Background You are working for a design consultancy partnership and a company involved with the design of a vacuum chamber for an electron beam welding machine has requested your services. There are however certain novel aspects to this latest design, which require your expertise in conceptual design. The vacuum chamber must be cylindrical, with its axis vertical, and access to the chamber must be via a removable top (see figure 1). The internal pressure is reduced to give an almost pure vacuum, and so the top plate itself is quite substantial. Electronic equipment to control the welding process is also located on the top plate, which adds bulk as well as weight (top plate plus equipment 400 kg). A significant number of potential customers have been identified for this new product, as long as the minimum operational height limit is not exceeded (see figure 1). In addition, suitable fixings to the top must be incorporated. Suggested fixing points are shown in figure 1, but these can be modified/improved to suit your design.