Coal Age : devoted to the operating, technical and business problems of the coal-mining industry, Vol. 26, No. 17

M cGraw -Hill Company, Inc.

Devoted to the Operating, Technical and Business

James H. McGraw, President n , , „ ,, ^ ,

E. J. Mehren, Vice-President

Froblems ot the Coal-Mimng Industry

Engineering Editor

Y olum e 26 N E W Y O R K , O C T O B E R 23, 1924 N um ber 17

“ M m l S l i n g i n g ” T h a t ’ s W o r th W h ile

S

“m u d iz in g ” are disturbed lest Cocd A ge advocate th is “ silly slopping around of d irty w ater” in mines.

They shouldn’t become so exercised u n til the coal indus­

try learns more about th is Rocky M o un tain development in m ine protection a g ain st coal-dust dangers. W e are not prepared to say th a t “m u d iz in g ” is the th in g , and neither is anyone else, not excepting even the developers of the process. However, no m in in g m an who sees the results goes aw ay condem ning it.

W e are w illin g , at least, to say th a t it is advan- tageous th a t so m uch attentio n has been centered on the rock-dusting problem th a t this new scheme was conceived. T hat, in itself is a wholesome sym ptom for coal m in in g . As to “m u d izin g ,” there is no deny- ing th a t it has virtues. The th in m ud m ix ture fills crevices and rounds off tin y ledges, thus positively reducing the o pportunity fo r coal dust to collect. T hat alone is enough to m ake it a valuable practice, especially in dry mines. Perhaps “m u d iz in g ” w ill fo rm so effec- tive a base upon w hich to b uild a dry dustin g system, th a t it w ill w in its way into every well protected m ine.

A t any rate exhaustive experiments w ith m ud should certainly proceed. The coal in dustry should ąuickly learn all there is to know about th is practice.

O n e M o r e L a u g h

M

The C anad ian G overnm ent is about to take 20,000,000 tons o f coal business in the eastern provinces away from A m e rican producers and give it to the C anadian m ines by guaran te e in g to ju s t about pay the fre ig h t on the coal i f the m ines can’t sell it any other way.

W ould you believe it? P in can prove th a t th is is all M r. Hoover’s fa u lt. M r. Hoover’s D e partm ent of Com- merce w hich, P in grieves to say, w ill receive $3,400,000 +his year w ith w hich to pay its useless expenses, has

“been foster fa th e r to the very regulatory proposals w hich frig h te n e d C anada out of our m arkets,” so P in says. Therefore Canada fears it cannot depend upon the U n ite d States fo r a re gular supply any longer, So it w ill depend, rather, upon its own M a ritim e Province m ines. Ju s t how a subsidy of five m ills per ton— or

“ju s t about enough to pay the fr e ig h t”— is go in g to keep those wild-eyed m iners in eastern C anada on the jo b is too th ick fo r us. B u t never m in d . T h a t’s th<>

case anyhow. P in has spoken and M r. Hoover is to blam e fo r e v e ry th in g ; take P in ’s w ord fo r it.

W h a t surpasses our mediocre u n d e rstan d in g is th is : W h y has M r. C ushion been so ready to figurę out crimes to charge a g a in s t M r. H oover? A ll M r. Hoover ever did was to sh u t the door of the D e pa rtm e n t of Com- merce to a m an who w ould not be square w ith ideas

M r. Hoover expressed in interview s. So w hy all th is hectic flush every week? W ell there is one good reason.

The coal in dustry likes a laugh as well as anybody.

M o r e P e r m a n e n c y ; L e s s M a k e - S h if t

I

The use of more m achinery and larger ą u a n titie s of electrical apparatus is economically demanded by the mines of today. Eaoh new piece of e ąuipm ent makes everyone from the m ine r to the official m ore dependent upon its successful operation. W hen a m otor, pum p, controller or even a signal fails, someone usually m ust stand by idle. Occasionally the fa ilu re of even a smali piece of eąuipm ent w ill sh ut dow n a whole m ine.

Poorly installed apparatu s is always a lia b ility ; dangers and accidents m u ltip ly w hen m achinery th a t is loose, im properly installed and in disrep air is allowed to be operated. Savings theoretically attainab le are often lost because a m achinę has been incorrectly assembled.

Most companies need to standardize some o f th e ir apparatus and to employ men who realize the grow ing dependence of the entire organization and p la n t upon the mechanical and electrical eąuipm ent installed. The days of m ak e sh iftin g are about ended.

N o w I t C a n B e T o l d B e s t

W

Some contend th a t it is well to let the p ub lic forget the subject entirely and th at, therefore, the less said now the better. To us th is ^eems like c lin g in g to public-be-damnedism. The more the people o f th is country know about coal all the w ay fro m face to furnace, the better. I f there is a n y th in g it should not know, th a t th in g oug ht to be trim m e d out o f the in d ustry a t once, if not sooner. W e believe the tr u th about th is in d u s try can profitably be told and th a t it oug ht to be told now above all other tim es.

In years gone by, every tim e the in d u s try has m ade 569

570 C O A L A G E V ol. 26, N o . 17 a concerted effort to tell the public about coal, the

economic and political situation was such th a t coal was in ill repute the country over. Therefore, the lesson in coal was offered ju s t when public acceptance was hardest to w in. W h y w a it u n til the industry is on the defensive? T hat isn ’t good salesmanship. W hy reserve all our selling effort fo r a tim e when the salesman has to break down the customer’s locked door in order to get his all too hostile atte n tio n ? He can w alk in w ith a smile now, because the price of coal never was lower, considęring the cost of production.

