Advanced ship system designs
We're not just investing in technology to provide more efficient and low emission marine power and propulsion systems; we are also developing a family of very efficient vessel designs.
These vessels combine low power requirements with large load capacity and excellent sea-keeping. Based on the award winning Environship concept, CO2 emissions can be cut by up to 40 per cent compared to conventional oil-fuelled vessels.
The low resistance hull incorporates a wave-piercing bow to reduce both speed loss and consequent accelerations in a seaway. Each vessel design also features a lean burn Bergen gas engine, hybrid propulsion system and an integrated rudder and propeller system. Tanks for LNG are located where they have minimum impact on cargo capacity.The wave-piercing bow has several advantages. For example, it is highly beneficial for merchant ships on fixed routes where it is important to maintain a given speed to arrive at the scheduled port on time. Vessels featuring conventional bow designs must often cut speed to avoid bow damage and unacceptable acceleration levels when seas are too rough. As a consequence they frequently have to drive harder when the sea state permits to make up lost time. This in turn leads to an uneconomical operating mode, increased fuel consumption and more exhaust emissions.
In developing the new bow form, our merchant solutions team has addressed these challenges. The new design gives a significantly better performance at sea. In addition to less speed reduction and reduced accelerations, it has reduced the risk of hull plate deformation at the front end of the vessel in high seas.
We used computer simulation extensively in developing the new design, based on realistic weather conditions in typical operating areas. The results of this simulation speak for themselves:
- The new bow demonstrates a reduction in resistance of between five and eight per cent compared to an optimised conventional raked bow with bulb.
- Accelerations in the forward part of the vessel are reduced by five to ten per cent, again dependent on wave period.
We are applying the bow design to a range of vessel types, such as passenger, ropax and roro ships, tankers, bulk carriers, LNG bunkering vessels and superyachts.
In the offshore sector our UT 790 WP multi-purpose vessel embodies our design thinking for the next generation of offshore anchor handlers. It has a wave piercing bow and a beam of 23 metres. Shifting moorings in very deep waters needs high bollard pull, which in turn demands plenty of stability. That's what this design provides.
Traditionally, a large beam for stability would imply extra hull resistance, but we have used a new form that has a lower resistance to slimmer designs. The UT790 hull (red) has lower resistance than traditional 22 metre and 20 metre beam hulls.
The design has also been applied to supply vessels like the UT 754 WP. The upper portion comes into effect in severe head seas, shedding green water and keeping spray off the wheelhouse. At the same time the full beneficial effect of a bulbous bow is gained in a hull form that is easily driven despite its wide beam and large capacity. This gives good fuel consumption over a range of transit speeds. The UT 754 WP Far Solitare entered service in 2012 and was designed and developed in close cooperation with Farstad Shipping with diesel-electric propulsion. Gas (LNG)-electric propulsion is also an option.