Ask a naval architect working in 2015 what their biggest technical challenges were, and you would have heard about hull form optimisation, structural scantlings, and stability calculations. Ask the same question today and the answers look completely different: integrating BWTS systems into engine rooms that were never designed to accommodate them, 3D laser scanning as-built vessels whose actual geometry differs significantly from their original drawings, and designing hybrid propulsion packages that must interface with dynamic positioning systems to class requirements.
Green Ship Technologies has worked through all of these challenges on real projects — including BWTS retrofits on 25-year-old tankers where the original drawings were incomplete, and OSV conversions where the as-built hull differed from the approved design by enough to require new stability calculations. Here is what that experience has taught us about where ship design is heading.
Why Vessel Conversion Has Become a Strategic Priority
New vessel construction lead times at major yards are currently running at 2–3 years for most vessel types, and steel prices remain elevated. Against that backdrop, converting an existing vessel to a new purpose has become economically compelling for many operators. An AHTS vessel can be modified into an offshore wind farm service operation vessel (CSOV) for a fraction of a new build cost — but only if the engineering is done correctly.
Conversion projects are technically demanding precisely because the vessel was not designed for its new purpose. Deck strengthening for new crane pedestals, bulkhead modifications to create new accommodation spaces, propulsion changes to add DP2 capability — each requires detailed structural analysis, stability recalculation, and class approval before a single cut is made.
BWTS Retrofit: The Engineering Challenge Nobody Warned the Industry About
The Ballast Water Management Convention's IOPP renewal deadline has created a massive retrofit workload across the global fleet. What operators often do not anticipate is how complex the installation engineering actually is. A UV-based BWTS unit with its associated pumps, filters, and control panels needs to fit into an engine room that was designed decades ago with no spare space for it.
Our approach starts with 3D laser scanning — taking a millimetre-accurate point cloud of the relevant spaces before any design work begins. This eliminates the most common and costly retrofit problem: discovering at the shipyard that a pipe run shown in the drawings conflicts with a beam or another system that was added later. With an accurate 3D model, we route pipe work, electrical cable trays, and BWTS components in the virtual space first, then produce the detailed drawings for class submission. The class approval process is faster because the design is buildable.
Scrubber Installation Engineering
Exhaust Gas Cleaning Systems (EGCS) present an even more substantial engineering challenge than BWTS. A scrubber tower fitted to a large bulk carrier or tanker sits in the exhaust uptake path — the structural implications for the casing, mast, and funnel structure are significant, and weight and trim calculations must be rechecked after installation. We have completed scrubber installation engineering packages for vessels up to Capesize, including structural reinforcement design and the full stability impact assessment.
Hybrid Propulsion — Where the Work Actually Happens
Hybrid diesel-electric propulsion is no longer experimental on offshore support vessels and tugs — it is increasingly standard in newbuild specifications and is being retrofitted to existing tonnage. The integration work requires electrical load analysis, battery system sizing, power management system programming, and DP system interface design. Getting this wrong affects station-keeping safety in offshore operations — the engineering tolerances are tight and the class approval process is rigorous.
Vessels in Our Design Portfolio
- Well Stimulation and Hydraulic Fracturing Vessels
- Diesel Electric DP2 Field Support Vessels
- Offshore Construction Vessels with crane and ROV integration
- AHTS Vessels with battery hybrid propulsion packages
- Multipurpose Heavy Lift Vessels
- Small coastal passenger vessels for Indian waterways services
Working With Green Ship Technologies on Your Design Project
Our naval architecture team uses NAPA, MAXSURF, CAESAR II, and AutoCAD as standard tools, with 3D laser scanning capability for retrofit and conversion projects. We manage class submissions directly with IRS, ABS, DNV, Lloyd's Register, and Bureau Veritas, and can advise on which class society is best suited to your vessel type and trading area. Contact us at the concept stage — the earlier we are involved, the more value we can add.
