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By Charles H. Foreman

IN JUNE 1921, the Sullivan &lining Co., owned jointly by the Bunker Hill and Sullivan Mining & Concentrating Co. and the Hecla Mining Co, started work on the development of the Star Mine. The development work contemplated called for a crosscut from the Hecla workings on the 2000 level to the Star ledge. The length of crosscut necessary to encounter the Star ledge was approximately 8900 ft. from the Hecla shaft. By using workings formerly made by the Hecla Mining Co., only about 8100 ft. of actual crosscutting was necessary. This crosscut has a direction of S 20° W and would have a tendency to crosscut any ledges in the intervening ground.

Jan 1, 1924

Organization Place Date 1917 American Institute of Architects Philadelphia., Pa. Dec. 26-29 American Society of Mechanical Engineers New York City. Dec. 4-7 American Mining Congress State Chapter Phoenix, Ariz. Dec. 26-29 1918 American Society of Civil Engineers New York, N. Y. Jan. 22-25 American Institute of Mining Engineers New York, N. Y. Feb. 18-21

Jan 12, 1917

By Howard Willey

Mining operations of the Charcas unit at present are limited to the Tiro General mine at Charcas, in the State of san Luis Potosi, Mexico. The Tiro General mine was first operated during the Spanish occupation of Mexico for rich silver ores in an oxidized zone along the outcrop of the principal vein. In depth the ore is a complex sulfide with widely varying proportions of sphalerite, argentiferous galena and chalcopyrite ; and until recent years, it was economically impossible to carry on mining otherwise than irregularly in sections of the veins richest in galena and chalcopyrite. The advent of selective flotation brought the orebody as a whole within the field of economic interest, and a flotation mill of 650 metric tons daily capacity was constructed in the year 1925. The mining of partly worked-out sections of the mine, as well as the very heavy ground in most of the stopes opened in virgin ore, presented an unusually difficult problem. This paper describes the so-called "filled top slice" stoping method finally adopted as the standard system. Physical and Geological Conditions The principal orebody of the mine is an oreshoot about 1400 ft ng in a fissure vein striking about east and west and with an average lip of 70" to the north. The footwall of the orebody is fairly cleancu and regular both longitudinally and vertically and generally shows a dell-marked post-mineral slip. The footwall rock varies from a fairly strong limestone to a broken, metamorphosed limestone which requires heavy timbering. In some sections it is an altered, crumbly porphyry, which swells badly and necessitates frequent renewal of drift and raise tirnber. The hanging wall is irregular and frequently an assay wall. The stopina width ranges from a few feet up to more than 90 ft.; it averages about 30 ft. For the most part the hanging-wall rock is a shattered and altered monzonite porphyry, nearly aways requiring heavy timbering. The orebody is greatly fractured by post-mineral movement, which usually followed the footwall and left it as a smooth surface frequently covered with a slippery clay gouge. Two well marked transverse faults

Jan 1, 1931

By L. P. Durham

DuRing the early mine development period, 1929 and the first part of 1930, a 300-ton pilot-plant concentrator was built at Nkana mine of the Rhokana Corporation, Northern Rhodesia. This plant operated from May 26, 1930 until Oct. 26, 1931, treating 101,080 tons of Nkana ores and producing 4372 tons of concentrate. The plant was built, primarily, as a test unit to determine the grinding characteristics, floatability, etc. of the Nkana ores and other ores of the Rhodesian copper belt and to supply sufficient data on which to base the design of a 5000-ton concentrating plant at Nkana mine. The test unit operated wholly on development ores and no attempt was made to grade or select the ores from any section of the mine. The average assays for the 17 months of operation are given in Table 1. The first ground was broken for the 5000-ton concentrator during June, 1930, and the construction of the plant was completed in November, 1931. The plant started on Dec. 10 and has operated continuously since that date: The whole of the concentrating plant is compact and closely connected, yet with sufficient space for expansion of all sections up to 20,000 to 25,000 tons per day capacity. Mining operations are carried on along a length of about four miles on the easterly limb of the Nkana syncline. This length includes the North orebody, from which all production has thus far originated, and the Mindola orebody, now being developed for production. The ore-bearing measures in the North orebody are leached for some 75 ft. below the surface; the oxidized zone varies in vertical extent from 100 to 150 ft. Practically all the ore below the 200-ft. level is sufficiently

