Aker Philadelphia Shipyard began constructing its third and fourth product tankers for Kinder Morgan Inc. (KMI), Aker said Oct. 6.

The new, 600-foot long vessels will carry 14.5 million gallons of crude oil or refined products. They might use LNG as a fuel, and will be delivered between November 2016 and November 2017.

After construction, they will be sold to KMI subsidiaries, Aker said. For a four-ship series, the total value is $568 million.

Houston-based Kinder Morgan Inc. is North America’s largest energy infrastructure company.