Passage: Work on the foundation began on 4 August 1965 and was finished by the end of 1965. The concreting of the tower foot began on 15 March 1966. The concreting progressed rapidly, so that the 100 metre mark was exceeded on 4 October 1966. The shaft reached its final height on June 16, 1967. A total of 8,000 cubic metres of concrete was used to build the shaft, which was 248.78 metres high and weighed 26,000 tons.

Question: How much did the shaft weigh?
26,000 tons