Jan 1, 1935

By Jack F. Harang, P. B. Leavenworth

Development during the year 1941 on the Texas Gulf Coast resulted in the dis covery of 27 new fields as compared to 26 fields for the year 1940. Drilling.—During the year, 1405 wells were drilled. Of this number, 1031 were completed as oil wells with 375,000 bbl. daily of new production; 50 were com pleted as gas wells and 324 were failures. The most active area was Jackson County, where 375 wells were drilled and 336 of them accounting for 190,000 bbl. daily of new production. Types of Fields.—Of the 2 7 new fields, 14 are considered to be oil fields, 8 are listed as gas-distillate fields and 5 as gas fields. This may be compared to 26 fields found in 1940, of which 14 were oil fields and 12 gas-distillate fields. Producing Sections.—Frio discoveries retained their predominant position by having 10 Frio fields discovered in comparison to 6 fields in the Wilcox, 4 in the Yegua, 5 in the Miocene and 2 in the Jackson. In the previous year 15 Frio fields were found, 4 in the Wilcox, 2 each in the Yegua, Cook Mountain and Miocene, and I in the Jackson. Production.—Production increased over 1940 approximately 10 per cent, being 113,726,893 bbl. for the year 1941 and 104,127,247 bbl. for 1940. The statistics in Tables I and 2 include distillate and condensate as oil production because no separate reports have been compiled. It is hoped that this separation may be possible some day, but as a great many fields produce both oil and distillate and these arc commingled in pipe lines, separation of statistics will be more difficult than for other areas. New Fields Big Hill, Jefferson County.—Stanolind Oil and Gas Company's No. I George D. Anderson was completed as a gas well from a Frio sand at 8705 to 8720 ft., on Dec. 24, 1941, after having been drilled to a depth of 9500 ft. Additional development is being carried on but it is not possible to evaluate this discovery at this time. Brushy Creek Field, Lavaca County.— Shell Oil Corporation's No. I D. G. McManus was completed as the discovery well in the Brushy Creek field on Oct. 29, 1941, from a Wilcox sand through perforations at 7225 to 7230 ft., making gas and 180 bbl. of 59° gravity distillate. This well was bottomed at 10,998 ft. in the Wilcox. No statement can be made at this time as to the importance of this discovery. Chenango Field, Brazoria County.—J. N. Rayzor et al. completed their No. I Sarah J. Christian through perforations at 8564 to 8572 ft. in a Frio sand, for 453 bbl. of 37.7° gravity oil, on Feb. 6, 1941, after having drilled to 9564 ft. Several wells were drilled in this area during the year but failed to establish important production. This is considered a minor discovery. Clodine Field, Fort Bend County.—Providence Oil Company's No. I Hatfield was the discovery well of the Clodine field, being completed through perforations at 7499 to 7502 ft. for 108 bbl. of 51.2° gravity distillate, on June 19, 1941. The well was bottomed at 8090 ft. Several wells

