A practical treatise on the working and ventilation of Coal Mines, with suggestions for improvements in mining

Front matter

A PRACTICAL TREATISE ON THE WORKING AND VENTILATION OF COAL MINES; WITH SUGGESTIONS FOR IMPROVEMENTS IN MINING. BY JOHN HEDLEY, COLL1KBY VIEWER ASD -JIISIS3 AGEKT. LONDON: JOHN WEALE, 59, HIGH HOLBORN. WIGAN: H. B. RECKITT. MDCCCLI. CONTENTS. Chapter I. Introductory Remarks. II. Remarks on the Working of Coal Mines. III. Remarks on the Ventilation of Coal Mines. IV. The Working of Mines by Bord and Pillar. V. The Ventilation of Bord and Pillar Workings. VI. The Working of Mines by Long Wall or Long Work. VII. The Ventilation of Long Wall. VIII. The Working of Mines by Wide Work (Yorkshire Coal Field). IX. The Ventilation of Wide Work. X. The Yorkshire Long Wall method of Working Mines. XI. The Ventilation of Yorkshire Long Wall. XII. The Working of Mines by Narrow Bords and Long Work. XIII.

The Ventilation of Narrow Bords and Long Work. XIV. The Working of Mines by Narrow Ends, and getting the Pillars in ribs or jenkings. XV. The Ventilation of Narrow End Workings. XVI. Remarks on Safety Lamps. XVII. Observations on the use of Scientific Instruments in Mining. XVIII. Remarks on Fires in Coal Mines. XIX. Advice to Underground Colliery Managers, and Practical Hints on the Management of Mines. XX. Rules and Regulations to be Observed by Workmen in Collieries. DESCRIPTION OF PLANS. Plans 1, 2 & 3. Illustrating the method of Working by Bord and Pillar, and also of the Ventilation. 4. Illustrating the method of Working by Long Work, and also of the Ventilation. 5, 6 & 7. Illustrating the method of Working by Wide Work (Yorkshire Coal Field), and also of the Ventilation. 8 & 9, 10 & 11.

Illustrating the method of Working by Long Work (Yorkshire Coal Field), and also of the Ventilation. 12 & 13. Illustrating the method of Working by Narrow Bords and Long Work, and also of the Ventilation. 14, 15 & 16. Illustrating the method of Working by Narrow Ends, and also of the Ventilation. ERRATA. Page 107, line 18, for done, read be done. DIRECTIONS FOR THE BINDER. Plans 1, 2 & 3 to be inserted at Page 42. Plan 4 to be inserted at „ 52. Plans 5, 6 & 7 to be inserted at „ 62. Plans 8 & 9, 10 & 11 to be inserted at „ 66. Plans 12 & 13 to be inserted at „ 74. Plans 14, 15 Sr 16 to be inserted at „ 78. A PRACTICAL TEEATISE ON MINING.

Chapter I

Introductory Remarks. My object in publishing the following pages is to disseminate among Underground Colliery Managers, and others connected with practical mining, information upon the different modes of Working, and the most approved systems of Ventilating Coal Mines in this country. The want of a more extensive and general knowledge of mining among practical men, has from time to time been forcibly brought under my notice during the last few years, by circumstances arising out of the discharge of my duties as a Colliery Viewer; and for some time the idea has suggested itself of publishing a Work on the subject, which other engagements have, until now, prevented the completion of. I wish my professional brethren to bear in mind, that these pages are intended more particularly for the use B of Underground Colliery Managers ; it will be my endeavour to adapt them to the capacities of persons holding such, or similar situations.

In this Work I shall apply the term " Underground Manager'1'' to those persons who, in their respective localities, are known as Under-viewers, Overmen, Bottom -stewards, Underlookers, Undergound-bailiffs, and the like. During my professional experience of the past twelve years, partly in the Northern Coal Field, and partly in the Yorkshire and Lancashire Coal Fields, as well as in occasional visits made to other mining districts, my duties have almost daily brought me into contact with Underground Managers, amongst whom I have met with many skillful and expert pit men. But I have had occasion to observe that their skill and expertness were confined to the particular methods of working practised in their own localities, where, in a great many instances, the modes of working in other districts might be pur sued with considerable advantage.