“ B u t we can’t afford it today,” says a b ig p a rt of the suffering industry. W e ad m it th a t is a reasonable plea. B u t w hich is the better business policy: Spend a little money and effort continuously to prevent the regular and inevitable recurrence of fire, or w a it u n til it roars down upon us and then throw in ten tim es as m uch fo r protection and maybe lose it all?

C o a l C la im s C r e d it

C

perity. A nd it ought to do so. I t always has been easy fo r the country to blame assorted in d u s tria l ills upon h ig h coal prices. Let the country now recognize the fact that, in proportion to the cost of production, coal has never been cheaper th an in 1924. There is no better gage o f the trend of coal prices th a n Coal A ge index w hich is computed each week fro m the spot prices of fourteen prin cipal A m erican coals on the m a in mar- kets of the natio n “w eighted” w ith respect to sizes and volume of production. The average coal price th is week is $2.12. A year ago th is price was $2.25. On A ug. 4, when sum m er conditions still prevailed, it was $1.98;

on A p ril 1 it was $2.09 and on Ja n . 1, $2.17. N ot sińce before the w ar has the country seen such Iow prices.

A wise and well-known coal operator, ta lk in g before the executive heads of a great coal-consuming in d ustry in Chicago last summ er, remarked th a t great in d u s trial advances the world over have been based on low-priced fuel and th a t the coal operator today recognizes th a t low-priced coal is necessary henceforth in th is country.

He said, however, th a t the operator cannot continue selling his product below the cost of production for th a t w ould rot the fo un d a tio n of all industry.

T his m an adm itted th a t all too little progress has been m adę in the past in cost reduction. T his he said, has been chargeable largely to labor opposition and dis- couragingly unprofitable operation of coal m ines. W hat he said is true, but he could have said more. H e could have reported th a t never before has there been so m uch intense effort devoted to im p rov in g m echanical m ethods in coal m ines as in 1924. In d u s try is bound eventually to profit by it in lower costs. In fact there are already instances where costs per ton have been reduced as m uch as 25c. Never has there been a year in w hich union labor has had so severe a lesson in the short- sightedness o f its policy of obstructing cost-cutting m achinery. Perhaps it m ay change th is policy now.

I t is tru e the coal operator has no b ig 1924 profits w ith w hich to develop cost-cutting m achinery and m eth­

ods; he is b eing driven to it, instead, by desperate fear o f d estitutio n. So, even before unio n m in e rs’ wages are reduced, the in d u stry is w o rk in g steadily tow ard lower cost fue l and is th us p e rfo rm in g a duty to the n a tio n w ith o u t “ta k in g it out of labor.”

A U n io n M a n S a y s I t a t L a s t

D

One reason fo r th is was th a t coal operators knew Lonnie Jackson to be fa ir, square and sane. They were w illin g to deal w ith such a m an. A n d they are w illin g now. B u t unbending adherence to the Jacksonville agreement makes it impossible. L onnie Jackson says:

“ I do not believe in an organization ta k in g the stand th at there w ill be no backward step regardless of cir- cumstances. I believe th a t facts and figures should be governing factors in fixing wage scales at all tim es.

This is m y conception of the trade u n io n m ovem ent or collective b arg ain in g . L abor organizations should de- m and w hat they are entitled to at a tim e when condi­

tions are favorable and they should be w illin g to g ra n t concessions when th in g s are unfavorable and i f any d istrict is suffering on account of in e ąu ality it should be taken care of th ro ugh wage negotiations.”

Talk such as th is is not pleasant in the ears o f P re si­

dent Jo h n Lewis. I t is too true. A n d it is not pleasant fo r h im to hear L onnie Jackson say flatly : “ D a y by day I have seen m ines go non-union. I have seen non- union tonnage soar to an a la rm in g extent. I have seen operators, who were always w illin g to sign contracts w ith the U nited M ine W orkers, p e rm it th e ir m ines to flood because they cannot sign an agreem ent th a t w ill not perm it them to compete w ith non-union tonnage.”

Jackson knows th a t “ it w ill be the d uty of the officials of our organization as long as they w ork and receive pay therefor, to oppose w h at I am saying . . . b u t I am endeavoring to p u t before the m iners an d the public the facts as they appear to me. I am conscien- tious and I do not fear the result, whatever it m ay be.”

A nd there the case stands.

There isn ’t m uch fo r President Lew is to do or say in reply. He knows th is m an speaks the tr u th . B u t his own hands are tied effectively. H e cannot advocate a reduced union wage in western K entucky, because if he did he would be sacrificing his locals in Illin o is and other com peting fields— th a t is, unless he agreed also to a cut in Illin o is and the whole d om ain of unionism . A n d if he did th a t r ig h t now he w ould be doing a fu tile th in g . He probably would f a il to get the reduced scalę accepted and he certainly would succeed in g e ttin g h im self rushed out of a job. Such is the psychology o f the union m iner. No “ backw ard step” can be taken u n til the rank and file dem ands it, and th a t m ay not be u n til next summ er. T ill then, at least, conditions m u st rem ain in sta tu quo.

For the tim e being, everybody is rig h t. L onnie Jackson is r ig h t in advocating a cut, ju s t as the A lbe rta union m iners were r ig h t th is m onth in accepting a reduction rather th a n be sacrificed by the in te rn atio n a l.