Jan 1, 1942

By P. B. Leavenworth, Jack F. Harang

Development during the year 1941 on the Texas Gulf Coast resulted in the dis covery of 27 new fields as compared to 26 fields for the year 1940. Drilling.—During the year, 1405 wells were drilled. Of this number, 1031 were completed as oil wells with 375,000 bbl. daily of new production; 50 were com pleted as gas wells and 324 were failures. The most active area was Jackson County, where 375 wells were drilled and 336 of them accounting for 190,000 bbl. daily of new production. Types of Fields.—Of the 2 7 new fields, 14 are considered to be oil fields, 8 are listed as gas-distillate fields and 5 as gas fields. This may be compared to 26 fields found in 1940, of which 14 were oil fields and 12 gas-distillate fields. Producing Sections.—Frio discoveries retained their predominant position by having 10 Frio fields discovered in comparison to 6 fields in the Wilcox, 4 in the Yegua, 5 in the Miocene and 2 in the Jackson. In the previous year 15 Frio fields were found, 4 in the Wilcox, 2 each in the Yegua, Cook Mountain and Miocene, and I in the Jackson. Production.—Production increased over 1940 approximately 10 per cent, being 113,726,893 bbl. for the year 1941 and 104,127,247 bbl. for 1940. The statistics in Tables I and 2 include distillate and condensate as oil production because no separate reports have been compiled. It is hoped that this separation may be possible some day, but as a great many fields produce both oil and distillate and these arc commingled in pipe lines, separation of statistics will be more difficult than for other areas. New Fields Big Hill, Jefferson County.—Stanolind Oil and Gas Company's No. I George D. Anderson was completed as a gas well from a Frio sand at 8705 to 8720 ft., on Dec. 24, 1941, after having been drilled to a depth of 9500 ft. Additional development is being carried on but it is not possible to evaluate this discovery at this time. Brushy Creek Field, Lavaca County.— Shell Oil Corporation's No. I D. G. McManus was completed as the discovery well in the Brushy Creek field on Oct. 29, 1941, from a Wilcox sand through perforations at 7225 to 7230 ft., making gas and 180 bbl. of 59° gravity distillate. This well was bottomed at 10,998 ft. in the Wilcox. No statement can be made at this time as to the importance of this discovery. Chenango Field, Brazoria County.—J. N. Rayzor et al. completed their No. I Sarah J. Christian through perforations at 8564 to 8572 ft. in a Frio sand, for 453 bbl. of 37.7° gravity oil, on Feb. 6, 1941, after having drilled to 9564 ft. Several wells were drilled in this area during the year but failed to establish important production. This is considered a minor discovery. Clodine Field, Fort Bend County.—Providence Oil Company's No. I Hatfield was the discovery well of the Clodine field, being completed through perforations at 7499 to 7502 ft. for 108 bbl. of 51.2° gravity distillate, on June 19, 1941. The well was bottomed at 8090 ft. Several wells

Jan 1, 1942

By F. J. Chernosky

Most previous studies of coal flotation utilized chemically pure reagents. Since such reagents are not available in quantity, a study of various wmmercially available reagents as frothers was undertaken. Flotation procedures similar to those used in a large number of commercial coal flotation plants were employed. The reagents used were compared on yield-selectivity-wst basis. The selectivity was found to be relatively constant with yields above 70% but the reagent cost varied greatly. The types of reagents available were compared. In the past, a number of papers have been written on the use of various reagents as coal flotation frothers. For the most part, these have been an attempt to correlate the intrinsic chemical and physical proper- ties of the reagents or reagent groups to the floata-bility of various fine coals. Because of the type or nature of evaluations made, chemically pure reagents were normally used. Generally, these reagents are unavailable in commercial quantities. Therefore, the results obtained with these reagents were usually limited in usefulness to the plant operator or metallurgist. This paper presents the results of a study in which commercially available forms of various reagents were used as flotation frothers. Flotation procedures which would conform in general to those employed in a large number of commercial coal flotation plants were utilized. The objective of the test was to compare these reagents on yield-selectivity-cost basis, that is, 1) the yields obtained, 2) the ash levels obtained and 3) the reagent cost relating to these results. REAGENTS The reagents employed have been grouped into the following chemical classes: 1) aliphatic alcohols, 2) terpines, 3) glycols (synthetic water-soluble

