Upper hull design/build progressing
The photo above shows work in progress August 2011 on the upper hull structure of Quicksilver. Steps are made possible as each new batch of engineering drawings is released for manufacturing. Most of the upper hull has either already been built, or is in or approaching the detailed design stage.
Among the more recent major components added to the boat is the trunnion hoop – so called because it is situated astride the trunnion mounts (side mountings) of the craft’s Rolls-Royce Spey engine. This is the component shown above in manufacture at the premises in Aston, Birmingham, of Radshape Sheet Metal . Radshape joined the Quicksilver project in 2007 and we are extremely grateful for the considerable contribution their highly-skilled specialists have made to our engineering effort to date. Pictured welding, Mark Patrick has 15 years’ experience in this trade with Radshape. Our thanks to him, and to fabrication specialist Billy Howarth – who having joined the firm 28 years ago is Radshape’s longest-serving employee, and has led the Aston company’s work on Quicksilver. Thanks also to Mark Mitchell and Richard Massey in Radshape’s CAD department, who take our 3D designs and turn them into workable CNC programmes so all the constituent parts can be laser-cut from aluminium sheet. Mark has been with Radshape for thirteen years, Richard nine.
Primary function of the trunnion hoop – which is distinguished by its bright green colouring in the CAD images below – is to contribute strength and rigidity to the main hull module at one of its key structural junctures: the point where the rear sponson-arms, port and starboard, will exert significant loadings in the centre of the craft.
In a secondary function, the trunnion hoop is capable of supporting the weight of the engine. The Quicksilver team has not released any further details on this aspect of its design, beyond stating that the hoop is “adaptable in service”. Radshape delivered the trunnion hoop in January 2012.
A “sister” hoop structure situated close behind the trunnion hoop adds strength and rigidity to the rear part of the main hull module, and also serves as the upper-rear mounting point for the Spey engine. This hoop – which is coloured purple in the uppermost of the two images below – is referred to as the rear hoop and was fitted to the boat in 2008, having been manufactured to our design by Radshape in the early part of that year.
Both of these hoops are removable to allow the engine to be installed or removed. They are both all-welded fabrications in high-performance aluminium alloy: 6082-T6 for the trunnion hoop and 7020-T6 for the rear hoop. The extensive employment of finite-element analysis (FEA) techniques in the design phase ensured that both of the hoops are as lightweight as they can possibly be, conducive with their strength and stiffness requirements, and appropriate safety margins.
Other notable features in the upper hull region include the air-intake module. This is an all-composite, primarily carbonfibre/Zylon, structure which internally directs air smoothly into the engine and externally serves as the outer skin of the craft in the area above and between the front and rear sponson-arms.
The air-intake module is held in place by several supporting structures (coloured red , pink and gold in the CAD images above), one of which is a third hoop – known as the intake hoop. Made in 6082-T6 aluminium, this hoop is different in format to the others, not least because it bears two diagonal bracing struts which extend out to the tops of the sponsons. When structures such as this are designed in detail, a variety of calculations are undertaken and extensive FEA is conducted, in order to fully understand the forces that are to be managed. Form follows function, as the saying goes. The intake hoop was duly completed and went on the boat in April 2013.
An all-composite engine cover – composed of several sections, any or all of which are rapidly removable when access to the engine is required – will enclose the entire upper hull area of the boat, providing a streamlined and waterproof outer skin. The engine cover also contributes to the overall strength and rigidity of the boat, as it is being designed as a fully-stressed structural element.