Elon Musk, chief executive officer of Tesla Motors Inc., defended the safety of the company’s flagship Model S sedan after a fire involving one of the cars raised questions about its lithium-ion battery pack.
A Model S driven in Kent, Washington, near Seattle, on Oct. 1 struck metal debris on the road. The object appears to be a “curved section” that fell off a semi-trailer, Musk said yesterday in a statement on the company’s website. The car’s warning system alerted the driver to pull over and exit the vehicle, after which the fire broke out, he said.
“The geometry of the object caused a powerful lever action as it went under the car, punching upward and impaling the Model S with a peak force on the order of 25 tons,” Musk said. “Had a conventional gasoline car encountered the same object on the highway, the result could have been far worse.”
News of the fire, the first such incident involving a Tesla vehicle, triggered a 10 percent drop in the company’s shares over two days, reflecting concerns that the incident may tarnish the automaker. Tesla, already the world’s biggest seller of premium battery-powered cars, has soared fivefold this year after posting its first quarterly profit, repaying a U.S. loan nine years early and expanding Model S sales to Europe and Asia.
The Washington State Patrol and local authorities are investigating the incident. A review by U.S. safety inspectors isn’t likely soon because they are among workers furloughed during the U.S. government shutdown.
“All cars come with risks,” said Brett Smith, co-director of manufacturing, engineering and technology at the Center for Automotive Research in Ann Arbor, Michigan. The Model S “has a lot of energy stored there, and it has some risk like other cars,” Smith said.
“We’re driving around products every day that have ridiculous amounts of energy stored onboard in the form of gasoline,” he said.
Tesla rose 4.4 percent to $180.98 yesterday at the close in New York. The shares have climbed 434 percent this year, compared with a 20 percent gain for the Russell 1000 Index.
The collision punctured the battery pack’s aluminum casing, creating a 3-inch (7.6-centimeter) hole, Musk said. The fire caused by the impact was in the front battery module, one of 16 in the car, and “was contained to the front section of the car by internal firewalls within the pack,” he said.
The Model S battery casing offers more protection than that of gasoline-powered autos, said Musk, who is also the Palo Alto, California-based company’s biggest shareholder.
“A typical gasoline car only has a thin metal sheet protecting the underbody, leaving it vulnerable to destruction of the fuel supply lines or fuel tank, which causes a pool of gasoline to form and often burn the entire car to the ground,” he said.
The National Highway Traffic Safety Administration, which conducts crash investigations, is prohibited from doing any work on vehicle safety matters or discussing them, it said in an Oct. 3 e-mailed statement.
“Tesla is a young company,” Smith said. “There are going to be problems. Safety problems are of utmost concern. The most important thing is how a company addresses the issue.”