Jan 1, 1963

By M. R. Geer Olds, H. F. Yancey

THE increase in the number of coal-cleaning plants employing dense-medium processes occurring since 1946 is especially interesting when viewed historically. Both sand and magnetite were introduced as material for heavy mediums at about the same time, sand in the Chance process in 1921 and magnetite in the Conklin process in 1922, but from that point on their records diverge. The Chance process enjoyed a steady growth from its inception, whereas no additional magnetite plants were built in the United States for over 20 years. Then, following the close of the World War 11, magnetite was again introduced, this time with marked success. During the following years some 47 plants employing magnetite medium were built. This rapid growth of dense-medium cleaning has been concurrent with widespread adoption of full-seam mining on one hand and a return to a more competitive market on the other. At a time when changing mining practice has provided cleaning plants with dirtier coal and changing market conditions have simultaneously demanded a cleaner product, the industry has through necessity turned to improved preparation. The inherently greater sharpness with which dense-medium processes can separate coal from impurity is thus helping to hold the line against ever-increasing mining costs and at the same time assisting materially in retaining badly needed markets. Although dense-medium cleaning unquestionably offers a distinct advantage when the washing problem is difficult, other methods can provide almost equally high efficiency when the coal is easy to wash. Moreover, fine coal cannot yet be treated by heavy medium in a proved process, although the Driessen cyclone is in the pilot-plant stage. Most of the present types of dense-medium equipment have been in use only a few years, and the dearth of information in the literature concerning their performance characteristics is entirely understandable, Nevertheless this information is necessary if the process is to be intelligently applied to individual cleaning problems. Without data on the efficiency of a process in a particular type of separation, it is difficult to assess the advantage to be expected from it. Similarly, the role of particle size in heavy-medium separation is important in some cases, yet there is little published information on this aspect. To mention only one more of the numerous points on which essential information is lacking, the bearing of medium characteristics on performance has been discussed only in qualitative terms. It was with the hope of providing information on some of these points that the Bureau of Mines built a dense-medium pilot plant for cleaning coal at its Northwest Experiment Station in Seattle in 1950. The plant has been operated continuously since that time, and over 50 runs have been made on 7 coals exhibiting a wide range of washability characteristics. An idea of the magnitude of this work will be gained from the fact that examination of the plant products has involved some 600 float-and-sink separations and about 2500 ash determinations. A laboratory pilot plant is especially well adapted to investigate many aspects of performance because close control over test conditions can be exercised and because a large number of tests can be made rapidly. On the other hand, factors such as consumption of medium and other cost items can be investigated satisfactorily only in a commercial plant. Actually, the two forms of investigation should be complementary, with the laboratory work pointing the way for confirming tests in commercial units. Pilot Plant The dense-medium pilot plant employed for this work comprises a 24x30-in. drum-type separating vessel, a 12-in. densifier, a 12-in. magnetic separator, a 26-in. x 9-ft vibrating screen, and the necessary pumps and conveyors for handling materials. Arrangement of these units corresponds with the flowsheet used in most commercial plants, except that a thickener is not provided for the feed to the magnetic separator. Coal and refuse discharge from the separating drum to the vibrator, which is divided longitudinally down the center. Medium draining through the first 3 ft of the screen is recirculated directly to the drum. Sprays on the middle 3 ft of the screen rinse medium from the products, and the last 3-ft section is for dewatering. Dilute medium from the rinsing and dewatering sections is pumped to the magnetic separator, where magnetic solids are recovered. These are pumped to the densifier, from which they return to the medium-drainage sump by gravity through a demagnetizing coil. The drum-type separating vessel is a scale model of a commercial unit. Feed enters axially at one end of the drum just below the surface of the bath, and float material overflows through a circular opening at the other end. Particles sinking to the bottom of the bath are picked up by lifting flights bolted to the inner wall of the drum, elevated out of the bath, and sluiced to the vibrating screen. Baffles suspended in the bath prevent float material from entering the sink-lifting flights. About 8 gpm of medium is used to sluice the feed into the drum. An additional 15 to 24 gpm, depending upon operating conditions, is added through two pipes dipping into the bath behind the baffle on the side where the sink-lifting flights enter the bath. The bath available for separation is 2 ft long and 13 in. wide, giving an area of 2.08 sq ft. Depth of bath from the surface to the top of the sink-lifting flights, measured vertically below the axis, is 6 in.

