The Thunderbird machines are a series of vehicles imagined for the mid-1960s film and television Thunderbirds series developed by Gerry and Sylvia Anderson. The released work began with the Supermarionation television series Thunderbirds and was followed by subsequent feature films Thunderbirds Are Go and Thunderbird 6 in 1965–68. The series featured a large variety of futuristic air, land and sea vehicles and machines, the majority of which were designed by special effects director Derek Meddings. In the context of the series, most of the advanced machines appearing in the series belonged to the International Rescue organisation and were used during their rescues. These were known as the "Thunderbirds", of which there were five core machines and a variety of other rescue craft. It was after these that the series was named. In the series, all of the International Rescue vehicles were designed by the organisation's resident technical genius known as Brains. The use of these models in Anderson's Supermarionation productions beginning with Supercar was a significant advance in television production. Dirt and wear was applied as a way of adding realism and countering the miniature models' toy-like appearance. International Rescue's fleet consists of five principal craft; the Thunderbirds: Pilot: Scott Tracy A sleek, variable geometry (swing wing) hypersonic rocket plane, blue and grey in colour, used for fast response, rescue zone reconnaissance, and as a mobile control base. Thunderbird 1 is endowed with VTOL capabilities which are demonstrated in many episodes, and its take-off from Tracy Island is most often vertical. The length of Thunderbird 1 is a matter of debate, with various sources giving values of . However, the last figure is now generally accepted, placing the aircraft wingspan at . With a maximum speed of (Mach 19.7), it can reach anywhere on Earth within an hour's flight if a great circle route can be flown. Thunderbird 1 is hangared beneath the main house on Tracy Island and launches vertically from a pad camouflaged by a swimming pool which slides aside.