NOTES ON SYSTEMATIC TIMBERING.

By W. H. PICKERING.

This paper is not written in a didactic spirit, but with the purpose of raising a discussion upon a subject which, in the writer's opinion, has never received the attention it deserves.

Since the year 1868, no less than 1,640 lives have been lost in Yorkshire from falls of roof and sides, or an average annual loss of 48 lives. The average for the past 10 years has been 45, and during the same period the average annual loss in the United Kingdom has been 446; and, in 1901, 482 lives were lost. It must be remembered that the injured who linger more than a year and then die, are not included.

The writer is trying to collect statistics of such accidents in this district, and has already gathered enough to show that they are surprisingly numerous.

Satisfactory statistics of the number of non-fatal accidents are not available, as the Coal-mines Regulation Act gives no definition of a "serious accident," and opinions on the subject differ widely; but, during 1900, 1,682 persons were returned as being seriously injured by falls of roof and side, and the number for last year was 1,583. Many of these persons are crippled for life.

The 482 lives lost during 1901, from falls of roof and side, are classified in Table I.

During the last decade, the death-rate from falls has remained practically stationary. Such facts and figures should make even the most careless person pause, and reflect as to whether the right methods of getting coal are being practised. If the total of accidents from falls were accumulated by monthly or quarterly catastrophes, the public conscience would have been shocked long ago and probably drastic remedies would have initiated. But as the accidents claim one or two victims daily, the attrition of life passes almost unnoticed.

Safety of life and limb must always be the first consideration, but the economic point of view must not be overlooked. Every life sacrificed is a direct and serious loss to the country, and every fall is an obstruction and an expense in the mine. Such is the crying evil: what is the remedy?

TABLE I.-NUMBER OF ACCIDENTS AND DEATHS FROM FALLS OF ROOF
AND SIDE DURING 1901 IN THE UNITED KINGDOM.

It would pass the wit of man to prevent some of these accidents, but, in the opinion of the writer, the total would be very considerably reduced, and at the same time the mines could be more economically worked and with less loss of coal, if systematic methods of work and systematic timbering were the general rule instead of the exception. The magic of method will work miracles. The difficulties of changing the method of working in any colliery are enormous, for the officials and the workmen have absorbed the wrong idea, and often work a radically wrong method with astonishing success, but with undue risk and an unnecessarily high cost per ton. It may take many years for a manager to educate his workmen and officials to a necessary change, but it is well for one to be a sower even if one does not live to reap the harvest.

A thoughtful paper read before the members by Mr. W. E. Garforth, and illustrated by photographs, has brought home to the minds of all who were present, the importance of working long

wall faces in straight lines and at an angle with the cleat, when possible.

True longwall, that is, longwall in which the face is a straight line and is advanced in parallel slices, is the simplest and safest method of working coal, and there are few seams that do not lend themselves to it. But the direction of the working-face, the distances apart at which the gate-roads must be set out, the depth of the holing, and the thickness of the ripping, are vital points, which must be judiciously combined if the seam is to be worked to the best advantage. These points are too often settled haphazard, instead of receiving the anxious consideration that they merit. The object should be to distribute the "weight" evenly over a given area, so that the roof settles quietly; and the weight instead of being a master becomes a servant, helping to get the coal. True longwall work most readily lends itself to a thorough system of timbering.

Special timbering rules have now been established at most mines in the United Kingdom. The Special Rules regarding "timbering in mines" as first issued by the Home Office were as follows:

(a.) Propping of Roof.-Where timber or other material is used to support the roof, the owner, agent or manager shall keep posted up, at the mine, a notice specifying for each seam, or district of a seam, the maximum distances apart at which props or other roof-supports at the working-faces are to be set; and the persons setting props or other roof-supports shall see that this maximum distance is not exceeded.

(b) Supply of Timber. -Where the timbering of the working-places is done by the workmen employed therein, the miners shall have a sufficient supply of suitable timber such as is ordinarily used at or within 30 yards of every workingplace where mineral is being gotten, and the deputy shall see that such supply is so kept there.

(c) Drawing Timber.-Wherever timber has to be withdrawn from the waste or other disused parts of the mine, the prop-drawer shall have with him a ringerand-chain, dog-and-chain, or other suitable appliance ready for use.