In every coal district, strong prejudices are enter tained by practical men in favor of the methods or plans of working mines practised in the locality in which they reside. We cannot be surprised at this; since, in general, Underground Managers have been associated from early youth with a particular system of working, to which they have become so habituated, that they are unwilling to entertain, and still less inclined to adopt, any other. The North Country pit men can only talk of the bord and pillar workings — the Yorkshire pit men, of the narrow bords and banks — the Derbyshire pit men, and pit men from some of the Southern Coal Fields, of the long wall or long work. I am anxious to see Underground Managers made thoroughly acquainted with all the various modes of working mines, so that they may be competent to carry out that method of working which is best adapted to the condition in which a seam is placed.

There is much practical detail that I have not noticed in this Work. I take it for granted that persons in the office of Underground Managers, already possess a knowledge of practical detail in colliery management. If they do not, they have no business to fill such office. I have directed attention to the use of those instruments which indicate changes in the atmosphere that affect the safety of mines, by causing bodies of gas to be liberated from goaves and blowers. Some other instru ments which are useful to the miner are also noticed. I have appended to this Work such rules and regula tions as ought to be observed by workmen in, and about Collieries, and which direct the attention of Underground Managers to those means which should be used to preserve the health and lives of their men ; also some remarks on the Safety Lamp, together with rules to be observed for the proper use of it, in mines which yield fire damp.

These regulations for the Safety Lamp were first introduced by my friend Edward Potter, Esq., of South Hetton, Cramlington, and other collieries in the North of England, where they have been generally adopted. I have also added an address to Underground Managers, on their duties, and drawn their attention to some neglected points of practical detail. The remarks on the state in which gas exists in mines by T. J. Taylor, Esq., of Earsdon, Newcastle-upon-Tyne, noticed in the recent Report of Professor Phillips on the Ventilation of Mines, should be attentively read by practical men. It is essential that they should possess a knowledge of the state in which gas exists in mines ; as the means used to preserve the safety of fiery seams at moderate depths, where the gas exists in a feeble state of tension, and flows regularly from the seams, strata, and goaves, when not disturbed by atmospheric in fluences, will not be effective in those deep seams, where the gas is found of greater tension, and accumulated in natural cavities, in, and around the seams, whence it is liable to be suddenly liberated in large bodies, as the workings approach its receptacles.

Several valuable Reports on Mines and Explosions in Collieries, by eminent scientific men of the present day, have, at different periods been published, containing much that is instructive and interesting to the practical man. Among these are the following : — Reports on Gases and Explosions in Collieries, by De la Beche, Lyon Playfair, and Warrington Smyth, 1847. Report on the Explosion at Darley Main Colliery, near Barnsley, by Messrs. Tremenheere, and Warrington Smyth, 1849. The Report of the South Shields Committee in 1843, on the Cause of Accidents in Coal Mines, contains some useful information. The Report of the Evidence given before the House of Commons in 1835, on Accidents in Mines, together with the Report of Evidence on the Ventilation of Mines before the House of Lords in 1849, contains much that every practical man should know.

The recent Reports of Professor Phillips and Mr. Black well, on the Ventilation of Mines, should be attentively read by practical men. They contain much information that would prove eminently useful. I am indebted to these Reports for some valuable statistics upon the sub ject to which they refer. The recent Act for Colliery Inspection, if its provisions shall be properly carried out, will tend to effect many desirable reforms, by the introduction of better regulations, improved arrangements and ventilation in several districts ; and no one will rejoice more than myself to see these improvements carried into effect. Should my humble endeavours prove instrumental in imparting to Underground Managers a more extended knowledge of mining, than that which they may have obtained in their several localities, I feel persuaded that the interests, both of the proprietors and the employed, will be materially promoted.

