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By J. O. Nelson, C. J. Altstetter

Single crystals of hcp cobalt, 3 mm in diameter and up to 35 cm long, were grown using an electron-beam, zone-melting technique. The martensitic-phase transformation was studied in single-crystalline and polycrystalline specimens by making length-change measurements as a function of temperature under various elastic compressive stresses. Upon thermal cycling, single-crystalline or polycrystalline specimens repeatedly transformed almost entirely on the same variant of close-packed plane provided the maximum temperature did not exceed 600°C. Cycling to 1000°C resulted in transformation on more than one {111} variant. This behavior is termed multivariance. The multivariant transformation occurred very rapidly at an M, temperature 2° to 6°C lower than the M, of a transformation which would result in a single-crystal product. Elastic compressive stresses (up to 253 g per sq mm) tended to lower the A, and raise the M, temperatures, decreasing the width of the temperature vs dilatation hysteresis loop. The transformation habit plane and transformation shear direction of an as-grown single crystal were not grossly affected by elastic compressi?ie stress. This was evidenced by similar dilatations on the temperature us dilatation loops joy specimens with and without compressive stress. A dislocation mechanism is proposed to explain the observed results. IT has been shown that, on heating, cobalt transforms martensitically from the hcp to the fcc phase.' The transformation habit plane is (0001)hcp || (lll)fcc and the transformation shear direction is (1010)hcp || (112)fcc. The transformation involves a shear of 1g°28', which may be achieved by a shearing of a/6(112) of every two planes with respect to the plane beneath, thus changing the ABABAB stacking of hcp to the ABCABC stacking of fcc. Associated with the phase change is a 0.3 x 10"3 contraction in the habit plane and a 4.2 X 10"3 expansion perpendicular to the habit plane resulting in a 3.6 x X volume increase on heating.' On cooling, an identical volume decrease takes place. The temperature at which the fcc phase begins to form on heating (A,) is reported as 430°C, and the temperature at which the hcp phase begins to form on cooling from an elevated temperature (A&) is reported as 390oC1,3 Consequently, temperature vs dilatation plots have the form of a hysteresis loop. If heating or cooling is reversed during a transformation, a smaller hysteresis loop results. Upon heating, the transformation is always complete; whereas, fcc is often retained at room temperature as a metastable phase entrapped in the polycrystal-line hexagonal matrix.1,4,5 Two obstacles in the theory of the allotropic-phase transformation of cobalt have been: 1) a detailed knowledge of the product nucleus, and 2) a plausible method of propagation of the transformation. Bilby,8 christian, 7 and seeger 8,9 have suggested a "pole mechanism" as a means of propagation of partiai dislocations from plane to plane. A pole dislocation and a Shockley partial come together at a node. The a/6(112) Shockley partial rotates about the pole dislocation effecting the transformation shear. The pole dislocation must have a 2a/3(111) screw component which causes extension of the transformed region by two atomic planes with each full rotation of the Shockley partial. Bollmannl0 suggested, on the other hand, that transformation propagation occurs due to the stress fields of intersecting (111)-type stacking faults. As faults intersect, a stress distribution is set up about their intersection which is in turn reduced by the emergence of another fault on the second nearest plane. This process continues with the final result of a complete phase transformation. In view of the similarities between deformation and transformation in cobalt, the effect of stress on the transformation would, hopefully, yield valuable information concerning nucleation and propagation. In the present work single-crystalline and polycrystalline specimen length changes were measured as a function of temperature at various compressive loads. PROCEDURE Several orientations of single crystals of hcp cobalt in lengths up to 25 cm were grown by electron-beam floating zone melting from 99.95 and 99.999 pct, 3-mm-diam cobalt rod as supplied by Johnson

