were having great difficulty casting the part of Alan as they wanted a certain sound for him, being the youngest brother. David, who [was] a bit older than I am, told them that he had this friend, me, who would be great." Christine Finn, known for her role in the TV serial Quatermass and the Pit, provided the voices of Tin-Tin Kyrano and Grandma Tracy. With Sylvia Anderson, she was also responsible for voicing most of the female and child supporting characters. Supporting parts were occasionally voiced by John Tate, Paul Maxwell and Charles Tingwell; the latter two joined the cast in Series Two following their contributions to Thunderbirds Are Go. None of these three actors were credited for their performances. Design and effects The puppet stages used for the filming of Thunderbirds were only one-fifth the size of those used for a standard live-action production, typically measuring with a ceiling. Bob Bell, assisted by Keith Wilson and Grenville Nott, headed the art department for Series One. During the simultaneous filming of Series Two and Thunderbirds Are Go in 1966, Bell attended mainly to the film, entrusting set design for the TV series to Wilson. Since it was necessary for the art department's interior sets to conform to the special effects department's exterior plans, each team closely monitored the other's work. According to Sylvia Anderson, Bell's challenge was to produce complex interiors on a limited budget while resisting the effects department's push for "more extravagant" design. This task was complicated by the unnatural proportions of the puppets: Bell struggled to decide whether the sets should be built to a scale proportionate to their bodies or their oversized heads and hands. He used the example of FAB 1 to illustrate the problem: "As soon as we positioned [the puppets] standing alongside [the model], they looked ridiculous, as the car towered over them." He ultimately adopted a "mix-and-match" approach, in which smaller items, such as tableware, were scaled to their hands and furniture to their bodies. While designing the Creighton-Ward Mansion sets, Bell and his staff strove for authenticity, ordering miniature Tudor paintings, -scale Georgian- and Regency-style furniture and carpeting in the shape of a polar bear skin. This realism was enhanced by adding scrap items acquired from household waste and electronics shops. For example, a vacuum cleaner pipe serves as Virgil Tracy's launch chute. Puppets The head puppet sculptors were Christine