President Lew is is r ig h t because union politics w ill not perm it h im to do w h at he knows should be done. So the confused situ a tio n m ust rem ain confused— w hile sections of union te rrito ry go non-union or reject head- ąuarters control— u n til action is in itia te d by the ra n k and file. T hat action is a little closer because such m en as Lonnie Jackson have begun te llin g the u n io n the truth .

O ctob er 23, 1924 C O A L A G E 571

C o a l G etters

Is the Payroll Dollar Worth the Mine Dollar?

M a n y E x e c u t iv e s D o N o t R e a liz e T h a t W a g e s A r e I n v e s t e d

— T h e W a g e D o lla r S h o u ld P a y D iv id e n d s — H u m a ń E n g in e e r in g I s a s I n d is p e n s ib le t o S u c c e ss a s M in in g E n g in e e r in g

Ky H . J . Grossman

C le v e la n d , O h io

O

N o t only do m ost executives fa il to realize th a t in- vestment in payroll— wages— is ultim ate ly a m uch bigger investm ent th a n th a t in p lan t and eąuipm ent but they also fa il to realize th a t it is fun dam e n tally a more im p o rta n t investm ent as well. O n the average, business cash invested in payroll w ill exceed cash in- vested in m ine and eąuipm ent w ith in two or three years. Even in the largest enterprises the form er investm ent w ill exceed the latter w ith in five years.

I t is im possible to evade the fact th a t every waste- fu l practice in the m in in g o f coal is translated into cost. T his cost becomes a direct burden on the con­

sumer in the fo rm o f h ig h e r prices, if a profit is to be m ade on the o u tp u t of the m ine.

In c o n trib u tin g to th is waste and the re sultan t h ighe r cost of production, some im p o rta n t factors are:

the im p u ritie s loaded on the cars in the m ine and

No te— M en, a f t e r a ll, are th e g re a te s t assets t h a t a c o a l c o m ­ p a n y c a n h a v e . T he h e a d p ie c e s h o w s a g r o u p o f m in e r s w a itin g ' a t th e s h a f t b o tto m to b e h o is te d to th e s u rfa c e . T h is is th e r a w m a t e r ia ł w it h w h ic h th e h u m a n e n g in e e r in th e m i n in g in d u s t r y h a s to w o r k .

eventually shipped to the consumer, careless h a n d lin g or rough treatm ent of tools and eąuipm ent, absenteeism and “ idle days,” restriction of production, opposition to labor-saving devices, uneconomic restrictions, strife and friction , and the like. M uch of the waste com- plained of is due to the attitu d e of the executives tow ard th e ir employees and of the employees tow ard th e ir jobs. Perhaps a larg er portion of it m ay be charged ag ainst the attitu d e of the executives th a n against the attitu d e of the employees, fo r it is upon the form er th a t the latte r largely depends. In other words, i f executives in sist upon g iv in g 95 per cent of th e ir attentio n to the m echanical side o f the business and only 5 per cent to the h u m an side, they have little to com plain about if th e ir employees give 5 per cent of th e ir attentio n to th e ir jobs and 95 per cent to th e ir personal interests. Regardless of w h at percentage of attention the employees give to th e ir jobs, however, it is obvious th a t sooner or later any in a tte n tio n w ill be reflected in waste.

C o o p e ra tio n Is t h e O n ly A de quate S o lu tio n The ąuestion of how wastes an d the losses they produce m ay be lessened in a su bstan tial way, if not prevented entirely, m ay be answered w ith a single w ord

— co-operation. The task of o b ta in in g co-operation, however, is by no m eans sim ple. Some employers have trie d to obtain it by p lacing in d u s tria l spies in th e ir plants to report de linąue nt employees, who are dis- charged; b u t they have failed . O ther employers have striven fo r co-operation, th e ir various activities be in g classified under the head of w elfare work. They have trie d to w in the co-operation of th e ir employees by g iv in g th e m som e th ing; an d they also have failed.

672 C O A L A G E V ol. 26, N o . 17

T his n aturally b rin gs up the ąuestion as to how co- operation really can be obtained. In a negative way it m ay be answered by saying th a t it can rarely come fro m the inside of the organization, because the average executive is unable to analyze the motives th a t control his employees. To do th is properly and effectively it is necessary to approach the m atter fro m an “ outside or detached” (n o t disinterested) view point. The executive him self, being on the inside, the view point is denied him . In a word, it is a case fo r the train e d

“ m an engineer.”

L et us cite a case in point. In it figured a m in ę eąuipped w ith the most efficient m achinery, labor-saving devices, p le n tifu lly eąuipped and engineered, yet unable to produce coal at a profit. A survey of conditions in the m ine showed an antagonistic attitu d e on the p a rt of the employees tow ard the m anagem ent. T his resulted in th e ir opposing the purpose of the eąuipm ent and

Unnecessary d riv in g tactics indulged in by those charged w ith supervision also m ate rially adds to the m in in g cost thro ugh expensive labor turnover and in- creased antagonism from the workers. T his feeling expends itself in opposition to the m an ag em e nt’3 interests. Education of the forem en along s im ila r lines, supplemented by a strongly applied construc*

tive policy w ill elim inate these losses accruin g fro m the supervision. I t is all a case of d e te rm in in g m otives and w orking up the s p irit of co-operation th ro u g h understanding.