Jan 1, 1964

By Herbert H. Kellogg, Nathaniel Arbiter, Arthur F. Taggart

THE experimental work herein described is presented in support of the following broad hypothesis: Conditioning of metals and metallic sulphides by amine collectors involves metathetic reaction at the solid surface between the collector and an oxidized metallic compound, to produce a coating comprising an amine-bearing compound of low solubility in the system. The type of reaction is different in acid and in basic solutions; both types may occur simultaneously in near-neutral pulps. EXPERIMENTAL The experiments comprise contact-angle tests with a variety of metals and metallic sulphides and extraction tests on ground chalcocite. Contact-angle tests were made principally on metals. Covellite paralleled metallic copper in amine solution at pH 8.8 (Table 3) and in alkaline water, but maintained an angle of about 70° in 10-3 HCl solution, where metallic copper lost its angle. The tests with anionic collectors (Table I) indicate that the behavior of metals in general is parallel to that of their minerals in anionic solutions. It is believed that this is generally true with cationic collectors also, but the covellite test is a warning against a broad assumption to this effect. All test specimens were mounted in Transoptic.* All tests in conditioning solution were preceded by a test in distilled water; cleaning and polishing were continued in every case until the angle in water was zero. Subsequent transfers into and out of solutions and test cells were made in such a way as to prevent exposure of the surface to air.1 The amine used was primary laurylamine, Armour and Co., AM-1120. It was used in the form of the hydrochloride, obtained by precipitation with gaseous hydrochloric acid from an ether solution of the amine, and purified by two recrystallizations from ether-alcohol.2 Inorganic and other test reagents were standard laboratory grades. [ ] Temperatures were not controlled; the probable range of test-solution temperatures is 65° t0 80°F.

Jan 1, 1943

Jan 1, 1941

By H. F. Yancey, O. L. Furse

Although usually coal is screened with punched plate screens having round-hole perforations, there has been an increasing use of wire-cloth screens with square apertures, especially at pneumatic coal-cleaning plants and at other plants that use vibrating screens. It is therefore desirable to establish a relationship between round-hole and square-hole screens for use not only in experimental investigations of coal-preparation problems, but also for use in commercial operations. This need is apparent whenever it is necessary to substitute wire cloth for punched plate and still retain the familiar trade-size product. Although similar work probably has been done by industrial organizations concerned with the screen sizing of coal, the only recorded study of the subject other than the one described herein of which the authors are aware is that of Roesler,1 who screen-sized two samples of limestone and two of zinc concentrates crushed to pass 1/2 in. with a set of square and round-hole screens and found the ratio to be 1:1.23. Procedure In the course of a study of various methods for determining the friability of coal,2 it was necessary to screen-size the products of a series of friability tests of three different coals with both round-hole and square-hole screens. The coals used were from the Roslyn No. 3 and the Bayne mines in Washington and the Rolapp mine in Utah. Twenty 25-lb. samples of each of these three coals at 3 to 2 1/2 in. round-hole size were dropped from a height of 10 ft. to a concrete floor, and then screened with

Jan 1, 1934

By T. R. Cass

THE renewed interest in titanium, resulting from its increasing application as a structural material, has stimulated basic deformation studies on this metal. In the course of our work, we have developed a dislocation etchant and applied it to a perfection study of melt-grown single crystals as well as to a preliminary investigation of plastic deformation in titanium. The etchant, Keller's etch (21 cu cm HF, 64 cu cm HC1, 106 cu cm HNO3, and 160 cu cm H20), reveals the emergence of both grown-in and fresh dislocations on pure titanium and a-phase Ti-Al single crystals. Pits are produced only on surfaces within a few degrees of the basal plane; the more exactly parallel to a basal plane the surface is, the more distinct are the pits. The observed pit density, however, does not appear to depend on the surface orientation; the pits simul- taneously become less distinct as the misorientation from a basal plane increases. Etch times are short, a few seconds, for pure titanium; longer times are necessary for alloy crystals.

Jan 1, 1968

Jan 1, 1940

By R. D. Pehlke, J. V. Gluck

A study was made of the effect of small additions of metallic solutes on the thermodynamic activity of zinc in dilute solution with molten bismuth in the range 450o to 650°C. The experimental measurements were made in a multielectrode galvanic cell using. a fused LiCl-KCl electrolyte. The activity of zinc in binary solution exhibited a strong positive deviation from Raoult's law and obeyed Henry 's law to at least 0.050 mole fraction. The ternary addition of lead, gallium, or indium increased the activity of zinc. Cadmium or tin additions slightly decreased the zinc activity. Copper, mercury, silver, or antimony caused moderate decreases, while gold strongly decreased the zinc activity. The results are expressed in terms of Wagner's interaction parameter ejZn and a second-order cross-interaction parameter. The interactions for copper, gold, silver, and antimony showed a linear dependence with reciprocal absolute temperature, while the other interactions were essentially independent of temperature over the experimental range. Since tin and antimony decreased the zinc activity, the hypothesis of a purely periodic variation with atomic number was rejected. A semiquantitative explanation was possible with a free-electron model when relative electronegativities were used to express changes in the electron/atom ratio caused by the solute addition. Random solution and quasi-chemical models correctly predicted the majority of the interactions for which binary data were available to apply them. A knowledge of the thermodynamic interactions in liquid (and solid) metallic solutions is of considerable theoretical and experimental interest in the formulation of quantitative thermodynamic relations for metallurgical processes. The approaches to defining the interactions may be either phenomenological (i.e., "What mathematical function adequately describes observed behavior and permits extrapolation to new situations?") or theoretical, such as a specific model

