 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 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 . 
 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 <a href='None' title='1'><mark>the</mark></a><a href='negative_concord' title='2'><mark>water</mark></a> inside the shooting tank , creative camera angles and rapid editing <a href='uninflect' title='3'><mark>were</mark></a> 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 <a href='null_genetive' title='4'><mark>'s</mark></a>appearances <a href='uninflect' title='5'><mark>were</mark></a> provided by stock footage , the model was rarely filmed . Pod Vehicles <a href='uninflect' title='6'><mark>were</mark></a> designed on an episode @-@ by @-@ episode basis and built from balsa wood , Jelutong wood or fibreglass . To save time and costs , other minor vehicles <a href='uninflect' title='7'><mark>were</mark></a> built in @-@ house from radio @-@ controlled model kits . 
Da 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 tdascale of thdaodel did not correspond to no water inside thedaootin tank , creative camera angles and rapid editing was used to produce a sense of realistic perspective . Thunderbird 5 , the dat difficult vehicle fir Meddings to visualise , was based on the Tracy Island Round housee . Since most of the space station  appearances was provided by stock footage , the model was rarely filmed . Pod Vehicles was designed on an episode @-@ by @-@ episode basis and built from balsa wood , Jelutong wood or fibreglass . To save time and costs , other minor vehicles was built in @-@ house from radio @-@ controlled model kits .