Lightweight solutions positive
'Reduced weight reduces fuel costs and increases cargo capacity. That's why we think of great weight reduction solutions early on during projects,' says Terje Våge of Ulstein Design & Solutions in Ulsteinvik.
Although weight is an important design criterion that has to be taken into account, Våge says that the centre of gravity is just as important.
'For most ships that we work on, it is the weight of the steel structure, cranes, winches, and towers that is dominant. The weight of the ship's fittings usually only amounts to 5-10 per cent of the total weight. It's not a particularly large proportion, but even in this respect good lightweight solutions are preferable as fittings are often positioned high up and towards the front, which can have a significant impact on the ship's centre of gravity,' he says.
Våge says that Norwegian manufacturers are a long way ahead of the pack when it comes to material selection and weight, and that the fittings and insulation in ships built in, e.g. the Far East, are often significantly heavier than ships built domestically.
Work assignments must be solved
Ulstein Design & Solutions' task is to help customers "to create" a ship that solves their work assignments in the best way possible.
'When we design a ship, we have to fully understand the customer's needs and wishes, and "create a tool" that covers that need. Different types of ships solve different work assignments, but no matter what these variables are, weight is always an important parameter. Ships that are too heavy will have fuel costs that are too high and cargo capacities that are too low. When we choose solutions, our goal is to design a ship that offers the optimum performance for all parameters,' says Våge, and gives an example: ships that carry equipment to oil installations require large cargo decks, while seismic vessels need a big hanger, and a diving boat has completely different needs altogether.
'Very often when we sign contracts, deadweight and cargo capacity are included as separate points, as they are two of the very few specific figures that can be contractually tied up to speed,' says Våge.