Two South Korean owners have ordered feeder boxships at the country's Dae Sun Shipbuilding & Engineering.
The yard said on Tuesday that Namsung Shipping and Pan Continental Shipping had each contracted a 1,000-teu unit.
The eco-pair will be fitted with scrubbers.
Namsung signed for its firm vessel in November, with an option attached. It has 25 operational feederships.
Pan Continental has a fleet of six feeder vessels.
