How long did it take to drill the kola superdeep boorhole?

The Kola Superdeep Borehole took approximately 19 years to drill, starting in 1970 and reaching its maximum depth of about 12,262 meters (40,230 feet) in 1989. The project aimed to explore the Earth's crust and gather geological data. Despite encountering various technical challenges and high temperatures, it provided valuable insights into the Earth's composition. The borehole remains the deepest artificial point on Earth.