A method of heavy blasting in which a heading is driven into the rock and afterwards filled with explosives in large quantities. This is similar to a borehole on a large scale, except that the heading is usually divided into two parts on the same level at right angles to the first heading. This forms a T, the ends of which are filled with explosives and the intermediate parts of which are filled with inert material like an ordinary borehole. Similar to gopher hole blasting.