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June, 1943

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Improvements in safety in winding practice have largely kept in step with the safety accorded by improvements in the materials and methods used in constructing winding ropes. Although influences such as the introduction of steam for coal raising, the mechanical improvements of winding engines, more efficient design of drums, brakes and so on, have been important factors in making possible the winding of increased loads from greater depths, the greatest influence in this direction has undoubtedly been due to developments in the wire winding rope. Whereas safety was at one time largely dependent upon various devices and contrivances, the ultimate factor is the reliability of the winding rope. The effect of the wire winding rope on winding practice is illustrated in Table 1, which should be studied in conjunction with other factors illustrated in Fig. 1, page 25, of the February issue of this journal.

Before the early part of the nineteenth century hemp ropes were the only suitable type available for use for winding purposes. They were sometimes round and coiled on cylindrical drums, but generally they were flat and coiled vertically upon themselves between arms projecting radially from a disc. Sometimes they lasted two years, but not infrequently wore out in five to six weeks; Consequently rope costs were high, often being as much as from 4d. to 6d. per ton.

Wire ropes were suggested as early as 1790, but it was not until 1829 that they were introduced on a small scale. Actually in 1796. the Society of Arts offered a premium of Ј50 for an iron wire rope or chain. A wire rope was also supposed to have been manufactured for Haydock Colliery by Wilson, The first regular use of the iron wire rope was in the Hartz Mountains in 1834, where they were used for winding ore. They were designed and made by M. Albert, the chief director of the mining administration of Clanthsane. In 1835 the inventor published several accounts of the manufacture and use of wire ropes, and they were first brought to the notice of English mining engineers in an extract from M. Albert's works published in 1837. In 1838, Count Augustus Breuner, Hungary, published in the north of England his paper "On the use of wire ropes in deep mines." The first use of the wire rope was made in 1840 by Mr. M. Dunn at St. Lawrence Colliery, where it was applied to a horse-gin for raising coal in an underground staple pit about 40 ft. in depth; the rope was 2½ in. in circumference and weighed 4 lb. per fathom. The first real effort to popularise wire ropes was made by R. S. Newall Ltd., who erected in 1840 a wire rope works for the purpose in the North of England. The use of wire for winding ropes was an important innovation and a land-mark in the history of mining progress. In addition to Newall, Kuper, an associate of Sievers and Heinmann, well-known rope makers of the time, established a rope works at Camberwell, London. Kuper's works were taken over by Glass, Elliott & Co., which eventually, at a later date, became the well-known rope manufacturing firm of George Elliott & Co.

Chains were also used to a certain extent for winding. The drawing chain was introduced into collieries in South Staffordshire, in 1810, by Benjamin Edge of Coalport. The "flat rivet" chain was made of two flat iron links with through pins riveted with side plates alternating with three similar flat iron links and looped over the same pins. The weight of these chains was 21 lb. per yard and the breaking load 21.5 tons.

The "wood and stub" chain had three long, links alternating with three short links; the long links were filled with hard wood retained by nails at the edges. Many sizes were made, the maximum and minimum weighing 28 and 10 lb. per yard and having breaking loads of 30 and 10.75 tons respectively.

These chains were for a time popular in shallow pits in the Staffs., Salop and Welsh areas, but after 1850, with the increased popularity of the wire rope, they were gradually displaced and by 1870 there were only one or two chain winding systems in existence.

John Curr, a pioneer in several branches of mining practice, evolved in 1787 the flat winding rope constructed of hemp. It consisted of several small round ropes stretched together, and was made to lap upon itself in winding, thus serving the purpose of a counterbalance. It was not until 1841 that flat ropes made of wire were introduced for winding purposes, Pemberton Colliery being the first to apply them. They were in use at Wingate Grange in 1842, and in 1843 at the Benton and Gosforth Collieries, all in the North of England. The flat ropes were not entirely successful and from time to time miners objected to their use. For several years flat ropes were confined solely to winding while the round wire ropes were adopted for haulage purposes. From 1850, there was a decided acceleration in the installation of round wire winding ropes with the gradual replacement of the flat type, and by 1909 the latter type had fallen into disuse, although they still remained fairly popular on the Continent.

As early as 1837 it was realised that the weight of the winding rope had considerable influence on the load to be carried, and a tapered rope was used for the first time at Monkwearmouth. This was 8½ in. broad at one end and 5½ in. at the other and was valued at Ј300.