Jan 1, 1968

DAVID COLE, El Paso, Tex. (communication to the Secretary*).-I notice that Mr. Callow takes issue with me on certain points I have previously contributed to the Transactions, to which I would reply," follows: Regarding Inspiration: Mr. Callow's refinements of gravity methods made just prior to the advent of flotation in the Southwest were intended to be "down to the minute," and the gravity flow sheet for Inspiration ores which he brought out at that time as the result of his long campaign of experimentation was regarded by many as the last word in wet gravity work. It was not my intention to discredit this good work when I said "he threw small light on slime treatment." "Minus 200 mesh," however, is not-synonymous with "real slime." Repeated treatments by gravity methods will result in the separation of a very large percentage of the fine granular sulphides in sizes much finer than 200 mesh, and I gave him due credit for that. The unavoidable losses were made in the "real" slime which I mentioned in the paragraph which Mr. Callow refers to as my "statements on page 1871," and his refinements were not a solution to the real slime problem. Mr. Callow has called attention to the fact that his best results at. Inspiration in gravity work were obtained on Joe Bush ore and he presents a table, viz., Tests Nos. 68, 71, and 72; and asks us to consider and compare these results, made by his refined gravity methods, with the results obtained by 'flotation methods in the new mill "during the second half of 1915 and in August, 1916." Of course, the ore treated in the mill was what happened to come. It was not Joe Bush ore, and therefore comparisons of detail figures are of no value. In regard to Mr. Callow's statements under the caption "Callow Cells Adopted by Arizona Copper Company," I would say that those who have been sufficiently interested to read my paper and' his remarks will notice what amounts to contradictory statements on several points which I cannot allow to go unchallenged. I was on the ground constantly and got my information at first hand. The tables published were the official ones. Mr. Callow was not present during the period and has been laboring under that disadvantage.

Jan 5, 1917

By E. DeGolyer

I. INTRODUCTION VOLCANIC origin. was among the first of the theories advanced to account for the occurrence of the salt domes of the Gulf coastal plain, northern Louisiana., and eastern Texas, and it is still being re-stated in various forms by the most recent contributors to our knowledge of the geology of such deposits. Argument has been largely by analogy and attention has repeatedly been called to the Mexican oil fields, particularly those of the Tampico-Tuxpam region, because of the occurrence of oil in close proximity to volcanic plugs in those fields, an occurrence supposed to have some resemblance to the common occurrence of oil in the salt domes of the United States. The author, having spent several months of the past year in a general study of salt domes and in a detailed study of certain domes in the United States, and having been acquainted for some time with the exploration of similar domes in the Isthmus of Tehuantepec region, Mexico, and with the general geology of the Tampico-Tuxpam region, Mexico, has reviewed the various theories of volcanic origin for salt domes which have been advanced to the present time. The purpose of this paper is to present such review and to discuss the supposed Mexican analogy.

Jan 5, 1918

R. B. BRINSMADE, Ixmiquilpan, Hgo, Mexico* (written discussion). As the discussion of Mr. Graton's paper by Messrs. Norris, Patterson, and Crane has been from the standpoint of the mineral land-value owners, a few remarks in the interest of the "under dog"-the average taxpayer and citizen-may prove timely. In my discussion of Doctor Raymond's Paper1 and of the papers of Messrs. Gibson2 and Godson, 3 have endeavored to demonstrate, from both political economy and history, that our existing system of unrestricted private ownership of land is incompatible with equality of economic opportunity and, therefore, subversive of our democratic political institutions. In Mr. Graton's paper, the same land problem is important, though camouflaged by the failure of the Federal income tax laws to distinguish between land and capital, in the requirements for valuation, or between earned and unearned incomes in the levying of taxes. I disagree with Mr. Graton's statement, on p. 2967, as follows: The immense majority of mining ventures are failures. A multitude of disappointments is relieved by occasional success. Were it not for the chance of great rewards, all the vitally necessary but mainly unremunerative work of exploration would not be undertaken. In contrast with nearly all other fields of endeavor, it is altogether unlikely that, on the whole, the gains in the successful mining ventures suffice to offset the losses in the unsuccessful.

