Spring-Pole Drilling: How was the drill bit lowered?

The principle behind spring-pole well drilling is very simple: A long pole acts as a spring-loaded lever to raise drill tools upward after they have been pulled manually downward. The well is drilled slightly deeper each time the drill bit strikes the bottom of the borehole. How do you lower the string of drilling tools so that they continue to make contact with the bottom?




The U.S. Bureau of mines produced a silent movie in the early 1900’s demonstrating different methods of oil-well drilling and the technological progress that had been made since the Drake well was drilling in 1859. Included in that movie was a scene demonstrating spring-pole well drilling. The well-known photo shown above is a still frame from that movie. Visible in the photo is one leg of the tripod derrick with ladder rungs nailed to it; the front end of the spring pole; the two men drilling the well have their feet in rope stirrups that allow them to push down- or “spring”- the pole for drilling. A very interesting feature is the home-made “temper screw” attached to the spring pole and drilling line (identified with arrow).
In percussion drilling operations, some mechanism was needed for letting out more drilling line, or lowering the drill rods, and allowing the hole to be made deeper. The elongation winch, or “slipper out”, used with the Canadian-type rigs could let out a chain to lower the string of drill rods. The American standard rig held the drilling line in a cable clamp and deepened the bore hole by slowly backing out a heavily threaded frame known as the “temper screw” which was carried on the front end of the walking beam.
The spring-pole rig pictured above used a very simple, home-made, version of the temper screw. A long steel plate is drilled through with holes every few inches along its length. The bottom end of the plate has a clevis for attaching the drilling line with a hitch knot. Enough extra line is let out to allow the entire plate to be lowered toward the borehole as the hole is gradually drilled deeper. The plate could be put through a slot in the spring pole, or mounted to the side of the spring pole and held in place with a bolt or steel pin. When the tools needed to be lowered during drilling, the pin holding the ‘temper screw’ in place was pulled out and placed through a higher hole in the plate. When the temper screw was drilled up to the top hole in the plate, the tools were pulled from the hole and the debris removed with a bailer. After bailing, the drilling tools were run back in to the bottom of the bore hole. The place was re-pinned to the spring pole starting at the lowest hole. The hitch knot was loosened, and enough drilling line was played out to allow the entire ‘temper screw’ to be used. Drilling could resume after retightening the hitch knot.