The deeper Winnings or Collieries of the present day require to be opened on a more extensive scale than those of past times, in order to raise quantities some what commensurate with the expenditure: the increased depth, the greater extent of operations, and greater ac tivity in working, tend to increase the dangers of mining, and the responsibility of Underground Managers. To meet these increased exigencies, it is obvious that Underground Managers should possess greater intelli gence, and more extensive mining knowledge — require ments not only necessary for the management of our deep collieries, but also for the better management of collieries in general. It is to be regretted that in past times the education of the Working Miner has been greatly neglected. The consequences of this neglect have been made so apparent in the disastrous occurrences in mines, ascribable to causes which the moral and intellectual training of the Miner might have prevented, as to have induced a general feeling amongst persons interested in the management of collieries that steps should be taken to correct this evil.

It becomes manifestly the duty of Proprietors for their own sake, no less than for that of the men in their employ, if they have not the means of imitating the laudable example set in many parts of the country, of providing Schools for the accommodation of their work people and of others in their neighbourhood where public instruction is not sufficiently afforded to promote to the utmost of their power such means as exist in their localities for the furtherance of the education of the working classes. The establishment and encouragement of Public Schools, of Reading Rooms and Lending Libraries, the erection of a better class of Abodes, and the exertion of a superintending care over, and the taking a kindly interest in, the welfare of the Working Miner and his family, with much that need scarcely be here particularized, would tend to elevate the character of the Miner, to make him exchange his, at present too often reckless and improvident habits, for such as would evince a more just sense of his duty to his employer and himself; and finally, and above all, by enabling him to exert a more enlarged comprehension of the sources of danger con nected with his employment, and of the instrumentality of the means to be used in repressing it, induce him to act with the unceasing caution indispensably necessary to avert the sacrifice of life.

Chapter II

Remarks on the Working of Coal Mines. In working a Colliery the Owner is anxious to raise the greatest proportion of round, or large description of coal, at the lowest cost, consistently with the proper management of the mine. Large coal realizes a better price, than the small kind of the same quality. The labour of the miner, and the method of working a mine, have an important bearing on the yield of large or round coal, and to this consideration I would here direct the attention of Underground Managers. There is in all coal districts, it must be admitted, a great want of improvement in the skill and labour of the miner, entailing a considerable yearly loss in regard to the yield of large coal, and which might be avoided by care and diligence on the part of Underground Managers. In the course of my experience I have had occasion to observe that this loss has generally been prevented where the men have been properly trained.

It is to be regretted that Underground Managers do not bestow more attention to the training of their Pit Men, so as to increase the number of good workmen. With the view to raise the working character of the Miner, and instruct him better in the discharge of his duties, I have noticed the means to be pursued, in my advice to Underground Managers in Chapter 19 of this Work. The conditions in which seams are placed, with regard to the roof, floor, and natural formation, and the distance of workable seams above or below, are so various, that it is impossible for all to be profitably worked after the same plan. The method of working should, therefore, be adapted to circumstances ; and it has to a great extent, with reference to the quality of the coal, a direct influence on its commercial value, one system of working producing from thirty to forty per cent, or about one-third more of round coal than ano ther, the round coal having the preference in the market.

One seam will be worked to the greatest advantage by the bord and pillar, (See Plans 2 and 3) ; another by long work, (See Plan 4) ; another by narrow bords and by long work, (See Plans 12 and 13) ; another by narrow ends, and the pillars got in jenkings, ribs, or faces, six to eight yards wide, and having one end loose to the goaf or where the coal is entirely excavated, (See Plans 14, 15 and 16). The older explored coal fields have each their peculiar modes of working, modified to suit the circumstances and conditions of the roofs and floors of the seams. In the more recently explored coal fields modifications of the methods of working mines practised in the old working coal fields are commonly adopted. Bord and Pillar or Post and Stall workings are peculiar to the Newcastle or Northern Coal Field, and in that district the arrangement of the workings, the prin ciple of ventilation, and the good discipline established in the well regulated collieries should be more generally imitated by the collieries in other coal fields.