CO-ORDINATION REDUCES PAYROLL LOSS

The annual payroll loss in some m ines is alm ost unbelievable. In a large operation the payroll was found to be sustaining an annual loss of 25 per cent of the total wage disbursem ent. B y developing a greater degree of co-ordination and construetively

Those Who Actually Produce

Coal

C o lo r m a k e s litt le d iffe re n ce in loy- a lty . T h e im po r- t a n t c o n s id e r a tio n in a n y in d u s t r ia l en- te rp ris e is m o r a le . T h is m a y be in- t a n g ib le , in c a p a b le o f m e a s u r e m e n t or a p p r a is a l, y e t i t is n o n e th e less h ig h ly im p o r t a n t . T he loy- a l t y o f e ve n s u c h m e n as these roof- b ru s h e rs is w e 11 w o r th s e c u r in g by

th e m a n a g e m e n t o f a n y m in e .

labor-saving devices, thereby re strictin g production, and causing great losses and wastes. They had been educated by outsiders to believe th a t these practices were to th e ir interest.

A n intense educational effort in the simple economics of the situation, developed a comprehension of the fallacy of th e ir previous methods and practices. T his resulted in the economical and cleaner m in in g of coal, w hich perm itted the operator to offer a price in- ducem ent and to extend his area of d istrib u tio n , thereby p ro v id in g more stable em ploym ent under more agreeable conditions fo r his workers. The secret was the “outside” or analytical view point and the edu­

cational method practically applied. Thus success was achieved th ro ug h e n listing the co-operation of the employees and th e ir interest in th e ir w ork to a point where they had a f a ir un derstanding of the id e n tity of interest. The executives of th is m ine had been neglect- in g its greatest asset— the goodwill and understanding o f th e ir workmen.

m olding the employees, as well as the forem en an d con- tractors to the proper appreciation of th e ir responsi- b ility and to an und erstanding of sim ple economics, the greater p a rt of th is loss has been recovered.

T hat the m inds of m ine workers are not closed to developments of an economic n a tu rę is proven by an experience recently had in a non-union operation.

Although the m ine was operating more or less con- tm uously under a reduced wage scalę, the conditions ot the coal m arket plainly indicated a c u rta ilm e n t of output R e alizin g th a t a reduction in price w ould stimu- late sales, and th a t they would be fa r better off w o rk in g for a slight reduction five days a week th a n one or two days a week at a h ig h e r scalę, the m iners made th e ir views know n and graciously accepted the reduc- lon m wage N o doubt when orders are ag ain plenti- tu l they w ill prom ptly receive a su b stan tial increase trom this constructively inclined operator.

In u n de rtaking the reduction o f m in in g losses s i^ h t m ust not be lost of th a t fact th a t every w o rk in g force

O c to b e r 23

,

Common Ground

F ir s t a id t r a in in g in m o s t cases h a s do ne f a r m o re t h a n te ac h m e n h o w to a p p ly b a n d a g e s — it h a s t a u g h t th e m h o w to m e e t a n d a p p re c ia te e a c h o the r. W h e n em- ployee a n d em ploy- er m e e t in a c o m ­ m o n cause , differ- ences o f o p in io n are a p t to be fo rg o tte n . N o t h i n g w e ld s p e o p 1 e to g e th e r m o re flr m ly t h a n to w o r k fo r a c o m m o n o b je c tiv e o r to p la y o n th e s am e te a m .

is made up of three types of employees— conservative, radical and neutral. A nalysis of m ines and plants in more th a n 50 industries has shown that, in a group of 100 typical employees, 10 per cent are conservative, another 10 per cent are radical and the rem ain in g 80 per cent are of neutral motive.

There is no loss on the payroll dollar of the first group, because the employees in it return a fu li day’s work fo r the wages they receive. The radical-motive group w ill produce only 50 per cent of a fu li day’s work, w ith a conseąuent loss of 50 per cent of the wage investm ent in them. The 80 employees in the neutral- m otive group produce only 75 per cent of a fu li day’s

A R e lia b le C ru sh er In s ta lla tio n

A t a certain m ine in Illin o is a r in g crusher was in- stalled about three years ago. T his m achinę is driven by a 50-hp. m otor and is used to reduce large coal to stoker size. Since its in stallatio n it has crushed a total of 240,000 tons of coal, some pieces being as large as 2 ft. chunks. On the average about 1,100 tons of fuel are passed th ro u g h th is m achinę each sh ift.

work, and there is a loss of 25 per cent on th e ir p ay ­ roll dollar. The net result is, in th is case, w hich is typical, a loss in productive value of 25 per cent of payroll investm ent per hundred employees.

Appreciation of science in m achinery and m in in g engineering is essential in the coal in d u stry but, unless the good-will of the employees can be obtained, no- system w ill earn satisfactory dividends. The co- operation of the m ine workers can be h ad by any employer who w ill meet them h a lf way. The view point of the employee is the m ost neglected factor in our modern m in in g industry. I t deserves fa r greater con- sideration th an it now receives.

Thus fa r no repairs whatever have been necessary on this m achinę. Expense of operation, in c lu d in g in- terest, depreciation, etc., am ounts to $13.39 per day, which brings the cost of crushing to 1.2 cents per ton.

M any coal m ines d u rin g recent years have installed crushers so as to be able to supply stoker fuel to the trade whenever the dem and fo r th is grade is strong.

The results obtained in th is in sta llatio n in Illin o is show how reliable these crushers can be made.

