Small Waterplane Area Ships
Small Waterplane Area (SWA) ships have excellent seaworthiness, very low speed loss in waves, low wave resistance, and large deck area distant from the waterline. Development of ships of this kind has been steadily increasing. I am involved in R&D on advanced SWA hull forms in collaboration with Victor Dubrovsky (see information about our new book). An example below shows the schematic of a trimaran with SWA main hull and conventional outriggers that can serve as fast military Sealift with speeds exceeding 50 knots (our paper on this concept was published in Naval Engineers Journal, vol. 116(1), pp. 68-78). Another picture shows a semi-planing SWATH concept that has a special hull shape for efficient operations at displacement Froude number of about 3 (model test results are given on the right). Besides applied work, we are also doing fundamental research involving systematic series tests (here is a pre-print of our paper that will appear in Ocean Engineering journal). Example of residual resistance coefficient versus length Froude number (strut bow coincides with the hull bow) is shown in the last figure.