The Long Wall or Long Work mode of working is peculiar to the Derbyshire and some of the Southern Coal Fields. By this method the whole of the coal is got at one operation, by working in banks of various widths towards the rise from the shaft, and maintaining roads through the goaf or broken by building strong stone continuous pillars with the fallen roof: also by driving narrow bords to the extremity, and working the coal towards the shaft or homewards by long work, leaving the goaf behind. In this latter case no roads are maintained through the goaf. Wide Work is a mode of working peculiar to the Yorkshire Coal Field ; a series of bords from seven to ten yards wide, separated by a pillar of coal one yard thick, (and not got out) form a bank, which is worked towards the rise of the mine or from home, pillars of coal twenty to forty yards wide being left between two such banks, and worked towards the shaft or homewards, after the banks on each side are driven the determined distance.

It has been, and is still the practice in many mining districts, in working seams by the bord and pillar, to leave large areas of pillars standing until a considerable portion of the Royalty is excavated in bords or drifts. Long standing pillars do not yield so great a proportion of large coal as those which are more expeditiously worked, and in many instances I have known pillars of long standing to be entirely lost. The exposure of some roofs to the atmosphere for a length of time in the excavated bords, causes a general settling of the roof on the pillars, and crushes them. The loss by crushed pillars is great, and is well known to be so by those who have experienced it. A greatly improved method of working mines has now for some time been practised by the Viewers in the Newcastle Coal Field.

The coal is got in districts, panels or divisions, and whole coal and pillars are worked simultaneously in the same district or division, (See Plan 2). This arrangement of the workings is adapted to a flat seam, and reduces to as great an extent as possible, consistently with the proper working of the mine, the area standing in pillars — these pillars remaining ungot from two to four months, according to the length between the bord or drift faces, and the faces of the working pillars. The arrangement of the workings in Plan 3, is adapted for working seams which have an inclination in the direction of bord-ways course, in districts, panels or divisions. Seams with an inclination cannot have whole coal and pillars worked simultaneously in the same district as cheaply as flat seams : the increased cost of conveying the coal up bank, or up the rise of the mine from the faces of the pillars to the head-ways or end, along which it is taken to the main-roads would be considerable, and the conveyance would be imprac ticable in steep seams.

In the system of working shewn on Plan 3, a district or division of the seam is excavated in bords or drifts before the pillars are touched. The operation of removing the pillars begins at the rise part of a district or division. Advantage is taken of the inclination of the seam in working both bords and pillars, to convey the coal by mechanical means from the panel to the main -road. When Incline or Engine planes are used in a mine, a sufficient width for a travelling -road should be left clear of the passing waggons or tubs. Plan 13 shews an arrangement of the workings to get a seam with a tender roof, in districts or divisions, by narrow bords (in pairs) and long work : this arrangement affects the principle of Ventilation, shewn on Plan 12, but does not render any alteration in the working of the mine necessary, except as regards a little more preparation being required, before the getting of the pillars commences.

The same may be said of Plans 15 and 16. In the course of my experience, I have worked mines by the various modes treated upon in this Work, and I have invariably found that the produce of large or round coal has been the greatest by working long work wherever circumstances were favorable. Many are of the opinion that deep seams cannot be worked with advan tage by long work. The deep Seam at Monkwearmouth Colliery, Durham, 1800 feet below the surface, is however now successfully worked by this plan, and is producing a considerably greater yield of large or round coal, than is obtained by working bord and pillar. A moderately strong seam, at any depth from the surface, may be got by long work, if the roof is suitable for building the necessary packs or walls through the goaf, and less injury is done to upper seams, than by other methods of working, as the packs or walls through the goaf cause large areas of the roof to settle gradually.

