General Dynamics NASSCO has started construction on the third of five tanker ships ordered by American Petroleum Tankers (APT), following a steel cutting ceremony at its shipyard in San Diego, US.
The 610ft-long and 50,000dwt product carriers being built for APT will be LNG-conversion ready and have a capacity to carry 330,000 barrels of cargo.
NASSCO commercial programmes director Parker Larson said: "This is an exciting time in the US maritime industry.
"These Jones Act product tankers demonstrate implementation of state-of-the-art design technologies that achieve world-leading fuel efficiencies and also represent new jobs in our shipyard."
Construction of the first vessel in this series, APT-1, started in September 2014. The Eco-class tankers have been designed by DSEC, a subsidiary of Daewoo Shipbuilding & Marine Engineering of Busan, South Korea.
With its new Eco design, the vessel will offer better fuel-efficiency and be equipped with the latest environmental protection features such as a ballast water treatment system.
The G-series MAN ME slow-speed main engine and optimised hull form will also contribute to the improved fuel-efficiency of the vessel.
American Petroleum Tankers president Rob Kurz said: "These world-class vessels will be a welcome addition to the APT fleet as we continue to strive toward providing our customers with the highest level of service."
This five-tanker contract enables NASSCO to add 500 jobs to its existing 3,000 workforce, the company stated.
Delivery of vessels under this contract is expected to close in 2017, with the fifth tanker scheduled for receipt in the second quarter of that year.