T
H E D EGREE and extent to which the engineering sciences are applied to the solution of problems arising within any industry largely determines the direction in which that industry moves. Natu- rally, there are economic forces to which engineering principles cannot be applied, but, generally speaking, in the fields of design, production and utilization, proper and suffi- cient engineering is necessary and essential fo r the success of an industry as a whole and of the indi- vidual units in any given industry.
Indirect costs in the form of penal- ties which arise out of a paucity of engineering invariably are greater than the direct costs, with the re- sulting benefits, of having it. No monopoly based upon natural laws
alone survives indeflnitely fo r the reason that engineers and scientists accept the challenge offered and pro- ceed to develop substitutes. The coal industry is not exempt from these generalizations.
I t is worth while to state the situation which surrounds the coal industry today. Knowledge of these conditions is essential in the appli- cation of engineering principles to the various problems. The natural conditions of roof, bottom, thickness of vein, inherent ąuality of coal, in- clination of vein and geographical location are things over which no one has control. They must be ac- cepted as they are. Coal’s so-c-alled monopolistic grip on the energy mar
ket has been ba.dly shaken by natu
ral gas, fuel oil and hydro-electric
By PAUL WEIR M in ing Engrineer, Chicago
power. Convenience and cost are the factors involved.
Mine labor is almost completely unionized and a related, universal wage scalę on a relatively high basis, with a seven-hour work day, is in effect. Certainly the trend of wage scales is not downward. Coal is confronted with an ever-increasing cost of transportation to markets, which usually exceeds the market value of the coal. Minimum mine priees fo r all sizes and grades of bituminous coal, based on weighted average costs of production, recently have been established by the National Bituminous Coal Commission.
H igher wage scales, higher freight
February, 1938 — C O A L A G E 61
rates, and elimination of sales below tanee in achieving the improvement in product and reduction in cost dations. These consideratioris, while generał, are fundamental. Their proper application taxes the ingenu- ity of the engineer. With the vast in ehanical mining freąuently intro- duces a change in the “time element,”
as the life of the individual working place may be shortened by one-half to two-thirds. Such reduction may pennit advantageous changes in cen
ters and width of rooms and entries without affecting the percentage of recovery. Bucky, in the January, vailing dimensions wherever possible to provide larger ąuantities of coal per fali are evident, not only in loading but also in cutting, drilling, shooting and transportation. Greater concentration of work follows. The
ting, drilling and transportation eąuipment (locomotives, cars, con
yeyors and tractors) now available permits flexibility in selection and application of machines that go to make up a loading unit. The combinations which are possible as- sist in fitting the unit to existing natural conditions.
At present there are ayailable two sizes of track-mounted and four sizes of caterpiller-mounted machines.
Howeyer, under extremely diffleult natural conditions, replaeement of kinds of track-mounted machines:
namely, straight cutting, slabbing, cutting and shearing, and shearing.
Shortwall machines may be moved on track-trucks or on caterpillar- trucks. In addition to these there are longwall machines and longwall- shortwall combinations, as well as shortwall top cutters.
Transporting coal from the face to the preparation plant may be done by conventional locomotives, cars and track. Conyeyors may re- pletely replaced by conyeyors. “Auto- motive” haulage also makes track trends. The small-sized loading ma
chinę, the uniyersal cutting machinę, long portable conyeyors, and auto- motive haulage are ąuite recent con- tributions. Present trends are toward eąuipment suitable fo r use in thinner yeins and inferior natural conditions and also toward improve- ment in performance in thicker veins.
The selection of the individual pieces of eąuipment that go to make up a loading machinę unit depends
62 C O A L A G E — Vol.43, No.2
priraarily upon the natural conditions of vein, roof and bottom. Obviously these things automatically eliminate sonie types of machines. In addition to this, eonsumer requirements, pres- ent mine layouts and the necessity fo r using existing eąuipment impose further restrictions on choice. Fur- thennore, the individual pieces must synehronize one with the other into a closely associated with engineering developments in methods and eąuip
ment fo r moving tremendous ąuan- ereation of complete programs whieh tell the expenditure, the expected
Service and production records are not always readily available. Past records, for the m ajority of mines, are incomplete. In addition, the breakdown of costs is not always sufficient to provide detailed infor- mation. Inąuiry as to methods some- times reveals “excuses” instead of
“reasons” for procedure. Likewise, because of lack of proper records,
terials is hapliazard and inconclu- sive. Schedules fo r systematic main- tenance are based on serviee records.
Daily cost sheets showing operating and maintenance eharges fo r the in- dividual units as well as for the mine as a whole are indispensable if good engineering praetices are to be fol- lowed. Yariations in performance
reąuire investigation. Carefully plan- ned and executed time studies on the performance of eąuipment reveal chances fo r improvemeńts. They coal. There is inereasing recognition of the faet that each mine presents a special problem in cleaning.
Much that has been said about the operation and maintenance of under
ground eąuipment applies eąually as well to meehanieal cleaning plants.
There is no substitute fo r daily records of plant operation. H ap- hazard control without eontinuous tests results in a product containing too much refuse, a refuse containing too much coal, or both. There is inereasing recognition that close at- tention to plant control results in eeonomical utilization. The combined effect of intense competition in the fuel market and inereased eonsumer demand for better fuel has developed the practice of rendering engineering servico to the eonsumer. Combustion engineers, with an intimate knowl
edge of their coals and of combus
tion eąuipment, endeavor to provide the eonsumer with greatest economies of operation. At the same time the producer is discovering the necessity fo r a better understanding of the physical and combustion eharacteris- tics of his coal in order to apply the consideration in the development of methods and design of eąuipment. It is worthy of note that in those mines in whieh engineering has produced a high degree of efficiency, accident prevention work has been intensified.
Progress during the past 10 ex- ceeds that of the earlier 20 or 30 years. The pressure of intense com- petition has been the chief cause.
However, the willingness of the en
gineers to critically examine tradi- tional methods and eąuipment, to intense competition of the present.
Improvements during the next ten years should completely overshadow those of the past decade.
February, 1938 — C O A L A G E 63