 The largest model of Thunderbird 3 , whose design was based on the Soviet Soyuz rocket , was six feet ( 1 @.@ 8 m ) 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 <unk> , 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 <unk> were designed on an episode @-@ by @-@ episode basis and built from <unk> wood , <unk> wood or fibreglass . To save time and costs , other minor vehicles were built in @-@ house from radio @-@ controlled model kits . 