In most of the mines-inspection districts, the rules have been amplified and strengthened and have been dove-tailed into the code of Special Rules. In Yorkshire, they have been taken as they were issued, and placed at the end of the Special Rules as an addendum.

The duty of specifying by notice the maximum distances at which timber shall be set is variably interpreted. One manager

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will be content with a meagre specification of distance, posted up with the Special Rules; while his neighbour will draw up a comprehensive system of rules for timbering, and post the notice in every working-place. It is surely desirable that the notice should not only comply with the letter of the rule, but that it should be so drawn as to give practical effect to the scheme of systematic timbering, which the manager should devise so as to suit the working of the mine under his charge, and to be a means of educating the officials and workmen. It is not easy to draft a model code, when we remember that seams worked in this country vary from 30 feet to 18 inches in thickness, but the following notice is suggested as embodying most of the vital points:

Name of Colliery or Mine

Name of Seam ...

In compliance with Special Rule......, the following system of timbering has been adopted for the above seam :-

(1.) The timbering of the working-places shall follow, as far as circumstances will admit, the plan of the system, which is posted up at the station.

(2.) The rows of props must be set parallel with the face, and the distances between the rows shall not exceed .....feet, and between the props shall not exceed......feet.

(3.) The props must be set off and on, as shown on the plan.

(4.) Every prop, not being under a bar, shall be capped with a lid not less than......feet long and of sufficient thickness.

(5.) As far as possible, all lids must be fixed so that the natural breaks and joints of the roof shall be crossed at right angles.

(6.) Holing sprags shall be set as soon as there is room, and shall not be placed more than......feet apart; and when the holing exceeds......feet deep a further row of sprags shall be set.

(7.) Where the coal is more than......feet thick or is overhanging, or lies at an angle, cockers or long sprags shall be set.

(S.) Bars shall be set at the way-ends, as shown on the plan, and shall not exceed......feet apart.

(9.) All timber must be fixed as soon as there is room, and, where necessary, fore-sets must be set.

(10.) Additional timber shall be set when and where required.

(11.) Pack-walls shall be carefully built, and pinned to the roof as soon as possible.

(12.) When drawing timber a workman shall use a ringer-and-chain, and other suitable tools.

(13.) Where necessary, catch-props and other temporary timber shall be set to keep the timber-drawer safe.

It is suggested that a copy of the preceding notice should be posted at the stations, and other convenient places in the pit, and where possible, in every working-place; and that it should be

given to each miner with the Special Rules. However good a system may have been devised by the manager, it is only by hammering it into the workmen and subordinate officials that it can be successful in practice. Even those who are unwilling to learn must be educated, though such a task is a thankless one. What is wanted is the formation of public opinion, not only among managers and officials, but also among the workmen, in favour of effective systems of working and timbering. The suggested plan should be on a large scale, and should show graphically the system of timbering.

Next in importance to systematic setting of timber, is the systematic and regular drawing and recovery. Props left straggling in the goaf prevent the roof from settling down quietly and regularly on the pack-walls, and are often the cause of sudden weights and bumps. All timber should be drawn by or under the direct personal supervision of skilled men, and a very liberal supply of proper timber-drawing appliances, such as ringers-andchains and long-handled "bunters" and prickers should be provided in every district of the pit.

A manager must exercise all the skill and judgment with which nature has endowed him and which experience has strengthened, to devise a system of work and timbering which will best suit the seams that he has to work, and such methods will necessarily differ widely.

The following is not put forward as a model system suitable for most seams; but it is given as an instance of a system of timbering which allowed a seam to be economically worked under an exceedingly dangerous roof with almost perfect safety (Plate III.).

The seam is worked longwall, and the line of the working-face cuts across the cleat at an angle of about 30 degrees. The holing is made in a stratum of fire-clay, under the coal, and the bottom section of the seam is blocked down far enough to let the miners hole 4 feet deep, as the fire-clay is only 8 inches thick. timber is set in ranks parallel with the face. spaced 24 feet apart, and the ranks are placed 4 feet from the face where the tubs pass, and 24 feet from the face where the coal is being holed. There is a bar, 5 feet long, over each prop and the

The The props are