The SWATH concept (small waterplane area, twin hull) is well known, although perhaps under utilised, with a reputation for seakindly motion and stable operation in rough seas. SLICE technology splits the twin hull concept into four hulls for vessels with a lower wake and higher speed requirement. The first vessel is being designed under the Lockheed/Guido Perla teaming agreement is a 350-person, 34-knot ferry measuring 38.71m, with a beam of 19.05m and a draft of 4.71m.

This new design is capable, claims the designer, of meeting the low wake and wash characteristics required for operation in Puget Sound and other areas worldwide. The concept is currently being considered by Washington State Ferries as replacements for its current fleet which are the subject of litigation. A high wake profile has prompted a legally imposed 'slow down' and lower wake alternatives are actively being sought. Should the Lockheed solution be adopted, the vessels could be built at Nichols Brothers Boatbuilding, located on nearby Whidbey Island, and well known as one of the US's leading builders of Incat designs.

According to Terence Schmidt, technical programs manager at Lockheed Martin, the key innovation in the SLICE concept is the reduction of wavemaking drag. Whilst SWATH hulls have increased stability in high seas, they are still restricted to slower speeds and this factor has, he contends, limited the effectiveness of the form.

Full article: Ship and Boat International Jan/Feb 2000