Current work – Outer hull construction

Underside shape revealed

Patternmakers Eddie Brown and Shaun Wright

The key focus for us for some considerable time now has been the outer hull structure. Much of the activity has been conducted behind closed doors, with no photos released, as there are aspects of the task that are as-yet confidential. However, we want to offer a glimpse into some of the work involved, so to that end we are going to be releasing several more images, exclusively to this website, that provide a tantalising glimpse of the external size and shape of the boat, and demonstrate the scale of the work that's been going on.

What is shown here is the pattern for a major portion of the outer hull structure. The shape of the bottom and sides of the boat can be clearly made out, as can the step – a feature on the underside of the hull that will help the boat to 'unstick' from the water and rise up onto the surface, into the planing condition. One major feature is missing from what is seen here, and that is the pattern for the chine – a curved lip at the front of the hull that, like the step, will help the boat rise onto the plane.

When composite materials are to be used in construction, as they will in this case, either a pattern or a mould must be made – and in some cases, both – to provide a foundation upon which the materials to be used for construction can be ‘laid-up’ in the desired shape. In this case, the shape is the underside and flanks of the boat, extending from the tip of the bow to a bulkhead some 25 feet aft. This area is delineated by the red line in the CAD image at the foot of this page, which also shows the positions of the main-hull spaceframe, the Rolls-Royce Spey engine, the air-intake module, the main sponson-arm and the foredeck.

The hull pattern shown here is an outstanding example of the patternmakers' craftsmanship. It was made entirely by hand, by Millfield Patterns Ltd. in Newcastle upon Tyne, with timber being used throughout. Its weight has been estimated at one ton!

Construction of this pattern was but one of many major tasks standing between us and completion of the outer hull structure, and all manner of engineering activities have been keeping us gainfully engaged as we strive towards that goal. They have ranged from conceptual design at the very outset to determine the ideal outer-hull shape, to windtunnel testing and computational hydrodynamic (CFD) analysis in verification, and structural (FEA) analysis too, plus a lot of other CAD work, including some very specialised complex-surfacing work, then on through the various stages of selecting and sourcing appropriate composite materials, followed by the manufacture of small samples of hull structure for 'three-point' bending tests to destruction, and impact-testing.

During this time we also manufactured the first element of the outer hull structure, the foredeck: a task that required not only a pattern to be made beforehand, but also a fibreglass mould. With the mould completed, carbonfibre skins were laid-up either side of an Airex structural foam core, to create a very strong yet lightweight sandwich panel that will be joined to the lower element of the outer hull in due course.

The lower element of the hull is being made from a combination of Kevlar and the highly-engineered balsawood product Baltek, with 'lay-up' work currently under way at a secret location in Lincolnshire involving extensive use of the resin-infusion method, whereby epoxy resin is drawn into the Kevlar under vacuum both before and throughout the curing process. A variety of metallic fittings are being incorporated into the structure during construction, to serve as connecting-points between the outer hull and the high-tensile steel spaceframe, which has already been built.

Overall, the outer hull's design and construction is by far the most complex and time-consuming task ever undertaken internally by the project, and it has been occupying most of our attention for longer than we would ideally wish. However, the job has to be right first time, so the care and effort being expended is entirely justifable.

Specialists who've contributed to different stages of the outer hull's development include Lorne Campbell, Mike Coulthard, Mark Evans, Mike Green, Tim Harrison, Simon Hart, David Johnson, Ed Lupton, Jeff White, Bill Woodhouse and Shaun Wright, with industrial support coming from 3A Composites SA of Sins, Switzerland, Competitive Carbon Composites in Nottingham, Millfield Patterns Ltd. in Newcastle upon Tyne, M. Wright & Sons Ltd. of Quorn in Leicestershire, Trident Foams Ltd. of Furness Vale in the High Peak district of Derbyshire, and Wessex Resins & Adhesives Ltd. of Romsey in Hampshire.

Our thanks to everyone involved – and to our logistics specialist, Bob Johnson, and the rest of his team at BSJ Holdings in Sleaford, as the task of moving patterns, moulds and finished components from one part of the country to another at progressive stages of the build process is not only exacting but potentially back-breaking at the same time!

We'll be issuing further images and information on the outer-hull build shortly.

Images © QWSR Ltd.