The Ghost Car of the Rocky Mountain Region

T he U n ite d S ta te s F u e l Co., w it h h e a d ą u a r te r s in S a lt L a k e C ity , U ta h , o p e ra te s th e o n ly w h ite c o a l c a r in c a p t iv it y — a n d o n ly o ne . T h is ca r, w h ic h s h in e s o u t lik e L it t le E v a a m o n g th e T ops es a n d th e S im o n L e g re e s o f c o a l traffic, is u s e d as a n a d v e r t is in g

fe a tu r e fo r “K i n g ” co a l. I t m a k e s tr ip s here a n d th e re a m o n g th e c u s to m e rs o f th e c o m p a n y , a t t r a c t t n g a t t e n t io n w h e re y e r it goes. I n th is p h o to g r a p h , i t s ta n d s in th e lo a d y a r d o f th e B la c k h a w k m in e a t H la w a t h a , U t a h .

574 C O A L A G E V ol. 26, N o. 17

How Dangerous Ground Currents Were Prevented And Confidence of Workmen Regained*

S t r a y C u r r e n ts W ere E lim in a t e d fro m S h a f t a n d E ą u i p m e n t b y I n t e r c o n n e c t in g C a b l e s — L e a d s o n F ir in g C a p s S h o u ld B e S h o r t C ir c u it e d U n til U s e d — D a m a g e d B l a s t i n g

C a b le s M u s t B e R e p la c e d a t O n ce

Electrical Engineer, E. E. W hite Coal Co., Stotesbury, W. Va.

I

As two men started to descend the sh aft to locate the open circuit, so th a t the work could proceed, the charge of dynam ite exploded. Fortunately, no one was in- jured, as the shot had been well placed and properly loaded, so th at no rock was throw n to the surface.

I t was now evident th a t conditions were extremely dangerous, and the cause of this prem ature explosion m ust be found and elim inated. The confidence of the workmen had been shaken and some of them refused to proceed w ith the work unless steam instead of elec- tric ity was used fo r hoisting and p u m p in g purposes.

Because of the fact th a t all the eąuipm ent was elec- trically operated and the m achinery fo r sin k in g h ad all been installed, it was practically out of the ąuestion to use steam. I t was therefore evident th a t the cause of th is explosion m ust be found and remedied.

I t was known positively th a t the circuit leading to th is charge of dynam ite was open, and th a t the switch had been disconnected some tim e previous to the detona- tion o f the charge. I t was also believed th a t the shot had in some way been detonated by w hat is commonly knowjn as a stray current.

Tests Madeto De t erm in e Exact Cause

A num ber o f tests were made to determ ine the exact, cause. In m a k in g these tests, first, all the switches were opened, and an o rdinary electric blastin g cap was connected between the compressed a ir line and the dis- charge line from the pum ps located at the bottom of the shaft. The in stan t the connection was made the cap was fired. This showed th a t a sufficient difference of potential existed between these points to detonate an electric b lastin g cap. A connection was made between the a ir line going down the s h a ft and the ground adja- cent thereto. A g a in the cap was fired, b u t not instantly, thus show ing th a t there was not at all tim es sufficient voltage between these points to fire the cap. A connec­

tio n was made between the electric hoist fram e and the ground and the cap was fired instantly. A connec­

tio n was made between the sh aft bottom and a wet place near the surface and the cap was fired in a few seconds.

F ro m these results it was evident th a t sufficient dif-

•Paper presented before M ining Section of National Safetv Council, Louisville, Ky., Oct. 2.

ference of potential existed between the places selected to fire blasting caps connected in an o rd in ary c irc u it in the shaft. To equalize the difference o f poten tial exist- in g at these various places, connections were m ade w ith heavy copper w ire as follow s: The fram es o f all the m achines on the surface, and the pipę lines g o in g dow n the sh aft were electrically connected; holes were dug near the hoist and compressors, and gro u n d connections were made by b u ry in g a coil of wire, and b o ltin g the

Drilling a Hole by Hand

e n c e - d a m n thM r t h le be .d r i.n f d |n ro c k o r c o a l m a k e s lit t le differ- ce earthy materials form a conductor that nnrrv

sufficie nt s tr e n g th to set o ff^ a d e to n a to r^ m g h - r e t is U m r a iIs ’ &a sl<ets in p ip ę lin e s a n d a h u n d r e d a n d one o th e r th in g s n o t p e rc e p tib le to the eve, m a y in flu e n c e n o t o X

the m a g n itu d e o f s tr a y c u rre n ts b u t t h e ir p l t h as w e ll V

connections to the fram es of the m ach in es; salt w ater w as poured on these coils of w ire to in crease the con- ductivity, and earth packed over them to fili the holes and insure good contact with the ground.

T ests were then m ade with a m illivoltm eter and no difference of potential g re a te r than 100 m illivolts could be detected between any two pipes, between a pipę and

fheUshaft°r tHe t0P ° f thG ShEft ^t0 the bottom of

A fter these tests had been completed several b lastin e cash Z " T r t0 the W° rkmen’ and a P ™ * of $25 "n cash offered to anyone who could cause a cap to fire at

any place except by the use of the blasting circuit I r e a r z 5 WatCh eff0rtS the me^i to fire

explode N ot hJS precaut,0,; s used 1” ^ they should r T h w ng successfu l in th eir attem p ts it w as caps^handed to T b ° f ^ WOrkmen believed th at the ps nanded to them were im perfect. They thoue-ht

hese caps t ° be “ phoney.” In order to dispel th is sus- P on each cap w as connected to the b la stin g machinę

