Classification society DNV on Thursday (28 August) shared on its technical support and evaluation of the different measures taken by Hapag-Lloyd in its major fleet upgrade programme of modifying over 100 container vessels to reduce fuel consumption, emissions and costs per tonne-mile, and maximize cargo capacity: 

Adapting flexibly to new regulatory and market conditions has always been key to the success of Hapag-Lloyd AG (HLAG), enabling the company to build a legacy of over 175 years. Increasing demand for container transport and new emission rules prompted the container liner company to explore strategies to improve energy efficiency and the cargo carrying capacity of the fleet, which is partly owned and partly chartered.

Joining hands for the Loadability Push

As these plans began to take shape, HLAG asked their long-standing partner DNV to assist with an extensive fleet upgrade within the scope of the company’s Strategy 2030. The corporate goals include positioning HLAG as the “Undisputed Number one for Quality” in the container shipping market and taking the next steps towards HLAG’s sustainability goals of reducing its carbon emissions by one third by 2030 and achieving net-zero by 2045.

The Fleet Upgrade Program as outlined in 2021 endeavours to determine the most economically feasible optimization measures for each ship to minimize operating costs and carbon emissions per tonne-mile and boost its cargo capacity. As the classification society of the relevant vessels, DNV is in charge of ensuring compliance with the latest rules and regulations. In addition, HLAG consulted with DNV’s class-independent Advisory experts, for engineering and technology advice, especially with regard to bulbous bow retrofits. “Our experiences working with DNV on our fleet in service have always been positive,” says Martin Grieger, Director Fleet Upgrade at HLAG. “Furthermore, being both an owner and operator, we’ve a dedicated Fleet Upgrade Team at HLAG that enables us to orchestrate such a project.”

DNV study explores feasibility of optimization measures

The team at DNV’s Container Excellence Center (CEC) in Hamburg has been supporting the initiative from the very beginning. In early 2021, DNV launched a systematic study into the optimization potential of 78 ships representing 11 different series. “DNV carried out calculations to verify the feasibility and potential cargo capacity increase,” Grieger points out.

DNV collected its findings in a comprehensive fleet overview spreadsheet that reflects the implications of four different retrofitting measures for each vessel or class: hull line optimization through modification of the bulbous bow; propeller retrofit; height increase of lashing bridges and deckhouse elevation; and draught increase.

Intricate interdependencies to consider for retrofitting

“All of these measures have short payback times,” explains Jan-Olaf Probst, Executive Vice President Business Development at DNV. “And they’re highly interdependent: retrofitting a new propeller to account for a ship’s reduced cruising speed typically requires modification of the bulbous bow to optimize the flow pattern around the hull and maximize efficiency; and increasing the height of lashing bridges might require an increase of draught, hatch cover reinforcements and in some cases, a deckhouse elevation to maintain the required line of sight. All these factors must be considered ship by ship.”

A good example are the seven T-class vessels modified to generate 900 additional container slots. “This was a compelling business case for us,” underlines Martin Grieger. “We increased the draught, raised up the lashing bridges and even cut off the top of the superstructure to raise it by six metres.

Note: The full article by DNV can be viewed here.

Photo credit: Hapag-Lloyd
Published: 1 September, 2025