Jan 1, 1954

By E. J. KENNEDY

METHODICAL AND EFFECTIVE: thus may be characterized the fall meeting of the Iron and Steel and Institute of Metals Divisions at the Hotel Statler, Buffalo, N. Y., on Oct. 4 and 5. Approximately 200 registered. Interest centered 1111 the technical papers which were keenly followed, with substantial discussion: During the entire week of the National Metal Congress (Oct. 3 to 'i), there were also other sessions of interest' to metallurgists, directed by the America11 Society for Steel Treating, American Welding Society, Production Division of the Society of Automotive Engineers, the Iron arid Steel and Machine Shop Practice Divisions of the American Society of Mechanical En,' the Wire Association and the American Drop Forging Institute. The National Metals Exposition at the 174th Regiment Armory was well attended.

Jan 1, 1932

By Kirtley F. Mather

FROM almost every point of view, petroleum was "strategic mineral number one" during the World War that ended in 1945. Even the spectacular advent of the atomic bomb in the final days of the conflict did not displace it from its position of prime importance, although within a few years uranium will almost certainly be the "number one" material in the minds of military strategists, if it is not even now in that position. But both as fuel and as raw material for chemical industries, petroleum will hold the center of the stage for many years to come. Hardly any other substance illustrates so fully the manner in which science and technology may be combined to achieve the utmost success in contributing to human efficiency and comfort. Fundamental to any understanding of the problems implied by my topic

Jan 1, 1948

By S. C. Hollister

An evaluation of the function of the engineer, so that means whereby education can best serve his needs can be adopted. THERE has been a steady increase in specialized branches of engineering during recent years. Some of these are simply specializations in the function of engineering, such as welding engineering, tool and die engineering, petroleum engineering, and refining engineering. Others are associated more closely with the basic sciences, as for example, geological engineering or engineering physics. Still others tend toward the border line of business, such as administrative engineering or general engineering.

Jan 1, 1950

By H. C. Heard

The review by Professor J. C. Jaeger (Chapter 1) briefly summarizes and discusses a select group of papers by various workers dealing primarily with aspects of fracture in brittle rock materials. Professor Jaeger's treatment is primarily concerned with the correlation of phenomenological and theoretical failure criteria with empirical results from short duration tests at ambient temperatures and generally at low lithostatic and interstitial fluid pressures. As engineering rock mechanics becomes more concerned with new techniques of mineral exploration and production at increasingly greater depths in the crust, it is well to be aware of the effect of the environment -that of the superposed stress field upon the lithostatic and interstitial fluid pressure, the temperature and the duration of the loading upon the failure of rocks either by fracture or flow. All results to be discussed here are from laboratory tests on small homogeneous samples, thus caution should be used in the direct extrapolation of these results to large inhomogeneous rock masses having quite different boundary conditions in the earth. The purpose of this supplement is to briefly point out the major effects of these parameters as examined singly, with all others held constant, and to cite some recent results which apply to the main theme on the brittle failure of rocks. The total stress field imposed upon a small volume of porous and permeable rock in the earth's crust may be thought of as the sum of an applied differential stress, plus a lithostatic pressure, plus an interstitial fluid pressure. The differential stress portion may be completely specified by nine components, six shear and three normal. If the small volume element is in rotational equilibrium, by suitably choosing our coordinate axes we may resolve these nine components into the three principal com-

