Spring Pole and Other Hand-Powered Drilling Rigs (Part 3)

Lowering the Drill Rods
If a shaft is excavated through the soil to the rock, a wooden box can be constructed for a casing from the rock to the platform, as shown in Figure 2, instead of using the piping for the rods to work in.
In either case, or assuming that the hole has been drilled some depth from the surface or from the bottom of the casing, the operation for lowering the rods is as follows:
A drill bit, Figure 7, is fastened to a drill rod, Figure 6, then tightened with the wrenches, Figures 11 and 12, and lowered in the hole in the center of the platform, C, and through the casing or into the drill hole. The longer rods are used first, such as the depth will permit.
The top of the drill rod is held at the squared part of its shoulder by the foot wrench, Figure 11, on the platform, while another rod is coupled to it and tightened by means of the hand wrench, Figure 12. The swivel of the windlass rope is screwed to the top of the rod and the whole length of rods is lifted by the windlass a few inches. The weight thus being relieved from the foot wrench, it is removed and the rods are lowered until the upper end [of the top rod] is near the platform. The foot wrench is again placed around the squared end of the rod and the whole weight of rods allowed to hang from it as it rests on the platform. The swivel of the windlass rope is removed and lifted, and other rods are likewise joined and lowered by the windlass.







On nearing the bottom of the casing or hole, such lengths of the 6-, 4-, and 2-foot rods are used as will leave about 2 or 3 feet above the platform when the bit is resting on the rock. The windlass rope and swivel are then removed, and the brace head with its swivel is screwed upon the drill rod. The entire length of rods is slightly raised and the end of the spring-pole rope is passed through the swivel and tied by a hitch knot [a simple ‘temper screw’ can be used in place of the hitch knot]. The rods are then allowed to suspend from the spring pole and are in readiness for the operation of drilling. Each joint of the rods is oiled as connection is made, so as to permit readily uncoupling them when they are lifted.

Drilling
If the rock drilling begins at the surface, a hole is first drilled as deep as possible by hand. A drill bit, Figure 7, with required length of drill rods, Figure 6, are then lowered through the hole in the center of the platform, C, into the drill hole. The lower end of the brace head , Figure 9, is then connected to the top of the drill rods and the swivel of the spring pole is secured to the top of the brace head.
By means of a hook on he windlass rope, or by the two or four men, the brace head and the length of rods are lifted 2 or 12 inches, depending on the weight of the rods, and then the lower end of the spring pole rope is passed through the swivel on the brace head, tightened and tied in a hitch knot. the weight of the rods is thus allowed to suspend from the spring-pole rope, with the drill bit an inch or so above the rock, so that the up and down strokes given by the two to four men at the handles on the brace head the bit will come with a sufficient force against the rock to deliver a cutting blow on the rock.
Four men operate the drill on heavy work, two men on light work. They stand between the handles on the brace head, each one taking hold of two handles so that their hands lap. Then, assisted by the springing action of the pole in the return movement, they bear down and release or drop and lift the rods by the handles of the brace head, as the case may require at the beginning or the end of the drilling to impart a blow with the drill, at the same time they walk around the rods to the left to prevent the rods becoming uncoupled, taking a step with each blow or two so as to turn the rods and drill the hole while cutting.
The play of the spring pole varies from 4 to 8 inches at the beginning of drilling to from 12 to 14 inches at a depth of 200 feet. After drilling 4 or 8 inches, as above, depending upon the depth of the hole, the hitch knot is loosened by a splicing iron and the drill, rods, and brace head are lowered so that the drill bit comes within an inch or more of the rock, depending upon the weight of the rods. This process is repeated until the hole becomes so filled with drilling as to impede progress. Not more than one or two feet can be drilled at a time when it is necessary to draw out the rods and remove the drillings with the sand pump as described further on.
After the drill and its rods have been sunk so that the brace head comes too near the platform to permit the men readily operating it, then the spring-pole rope, and brace head are removed and the rods lifted and the first joint is held on the platform by the foot wrench, while the rods are changed or other lengths added. Such lengths as may be desired by increments of 2 feet can be obtained by combinations of the 2-, 4-, and 6-foot lengths and finally adding a 12-foot rod and repeating again the additions of the 2-, 4-, 6-, and 12-foot rods as the hole becomes deeper. The 12-foot rod remains in place to form the increasing length of the drill rods. The lowering of the rods with the increasing depth of the hole is described under “Lowering of the Drill Rods”.
At the beginning of the drilling, when the weight of the drill rods is not so great, the adjustment of the spring-pole rope is such that as the rods will suspend there from they will be a few inches above the rock. This depends also upon the spring of the pole. The blows are then effected mostly by bearing down on the handles; the return by lifting the rods, assisted by the spring of the pole.
As the hole becomes deeper and the weight of the rods heavier, the blows are delivered by the downward weight of the rods in addition to the bearing down on the handles. The return being effected by the spring of the pole.
All drilling be necessarily done in the presence of water, if such is not present in the strata of the rock, the small quantity must be arranged for. There must be sufficient to always keep several feet of water in the bottom of the hole for the most rapid progress and the greatest depth of drilling between the removals of the rods.
The reamer, Figure 10, is used to true the hole if any ridges or projections have been left in the drilling, or to enlarge it if the drill bits become worn so that the hole is less than the regular size. The reamer is worked in the same way that the drill is operated. The fishing tools, Figures 15 and 16, are for removing drill rods or the sand pump if they drop or become detached in the hole.

