The purpose of TRIMAR is to examine the capabilities and shortcomings of the tools currently
available in designing trimarans. To this end, two quite different ship types have been addressed:
The first ship is a high speed passenger ferry with a service speed of 37 knots. For such a ship the seakeeping performance is the greatest unknown, since the service Froude number is high, which represents a relatively unknown set of conditions for multi-hull vessel design. Moreover, with this ship some equivalent catamaran data have been made available to allow comparisons between the two hull types.
The second ship is a trimaran frigate which has a number of operating scenarios including stealth, cruising and sprint modes of operation. Here, the challenge in design is the resistance and propulsion characteristics of the vessel. Both ships are propelled by waterjets in various combinations.
The preliminary designs have been completed and models have been made. Both models have recently been tested at MARIN: the ferry in the Seakeeping and Manoeuvring Basin and the frigate in the Deep Water Towing Tank. The ferry has been tested in a wide range of sea states and headings as well as a number of manoeuvring trials. The ferry model is segmented and the outriggers are instrumented for the measurement loads. The frigate has undertaken the normal
resistance and propulsion tests for different configurations of outrigger position: both longitudinally and athwartship.
The work remaining is to analyse the differences between model test results and analytical predictions as well as making comparisons in seakeeping behaviour between the trimaran ferry and an equivalent catamaran ferry.