Jan 3, 1920

By D. W. Gillmore, C. C. Wright

DEWATERING is a major problem in the preparation and utilization of fine-sized coals now being recovered in increasing amounts from colliery effluents, refuse banks, and silt ponds. Of the various methods which have, been proposed for dewatering fine coal, gravity drainage is probably the oldest and most widely used, and yet little information on this subject has been published. Consequently a laboratory investigation of gravity drainage phenomena was undertaken not only to provide basic data for predicting the drainage behavior of fine coals in cars, bunkers, basins, and silos, but also to obtain some understanding of the moisture retention properties of fine coal. Because of practical interest in the problem, a reproducible laboratory technique, which simulated plant conditions as closely as possible, was developed for the evaluation of drainage variables. The ap- paratus selected consisted of vertically-mounted lucite columns, nominally 4 to 8 ft in length and 2, 3 or 6 in. in diam; the bottom of the column was provided with a rubber stopper through which was inserted a -in. diam drainage tube; a wad of glass wool was placed on the upper part of this outlet tube to retain the coal and a plug was temporarily located at the lower end to prevent drainage during charging of the column, see Fig. 1. The most satisfactory testing procedure is as follows: 1—The fine coal, which has been thoroughly

Jan 1, 1953

By D. W. Gillmore, C. C. Wright

DEWATERING is a major problem in the preparation and utilization of fine-sized coals now being recovered in increasing amounts from colliery effluents, refuse banks, and silt ponds. Of the various methods which have, been proposed for dewatering fine coal, gravity drainage is probably the oldest and most widely used, and yet little information on this subject has been published. Consequently a laboratory investigation of gravity drainage phenomena was undertaken not only to provide basic data for predicting the drainage behavior of fine coals in cars, bunkers, basins, and silos, but also to obtain some understanding of the moisture retention properties of fine coal. Because of practical interest in the problem, a reproducible laboratory technique, which simulated plant conditions as closely as possible, was developed for the evaluation of drainage variables. The ap- paratus selected consisted of vertically-mounted lucite columns, nominally 4 to 8 ft in length and 2, 3 or 6 in. in diam; the bottom of the column was provided with a rubber stopper through which was inserted a -in. diam drainage tube; a wad of glass wool was placed on the upper part of this outlet tube to retain the coal and a plug was temporarily located at the lower end to prevent drainage during charging of the column, see Fig. 1. The most satisfactory testing procedure is as follows: 1—The fine coal, which has been thoroughly

Jan 1, 1953

By William B. Phillips

This paper was prepared at the request of Capt. A. F. Lucas, Chair man of the Institute's Committee on Petroleum and Gas; as a pre1iminary.discussion of the fuel oils which are used in the Southwest, giving their composition, uses, prices, etc. Should it afterward be found desirable, these observations may be extended over a larger area. In this connection, I suggest that samples of all kinds of fuel oils, including various tars, from all over the country, be collected and sent to some testing laboratory for examination. We would be glad to extend the facilities of the laboratory of the Bureau of Economic Geology and Technology, at the University of Texas, for this purpose, and to do the work free of all expenses. After such examinations are made and the results classified and studied, it would be possible to suggest specifications under which fuel oils should be purchased, and to arrive at some conclusions respecting the uniformity of such specifications, with due allowance for climatic and other more or less local conditions. While such specifications do not now depart from a common standard anything like as much as specifications for illuminating oils do, yet there are discrepancies which should not exist. Some of these discrepancies are of lessening importance, due to the pronounced tendency to distill every crude oil that can be distilled with profit, and to send residues into the market for fuel oil. Residues from the refineries are of a more uniform chemical composition and physical nature than many of the crude oils that go direct into the fuel market. The lower flash-point oils are disappearing from the fuel trade and in place of them we are getting oils that do not flash below 220" F., nor burn under 320" F. In the Southwest, it has not been long since we had fuel oils that flashed as low as 110" F., and the average flash point over a considerable period was 151" F. Now we are using oil that flashes at about 30" lower than the former burning point, which was 258" F. In other words, the flash point has risen, on the average, 100"; and the burning point about 75".