Jan 1, 1967

By M. H. Sommer

MANY attempts have been made to develop a relation between the tensile properties and the deep-stamping qualities of metals com-monly used in deep drawing. These operations are generally performed cold and the metal is always stressed beyond the elastic limit. However, the problem cannot be readily solved without a proper investigation of (1) the relation between actual stress and actual strain in the plastic range and (2) the stresses that are set up in the metal during the process of deep stamping. Much work has been done in recent years to add to our knowledge on plastic deformation of metals and the shortcomings of the ordinary tensile test, particularly in the plastic range, have been sufficiently recognized. It has been widely acknowledged that the local contraction, which appears in a tensile test after the maximum load is reached, is not a general characteristic of the material but is peculiar to this form of testing. The plastic deformation of materials is explained by the slip of their crystals along certain planes and this rearrangement should be similar whether observed in a tensile, compression or torsion test, and if the results of any of these forms of testing show deviations, it must be due to other influences, as for example the local contraction in a tensile test. For this reason the tensile-test curve as obtained from the measurements taken on a tensile-test machine or registered by an autographic device has been supplemented by the so-called "actual stress-strain curve," which is constructed from the observed tensile-test data by eliminating the effect of local contraction and is in complete alignment with the stress-strain values obtained in a compression or torsion test. The actual stress-strain curve shows the increase of actual unit stress in relation to unit elongation beyond the yield point and

Jan 1, 1934

By M. T. Abasov

Among a host of challenges dictated by the explosively developing scientific and technical revolution, the improvement of control and management is one of the most essential problems. This problem is also of far-reaching importance for the oil and gas industries. An oil and gas extracting complex is an involved multilink system characterized by a great number of elements and by intricate interconnections between these elements. Of paramount importance for these systems is the quality of control. Any deviation of the control from the optimum reduces the effectiveness of the system and deteriorates its basic technical and economic factors. In case of large systems, even a relatively small deviation from the optimum may result in considerable material and power losses. Optimization of control of large production systems is therefore one of the basic means to enhance their effectiveness. The present paper discusses a development control problem for a multilayer gas deposit using the method of simultaneous exploitation of several strata by means of a single well. The optimum control is achieved by determining the dynamics of changes in the number of producing wells in a reservoir with regard to the depth of occurrence of these reservoirs as well as the difference in the time of introduction of the wells from drilling and their transfer to another reservoir. A mathematical model was constructed for the problem under consideration and a method was given to solve this problem. The problem was dealt with under the assumption that either each of the reservoirs or a part of them have vertically overlying areas and that there is no hydrodynamic interference between the horizons. It was

Jan 1, 1977

By Finney, W. R.

MUCH has been said and written of the "Big Inch," of the terrific obstacles encountered in its construction, of the colorful and tough men engaged in its building, but little has been publicized of the engineering and economic problems behind the scenes. Long before Pearl Harbor it was apparent to the petroleum industry that a critical oil shortage could be expected along the Atlantic seaboard, owing to delay in tanker deliveries as a result of convoy movements, and to allocation of vessels for foreign shipments. This area, with a normal consumption of approximately 1,800,000 barrels per day of oil and products, was almost entirely supplied by tanker. Pipe lines supplied an average of only 20,000 barrels per day in 1939, 40,300 barrels per day in 1940, and 55,000 barrels per day in 1941. A small amount of oil and products was also delivered via barge.