This method of working is not favorable for a tender seam having a heavy roof, as the weight on the bank face in such cases crushes the coal. If a mine is first cut out to the boundaries, and then worked towards the shaft, leaving the goaf entirely behind, less coal will be crushed, and a smaller cost incurred in maintaining roads than by getting the coal from the shaft towards the boundaries. This method of working a mine may be pursued in a colliery of limited extent, as only a short period will thus be required to open the mine ; but in an extensive Royalty, where a mine has to be got with a pair of shafts, the necessary preparations will obstruct the vigorous working of it for some years, involve a large outlay, loss of interest on capital, and for the time delay a return of profits on the mine.

If the getting of an extensive Royalty is begun at the shaft and continued towards the extremities, the necessary workings to open out the mine to the boundaries can be pushed forward at the same time. By working the mine after this me thod, under judicious management, whatever loss may be sustained by the coal being crushed, and by the extra cost of maintaining the roads, will be more than compensated for by an earlier return on the outlay. When the mode of working a seam is determined upon, a plan of operation should be laid down, with an arrangement of the workings, suited to carrying out the best system of Ventilation. The shafts should be well supported by leaving sufficient solid coal around them. The roads of the mine should also be protected by strong pillars of coal, proportioned to the depth of the seam below the surface.

When these pillars are left of insufficient strength, and the coal is got around them, the sinking of the roof crushes them, and also damages the roads, whereby a considerable addition is made to the expenses of the mine. When at length the pillars are got, they yield but a small proportion of round coal, and much beside of the coal is lost in the mine through the broken state of the roof, which requires a considerably increased quantity of timber to support it during the working of the pillars. The workings should be systematically carried forward, and the workmen, under no circumstances, allowed to drive places in the mine without proper directions being given ; order and regularity being no less essential to the safety of a mine, than to the economical and profita ble working of it. That haste, which is common among inexperienced adventurers in the coal trade, to raise large quantities of coal, in an incredibly short time after the shafts are sunk, cannot be too strongly condemned : such persons cannot see why they should not at once com mence raising large quantities, and think that others are supine who do not, as soon as the shafts are sunk, begin a wholesale raising of coal.

The experienced coal owner or manager is however aware that there is some preparation absolutely necessary, before this can be done with propriety. This hasty wholesale raising of coal before the necessary preparations are made, is frequently attended with disastrous results. There is no difficulty in working a seam systematically, and ventilating it on the best principles, when it is unin terrupted with Dykes, Throws, or Faults; and it is obvious that any seam may be worked in the manner here described with much less anxiety and care, than one worked without plan, order, or system. Where Dykes, Throws, or Faults are numerous in a seam they offer great obstacles to the carrying out a good system of ventilation, and the resources of a Manager may be frequently taxed in working such seams ; but let him be assured that extraordinary difficulties may be overcome by a plan concerted with care, aided by such means as practical experience and sound judgment may suggest.

In some mining districts the Proprietor lets the working of his mines to a Contractor (in Staffordshire called a Butty), who provides all labor to raise the coal and to maintain the mine in a workable state. The Contractor again sub-lets the different branches of labor to the workmen. This way of letting mines operates to a great extent prejudicially to the introduction of good ventilation and discipline ; almost every man's object being, under such circumstances, to make the most of his bargain, he attends to such of his duties as bring him a return for his labour, until urgent necessity requires the contrary, and thus, provisions which are necessary for the safety and welfare of the mine are neglected. I admit there may be Contractors who feel the responsibility that rests upon them, and provide not only good ventilation, but conduct the mine under as good regulations as circumstances allow.

But the practice being bad, the sooner it is abolished the better, and in its place an approved system of management introduced, whereby the mines may be placed on a footing more secure from accidents, and the produce be raised with greater economy. c

Chapter III

Remarks on the Ventilation of Mines. The extensive Winnings or Collieries of the Newcastle Coal Field, and the large quantities of gas met with in many of the seams, require a powerful and well or ganized system of ventilation, and an effective discipline, to preserve the Mines in a state of safety ; and in no other coal field is the ventilation and discipline of mines carried to greater perfection. The deep collieries of this, and of other coal fields, are liable to sudden eruptions of highly compressed gas, which exists in cavities in, and around, the seams, and bursts into the mine in large quantities, as the workings approach its receptacles, the most powerful ventilation being found inadequate to dilute sufficiently these outbursts of gas so as to render them inexplosive. The following par ticulars of some discharges of gas shew the high state of tension in which it exists, and also the large quantities suddenly given off.

