It is quite save to say that the crawler transporter is NASA's eldest piece of hardware for space missions, that is still in use. Built in the years 1964 -1965, it is celebrating its 40th anniversary these days !
With an overall size of 39.9 m x 34.4 m (131 ft x 113 ft) and a weight of 2,494,000 kg (5,500,000 pounds) it is also safe to say that it is the biggest ground vehicle ever built.
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One of the rare color
pictures of the CT in the Saturn/Apollo stage.
Courtesy of NASA