Jan 1, 1915

By L. P. Teas

In spite of the influx of operators into the Gulf Coast anxious to retrieve their depleted production in other fields, and in spite of very active application of the most scientific geophysical methods to locate new producing areas, the results have been very discouraging and the year has failed to produce more than the average results for a Gulf Coast year. During the year seven new oil fields, some of which are still of very little importance, and one new gas area have been discovered. These fields are Tom Ball, Greta, Cleveland, Raisin and Garwood in Colorado County; Louise and Premont in Jim Wells County, and the new producing gas area near Ace in southern Polk County. During the year salt has been found for the first time at Carlos and Esperson. New producing areas have been developed on East Stratton Ridge, Hockley, Hull, Port Neches, near Pettus in Bee County, and on the O'Connor Ranch in Victoria County. The total production for the Gulf Coast for the year was 62,837,435 bbl., an increase of 18,589,000 bbl. over 1932. During the year, 1307 wells have been drilled of which 207 were wildcats, compared with 653 wells and 141 wildcats the previous year. The total daily production at the end of the year was 165,201 bbl. At present there are 3100 oil wells producing. The average production per well is 55.5 bbl. per day. The price of crude fluctuated considerably during the year, beginning at 80c per barrel and closing the year at $1.04 per barrel. Completion data for 1933 are as follows:

Jan 1, 1934

Discussion of the paper of FRANCIS S. PEABODY, presented at the St. Louis meeting, October, 1917, and printed in Bulletin No. 125, May, 1917, pp. 775 to 781. THE CHAIRMAN (CARL SCHOLZ, Chicago, I11.).-Coal wastage is undoubtedly one of the most prominent topics before the coal operators of the United States today. Even those who have been in the business only 25 years, like myself, know that the exhaustion of coal is something that should and must, be curbed. If it is not, before long we shall discover that the great coal resources of the country are not what we-thought they were; we have been so accustomed to work at the best and thickest coal alone, that it will be difficult for us to realize one of these clays-and that (lay is not far distant-that we are no longer the rich nation in coal that we thought we. were. In this connection I feel obliged to attach a little blame to the Geological Survey for misleading the people. There are several members ,here who assisted in that work, and I am going to ask them to defend themselves. The Geological Survey deals with coal seams of much less thickness than we could now expect to, mine, particularly with the present high wages, excepting at a prohibitive cost. The Geological Survey, in its estimates, does not discriminate between thick and thin seams, but simply estimates our resources at so many hundred thousand billion tons of coal. I believe they include seams from 15 to 18 in thick, but you all know that a vein below 3.5 or 4 ft. is not considered economical to mine at this time. R. V. NORRIS, Wilkes-Barre, Pa.-Mr. Peabody has evidently been thinking almost entirely of Illinois conditions, with which I regret to say I am absolutely unfamiliar. In some West Virginia mines the total recovery at present is considerably over 90 per cent. and extraction-, as high as 97 or 98 per cent. are claimed.

Jan 1, 1918

By F. D. Mahone

Much crude oil, as produced from the well, carries varying amounts of water, which may be present as free water in globules sufficiently large to settle out, in time, if the fluid is allowed to stand, or as an emulsion formed by myriads of minute water particles, each surrounded and entrapped by a film of oil through which it cannot break under the action of gravity alone. Such an emulsified mixture of oil and water is commonly termed "cut oil." When such an emulsion is subjected, under proper conditions, to the influence of a high-potential alternating-current field, the minute water particles rupture the enveloping oil films and coalesce into larger water droplets this procedure continuing until all the water is freed into drops of such size that they readily settle out. This action has been photographed by the micro-moving-picture camera; under the microscope, the breaking-up of the emulsion, as described, is seen to be accomplished in a few seconds. The low power requirements of the process, from records of commercial plants, substantiate the theory that the action is that of a multitude of electrical condensers in series, rather than that of a number of conducting paths. The minute water particles serve as the metallic elements, or plates, of the condensers and the separating oil acts as the dielectric. Such surface charges as the particles may have are removed, and the intervening oil is broken, probably electrically by the voltage and mechanically by the attractive force between adjacent oppositely electrified particles. The principle of breaking up an emulsion under the influence of an alternating electric field was discovered by F. G. Cottrell and Buckner Speed, through experiments conducted, at the University of California, which resulted in a plant being installed on the property of the Lucile Oil Co. in the Coalinga field, California, early in 1909. This plant was able to reduce 14-per cent. emulsion to less than Pper cent. with commercial success. Standard Cottrell Apparatus The present standard Cottrell apparatus consists essentially of the electric treater and a settling or trap tank. The treater is a galvanized-iron tank approximately 3 ft. in diameter and 10 ft. high, which con-

