The Future belongs to efficient Ships

Innovative concepts call for rapid developments

© e4ships


“Efficiency” has become a keyword, which, in the shipping business, unites many approaches to the optimisation of economic efficiency and environmental protection under one roof. Probably the biggest change in the field of shipping now looming on the horizon is the development of fuel cells for all kinds of tasks in a ship through to propulsion.

Although so far only an excursion steamer on the Alster lake in Hamburg, or the first few sport boats derive their propulsion energy from a fuel cell (in which hydrogen combines with oxygen to form water, by which process energy is released in the form of electricity), the beginning of July saw the start of the research project “e4ships”.

Manufacturers, shipyards, research institutions and the Federal Government have joined forces in this project. The first aggregates for at least part of the power supply on board are to be fitted as early as 2012, in ten years' time it may be possible for all the energy for a ship to come from fuel cells. The pioneers are cruise shipping companies that, besides environmental protection, focus on the feel-good factor for their passengers.

Skysails is also experimenting with a new form of propulsion. A sail, similar to a paraglider, is supposed to pull ships along in a following wind and to ease the burden on the main engine. Although many approaches of new technologies are still in their first stages of development and have yet to prove themselves, due to the strong increase in operating costs, a large number of already known technologies are currently being assessed for potential installation on board ships.

However, changed requirements to be fulfilled by the whole operating technology – lower cruising speeds, a reduced rotation speed of the main engine, more exacting environmental requirements, more intelligent control technology, new materials – meanwhile frequently turn the question mark from “Is it worth it?” into the exclamation mark “Do it!”.

The search for a ‘better' ship starts with the optimisation of the ship's hull. New computer programs and more powerful computers can still elicit one or two per cent less water resistance from a hull that has been designed using conven tio nal methods. The advantage for a Panmax container vessel for example is in the form of an approximate saving of 1,500 tons fuel per year.

The shape of the bulbous bow also has a big influence on water resistance. The depth of immersion and efficiency of this depends in turn on the load. A report on the optimisation of the fluid dynamics of the rudder has already been dealt with in OnBoard. And of course the outer shell of the ship's hull has a great influence on resistance and thus also on fuel consumption. A clean hull is therefore of great importance – no matter whether this is achieved with innovative coatings or through regular cleaning.

Large potential savings are seen in connection with the main engines. Optimisation of the rotation speed, fuel injection or cylinder lubrication (such as is being fitted in the newbuildings from the very beginning and has been retrofitted in the “HLL Atlantic”) and heavy oil additives are the buzzwords here. Heat recovery from exhaust gases is technically already far advanced and has, of late, also become economically interesting. Surely, some of these aspects are only variable before the ship is built. And yet many details can still be changed during current operation in the course of a service lifetime of more than 20 years.

A ship needs energy not only at sea; but also in the port it requires large quantities of power for lighting, pumps or cooling. Supplying power from more efficient systems than the main engine – for example through fuel cells – or reducing the power consumption (LED lamps, lighting control system, better insulation of reefer containers) are two ways to achieve the same goal from different directions. Conclusion: the future belongs to efficient ships.

top