A suspension system for a vessel, the vessel having at least one left hull, at least one right hull, and a chassis portion, the suspension system comprising:
- locating arrangements for constraining motion of the at least one left hull and the at least one right hull in at least a longitudinal and a lateral direction relative to the chassis portion;
- and
- a plurality of supports for at least partially supporting the chassis portion relative to the at least one left hull and the at least one right hull;
- the plurality of supports including
- a front left support ram including a front left support compression chamber forming at least part of a front left compression volume,
- a front right support ram including a front right support compression chamber forming at least part of a front right compression volume,
- a back left support ram including a back left support compression chamber forming at least part of a back left compression volume, and
- a back right support ram including a back right support compression chamber forming at least part of a back right compression volume;
- the front left support ram and the back left support ram being connected between the chassis portion and longitudinally spaced points on the at least one left hull;
- the front right support ram and the back right support ram being connected between the chassis portion and longitudinally spaced points on the at least one right hull;
- a front left diagonal conduit connected to and forming part of the front left compression volume,
- a front right diagonal conduit connected to and forming part of the front right compression volume,
- a back left diagonal conduit connected to and forming part of the back left compression volume,
- a back right diagonal conduit connected to and forming part of the back right compression volume;
- the front left compression volume and the back right compression volume are selectively interconnected by a first diagonal support interconnection valve between the front left diagonal conduit and the back right diagonal conduit;
- and
- the front right compression volume and the back left compression volume are selectively interconnected by a second diagonal support interconnection valve between the front right diagonal conduit and the back left diagonal conduit;
- a deck attitude control system comprising
- a controller,
- at least one force sensor, at least one pressure sensor, at least one acceleration or position sensor,
- a first diagonal actuating arrangement for controlling fluid flow between the front left compression volume and the back right compression volume, and
- a second diagonal actuating arrangement for controlling fluid flow between the front right compression volume and back left compression volume;
- the first diagonal actuating arrangement including the first diagonal support interconnection valve and the second diagonal actuating arrangement including the second diagonal support interconnection valve;
- the controller configured to control the first and second diagonal actuating arrangements in dependence on signals from the at least one force sensor, at least one pressure sensor, at least one acceleration or position sensor to control a position of at least one point on the chassis portion relative to at least one reference.