the whole and filmed separately. The architecture of the mansion was based on that of Stourhead House, located on the Stourhead Estate in Wiltshire. In the absence of head designer Reg Hill, who was serving as associate producer, Meddings was further tasked with designing the Thunderbird fleet and FAB 1. Scale models for the six main vehicles were built by a contractor, Master Models of Middlesex. Models and puppet sets combined, more than 200 versions of the Thunderbird machines were created for the series. During the designing and filming process, Meddings' first priorities were realism and credibility. With the exception of Thunderbird 5, each vehicle was built in three or four scales. Meddings' swing-wing concept for Thunderbird 1 was inspired by his wish to create something "more dynamic" than a fixed-wing aircraft. He remained unsatisfied with the prototype of Thunderbird 2 until he inverted the wings, later commenting, "... at the time, all aircraft had swept-back wings. I only did it to be different." This decision was made out of personal preference and was not informed by any expert knowledge on Meddings' part. He described the Thunderbird 2 launch as "probably the most memorable" sequence that his team devised for an APF production. The largest model of Thunderbird 3, whose design was loosely based on the Soviet Soyuz rocket, was tall. Thunderbird 4 was particularly difficult to film: as the scale of the model did not correspond to the water inside the shooting tank, creative camera angles and rapid editing were used to produce a sense of realistic perspective. Thunderbird 5, the most difficult vehicle for Meddings to visualise, was based on the Tracy Island Round House. Since most of the space station's appearances were provided by stock footage, the model was rarely filmed. Pod Vehicles were designed on an episode-by-episode basis and built from balsa wood, Jelutong wood or fibreglass. To save time and costs, other minor vehicles were built in-house from radio-controlled model kits. As the puppets of Lady Penelope and Parker needed to fit inside, the largest of all the models was the seven-foot FAB 1, which cost £2,500 (about £ in ) to build. The Rolls-Royce's name and colour were both chosen by Sylvia Anderson. Rolls-Royce Limited supervised the construction of the plywood model and supplied APF with an authentic radiator grille for close-up shots of the front of the car. In exchange for its cooperation,