Blueprints and reality always differ, as production procedures and workmanship vary between highly developed and developing countries. And supposedly minor details can have a significant impact on fuel consumption.
DNV GL's investigations showed that weld height increases a ship's fuel consumption more than previously thought. The Build2Design team investigated weld heights in detailed CFD (computational fluid dynamics) studies. Raising weld height from 3mm (good standard) to 7 mm (poor standard), increased the plate friction resistance by 15%. In the case of a large tanker or bulk carrier with 10% poor welds, this translates roughly into 100,000 USD of additional fuel costs per year.
This is one example of DNV GL's new Build2Design service. This service identifies critical details of a ship's design, based on hydrodynamic experience and CFD based insight. There are criteria for critical details, guidelines and acceptance. Besides welds, the Build2Design service focuses on bilge keels, anodes and other appendages. The experts stress that areas of attention and associated acceptance criteria are design specific. Build2Design is available for vessels being built to DNV GL class, and this service is carried out collaboratively between the owner, the yard and DNV GL.
Latest insight from DNV GL research as described above is already incorporated in DNV GL's Maritime Academy course "Energy Efficient Operation of Ships - Masterclass". The complete overview of what Maritime Academy offers with emphasis on energy efficiency you find on our website.