Descent into a Shale Pit, 1870

DESCENT INTO A SHALE PIT.

By far the largest shale work in the United Kingdom is that of James Young & Co., whose manufacturing premises at Addiewell have been planted in the very heart of the shale district owned by them, on the confines of East and Mid-Lothian. We were privileged with the permission to descend one of the pits of this company in order to see the minerals in their native bed, and to note the method pursued in their retraction. The pit selected of descent is classed as No.2 of a series of 13 pits worked by this company. No 1 adjoining in communication with No.2 below, and the water which accumulated in both pits is extracted by a powerful pump, which. operating by three lifts in the shaft of No 1, pours out perpetually a cascade of water into a pond near at hand. From this pond the steam power of the huge chemical works hard by is supplied with an abundance of water – a most convenient circumstance during the recent very dry season. Coal is reached in beds in both pits—in No. 1 at 34 fathoms and in No.2 at 81 fathoms and deeper.

In company of a gentleman connected with the chemical works, and a young man in charge of operations below, we set about descending. The belching of the pump close by led us to expect at wet reception at the bottom of the the shaft, and some provision was made in our integuments for the probable occurrences Being provided with lamps, which we held in the left band, to keep our “sicker” we seized with the right the iron bar which crossed the cage from side to side and our descent began.

Being a little inexperienced in these matters, we do not confess to feeling the qualms said to afflict above-ground people when they first find themselves suspended in a min gage, held by a string suspended over a yarning gulf probably 100 fathoms deep. The string, of course, might break, and then what? The thought, in a silent answer to the question, is indeed awful. For the moment we live by our faith on that string, and have the lively wish that the period should prove as brief and safe as possible. We may well suppose that the most veteran miner would experience sensations of an unpleasant kind were he hung within his cage in free air an equal height over a cliff with the roaring ocean beneath him. The danger might, in fact, be equal in both cases. The narrowness of the mine shaft assists to mask the peril to the eye in the descent. The motion of the engine was made intentionally very slow, giving us the more opportunity of inspecting the shale of nearly 100 fathoms on our downwards journey. It was strongly lined with vertical beams in the angles, crossed by thick horizontal planking leaving spots here and there bare for the inspection of the minerals, and there free escape of water, which about half way down began to ooze copiously from the rocks. This flow increased in the descent until the bottom it had the character of a heavy shower of rain down the shaft and streaming down the sides. This water accumulates in a sump or receptacle at a lower level from whence it is extracted by pumping, leaving the pit dry.

This pit is new, the operation of mining in it having commenced within the present year, and several workings were accordingly at no great distance from the bottom of the shaft, and these it was our business to explore. We were , before coming down, shown on paper the plan of the workings and what was seen below was rendered more intelligible by that means. The method of working shale or coal partakes sometimes of the nature of panel work.

Galleries are first cut in the line of strike, at the bottom of each of the two principal shafts, and one of them, in this case is used for drainage, the other for a principal path. At right angles to these , and on the rise of the shale or coal, a number of parallel galleries are driven at certain intervals being much more considerable than in pillar and stall working. The whole area of the shale is thus divided into a number of rectangular portions, each one of which is a kind of panel, and a sufficient wall of separation being left, the interior area of such portion is removed.

Following this plan there are three runs or galleries at different elevations., with panelling or cross workings intermediate. The lowest down of the three is of short length, and only a receptacle for the superfluous water. The central or principal one is brick built, and arched for some part of the way, and the roof is at intervals supported on pillars and beams of round timber, on to the later advance in the workings. The main road affords in its roof and sides abundant room for the workmen to move to and fro in their operations. The necessity of spragging or propping the roof is generally very great in shale pits where not compact and cohesive rock but soft beds form it. The vast pressure of the super-incumbent strata squeezes these soft beds, and any inequality in the resistance caused by the operations of the miner reads tends to cause the roof to sink gradually or to fall in masses, and the floor to rise until these parts world approach and ultimately fill up the space occupied by the shale that has worked out. Apart, then, from the consideration of possible accidents to miners from roof falls, there exists the necessity of propping the roof well to keep the ways open, more especially in a mine that it may come to be worked for many years. The requirement is well provided for is this case We come at length to the end of our journey, or to the face of the workings. Where the depth and character of seam could be well seen and estimated. Here we came upon a miner at work. He was busy lengthening that principal path of which we had come. Hearing voices in the distance, and seeing apparent strangers approach, he ceased from he labour, leaned on a hatch beside him, and folded his arms for a little, while we examined and talked about the quality and position of the mineral deposit before and around us. The miner in his rough attire, with his blackened hands and face, is at once interpreted by his peculiar occupation, and to know correctly what occupation means we must go beneath the ground for the purpose.

Here, about 24 inches of the shale deposit were regarded as excellent—a chip of it, on trial, we found, burned like a taper, and about 35 inches more esteemed of a greatly inferior kind. It require a practised eye to distinguish this difference, but it is pretty obvious even to the uninitiated when it is pointed out. The bituminous deposits appear to shade by degrees into the rock formations that overlie and underlie them – differing thus from coal, which most commonly is abruptly diverse from the other minerals with which it is associated in nature, these frequently being either sandstone or limestone.

Leaving this lower gallery, our next business was to inspect the one higher up, and for this purpose we had to scramble our way through one of the transverse cuts above referred to, made between the mineral pillars left support the roof. The undisturbed shale has a glassy surface, and proves slippery door to tread upon, More especially if that floor is a slope, as in this case. By a little assistance we attained the desired elevation, and proceed here again to the innermost recess of the workings. Another miner was here at similar work to that of his fellow lower down. The particular operation of this man was that of "undercutting" the shale facing, with a view to blasting at a point higher up, so as to dislodge a greater quality of the mineral. The work was lengthy and laborious, involving the use of the of the pick for eight or nine hours in a reclining posture. The difficulty of effective ventilation at such points adds to the discomfort of a constrained attitude in the worker. He toils hard and breathes heavily contaminated atmosphere. The air, doubtless, from the miner's own respiration, the combustion of his lamp assisting, feels oppressive in narrow nooks, and the long hours such spots and at such a task are not favourable to health or longevity. This person was a young man in his prime ; but much labour most be detrimental to the miner who is up in years.

Shale in situ has a singular appearance. Lamp in hand, the light from it it flashed back from a thousand polished surfaces of minute extent, caused by the fossiliferous character of the substance. It does not possess the compactness of coal, nor certainly the usual solidity of sandstone or limestone, but appears in mass an edifice of fossil vitreous material easily broken into fragments. It possesses a considerable cohesive force however, and the miner has to work his way through it by the aid of gunpowder. The blast bores follows undercutting below the shale front. The blast bores are worked by means of screw augers of great diameter approaching 3 inches, in length from 2 to 3 feet, worked into the mineral. The reaction in support of the operation of the borer is obtained from a beam made to cross the roof of the gallery, and supported at the ends by vertical timber bearers. The hazards attending the use of gunpowder in foul mines we have already spoken of, and referral to method of igniting the charge which should get over that peril. Nothing more on that subject need he said here, and we conclude with the remark that, in the went of any experimental means to testing the air currents in this shale, we cannot speak with confidence on that point, but the sensational evidence of the condition of the ventilators seemed assuring and satisfactory.

The North Briton, 29th October 1870