Drilling a 2 or 3 foot hole can be done with normal equipment, while drilling a ten, fifty, or one hundred foot diametervertical hole would require an entirely new invention.
The most representative landscape features are a number of large depressions, the Tiankengs, with nearly vertical walls and a depth and diameter typically more than 100 m each.
If approved by Lancashire County Council the well will be 8.5in (22cm) in diameter and extend approximately 1km from the current vertical well, more than a mile beneath the surface.