Design / Construction


Building confidence!

The focal point of our efforts is the construction of theQuicksilver craft. This huge task is being largely undertaken by engineering companies that have supported the project by purpose-making components to our design, or donating off-the-shelf components, or donating standard or specially-made materials that match our requirements.

Contributing companies have all sorts of different specialisations. The range of facilities, expertise and experience needed to progress the construction from start to completion is vast. Firms large and small have risen to our cause of creating a new boat that is every bit as pioneering as it is inspiring.

Here are some insights into the types of work undertaken to date ...

Process engineering

An early breakthrough for the project came when a major British company demonstrated its willingness to manufacture for us. The plan was that if a sufficient number of companies joined in like this, the boat could be built. Accles & Pollock manufactured a substantial quantity of high-tensile steel tubing for the main hull structure. The bulk of the work was undertaken at their plant at Oldbury near Birmingham, but the first stage of the production process, pictured here, took place at a Corus/TATA Steel foundry in Wednesfield near Wolverhampton.

The steel was initially in solid cylindrical billets. These were bored through to a basic tubular form known as a 'tube hollow' and drawn out to longer lengths, then when the process transferred to Oldbury the tubing was shaped into square section and heat-treated. It was now in the extremely rare, supremely strong BSI T59 specification, at 16-gauge, that we required. This has a tensile breaking strain of 55 tons per square inch, yet the tube wall-thickness, at a mere 1.59mm, saves weight.

By their support, Accles & Pollock had set Quicksilver's construction in motion. We are thankful to Paul Rollason, who led their technical input.

Fabricating steel structures

The next stage of building the boat was employing the steel tubing to fabricate a large spaceframe, the primary element of the main hull structure. It is analogous to the skeleton in a human body, in that everything else is attached into and onto it.

BOC Gases had undertaken to play a major role. Due to the type of steel we were using, they had to develop a special welding procedure, which was duly tested and certified by The Welding Institute in Cambridge. Three of BOC's developmental welding specialists were assigned to the spaceframe fabrication programme. Left to right are Craig Rollinson, Steve Moynihan and Chris Birch.

Fabrication occupied hundreds of working hours. Over 130 individual tubular elements had to be precisely cut, carefully positioned and TIG-welded.

The spaceframe was designed by Glynne Bowsher. When a subsequent decision was taken to modify it so it would suit a new version of the boat, Roland Snell designed the revisions. He also designed engine-mountings, in steel. The Radshape company of Aston, Birmingham, implemented the modifications and made the new parts.

Fabricating aluminium structures

A row of four aluminium hoops add strength and rigidity to the main-hull spaceframe. Our longstanding sponsor Radshape has been manufacturing them to our design. There's one more to do.

Achieving a lightweight construction was a key goal. We conducted finite-element analysis (FEA) when designing each hoop, to determine where material thicknesses could be reduced to save weight without unduly reducing strength and stiffness. Analysis modelled the forces that will be transmitted through the hoops when the boat strikes disturbances on the water's surface at high speed.

The design of each hoop is distinctly different, as they all have important secondary functions. For example, the third one doubles as the upper-rear mounting point for the engine. Any or all of them can be unbolted from the spaceframe to facilitate the removal of the engine and/or access to other components housed within the hull.

Radshape laser-cut all the parts. Material thicknesses vary from 3mm to 6mm. Hoops one and two are made from BSI 6082-T6 aluminium sheet, while hoop three is made from BSI 7020-T6 aluminium sheet with a steel engine-mounting assembly bolted into it.

AHT Ltd. of Dudley in the West Midlands will heat-treat the hoops later, augmenting their strength.

Patternmaking

With much of the main hull structure now built, our attention has turned increasingly to the other tasks that have to be done to make it capable of going on the water. The major components described above can be thought of as the internal structural elements, so now the external elements are needed.

A decision was made to use composite materials, which meant in turn that it would be necessary to manufacture a variety of patterns and moulds. Some of the patterns are constructed from timber, while others are machined from solid blocks of special-purpose patternmaking foam material.

The largest of the patterns is pictured here during its construction. Made entirely by hand, it is the pattern for the lower portion of the hull, extending from the foremost tip of the bow to the back of the spaceframe. As can be seen, timber has been used throughout.

This impressive example of the patternmakers' skills is nearly 30 feet long. With all of the longitudinal stringers in place and the exterior fully skinned, the weight of the completed pattern on its integral base is estimated at one tonne.

Manufacturing composite structures

Seen here during manufacture is the 2.35-metre-long foredeck element of the boat's outer hull structure. Multiple layers of carbonfibre have been laid-up in a purpose-made fibreglass mould. A vacuum bag has been tailored tightly over it, so that the air can be extracted and the carbonfibre infused with epoxy resin drawn in via a system of plastic tubes, taps and electric pumps. While the carbonfibre layers are compressed firmly together under vacuum, a process of curing takes place, hardening the fabric to a solid form. The white layer visible here is an absorbent material which soaks-up excess resin and is disposed of with the vacuum bag, post cure.

When this stage of the process was completed, a 15mm-thick layer of Airex structural foam was laid-up on the carbonfibre and bonded firmly to it by repeating the vacuum-bagging process. Airex is a lightweight core material made by the Swiss firm 3A Composites SA.

Further layers of carbonfibre were then applied atop the Airex, creating a sandwich-construction panel that's very stiff and strong for its weight. The inner and outer carbonfibre skins are both 1mm thick, resulting in a panel thickness of 17mm.

The foredeck was made to our design by Nottingham firm Competitive Carbon Composites. They also made the mould, which was produced from a high-density foam pattern machined by Trident Foams Ltd. of Furness Vale in the High Peak district of Derbyshire.

All images this page © QWSR Ltd.