Two sudden outbursts of gas which took place at Walker Colliery, near Newcastle-on-Tyne (in a seam 960 feet deep), as related by Mr. Clarke, Viewer, are recorded in the Reports of Sir H. De la Beche, Dr. Lyon Playfair, and Mr. Warrington Smyth, on Gases and Explosions in Collieries; and also in the recent Report of Professor Phillips, on the Ventilation of Mines. The first took place on the 13th of November, 1846, when approaching a slip dyke or small fault, with a pair of drifts. A mass of coal 8 feet long, 4 feet wide and nearly 6 feet high (about 1 1 tons in weight) was forced from the bed, and a large discharge of gas ensued. Two men were working with lamps in the drift in which the discharge took place ; one of the lamps was put out, the other was partially covered with the fall of coal but continued to burn until it was taken from under the coal, and the wick was drawn down.

The two men then hastened to warn the rest of the men in the pit, extinguishing the lamps as they went along, and finally retired to the shaft. (The steps taken by the men on this occasion were according to the rules of the Colliery.) About 41,681 cubic feet of the air ways were observed to be foul, or in an explosive state. After fifteen to twenty minutes had elapsed, there were no longer traces of fire damp ; the air moved in that part of the mine, where the outburst took place, at the rate of 6 \ feet per second, and the quantity which passed in one minute was 10,483 cubic feet. A second discharge from another point of the same slip dyke took place on the 10th December, 1846. The dyke was in this instance cautiously approached by bore-holes kept ahead of the face of the drifts, the last bore-hole having not only reached, but passed through the dyke or fault into the coal beyond; no discharge of gas ensued even where the Colliers had excavated coal beyond (on the rise of) the dyke, until a portion of the roof was taken down ; then the danty or inferior coal was displaced above where the bore-hole passed, a violent noise was heard like the blowing off of steam, and a heavy discharge of gas took place which fouled the air-courses for 641 yards in length, and an area of 86,306 cubic feet.

At 400 yards from the point of efflux, a deputy met the foul air, saw his lamp fire, and drew down the wick ; the gas continued to burn in the lamp for ten minutes, making it red hot, and then went out. At 641 yards from its source, the gas was met by four men and boys who immersed their ignited lamps in water. The explosive atmosphere, though not observed farther, probably extended farther. The air was circulating at the rate of 5^ feet in a second, and the quantity circulated was about 16,000 cubic feet in a minute. After twelve to fifteen minutes had elapsed, there was no longer any appearance of gas, except near the point of issue of the blowers, where it came off warmer than the air. The Davy Lamp which, on these occasions, saved the mine from explosion, has been used exclusively in Walker Colliery since the accident in 1817- In sinking two shafts at this colliery, the extraordi nary tension force which the fire damp possesses in its underground reservoirs was most strikingly shewn.

In both cases a considerable quantity of solid freestone was moved up, and immense discharges of fire damp took place. Professor Phillips, in his recent Report on Mines, mentions another instance of a discharge of gas, which occurred at Haswell Colliery, Durham, the particulars of which were communicated by T. J. Taylor, Esq. of Earsdon, a gentleman whom I have before referred to. The discharge took place at the face of a pair of exploring drifts, through which nearly 10,000 cubic feet of air were passing per minute, with a velocity of 4. 39 feet per second, and through a sectional area of 37 square feet. Safety Lamps were used at the face. While the Hewer was working in the usual manner in the back drift, he heard a noise, and immediately retreated to the stenting or opening next the drift face ; the sound being like that of falling water, and occasioned by the rushing out of the gas at the face.