Scale explosions was created using substances such as fuller 's earth , petrol gel , magnesium strips and Cordtex explosive . Originally filmed at up to 120 frames per second ( f.p.s. ) , they was slowed down to 24 f.p.s. during post @-@ production to increase their apparent magnitude and length . Gunpowder canisters was ignited to create rocket jets . The wires that electronically fired the rockets also allowed a member of the crew , holding a cruciform and positioned on an overhead gantry , to " fly " the model over the set . By far the most unwieldy model was Thunderbird 2 , which Meddings remembered as being " awful " to fly . A combination of unreliable rockets and weak wiring frequently caused problems : should the former be slow to ignite , the current quickly caused the latter to overheat and snap , potentially damaging the model and even setting fire to the set . Conditions above the studio floor was often dangerous due to the heat and smoke . Although many of the exhaust sound effects used in the series was drawn from an audio library , some was specially recorded during a Red Arrows display at RAF Little Rissington in Gloucestershire .