Jan 1, 1924

By K. S. Lane

The problem of stability of slopes in reservoirs is one of real interest in civil engineering. The problem is whether the valley walls will remain stable or whether they are likely to slide as conditions are changed by storage of water in the reservoir. If major slides are indicated, as on the walls of relatively steep canyons, one must estimate whether they will be so located and of sufficient size as to interfere with operation of the reservoir-as by blocking the outlets, or by displacing sufficient water to over-top the dam in a huge wave. Some cases involve problems in soil mechanics for slides in earth or weaker rock; other locations need the assistance of rock mechanics for slides in harder rock. While this is not a new problem, attention has recently been focused on its importance by the hugh landslide into the Vaiont reservoir in 1963, which claimed the lives of over 2000 people and forced abandonment of the dam and powerhouse. VAIONT RESERVOIR SLIDE Fig. 1 shows Vaiont Dam in Italy which is a double curvature arch, 875 ft high, located on a tributary of the Piave River, north and west of Venice. When completed in 1960 it was the highest arch dam in the world. In 1960 a sizable landslide (some 700,000 cu yd) occurred on the left abutment a short distance above the dam. Following this, the reservoir was held down for construction of a by-pass tunnel through the right valley wall to insure connection with the upper end of the reservoir in event of further slides. In October 1963 a giant landslide occurred on the left valley wall, over a width of some 14 miles (see Fig. 2). Over 300 million cu yd slid into the reservoir, displacing the water and forming a hige wave 700 ft above the top of the dam as it hit the opposite, or right, wall of the valley. The wave then passed some 500 ft over top of the dam, followed down the tortuous winding canyon and debouched into the

Jan 1, 1967

By A. M. E. Eilers

No one who has visited our Western mining districts, and studied the economical part of the beneficiation of the ores occurring all over that vast extent of country, can underrate the high importance of the above subject. By far the larger number of the districts which contain smelting ores, i.e., argentiferous and auriferous lead, or copper ores, are situated in the Great Basin, that great plateau between the Rocky Mountains on the east, and the Sierra Nevada on the west, almost the whole of which is comprised at present in the boundaries of Nevada, Utah, and part of Arizona. This region is essentially a barren country. The extreme dryness of the atmosphere permits but a scanty vegetation in the plains ; and even in the detached mountain-chains running through it-generally from N. to S., or from N. W. to S. E.-there are no trees found except dwarfed pines and mahogany, at the head of sheltered ravines, and a few cottonwoods and willows, which fringe the insignificant streams, before the water sinks in the arid plains. Nearly all the mountain-chains in this region are rich in silver ores. That class of these ores which is adapted to amalgamation, and rich in silver, has been worked with profit for more than ten years. But before the advent of the transcontinental railways, mining was restricted to these ores alone, and the consumption of fuel could be met with the scanty supply of forest trees in the immediate vicinity of the mining districts. Since, however, the Union and Central Pacific Railroads have brought the Great Basin nearer to the commercial centres of the East and the Pacific coast, thus reducing the expenses of freight and labor materially, other silver deposits, containing poorer ores in greater abundance, have been rapidly taken

Jan 1, 1873

By C. G. Massey, L. C. Acton

A first-class haulage level railroad was considered of prime importance during planning of San Manuel because successful operation of the mine would hinge heavily on the ability to move large tonnages of ore rapidly, safely and efficiently. These principles, plus certain techniques developed from experience on the 1475 level, are being employed in preparation of the 2075 level. At full production, twelve 23-ton trolley locomotives, each pulling fifteen 12-ton capacity ore cars, and fifteen 8-ton battery locomotives engaged in development, service and supply, will be in operation on the 2075 level 24 hours per day, seven days a week. More than 35,000 tons of ore will be transported every 24 hours. GENERAL DESCRIPTION The rail haulage system is designed to comfort- ably move twelve 180-ton payload trains per hour through the rotary dumps pulled by 23-ton trolley locomotives. The rail system is laid out as a simple double loop with one-way traffic of continuous haul as shown in the above diagram, and is comprised of about 30 miles of track on the 2075 level.

Jan 3, 1962

Jan 1, 1940