Rib Design

View all RIBS

Akesdesign has a great knowledge on design of Rigid Inflatable Boats (RIBS). As for Boat Designs, the RIB design is focused to join a comfortable deck layout with hull shapes that give comfortable and enjoyable ride in any condition. The stability afloat is due to well dimensioned tubulars and calculated watertight spaces that keep transverse and longitudinal stability even if the central rigid hull is flooded. The tubes are designed to touch the water with people inboard but slightly touch the water surface to avoid fouling. Naturally, all these features depending on user's request. The RIB design is optimized for operational requirements: at the same time s RIB can ben optimized for charter, tender, classic leisure users, high-performance demanding users, professional users, with a deck as efficient and comfortable as possible and naturally with a nice shape, never common or coarse.

As they say, a boat is not a car. The sea is unpredictable, it is salty, and it immediately highlights every poor feature of the boat. A boat first of all must sail well. For this reason, the main aim of the projects is the choice of an hull able to face every condition of the sea in complete safety. Our aims are: sea keeping in every condition: for the planing boats the hull is usually deep-V with medium deadrise ranging from 25 to 35 degrees, with a fore half-angle wider than 45 degrees; a very good length/beam ratio that allows some kinetic energy saving in the impact; an optimal number of spray rails in a suitable position that keeps away the sprays allows a dry navigation; high sheer and a correct incremental volume ratio during the wave impact in order to grant gentle decelerations. After 60+ different hulls launched and tested, all that met customer satisfaction and achieved their goals, ranging from heavy semiplaning catamaran to high performance twin stepped RIB, we have a great database and experience to design the right hull for each purpose.

Stiffness and seaworthiness are very important in order to sail quietly in every kind of weather condition. A careful statistical analysis of breakage experienced by pleasure boat’s hulls commonly used has been extremely helpful in order to create new ISO norms about structural stiffness. These statistics prove that breakage experienced by correctly used hulls produced nowadays are not very common and restricted to the eventuality in which the shipyard had not respected the minimal structural dimension criteria described by the norms, or in the eventuality in which there have been an assembling imperfection or, finally, in the case of an overexploitation of the boat; clearly a peaceful runabout exploited like a race boat and smashed into the waves cannot grant to remain unbroken. We don’t want the customer to fear the bad conditions: all Akesdesign hull are structured by a “big thumb rule” and tested with FEA stress analysis.

The seakeeping is crucial requirement for a seaworthy boat. Very few people go out to sea when it is rough, but nevertheless the boat should ensure such a safety that whoever finds himself in a difficult situation (and it can happen) should safely come back home. The sea-keeping is granted in the project of the boat or of the RIB by designing a good hull, a correct distribution of the weights in order to avoid bad trim angles, a remarkable sturdiness, unsinkable structure, static and dynamic self-bailing. The deck is designed in order to quickly evacuate the water due to a breaker wave . Therefore, there are watertight bulkheads, correctly inclined floor boards, big scuppers that immediately evacuate the water in excess. All this is valid regardless of the CE design category. Some simulations are launched to test the stability (righting lever) and the righting moment in every condition. Many of our boats have righting angles above 130° and some are even self-righting.

In the project of a boat a main point is the possibility of choosing the deck layout following personal requirements. Expecially for aluminum alloy designs, the customer can choose different layouts , of course in accord with seakeeping and safety regulations.

The hulls created by our design studio can achieve great performances compared to the performances of the boats of similar dimension and characteristics, therefore on equal used power they have the advantage of low consumption and of being faster. This is obtained due to great experience joined with latest analysis technologies, like Computational Fluid Dynamics (CFD) joint to the big experience.

Just few examples:

  • Akes 23, an aluminum boat with very deep V and good seakeeping capabilities, achieves 44+ knots with only 200 hp, while the consumption is about 1 liter per mile at 25 knots.
  • Vento500: extremely low consumption, until 3 miles per liter while the stepped hull achieves 33 knots at WOT with 40/60 hp.. but the main feature of this rib is travel through the waves at planing speed while most same-sized competitors point the bow to the sky and stay in displacement mode.
  • Med-extreme 8.5, is a twin stepped hull RIB, 8.5meters, achieved 56 knots with a single 300 hp. One of the word fastest hull.
  • Salpa Soleil 33: the stepped hull of this beautiful rib achieved 54 knots with a pair of 300 hp while most competitors need more horsepower with hulls that can’t afford the rough waves in the same way.

AKES Design: Your Dream, Our Passion!