Tidewater Barge Lines vessels carrying a total of more than six million gallons of gasoline have been involved in five mishaps on the Columbia River in the last year and a half. Scott Learn of the Oregonian reports that officials have little to say about the incidents, citing confidentiality of ongoing investigations that have lasted up to 16 months. Three times the vessels went aground. The other two involved accidents at locks. The Vancouver, Wash.-based company’s barges all have double hulls and multiple cargo compartments to reduce the likelihood of a spill from grounding, and reduce the amount of any spill. The company’s last spill was in 1993.