Jan 1, 1943

By G. Howell Clevenger, Bhupendranath Ray

Formerly great divergence of opinion existed in regard to the influence of copper in steel, as affecting its various physical properties. More recently the investigations of Stead,l Breuil,2 Wigham,3 Burgess and Aston: Ball and Wingham,5 Miiller; Dillner,7 and others have shown fairly good agreement in the major points. Copper steel has been shown by these investigators to possess special properties which make it valuable for certain uses. The general range of composition of the useful alloys of copper and iron, and of copper, iron, and carbon, has been quite definitely established, for the former by Burgess and Aston,8 and for the latter by Breuil9 and Stead.10 Stead11 has removed one difficulty in reconciling certain of the earlier data by calling particular attention to the influence 'of carbon in copper steels. Another point which caused confusion in the earlier investigations, particularly in regard to " red-shortness," was the presence of sulphur. Failure to note the presence of sulphur often led to attributing " red-shortness" to the presence of small amounts of copper. Turner12 has called attention to the fact that where copper exists in an iron ore it often occurs as the sulphide, so that the presence of copper in steel made from such ores might also, necessarily, mean the presence of sulphur. It is evident that the effect in this case might be quite different than where pure copper was added.

Jan 1, 1914

By A. B. Parsons

LECTURE, it appears, is a discourse that is supposed to be instructive. I am quite sure that you will derive no instruction from what I have to say. I will be satisfied if my remarks provoke thought along one or two mental paths that have not been traveled so fre¬quently as to be devoid of interest. I have no particular message apropos of professional engineers or professional engineering, and any conclusions that I may seem to reach will be purely tentative and incidental. Probably at times you have wondered, in a casual way at least, why so many people who are not, never have been, and never will be engineers, want to use the title. For example, I recently received a communication from a life insurance broker or salesman, whose chaste letterhead bore the legend "Estate Engineer." He was perfectly serious about it, as is also the expert accountant who assumes the imposing name of cost-analysis engineer. Dozens of equally amazing titles might be cited. Then there is that class of individuals who have been engineers, in the true sense of the word; who have gone into some other kind of occupation; but who cling tenaciously to the name engineer, usually prefixing some word or other which at once gives them away by telling what their work really is. For example, we have such pseudomorphs as the management engineer, and the sales engineer. It is quite evident that engineer is a word to conjure with. Evidently both the man who appro¬priates the designation without any justification and the ex-engineer who persists in calling himself an engineer even after he has abandoned engineer-

Jan 1, 1933

By Mark Sheppard

DuRing the winter of 1937, the writer visited a West Virginia stone quarry at which the overburden is stripped hydraulically. The quarry is in a bed of limestone, about 200 ft. thick, which outcrops on a hillside above a small river; the quarry face is 175 ft. high. The top of the stone is cut in all directions by erosion channels, which are filled with a tough, red clay. Some of the larger channels are 30 ft. deep and 8 ft. wide. The thickness of the clay overburden ranges from a few inches to 10 ft., the average being estimated as less than 3 feet. The topography of the district is rugged, and the hillside above the quarry face is not suited to the use of the usual mechanical methods of moving dirt. Until hydraulicking was started 10 years ago, the overburden was dug by hand labor, dumped to the quarry floor and transported to the dump in quarry cars. Cleaning deep channels was a slow and expensive process. When hydraulicking was started, the top of the quarry face was over 200 ft. above the level of the river. The pipe line was carried in a semicircle around the top of the quarry about 200 ft. from the face and about 50 ft. above it. As there is no adequate supply of water above the quarry, the water must be pumped from the river. As quarrying progressed the pipe line was moved until the discharge points are now over 300 ft. above the river. Water is pumped from the river by a four-stage centrifugal pump having a 5-in. intake and a 4-in. discharge. It is direct-connected to a 200-hp., 2300-volt, 1760-r.p.m. induction motor. At 1760 r.p.m. the rated capacity of the pump is 750 gal. per minute under a head of 600 ft. The pump is installed in a house of frame construction on the river bank, about 10 ft. above normal water level, which also houses the pump for the mill-water supply. Above the pumps are hoisting bays into which the motors are raised whenever the river reaches flood stage. An 8-in. suction line, equipped with a strainer and a foot valve, takes the water from a concrete sump at the edge of the river. The pipe line from the pump consists of 1750 ft. of 8-in. spiral steel flanged pipe and

