Designing vessels to meet changing global environmental trends

With the global change demanding changes to the environmental impact of vessels, via reduction of fuel consumption and greenhouse emissions; it necessitates a change to the naval architect’s design goals, to that of existing high speed craft. High speeds are undesirable for the environment, with an emphasis being placed on more moderate speeds, which are more environmentally suitable. Naval Architecture and Marine Solutions (NMS) wave piercing catamaran (WPC) offers a solution to environmental marine design. It can provide high deadweight, high manoeuvrability and shallow draft on a much shorter length at a reduced capital cost. The WPC is suitable for long distance routes, and shorter routes, its shallow draft and length permit it to enter a greater number of ports with reduced environmental impact, and with faster turnaround times, makes it viable.

A major cost for any ferry service is operating at part loads. The distinctive features of a WPC’s resistance means that power can be reduced considerably at lower deadweights whilst maintaining service speed.

A WPC is very manoeuvrable due to hull separation which reduces the powering requirements for bow thrusters, all of which reduce the demand on power and tankage and ultimately capital and running costs.

There has to be a cruising speed that a vessel needs to operate at, to maintain a suitable and economic overall timetable. The final design speed depends on the operator, and it needs to be a compromise between capital cost and the operational requirements of the vessel.  Quick turnaround times at port put reduced pressure on the trip time, making it possible to operate the vessel at lower optimal speed range for that vessel.

The catamaran offers many advantages:

• The hulls, which are principally intended to provide buoyancy and to house the propulsion machinery, divide the weight of the vessel equally.  Accordingly the length of each demihull can be reduced, which keeps the weight of the vessel and therefore the capital cost to a minimum. It also allows for a far more optimal displacement length ratio.

• The connecting structure, sometimes called the ‘bridging structure’, between the hulls, provides the transverse strength of the craft and provides for a large deck area, resulting in increased passenger carrying capacity.

• Increased safety levels. The WPC design can make it easier to increase the capacity of the vessel by increasing the upper deck capacity without impacting on the stability compliance.

• Attractive layout possibilities resulting from the wide beam.

The WPC design for our ferry offers a substantial number of opportunities to maximise the efficiency and reduce the capital and running costs, when compared to other designs, whilst minimising the environmental impact.

Compared to an equivalent steel monohull, our solution is much shorter, wider, with both lower capital outlay and operational costs.

For more details on our environmental marine design see  500 + Wave Piercing Catamaran Ferry.