Striking a Balance Between Efficiency & Safety
There is currently a highly unusual merging of the commercial desires of shipowners and the more idealistic demands of the regulators whether at the IMO, in Brussels or many other shipping centers. The catalyst is the growing societal concern for the environment.
Shipowners prefer ships that give them optimum performance and identifiable savings on running costs if they can be delivered at a competitive price. The current regulatory focus on environmental issues is providing such a challenge to ship designers. The energy-efficient ship of the future will burn less fuel, thereby emitting less CO2, SOx and NOx providing a win-win for the owners, the regulators and society.
As shipowners endeavor to establish a balance between design and operational issues that provide the desired gains in efficiency and environmental compliance, so too must their classification society endeavor to strike a balance between supporting these environmental initiatives and promoting the safety of the ships and their crews. This has been and will continue to be ABS’ focus as it assists in the development of these new, innovative approaches to energy-efficient designs.
There is no better example of the commercial versus idealistic positioning than the current debate over the Energy Efficiency Design Index or EEDI. This well-intentioned regulatory initiative, as originally proposed, carried the risk of diluting existing safety standards. The easiest way for a designer to meet or exceed the EEDI requirement is to reduce the installed power of the vessel by reducing the design speed.
It may be the easiest way but not necessarily the best approach. The installed power should be reduced by decreasing the power requirement without sacrificing the margin required for safe operation. The lack of adequate power to maintain safe operation in adverse weather or when maneuvering, has been a long-standing complaint of many shipowners.
The prospect of a future generation of under-powered vessels being spawned by the EEDI is simply unacceptable from a safety perspective and ABS was among the first to raise concern within the IMO of the consequences of their proposal.
ABS is of the opinion that, as urgent and necessary as environmental improvements may be, there needs to be considerable progress if the shipping industry is to meet the dual goals of promoting environmental compliance while, at the same time, promoting safety and commercial efficiencies.
Fortunately ABS also believes there is ample scope for enhancements in ship design and operations that will allow these improvements to be made. Those improvements will be through increased optimization of existing standard design bulk carrier and tanker hull forms to improve performance and reduce resistance in a seaway.
There will be improvements in propeller design and the associated water flow using advanced computational fluid dynamics (CFD). There will be improvements that stem from a better understanding of how biofouling increases resistance and degrades performance. In addition to further improvements in existing engine performance, there will also be step changes in operations, such as the growing adoption of flexible fuel engines that are able to burn gas, heavy fuel oils, distillates and even biodiesel.
There will also be increased research into and adoption of completely new technologies such as the application of nanotechnology to marine systems and coatings and the use of air lubrication to reduce the friction of the hull by injecting bubbles and creating air films or an air cavity. Full-scale and large model tests of air lubrication are being conducted with encouraging results.
Just as important as these new applications is the rethinking of some traditional design approaches. There is growing evidence that many bulbous bow configurations may actually adversely affect the open water performance of a bluff-bowed, high block co-efficient vessel in a seaway. Although some designers have developed new approaches to bow design, there is still a great deal to be done to identify the optimum configuration for the various types and sizes of vessels.
At the other end of the ship, there is the promise of equal or even greater efficiencies with respect to the manner in which water is directed onto the propeller and the design of the propeller itself. Using CFD, designers will be able to further improve propeller efficiency and smooth the wake to gain significant increases in performance.
These areas of research are in conjunction to that being conducted in fuel cells, solar powered auxiliaries, improved aerodynamics and the many other areas that are ripe for investigation. The breakthroughs of the future have yet to be identified but ABS believes there is a lot that can be done to return immediate benefits from improved operational efficiencies with the bonus of reducing the environmental impact of ship operations.
Our environmental research efforts are broad. This is the new frontier for the shipping industry and ABS is determined to lead the industry in identifying, understanding and applying these innovations in a safe, practical and effective manner.
Article is courtesy of ABS and has been issued with the permission of ABS
