American Petroleum Tankers’ (APT) subsidiary Kinder Morgan Energy Partners has contracted General Dynamics (GD) NASSCO to design and build an additional product tanker.

The 50,000 deadweight tonne LNG-conversion-ready product carrier will be 610ft-long and have a 330,000 barrel cargo capacity.

General Dynamics NASSCO vice-president and general manager Kevin Graney said: "NASSCO is very pleased to be continuing our partnership with American Petroleum Tankers by building a fifth ECO tanker."

"This additional order, plus NASSCO’s existing backlog of tankers and containerships, is a clear indication that NASSCO is the shipyard of choice for Jones Act vessel construction."

The new carrier will be based on the ECO MR tanker design, developed by DSEC, a subsidiary of Daewoo Shipbuilding & Marine Engineering (DSME) of Busan, South Korea.

The DSEC’s ECO design features a G-series MAN ME slow-speed main engine, a ballast water treatment system and an optimised hull form to achieve fuel efficiency and protect the environment.

Equipped with conversion-capable, dual-fuel-capable engines, the tankers will be able to accommodate a future installation of an LNG fuel-gas system and type-C LNG tanks.

Construction on the tanker will commence in the fourth quarter of 2015 at the NASSCO shipyard in San Diego, with delivery to take place in the second quarter of 2017.

This latest order brings NASSCO’s design and construction contracts to five for American Petroleum Tankers and three for Seabulk Tankers.