American Petroleum Tankers' (APT) fourth ECO Class tanker, which is currently under construction at Californian shipbuilder General Dynamics NASSCO's shipyard in San Diego, was named on Sept. 17.

Named the Bay State, the tanker is the fourth vessel in a batch of five 50,000dwt, LNG-conversion-ready product carriers ordered from NASSCO.

The 610-foot-long tankers, which are equipped with a new ECO design, have a 330,000 barrel cargo capacity.

The first three ECO Class ships, namely, the Lone Star State, the Magnolia State, and the Garden State, were delivered earlier and are in service.

The fifth and final vessel is scheduled to join American Petroleum Tankers' fleet in 2017.

The ships were designed by DSEC, a subsidiary of Daewoo Shipbuilding & Marine Engineering (DSME) of Busan, South Korea. The design incorporates improved fuel efficiency concepts through several features, including a G-series MAN ME slow-speed main engine and an optimized hull form, according to NASSCO.