The early wire ropes gave considerable trouble owing to excessive wear, and it was not until 1879 that the Langs lay rope was introduced. This excellent design not only exposed a greater wearing surface than the ordinary lay rope but also reduced the internal friction prevalent in ordinary ropes. To obviate the twisting characteristic of the previous types of ropes, Batchelor took out his patent for a locked coil rope in 1884.

In the early part of this century, with greater depth and increased loads to be wound, drums of considerable magnitude became necessary. Such drums had to be of large width and diameter which meant excessive angling of the rope, increased power and heavy foundations. From 1910-1914 the recoiling of the winding rope was introduced with a view to reducing the weight and width of the drum, with the resultant saving in power, and of reducing the amount of angling with the headgear pulley. This century has shown considerable improvement in the manufacture of ropes; the steel used in their construction has to be of the highest quality and must undergo severe tests for tensile strength, bending and torsional properties. Further consideration has been given to maintaining the rope in a satisfactory condition during its statutory life. The design of drums and their relative position to the headgear has been considered with a view to reducing rope angling to a minimum. In one instance, in order to wind from a depth of 900 yards, Morgan found it expedient to utilise at the Dolcoath Mine, Cornwall, an engine and drum, of moderate dimensions. He was faced with the problem of reducing angling of the rope to a minimum since, to coil the rope without overlapping, the drum would have to be excessively long to accommodate the length of the rope. To overcome this difficulty he adopted the novel procedure of mounting the winding engines on a carriage constructed of girders, running on wheels, which enabled the carriage surmounted by the engine to traverse laterally, with each drum revolution, a distance equivalent to the diameter of the winding rope. The total traverse was equal to the space occupied by all the coils of rope on the drum, so that angling was eliminated. Other advantages of this system were the reduction in size of the cylinders and the length of the stroke, made possible by the relatively small diameter of the drum, and a consequent increase in the number of revolutions and in the piston speed, thus permitting expansive working to a greater extent than would otherwise have been possible. The engine is illustrated in Fig. 1 and was traversed automatically by the worm wheel w on the drum shaft, geared into the toothed wheel t keyed on a shaft s, which ran the complete length of the engine and which was provided with a cog wheel c at each extremity geared into a rack built on the engine-house wall. The teeth of these cog wheels were equal in pitch to the diameter of the winding rope and consequently at each revolution of the drum shaft, the engine moved a distance equal to the space occupied by one coil of rope. This idea did not spread owing to the very heavy foundations and structural requirements, together with the high financial commitments necessary.

Hopwood & Marchal, to remove the prejudice attaching to a traversing engine, suggested that to reduce the cost of construction, the engine with its long drum should be situated at right angles to the plane of the winding pulleys, and the rope carried round guide pulleys fixed horizontally near the engine, and that these guide pulleys should be traversed to and fro at the same speed as each coil of rope is wound on and off the drum.

Research, especially by the Safety in Mines Research Board, on rope cores, on lubricants for internal preservation of the wires, on the effect of acidulated waters and mine gases, on metal fatigue and failure, and on the effect of rapid acceleration and retardation on rope travel, are among the contributions that the present century has made to the greater reliability of winding ropes.

Rope cappings

Types of capping used for attaching the cage chains to the winding ropes are illustrated in Fig. 2. One of the earliest forms was that shown in (a) and consisted of two semi-circular collars to encompass the rope. The collars were firmly held in position by means of two clamps but, for additional security, rivets r were driven through the collars and rope. The riveting always gave considerable difficulty; the holes had not to be driven through the rope in a haphazard manner, and unless care was taken, the drill driven directly in would sever wires and the core, thereby weakening the rope. To avoid injury to the rope, a short needle was used, having a point at one end and a head and eye at the other. The needle was struck by a hammer, or rotated by means of a rod through the eye, with the object of making an opening between the wires, without severing the cores, in line with the corresponding rivet hole on the opposite side. Many fruitless attempts had usually to be made before this was accomplished. When the riveting had been completed, the clamps were heated and driven into position.

The capping illustrated in (b) replaced the previous type; the two collars encompassing the rope were held in Position by three clamps, previously heated, driven into Position and allowed to cool, thus gripping the rope tightly by the resulting contraction.