O c to b e r 23, 1924 C O A L A G E 575

Drilling a Shot Hole Electrically

B y w h a t m e a n s a h o le is d r ille d m a k e s v e r y lit t le difference so f a r a s s tr a y c u r re n ts a re c o nc e rne d as th e re a l d a n g e r com es b e tw e e n th e tim e o f c h a r g in g a n d th e tim e o f firin g . N ote, how- ever, th e ro c k b a n d b e lo w th is s h o t h ole. I t m a y h a v e h ig h re s is ta n c e w h ile th e c o a l a b o v e a n d b e lo w i t m a y h a v e co m p ara - t iv e ly Io w re s is ta n ce . S u ppo se t h a t in in s e r tin g th e c a r tr id g e a n d p u s h in g i t h o m e one le a d w ir e is scra p e d b a re m a k in g c o n ta c t w it h th e co a l a n d t h a t th e b a re e n d o f th e o th e r w ir e to ue h e s th e d a m p floor. T h e n suppose t h a t a s tr a y c u r r e n t seeks p as sa g e fr o m th e c o a l to th e floor. W h a t w ill h a p p e n is o b viou s.

and fired, thus re storing the w orkm en’s confidence, so th a t the w ork could proceed w ith o u t fear.

The follo w in g rules were then posted reg ard in g blasting, and rig id adherence enforced.

R ule 1. Explosives must be placed in an insulated Container when being lowered down the shaft.

R ule 2. N o t more tw o m en m ay be in the sh aft when shots are being prepared.

Rule 3. The m uck bucket m ust not touch the bottom of the s h a ft d u r in g preparations fo r a blast.

R ule 4— The b lastin g m achinę m ust rem ain in the possession of the top m an, and m ay be operated only by the m an w ho prepared the shots, and then only in the presence of the top m an.

R ule 5. The whole length of the shooting cable m ust be inspected daily. I f a bare place is found, the cable m u st be th ro w n aw ay and a new one secured.

There are obvious reasons fo r each of these rules.

F irs t, i f the explosives are in an insulated Container w hile being lowered dow n the shaft, there is no danger of an electrical contact being made. Second, if only tw o m en are in the sh aft d u rin g the p reparation of the shot, it is certain th a t not more th a n two men could be h u r t in the event of an accident. T hird, if the m uck bucket does not touch the bottom , there is no danger o f stray currents r a d ia tin g fro m it. F o u rth , i f the b lastin g m achinę is in charge of one m an, one p a rtic u la r person is responsible fo r its safe keeping and i f the m an who prepares the shots is the only one allowed to use the m achinę, it is evident th a t no one w ill connect it u n til everyone is out of the shaft.

F ifth , i f a well-insulated b la stin g cable is used, and it comes in contact w ith any charged m achines or pipę lines, the in su latio n w ill prevent leakage of current to the b lastin g cap.

Since the accident m entioned above some th o u g h t has been given the subject, and im provem ents m ade in the w ay of h a n d lin g electric detonators, especially inside the m ines. In the case o f the E . E . W h ite Coal Co.

the m iners are ta u g h t to tw ist the bare ends of the w ires o f the b lastin g caps together and keep them in th is condition u n til they are finally connected to the

blasting circuit. T his sim ply means th a t in case the wires of the cap come in contact w ith a source of cur­

rent, the ends being short-circuited, there is no danger.

Caps are always delivered to the men in paper sacks properly closed at the top so th a t the ends of the wires can not come in contact w ith any source of current.

The men are tau g h t to suspend blasting cables on wooden posts, and never allow them to come in contact w ith m ine tracks. B lasting batteries are m ade in such a way th at a connection to them cannot be made unless the cable is held in one hand and the battery in the other.

Thus there is no danger of a w orkm an leaving his battery connected to a cable and going to the face and attaching another cap. Accidents have happened where m iners have left th e ir cables connected to b attery ter- m inals and attached blastin g caps at the charge.

To those who have studied electrolysis the subject of stray currents is a fa m ilia r one. M uch study has been given this subject, and some electric railw ay companies have gone so fa r as not to use the rails or ground fo r return circuits at all, in fact, th is is the case in Cin- cinnati. The danger here is not so m uch the prem ature explosion of shots b u t the electrolytic action on steel structures.

I f an electric current is passed th ro ug h a liq u id fro m one metallic plate to another, electrolysis w ill take place; th a t is, m etal w ill be deposited on the negative pole, and the positive pole w ill be dissolved. In an elec­

tric railw ay return circuit there is a difference of poten- tia l between parts of the system and the rails and other buried metals, such as pipę lines, steel structures, fire plugs, telephone cables and foundations o f b uilding s.

The am ount of these differences of potential depends somewhat upon the energy loss in the re turn circuit, it varies w ith the am ount of current flowing, and the resistance of the re turn circuit.

I t is therefore evident th a t if pipę lines and buried pieces of m etal are all connected together w ith low- resistance cables, these differences of pote ntial m ay be practically elim inated. However, it is not so evident th at different strata of earth are of relatively Iow re­

sistance and sometimes separated by a stra tu m of com- paratively h ig h resistance. Nevertheless th is accounts

- #

Loading a Hole

W h e n h a n d le d p ro p e rly e x p lo s iv e s a r e h a r m le s s : i f h a n d le d im p r o p e r ly th e y “ le t g o .” T he b la s te r m u s t n o t o n ly lo o k care- f u l l y to th e c h a rg e o f p o w d e r its e lf b u t a ls o to th e d e to n a to r a n d its le a d w ire s. T w is tin g th e b a re e n d s o f the se w ir e s t o g e th e r fo rm s a n e le c tric a l c o n n e c tio n b e tw e e n t h e m a n d g r e a t ly le ssens th e d a n g e r o f p r e m a tu r e e x p lo s io n . T h is process p r a c t ic a lly con- ve rts th e le a d s f r o m tw o s e p a r a te w ire s in to one c o n tin u o u s c o n d u c to r w i t h n o o p p o r t u n it y fo r c u r r e n t to flo w to th e c a p . F u r th e r m o r e , jo in in g th e w ir e s ’ e n d s keeps t h e m to g e th e r so t h a t th e y are n o t lik e ly to to u c h tw o p o in ts o f a p p r e c ia b ly d iffe r e n t p o te n tia l.