Removing the Drill Rods
In order to remove the drilling by the sand pump the rods must be withdrawn as follows:
The spring pole rope, swivel, and brace head are removed from the drill rods. The swivel of the windlass rope is coupled upon the top of the drill rods and lifted until the first joint comes above the platform. The foot wrench is then applied to the squared portion of the rod below the joint and the windlass rope is released so that the weight of the rods suspend by the foot wrench as it rest on the platform. The rod above the platform is then detached from the lower rods by the hand wrench applied to the squared portion of the rod above the joint, while the foot wrench remains firmly in place on the platform. When the upper rod is removed the swivel of the windlass rope is lowered and attached to the top of the rod suspended in the jaw of the foot wrench. The length of the rods is then again raised by the windlass and the weight on the foot wrench is relieved, which is removed and again grasped around the next lower rod as this is raised above the platform by the windlass. The operation is the repeated of letting the weight of the rods rest on the foot wrench and removing the swivel of the windlass rope, uncoupling with hand wrench, and so on until the whole length of the rods is removed.

Use of the Sand Pump
The sand pump, Figure 13, is the lowered into the hole with a half-inch rope into the mixture of drillings and water, and is worked up and down by pulling and letting go of the rope until the settlings have been well stirred up in the hole. The settlings then enter the pump through the check valve at the bottom. As soon as the pump is down as far as it can be lowered and is filled with drillings it is raised by hand or by the windlass and emptied. The hole will be cleaned after drawing up two to three sand pumps full of drillings or as soon as the water discharges clear from the pump. By sounding with the pump is can be distinguished when the sand pump has reached the bottom of the hole by the sharp jar in dropping it while holding the rope taut. The sand pump, now filled with sediment, is then removed.
Heavy drillings occur in drilling through hard or flinty sand stone, iron stone, etc., forming a coarse drilling as compared with that of easier-cutting formations- shales, slates, etc. Pasty drillings are formed in the presence of clayey slates, tending to slack in the presence of moisture, etc. If the drillings are very heavy or pasty, it is necessary to use the sand pump, Figure 14, which is lowered with the drill rods and operated similarly as in drilling until filled with sediment, and is then removed.

Examination of the Drillings
The drillings should be carefully examined, especially when searching for thin strata or seams. When the drillings from the neighborhood of such horizons are raised they should be poured out in separate places and allowed to dry for examination.
When a change in the hardness of the rock or formation occurs, the penetration of the drill into it can be distinguished by the differences in the sounding, ringing, or yielding of the drill due to the increased difficulty or ease in cutting. In this case, or when approaching the formation being sought for, drilling should stop and the rods be removed and the hole cleaned. The depth of the hole is noted at these various stages. Drilling is resumed, an inch or so being driven at a time, until the nature of the formation entered is determined. If it is one of importance, the drillings raised each time are poured out, dried, and kept separately.
In coal beds, as in other formations, the quality may vary at certain portions of the section. For this reason, each few inches of the drillings are kept separately for such examination and analysis as may be necessary.

Removing the Casing
After the hole has been drilled to completion, the pipe casing is withdrawn and the hole abandoned, unless it is to be used for some other purpose [such as a supply well of some kind].
To remove the casing, the pipe lift, Figure 5, is screwed to the top of the piping and the windlass rope tied to it. If the casing is very shallow, the pipe can be raised by the windlass if at the same time a long pipe or chain wrench is applied to the casing, turning it in the same direction as in the coupling, but with sufficient force to turn the whole length in the ground.
If the casing is of considerable depth, it is necessary to bind two iron clamps securely to the pipe below the shoulder of the pipe lift. Two screw jacks, resting on solid timbers laid across the platform and bedded in the earth, are then placed under these clamps, one on either end of the pipe. Power is then applied to both at the same time, and as they begin to loosen the pipe from the soil, it is pulled upon by the windlass rope. This arrangement is shown in Figure 18. The pipe may be thus readily loosened or it may require a continual use of the clamps and jacks, readjusting them with each few inches of play of the jacks, to remove all of the casing.
If the friction of the pipe against he spin, in removing it, is not sufficient to support it while uncoupling, it is supported by means of the clamps as follows: The pipe is raised or 12 feet, as most convenient for uncoupling. The clamps are then secured around the pipe just below the joint, and allowed to rest upon the timber supports, while the lengths above are uncoupled with a pipe wrench and removed. The pipe lift is then coupled to the pipe above the clamps; the latter are removed, and the pipe again lifted further up the hole by the windlass, the clamps again applied, and so on until the casing is removed.