To overcome the possibility of damaging the ropes by riveting the capping shown in (c) was adopted. This Consisted of a socket of slightly tapered - form, which had a conical-shaped opening bored through it. Near the larger end a bolt hole was cut, the two apertures being opposite each other. After the rope had been threaded through the socket, the rope wires were turned back upon themselves and secured in position by binding wire, forming a cone which was drawn into the socket. Often, for reasons of additional security, a conical wedge was inserted into the position originally occupied by the hemp core. The socket was then inverted and molten lead poured into it to fill up all interstices, thus giving greater strength and preventing rusting of the wires which, of course, could not be examined during service. The modern form of this socket is shown in (d), the capping metal consisting of antimony alloys, &c., in place of lead.

For deep shafts and heavy loads Heath suggested the capping shown in Fig. 2 (e) should be used. The end of the winding rope was to be brought round a small drum (a), looped round a ring (b) encircling the rope, carried beneath the drum (a), and finally returned through the ring (b) again. The end then lies parallel with the main rope and the two are fastened together by three glands.

Methods of counterbalancing

It was realised early in the history of winding that the load on the winding engine was a varying factor, and many efforts were made to arrange a system of counterbalancing so that the load on the engine was equalised throughout the wind. Counterbalancing can be obtained by different types of drums, but this will be dealt with at a later stage. The systems to be described are those which were attempted during the nineteenth century to overcome the unbalanced load.

Rope Balance. — This consists of a tail rope attached to the cages. It is fastened to the bottom of the cage at the surface, carried to the sump at the pit bottom, where it passes round a balk or pulley, and then up to .the other cage where it is securely attached. The load on the winding engine is therefore uniform throughout the wind apart from the coal raised. The objections to this method were the additional size of the winding rope required, especially if the shaft was of considerable depth, the extra strain on the winding rope capping, the necessity for strengthening the bottom of the cages, and the additional fitments on the cage and at the pit bottom. This system was introduced in 1875.

One of the best examples of the balanced rope system was that adopted by Meinicke, who, instead of attaching the balance rope to the underside of the cages, attached it to two auxiliary ropes which could be coiled on the winding drum proper, or on auxiliary ones. The auxiliary ropes passed over separate headgear pulleys, and the balance rope was equal to the weight of both the winding and auxiliary ropes. Originally, the balance and auxiliary ropes were left to hang freely in a special compartment of the shaft, but due to frequent fouling it became advisable to guide them in the manner illustrated in Fig. 3. The advantage of this system was that perfect counterbalancing action was obtained and no additional load was thrown on the winding rope capping; the system was too complicated, however, to be popular when compared with the ordinary tail rope beneath the cages.

Pendulum Counterbalance. — This method was only applied to shallow shafts where the necessity for counterbalancing was not of primary importance. The system is illustrated in Fig. 4. A weighted pendulum was raised by a chain attached to a drum on the shaft of the winding engine. At the commencement of the wind the pendulum was in a horizontal position, and therefore the full weight was assisting the engine against the load. As winding continued an increased portion of the weight was supported by rod (a) until the half-way point when it was in a perpendicular position; as the load was brought to the surface the rod returned to a horizontal position, the weight thereby acting against the engine during the second half of the wind.

Counterbalance Chain. — A third method consisted of using a counterbalance chain as shown in Fig. 5. This arrangement required a staple pit about 50 yards deep to permit the chain to be suspended therein. A rope (a) was attached to the drum shaft of the winding engine and to the balance chain suspended in the staple pit. The balance chain was approximately 50 yards long, and was so arranged that with one cage at the surface and the other at the pit bottom, the whole length was hanging in the pit. The rope by which it was wound up allowed the whole of the balance chain to rest upon the staple pit bottom when the two cages met in the shaft. It was, of course, necessary to pass the rope attached to the chain over the drum shaft in a contrary direction to the winding rope.

Inclined Plane. — Another system of counterbalancing the load, especially for shallow shafts, is illustrated in Fig. 6, but could only be used where the winding engine house was situated on sufficiently high ground to enable the weighted tub or truck to travel a considerable distance. This method was applicable to shafts of much greater depth than the chain counterbalance. The inclined plane for the loaded tub must have a gradient which varies throughout the travel, the steepest part being in proximity to the engine house. Sometimes the track on which the tub travelled was laid in the form of a curve, so as to permit the gradual change from one gradient to another. Half-way through the wind the tub reached the end of the track and was wound back towards the engine house for the remaining half of the wind.

(To be continued)

Drawings and Photographs accompanying the article