KSS New X Cat 30

The twin hulls of a catamaran are ideal for a trail and sail yacht, providing high stability, minimum weight and good performance.

The objective is to produce a craft which takes least time to get from the trailer to sailing. There are four sizes available: 26, 28, 30 and 33 feet LOA.


K S S  N E W  X  C A T  3 0

Design No 361 (Composite construction E-Glass and PVC foam)
The novel beam system is based on simple, sliding beam parts. The central accommodation supports the beam system and provides a comfortable saloon for the off-watch crew or non sailing family members. The hulls tuck under each side in the narrow condition. The rudder and outboard operate in either the narrow or the wide condition. The expansion and the raising of the mast can take place while underway under outboard motor - for least time spent at the slip.

Beam System
Most known catamaran beam systems are based on complex folding parts. The Kisskat beam system uses box section beam parts which are attached to the hulls, where the beam part on one side slides within the beam part from the other side, which slides within the central unit. The width is expanded and then the beam parts are fixed in the wide operating condition. The arrangement while in closed condition and changing width is stable at all times in calm to moderate wave conditions.
The full length of one beam part slides within the other. A plastic and stainless steel worm gear, between the beam parts, provides the force to slide, operated by hand or by electric motor. A lever or tackle system can also be used. The trampoline becomes tight in the wide condition.

The beam parts are tapered outwards. The other half of the larger beam has a parallel section to pass over the smaller beam part. Both ends of the smaller beam part are tapered.

The connection of the smaller beam part to the hull is a narrow structural member below and centrally positioned to coincide with a slot in the lower face of the end of the larger beam part.

When expanded, the ends of the beam parts remain overlapped by 30mm, with the smaller beam part, within the end of the larger beam. The fixing mechanism retains the two beams located relative to each other and against a channel within the central unit. A notch at the end of each beam part locates with a matching fixing pad, which is lowered onto the ends of the beam parts. It is held there with a ratchet strap, applying downward pressure on both beam ends at the same time.

Where each beam part exits the central unit, a saddle contact area matches the beam part section shape. On the small beam side, the saddle is 40 mm wide and smaller than the large beam section. This determines the length of the large beam part, which stops just short of this saddle when in closed position.

A ratchet strap is wrapped under the beam part and pressure is applied at each of the four positions of the beam parts in contact with the central unit, to cater for any reverse loading in wave conditions.

The low friction pads are used in the small contact areas.

A mould table, resin infusion and full foam sandwich structure ensure the best light weight structure in the least build time. The mould table provides a smooth gel coat finish for all of the exterior except the joins and round bilge of the hulls. KSS half hull shaping and kit assembly is the approach. The whole of the central platform is first laid out flat from the drawings. Bend lines and curved area are treated to allow shaping, before completing the inside skin. The saloon sides and top are bent from a single panel, to which the bulkhead and the forward panel are joined. Openings, recesses for windows and edge treatment for joining are built into the parts while being infused on the mould table. KSS build is unique to Kelsall Catamarans.

Length Overall LOA m
Beam Overall BOA m
Draft Dft m
Displacement D t

Sail Area sqm

Study Plan is available here