C O A L A G E

V o l. 26, N o . 17

A Place to Begin to Control Currents

TTnbonded or p o o rly b o n d e d tra c k s are a c o n tin u a l source of

•daneer a n d expense A n y c u r r e n t t h a t leaves a g e n e ra to r m u s t r e tu r n b y som e c ir c u it o r a n o th e r. I f the r a ił jo in t s p resent. a h ig h re sista n ce the c u r r e n t w ill p ass t h r o u g h the m a te r ia le offer in g a n easie r p a th .

fo r differences of potential between earth strata. By the same token, where current is flowing th ro u g h the earth, there are differences of potential between points on the surface, or between the surface and under­

ground, depending upon the difference in th e ir dis- tances from the source of current the conductivity of the various strata of earth and the am ount of cui rent flowing. The first experiments in wireless depended upon th is principle. W hen we consider the smali am ount of current necessary to fire an electric deto­

nator, and the smali am ount of voltage required, it is evident th a t care m ust be taken not to allow the bare ends of the caps or bare places in the b lastin g cable to come in contact w ith conductors, especially pipę lines, Steel rails, ponds of water, or wet places of relatively h ig h conductivity due to m inerał salts and acids.

I t is strongly recommended th a t all electric blasting- cap wires be tw isted together d u rin g the process of m anufacture, thus m in im iz in g dangers in the field should the wires accidently come in contact w ith mate- rials h avin g a difference of potential between them.

The cables used fo r the purpose of electric b lasting are usually poorly insulated and cheaply constructed.

The insu lation consists chiefly of cotton treated w ith paraffm. A great im provem ent could be made in th is direction w hich would add to the safety of electric blasting. M anufacturers of electric batteries used for firin g electric b lasting caps can improve th e ir construc- tio n by so a rra n g in g the batteries th a t no perm anent connection can be made to them. T his refers, of course, to the batteries used by coal m iners, where only one cap is fired at a tim e.

F or the benefit of those who w ish to calculate the resistance of blasting circuits, I ąuote lite rally fro m J . H . Horlick, Jr., of the Hercules Powder Co., who

very kin d ly furn ishe d th is in fo rm ation.

“ The actual am ount of current reąuired to heat the bridge of our electric blastin g cap sufficiently to set off the charge in the cap is approxim ately 0.4 amp.

However, in actual blasting, and w ith more th an one cap connected in the circuit, a greater current is recom­

m ended to take care of any slig h t v ariatio n in the bridges of the caps or of any leakage w hich m ay occur in the circuit, especially under dam p conditions or in

metal-bearing m aterials. F o r various types of connec­

tions we therefore recommend the fo llo w m g c u rre n ts.

1 F or series connection, not less th a n 1.5 am p.

2. F or straig h t parallel connections, not less th a n 0.6

“ T For p S ^ l- s e r ie f c o n n e c t io n s where the caps are in series groups and the groups m parallel, not t h 4n F o r^rie s- p a ra lld connections where the caps are

in parallel in groups, and the groups in senes not th an 1.0 amp. per cap in the largest p a r a f i egroup.

“ O f course, it is quite possible to get satisfactory sults w ith less currents th an r e c o m m e n d e d above, es- pecially when a num ber of caps are placed m the en cuit. However, the above m in im u m currents are recommended so as to have some m a rg m of P ° ^ e r take care of any irre gularities in the circ u it and p vide greater assurance of all caps firin g . .

“W ith the necessary current determ ined, the re ą u ir voltage then depends upon the resistance of the circui . In this consideration it is im p o rta n t th a t the resistance of the entire circuit, and not th a t of the caps alone, be calculated. F or instance, suppose we h ad a c irc u it con- sisting of ten 10-ft. No. 6 copper w ire E .B . caps m series w ith 500 ft. of No. 14 copper w ire to the source of power. The resistance of E .B . caps, of course, varies w ith the length and k in d of leg wires, th a t of H e r­

cules 10-ft. No. 6 copper w ire E .B . cap being 1.50 ohms.

Ten in series would therefore have a resistance of 15.0 ohms, while the 500-ft. of lead w ire w ould have a re­

sistance of 1.26 ohms. W ith the m in im u m recom­

mended current of 1.5 amp. fo r th is series circuit, the reąuired voltage by O h m ’s L aw w ould be about 25 volts. F or firin g only a single cap, a curren t of only about 0.5 amp. would be sufficient to use in cal- culating the reąuired voltage along the above lines, in which case about 1.5 volts w ould probably fire the 10-ft.

copper wire cap. I t is in tere stin g to note th a t i f a stray current should get th ro u g h the cap w ire in s u la ­ tion near the cap itself, thereby e lim in a tin g the leg w ire resistance, a voltage as Iow as about 0.6 volt m ig lit fire the cap. However, fo r more th a n one cap in regu- lar blasting circuits, we recommend calculations fo r reąuired power based on more th a n m erely theoretical reąuired current, in order to m o ft th oroug h ly insure the firing of all caps in the c irc u it.”

