German liner operator Hapag-Lloyd and tonnage provider Seaspan Corp are investing $120m to retrofit five neo-panamax boxships with methanol propulsion.

The vessels scheduled to be upgraded are the 10,000-teu Seaspan Amazon, Seaspan Ganges, Seaspan Thames, Seaspan Yangtze and Seaspan Zambezi (all built 2014).

The ships will be converted from conventional MAN S90 engines to dual-fuel engines capable of operating on methanol, at a cost of about $23m per vessel.