Dario's Lab

A Selection of Custom Work in High-Performance Marine Applications

Moth Control System Development

Under the Carbonix banner, in collaboration with Scott Babbage, Sailing Bits, and top sailors, we developed and tested over a number of seasons new mechanical solutions.

The aim was to reduce control surface drag by minimising friction and chatter.

Analogous to automotive suspension, the mechanical ride-height control of a Moth needs to filter out high-frequency noise (caused by ripples in the water surface) whilst reacting positively to actual variations in hydrofoil flight altitude.

Input is via a wand with a paddle at the bottom end that skims over the water surface. As the boat flies higher, the angle of the wand changes. These angle changes are transmitted via a series of adjustable linkages and pushrods to a flap on the trailing edge of the main foil. As the boat flies higher, the mechanism reduces flap angle to decrease camber and shed lift.

The mechanisms evolved from simple swivel pins to sophisticated geared assemblies using large-diamtre ceramic roller bearings and incorporating ratio adjustments that the sailor could tune ‘on the fly’.

Eventually we added a bowsprit to move the wand ahead of the boat and separate the paddle wake from the main vertical foil. Bowsprits are now ubiquitous in the class.

The similarity to automotive suspension is remarkable and this is another example of valuable crosspollination between different applications of engineering design problem solving!

Morticia SeaCart 30 Hydrofoil Conversion

Having pioneered competitive foils on our A Class catamaran and proven our ability to optimise foiling performance on our Moth control system, we were approached to retrofit lifting foils on a SeaCart 30 racing trimaran.

The SeaCart is a trailable carbon trimaran with proven performance and decent production numbers. However, it embodies a design philosophy very much of the displacement era (typified by ‘veed’ hulls with progressive reserve buoyancy).

Adding lifting foils required in-depth investigation of dynamic behaviour and structural loads.

We formulated a plan to progress from a ‘foil assisted’ phase (where the new foils add righting moment, reduce effective displacement, and provide pitch-stabilisation) to eventually full-foiling (adding horizontal spans at the bottom of the initial C foils).

Carbonix coordinated the project, enlisting D3 Applied Technologies for CFD and VPP work together with Ellis Engineered for structural modelling.

The mechanical design and fabrication, as well as composites work, was carried out by Carbonix.

The boat went on to win several prestigious events on the Australian East Coast and Pacific Circuit.

WaveChaser, Kayak, YuuZoo Maxi Yacht

As fledgling Carbonix grew in capability, having proven the team’s knack for rapidly meeting competitive technical challenges, more projects walked through the door.

Part of the founding strategy was to take on a variety of challenges in order to identify applications where our competitive edge could be maximised.

The images below show some instances of these varied applications.

WaveChaser was a new concept for summer off-the-beach fun. It used a pair of paddle boards as hulls, joined by a raised deck platform to create a surface-skimming catamaran. It was powered by twin windsurfer rigs.

Our customer’s idea was to maximise the modes a user could enjoy the equipment – two paddle boards, two windsurfers, or a skimming sailboat with a stable platform capable of supporting up to four people.

Carbonix designed and built prototypes addressing the modular construction and assembly solutions, whilst strictly controlling weight and maximising stiffness.

After initial sailing trials were successful, a set of lifting foils were added to further enhance performance.

Though WaveChaser used concepts and technologies derived from top-end competition, care was taken to design for production, minimising labour costs.

Another application of our knowhow to off-the-beach fun craft (and another collaboration with D3) was a pioneering foiling kiteboard that won a European Championship. This platform (pictured on the cover page for this section of the portfolio) benefited from learnings in the A Class and used surface proximity to control heave.

The Kayak project sought to apply lightweight construction and beautiful finishes to a ‘cruising’ hull with sufficient stability for open water cruising.

Our customer observed that the kayak market was split between racing hulls that were very light but difficult to ride and cruising hulls that were stable but tended to be built of cheap and heavy (if rugged) materials like ABS plastic.

Combining lightweight construction with a stable hull would make paddling more efficient as well as rendering it easier to carry the boat to and from the water, and lift it onto car roof racks and storage shelves.

The cockpit was also designed for optimum ergonomics, paying particular attention to the angle of the legs and lower torso to reduce fatigue.

The deck featured a raised foredeck (inspired by our Marbleheads), a built-in storage box in the aft deck, and integrated conduits and fittings for the steering gear.

Among various fitout options were Kevlar keel rubbing strips, kick-up rudders, and built-in carry handles made from billet machined aluminium.

This project represented the highest level of technology and craftsmanship applied to an object that would be a joy to own because it worked well and was beautiful and meticulously crafted.

Various construction techniques were tested including carbon/aramid honeycomb sandwich with an integrated centreline slip joint so the whole shell could be cured in one piece.

The image above right shows one of many simulations run to optimise a new appendage set for maxi yacht YuuZoo.

In preparation for the Sydney to Hobart race, and with a broader plan to build an Australian elite sailing squad aimed at ocean racing and the America’s Cup, Carbonix was engaged to project manage a refit of the veteran maxi yacht.

Among various upgrades to the rig and deck, a new canting keel and retractable canard were added.

This involved striking the usual balances of foil thickness, span, section, structural arrangements… Balancing weight and drag whilst ensuring ruggedness and user-friendliness.

The canard could also be trimmed up to five degrees either side of centreline to optimise angle of attack. The bearings required some very careful engineering and material selection. They had to take considerable side force and grounding loads whilst offering sufficiently low friction to permit lowering, raising, and rotating the foil whilst underway.

The pictures above and below show a selection of custom hardware developed for various marine customers.

Carbonix became a trusted source for highly optimised custom machined hardware in aluminium, titanium, and steel.

We also developed sophisticated moulding techniques to repeatedly and accurately make intricate shapes such as the tapered bent tubes shown below. These were cured in one piece with an internal bladder consolidating slip joints that straddled the mould split lines…

Carbonix designed and made the tooling as well as the parts.