11. Manual drilling rig

Manual drilling rig fabricated per a prototype by Robert Doms. The use of this rig for drilling on the Bóbrka oilfield was introduced by Henryk Walter. The method consisted in using the energy of free fall of a drill-bit-chisel loaded with a steel bar. The crucial element of this method were “Fabian’s jars”, a sort of tongs constructed by a German engineer. The set: chisels steel weight-bar and Fabian’s jars instrument, which was installed at the end of a rocking arm (beam), was lifted manually over the drilling spot on the height of the tongs stroke (travel distance) and installed in their top point. By a fast rotary movement the weight with the chisel was released from the catch and dropped freely to strike the rock and crush it. The set rotation provided a borehole, corresponding to the chisel diameter, which was usually 0.5 m. During the course of boring the well, wooden sticks were added, and the well walls were protected with metal riveted tubulars. The well bottom was cleared to remove the borings using a “pipe-spoon” (a bailer). The rig consisted of a tripod, a rocking beam with the drilling string (line) and a big wheel of 5 m in diameter which was called a driving wheel with the spokes located on its circumference. There was a hoisting drum in the centre of the wheel. A line was wound on the drum and run through a block suspended  at the top of the tripod. Running down and pulling out the drilling set and the drilling activities were performed by manual moving (pushing and pulling) the driving wheel using the spokes located on it. The pipe-spoon (the bailer) removing the drillings from the bottom was run into the borehole on a hemp or steel rope from a windlass (drawworks) operated manually, placed near the well.