DNV: how to de-risk ship retrofits through design, execution and verification

Hyoung-Seog Kim, head of Marine Solution Business Division at Hanwha Power Systems and head of Commercial Ship Engineering and Technology at Hanwha Ocean, together with classification society DNV, highlighted a means of closing the gap between expectations and actual performance in the case of ship retrofits, noting that more work is needed to quantify the before-and-after of ship performance. Owners considering energy-efficiency retrofits should focus on verified performance data, accurate engineering information and disciplined project execution to reduce technical and financial risk, according to Kim.
Kim said retrofit projects generally fall into two categories: regulatory compliance upgrades, such as ballast water treatment systems and exhaust gas cleaning systems, and performance-enhancing technologies including air lubrication systems, wind-assisted propulsion and hydrodynamic efficiency devices. “For this, I think verification of effectiveness is paramount,” he said. “While the theoretical benefits are quite clear, the burden to prove real-world gains is on the technology providers.”
He said third-party verification can help demonstrate real-world efficiency gains and build confidence among shipowners. Kim added that advanced control and operating systems are increasingly important to ensure retrofit technologies deliver expected performance under varying operating conditions.
One of the most common challenges during retrofit projects involves discrepancies between vessel drawings and actual onboard conditions, Kim noted, observing that external structural differences can be identified through 3D scanning before detailed engineering begins, helping to avoid costly rework during installation.
To minimise offhire time, he said design and procurement activities should be completed before the vessel enters the yard. Close coordination between owners, yards and suppliers is essential to maintain schedules and avoid delays.
“We see steady demand for FSU or FSRU conversion of ageing LNG carriers. Dual-fuel engine retrofits for conventional vessels are also highly interesting items,” Kim said. He also anticipates growing demand for onboard carbon capture systems as regulations become clearer, alongside increasing adoption of battery and energy storage technologies in short-sea shipping. 
“Currently, decision-making is slowing down recently as owners digest the last MEPC meeting outcomes. And looking further ahead, once regulations become more defined, I anticipate a surge in onboard carbon‑capture system (OCCS) installations.”