German boxship company Hapag-Lloyd has returned to shipyards for a slew of up to 12 ultra-large containership newbuildings worth more than $1bn and is weighing up LNG-fuelling for the vessels.

Newbuilding sources said Hapag-Lloyd has asked for quotes on six firm vessels of 23,000 teu each for delivery dates in 2023, along with slots for similar number of optional newbuildings.