Obstacles and Special Appliances in Drilling
A few difficulties are here described that are sometimes met with in drilling. The outfit that has been considered does not provide for overcoming all of then, as those difficulties requiring special appliances and are not of frequent occurrence. The method of overcoming these obstacles is here described in a general way:
- If the soil contains small caving gravel, sand, etc, it can generally be pierced by the piping assisted by the auger.
- Conglomerate or cement gravel can generally be pierced by the drill, but may tend to become loosened and fall into the hole and wedge the drill rods.
- In either of these above cases, or where the gravel is large and caving, or if there are boulders present, it will be generally found necessary to sink a shaft to bed rock.
- It may occur that, after casing off the soil and drilling through rock, a considerable depth of loose material will be encountered. Either a shaft will have to be sunk from the surface down through the lower strata of loose material or else the 3-inch hole drilled in the rock is gone over with an expansion drill and enlarged sufficiently so that the casing can be driven through the rock and the lower bed of loose material.



Expansion Drill- Figure 19 shows one of the forms of expansion drill suitable for this work and its method of operation. The drilling bits are caused to spread to the desired gauge for drilling, either by their shape or by springs or by the action of the drill rods.

Multiple Casing- Another plan is to sink casing pipe, 4 ½ or 4 ¾ inside diameter, through the first soil [layer] to the rock, and from there drill a 4 ½ inch hole to the lower loose material, which will permit of entering the smaller casing pipe inside the larger casing and driving it through the lower strata of loose material to the rock, and the drilling of the 3-inch hole can then begin at that point.
If there are repetitions of the above formations, either the plan of expansive drilling or the plan of multiple casing can be used. Figure 20 shows the method of multiple casing through two strata of loose material below the surface.
Swelling clay slates are sometimes encountered which require continual reaming of the hole to prevent its closing.





Speed and Cost of Spring-Pole Drilling
This will vary with the size of the hole and nature of the formation traversed. The out fit considered has been for drilling a 3-inch hole, although similar outfits are arranged for drilling 1 ½ and 2-inch holes. The latter [1 ½ and 2 inch diameter drills] are adapted for shallow holes or for strata known in advance to be soft enough to be penetrated by a light-weight outfit. The former outfit [3 inch diameter drill] is preferable for general use, especially for the maximum depth of hole mentioned, or where some hard-drilling rocks are encountered, or if it should be found that, after starting to drill a 3-inch hole, that a strata of loose material exists below the rock, the hole will then be large enough to let a smaller casing pipe down in the 3-inch hole to the rock below, and from there drill a 1 ½ or 2 inch hole. A 2 inch outfit can be readily operated by two men.
In Pennsylvania and Ohio spring-pole drilling of 1 ½ and 2 inch holes have in instances been driven at the rate of 8 to 10 feet a day for the first hundred feet and 4 to 8 feet a day for the second hundred feet. for holes averaging 150 to 180 feet deep the contract price is as low as 65 cents a foot from the surface, the contractor furnishing the [drilling] outfit. The strata in these cases are generally 10 to 30 feet of soil, with limestones, sandstones, slates, and shales below.
In some instances of drilling 3-inch holes about 200 feet deep, the average rate of driving has been 6 feet per day, requiring 34 working days for completion, the speed being 7 to 8 feet a day for the first hundred feet and 4 to 5 feet a day for the second hundred feet. The contract price being 90 cents per foot from the surface, the [drilling] outfit being provided for the contractor.
The speed of drilling in this instance is somewhat slow due to hard, flinty, sandstones encountered. Following is given the section of the strata in which this drilling was done, 43 feet of surface soil and large, loose, gravel being excavated before drilling began.



As compared with diamond drill boring,
1 ¼ inch hole in similar formations, at right are the relative speeds [of the different drilling methods].



The average speed of boring for a 1 ¼ inch diamond drill hole 200 feet deep is 18 to 20 feet a day or about 11 days for its completion. For a 800- or 900- feet hole the speed is 16 to 18 feet daily or about 43 to 49 days for completion. For a 1000- foot hole the average speed will be about 15 feet daily or about 60 days for its completion.
The moving and erecting of the diamond drill from one location to another preparatory to operating, especially in rough countries, is more expensive than with the spring-pole outfit. Allowing 3 days for changing position in addition to 11 for drilling a 200 foot hole it will require about 14 days for drilling a 200 foot hole with changes of location, or about 24 holes 200 feet deep can be drilled yearly, equal to a total of 4800 to 5000 feet
[drilled] yearly. About the same number of feet will be drilled in a year if the holes are of greater depth, say up to 900 or 1000 feet, in the case under comparison.
With the spring pole a 3-inch hole 200 feet deep would be completed in 34 days. Allowing one day for moving and erecting, about 35 days would be required to drill a 200-foot hole and change location, or about 8 or 9 holes 200 feet deep can be drilled
yearly, equal to a total of 1800 feet yearly.