Jan 1, 1938

By Mark Sheppard

DuRing the winter of 1937, the writer visited a West Virginia stone quarry at which the overburden is stripped hydraulically. The quarry is in a bed of limestone, about 200 ft. thick, which outcrops on a hillside above a small river; the quarry face is 175 ft. high. The top of the stone is cut in all directions by erosion channels, which are filled with a tough, red clay. Some of the larger channels are 30 ft. deep and 8 ft. wide. The thickness of the clay overburden ranges from a few inches to 10 ft., the average being estimated as less than 3 feet. The topography of the district is rugged, and the hillside above the quarry face is not suited to the use of the usual mechanical methods of moving dirt. Until hydraulicking was started 10 years ago, the overburden was dug by hand labor, dumped to the quarry floor and transported to the dump in quarry cars. Cleaning deep channels was a slow and expensive process. When hydraulicking was started, the top of the quarry face was over 200 ft. above the level of the river. The pipe line was carried in a semicircle around the top of the quarry about 200 ft. from the face and about 50 ft. above it. As there is no adequate supply of water above the quarry, the water must be pumped from the river. As quarrying progressed the pipe line was moved until the discharge points are now over 300 ft. above the river. Water is pumped from the river by a four-stage centrifugal pump having a 5-in. intake and a 4-in. discharge. It is direct-connected to a 200-hp., 2300-volt, 1760-r.p.m. induction motor. At 1760 r.p.m. the rated capacity of the pump is 750 gal. per minute under a head of 600 ft. The pump is installed in a house of frame construction on the river bank, about 10 ft. above normal water level, which also houses the pump for the mill-water supply. Above the pumps are hoisting bays into which the motors are raised whenever the river reaches flood stage. An 8-in. suction line, equipped with a strainer and a foot valve, takes the water from a concrete sump at the edge of the river. The pipe line from the pump consists of 1750 ft. of 8-in. spiral steel flanged pipe and

Jan 1, 1938

By Mark Sheppard

DURING the winter of 1937, the writer visited a West Virginia stone quarry at which the overburden is stripped hydraulically. The quarry is in a bed of limestone, about 200 ft. thick, which outcrops on a hillside above a small river; the quarry face is 175 ft. high. The top of the stone is cut in all directions by erosion channels, which are filled with a tough, red clay. Some of the larger channels are 30 ft. deep and 8 ft. wide. The thickness of the clay overburden ranges from a few inches to 10 ft., the average being estimated as less than 3 feet. The topography of the district is rugged, and the hillside above the quarry face is not suited to the use of the usual mechanical methods of moving dirt. Until hydraulicking was started 10 years ago, the over- burden was dug by hand labor, dumped to the quarry floor and transported to the dump in quarry cars. Cleaning deep channels was a slow and expensive process. When hydraulicking was started, the top of the quarry face was over 200 ft. above the level of the river. The pipe line was carried in a semi- circle around the top of the quarry about 200 ft. from the face and about 50 ft. above it. As there is no adequate supply of water above the quarry, the water must be pumped from the river. As quarrying progressed the pipe line was moved until the discharge points are now over 300 ft. above the river. Water is pumped from the river by a four-stage centrifugal pump having a 5-in. intake and a 4-in. discharge. It is direct-connected to a 200-hp., 2300-volt, 1760-r.p.m. induction motor. At 1760 r.p.m. the rated capacity of the pump is 750 gal. per minute under a head of 600 ft. The pump is installed in a house of frame construction on the river bank, about 10 ft. above normal water level, which also houses the pump for the mill-water supply. Above the pumps are hoisting bays into which the motors are raised whenever the river reaches flood stage. An 8-in. suction line, equipped with a strainer and a foot valve, takes the water from a concrete sump at the edge of the river. The pipe line from the pump consists of 1750 ft. of 8-in. spiral steel flanged pipe and 800 ft. of 4-in. spiral steel flanged pipe. The connection from the pump

Jan 1, 1938