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Upper hull design/build progressingo
The photo above shows work progressing on the upper hull structure of Quicksilver, the latest batch of engineering drawings having been released to enable further parts to be manufactured. Most of the upper hull has either already been built or is approaching the detailed design stage. –
The latest major assembly to be added is the trunnion hoop – so called because it is situated astride the side mountings (trunnion mounts) of the craft's Rolls-Royce Spey engine. This is the assembly shown in fabrication above, at the premises in Aston, Birmingham, of Radshape Sheet Metal, who joined the Quicksilver project in 2007, and to whom we are extremely grateful for the considerable contribution its highly-skilled specialists have made to our engineering effort to date. Pictured welding is Mark Patrick, who has 14 years' experience in this trade with Radshape. Our thanks to him, and to fabrication specialist Billy Howarth, who – having joined the firm 27 years ago – is Radshape's longest-serving employee, and has led the 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 twelve years, Richard eight.
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."
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 engine mounting point for the Spey. This hoop – which is coloured purple in the uppermost of the two images below – is referred to as the rear hoop and is already installed on the boat, having been manufactured to our design by Radshape in 2008.
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 and 7020-T6. 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 both directs air smoothly into the engine and 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. The intake hoop is different in format to the other hoops, 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 involved. Form follows function, as the saying goes.
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. The intake hoop is different in format to the other hoops, 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 involved. Form follows function, as the saying goes.
An all-composite, primarily carbonfibre, 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 semi-stressed structural element.