Aker Philadelphia Shipyard (APSI) has commenced construction on the remaining two 50,000 dwt product tankers in a four vessel order for American Petroleum Tankers (APT), a Kinder Morgan subsidiary.

The product tankers, which will be used to transport crude oil or refined products, will have a carrying capacity of 14.5 million gallons.

The tankers are based on a Hyundai Mipo Dockyards (HMD) design and are expected to facilitate fuel efficient operations while featuring flexible cargo capability.

"With construction underway on these two product tankers, we celebrate the capstone of an exciting eight tanker series that is part of Philadelphia’s contribution to the energy landscape of this country."

The tankers will also be constructed to allow the use of liquefied natural gas (LNG) for propulsion in the future.

The tankers will comply with the latest regulatory requirements and are slated for delivery in 2017.

The tankers are the final of a series of eight product tankers being built at the shipyard for APSI’s customers.

APSI president and CEO Steinar Nerbovik said: "With construction underway on these two product tankers, we celebrate the capstone of an exciting eight tanker series that is part of Philadelphia’s contribution to the energy landscape of this country.

"The 1,100 men and women working at the shipyard will be busy for years to come completing these tankers and the other vessels we have under contract."

Earlier, the shipyard was awarded a similar contract for the delivery of three product tankers by Crowley. The first two 50,000 dwt tankers for APT to be delivered in 2016 and 2017.

Additionally, the shipyard has construction orders for two containerships to be delivered to Matson Navigation Company in 2018.