future power failures. Con Ed, with its highly respected, 30-year-old failure analysis lab, was the logical choice to diagnose the causes of cable breakdowns in vast metropolitan networks. Con Ed's database contains 80,000 records of cable failures they've analyzed.

View a Slide Show of the Center's work

"We go to all our different databases to put our information quilt together, considering every potential cause," says Vincent Ammirato, a senior engineer at the Center. Full analysis of a failed cable takes several weeks, after preliminary reports have cited a suspected cause. "Working backwards to correlate with the hypothesis, we perform simulations and test chemistry, hardness, moisture and endurance," he adds.

EPRI members  from around the country send as many as 30 cables that have stumped their own company’s best investigators. In addition, the Center's staff of chemical, mechanical, materials and electrical engineers performs about 1,800 mostly visual autopsies on cables that belong to Con Ed.

Cable sections sent in for examination are usually three to five feet (one to 1.5 meters) long and an inch to six inches (2.5 to 15 centimeters) wide. They arrive at the center via plane, train and truck in containers including sealed PVC tubes shaped like shoulder-fired missiles. All samples have been tested to confirm that they contain no significant levels of polychlorinated biphenyls (PCBs), a highly toxic man-made chemical that is often used inside a cable and come with information from the utility about the specific cable or splice and the conditions under which it failed.  

It is key, says Neil Weisenfeld, director of the Center, to protect the tubes and transport them rapidly to preserve any possible evidence such as moisture levels in the insulation or marks on the lead covering.

Once the damaged cargo arrives at the center, it is photographed and videotaped—and the autopsy begins on a long rectangular steel table there. "I'm checking for color, oxidation, smell and oil viscosity—everything but taste," senior engineer Richard Ragusa says as he delicately taps on a length of failed cable. Ragusa and fellow engineers Ammirato and Joseph Watts, all in blue lab coats, slice through the cable's layers to carefully photograph, analyze and determine its age.

Sometimes they can immediately determine the likely source of trouble, such as water damage evidenced by visible stains. If still unclear about the cause of a problem, the engineers take the specimen to a room filled with state-of-the-art instruments where senior engineer Ammirato cuts a sample from the outer sheath of the cable section with a diamond saw blade and encapsulates it in epoxy, which holds the metal firmly. A vacuum chamber removes any bubbles in the epoxy, because they might hide defects in the sample, such as a crack.