Classe 950

Designed for a North American client who wanted to compete in both Europe and the US in

singlehanded and double handed events, with this being seen as a stepping stone to the class

40 and open 60.

Studying the latest designs we were able to put together what we called baseline1 which

represented the latest, tested shapes and configurations.

Baseline1 was then put thru our VPP which delivered great data on heel angles, trims etc

which allowed us to move onto the CFD where we were able to refine shapes and chine

geometries for these angles.

Over 50 hulls were tested and good gains were made in surface area and resistance pushing

thru waves, with the best gains being made at top and bottom end speeds whilst retaining

good moderate air power and resistance.

The VPP numbers also allowed us to refine the keel, rudder and bulb shapes in the speed

ranges they would be most commonly operating , and surprisingly only a small change in nose

radius's was needed to give the performance required again at the identified heel angles.

Having sailed on one of these boats in Europe last year it became clear what needed to be

improved upon for the next generation and led to the movement of the rig, foils and hull

volume aft to take the pressure off the bow sections and counteract the pushing of the sails

and rig.

The other thing that stuck out from early studies was the amount of lift these big sterns with

low chines were creating at moderate to high speeds. Too much lift, really plunging the nose

down even harder, so we took a leaf out of the Ericson's boys book and raised the chine aft and

softened it forward.

This allowed less chine immersion at high angles and speeds and at low heel angles it lifted a

large section of hull clear of the waves allowing the bow to lift and stay up for longer.

This stern shape also having the added bonus of being fast in the light downwind and at

anytime the boat heel was between 0 and 7 degrees.

Moving everything back also had the plus of stopping the boat bouncing when planning down-

wind which is one of the greatest killers of speed at top end pace.

The shape and buoyancy in the bow also got a lot of attention as there needs to be a balance

between fineness to slice thru waves and fullness to create lift. Moving the hull volume aft

meant the bow entry angles were already reduced but made straighter to stop any bouncing.

The final bow solution chosen has a fairly flat forefoot and what we call a discontinuity

halfway up the topsides, this is essentially a softened chine to force spray off the hull, plus

getting rid of a large chunk of windage at heel upwind and down.

We totally steered clear of the chines fwd after the disasters from the Telefonica boats in the

last VOR where when the chines went negative they would actually drag the bow down more.

Ergonomics

Two cockpit layouts were designed, one with twin companionways and a central control table

the other as shown , both have advantages and disadvantages , but the one chosen was the

simplest as far as build and functionality were concerned. All lines coming from the mast exit

below the deck, run along the aft face of the angled mast bulkhead then along on the inside of

the cabin sides in watertight cavities and to the winch system just forward of the helmsman

and just aft of the seated off watch crew.

The aft cockpit was kept as clean as possible to reduce windage and allow waves to pass thru

quickly. A decision on twin or single rudders is to come at the last possible moment to allow

for further testing and thoughts

The final major choice was where to hang the rudders. Either under the boat, which offers less

drag and needs a slightly smaller blade than the transom hung version (due to its ventilation

problems),or the transom hung version which you can lift the windward rudder out reducing

surface area considerably when heeled which is great for long tacks or gybes.

Engineering

The boat is designed around our well proven fore and aft girder system that transfers forces

thru the entire hull rather than needing more localized reinforcement, the aft girders attach-

ing to the stern at the same place as the back stays are positioned again reducing the boat

twisting from rig loading.

Materials that can competitively be used are plywood, cedar and glass and foam and glass and

because of our fully integrated CAD system we can quickly produce full cutting files for each

option.

The first boat is the foam and glass option.

Version 2, the home build

In the past two years this office has been asked to design a great deal of Home build models

which we thoroughly encourage, so part two of the 950 design process was to design a

multi chine version of the tested hull shape and cabin, to help this side of our sport.

We have done so and produced a hull shape that is very close to the original rounded shape but

ten times easier to build. All panels come in kit sets or modules making for quick accurate

builds.

Hull bottom and topside panels are nearly flat, with the middle chine area having some shape

to it, but not one that is beyond the materials properties. Again all the materials allowed in

the class rules can be used but this design has more flat surfaces which requires less work and

expertise.

Bulkheads and girders are interlocking and part of the hull jig to reduce material wastage.