Take No Chances With a Damaged Blasting Cable

B a re spots in a c a b le m a y to u c h a m in e r a ił, c h a r g e d c o n d u c to r o r a p ip ę c a r r y in g c u r r e n t a n d fire a c h a rg e . In s p e c t th e ca b le every d a y a n d re p lac e it w it h a n e w one if it is d a m a g e d .

O c to b e r 23, 1924 C O A L A G E 577

Equipment and Safety Methods in Alabama

A u x ilia r y F a n D r iv e s A s s u r e R e lia b le V e n tila tio n — R o t a r y D u m p s D is c h a r g e W h o le T r ip a t O n e O p e r a tio n — M e c h a n ic a l S a m p le r s I n flu e n c e C o a l Q u a lit y — D u s t L a i d b y W a sh in g D o w n M in e S u r f a c e s

By Milton H. Fies

V ic e - P re sid e n t, D e B a rd e le b e n C o a l C o rp o r a tio n , B ir m in g h a m , A la .

V

A t practically all m ines where power is available vari- ous types of fans are used. A t some d r ift operations smali fa n s of about 5,000 cu.ft. per m in u tę capacity are em ployed; one m achinę fu r n is h in g a ir fo r one or two openings. A t larger developments, where m ethane is .generated, there are usually two drives to each fan.

One of these is generally a m otor and the aux iliary drive a steam, gasoline or kerosene engine.

A t the N o. 1 a ir sh aft of the W oodw ard Iro n Co. a No. 16 Sirocco fa n has been installed. T his is driven norm ally by a 150-hp. m o tor; the aux iliary u n it con- sists of a 100-hp. Fairbanks-M orse kerosene engine.

T his engine is direct-connected to the fa n sh aft by a sliding ja w clutch. The m otor is connected to the fa n by a belt, the pulley being loose on the sh aft b u t pro- vided w ith jaw s cast in the h u b to engage a sliding

■clutch. In case of power failure , it is only necessary to thro w out the clutch on the belt pulley, throw in the other clutch and start the engine.

The engine is started w ith compressed a ir from a re-

«eiver. T his is always kept up to pressure by a smali compressor th a t is driven by a 9-hp. gas engine. The entire change can be m ade in less th an 5 m inutes.

Storage batteries are provided to fu r n is h ligh ts fo r the attendant at the fa n in case of power failure. The layout of th is au x iliary drive is shown in F ig . 23.

Both the continuous and split systems of ven tilatio n are in use in the m ines of A labam a. In the larger and better-equipped operations, the split system is preva- lent. Concrete overcasts and stoppings made of m ine rock, faced w ith a *nixture of clay and cement, are fo und in the better-class mines.

In So m e Min e s Mu ch Water Must be Handled I t has been fo un d th a t as pillars are removed, par- ticu la rly in the W a r rio r field, the cost of p u m p in g increases greatly. In some of the P r a tt mines, where p illars were robbed as the entries were driven to the boundary, fro m 10 to 15 tons of w ater have been pum ped fo r each ton of coal produced. I t is now the custom, at the larger operations, to extract not over 50 per cent o f the coal as the m ine advances, leaving large thick pillars. These are robbed as expeditiously as is prac- ticable tow ard the end of the m in e ’s life. The reduc- tion in p u m p in g by th is m ethod w ill be great.

In the C ahaba field, where all the beds pitch, p u m p in g is a large item of expense, m a in ly because there are conglom erate and other porous strata above the coal measures. The d rainag e problem is sim plified, however, by the a b ility to lead the w ater to a com m on point.

Methods employed in tim b e rin g vary greatly accord-

N o t e — F o u r t h a n d la s t i n s t a llm e n t o f a r tic le e n title d , “A l a b a m a C o a l- M in in g P r a c tic e s ,” p re se n te d a t th e B ir m in g h a m m e e tin g o f the A m e r ic a n I n s t it u t e o f M in in g a n d M e t a llu r g ic a l E n g in e e rs .

in g to the top, and no set principle is followed. The cost of tim b e rin g ranges from lc. per ton to 7 or 8c., depending on the naturę of the top and the accessibility of the tim ber. I n recent years, the cost of tim b e r has increased, th ro ug h the exhaustion of the supply readily available. I t is not uncom m on a t some m ines to have the tim be r shipped in by ra ił or hauled 10 to 15 miles in trucks.

In the larger, better-eąuipped mines, slope and m a in haulage track is laid on sawed creosoted ties w ith 40 to 60-lb. steel. O n cross entries, where m ule haulage is used, the raił is 20 Ib., b u t w ith locomotives it is 30 to 40 lb. Room rails vary from 12 to 20 lb. in weight.

In m edium and steeply p itc h in g beds, as a generał rule, mules are used on all cross entries fo r gath e rin g coal to the slopes. W here the p itch is fro m 0 to 5 deg.

locomotives are employed almost entirely fo r g ath erin g and main-line deliveries. Storage-battery and gasoline machines are used at a few operations and in a few cases endless and tail-rope haulage systems are found.

Belt Conveyor Used as a Slope Hoist

A t one m ine in A labam a, a belt is used fo r h o istin g coal up a slope. T his conveyor operates on a p itch of 19 deg. 53 m in . The belt is 4 ft. wide, w ith tro u g h in g idlers on the upper and s tra ig h t b e arin g idlers on the lower strand. H ead and ta ił centers are 485 ft.

ap art and the belt is kept ta u t by passing over an idler pulley to w hich a counterw eight is attached located ju s t under the head pulley. The coal is discharged in a one-car revolving dum p underground. U nder th is dum p is a hopper, w hich holds about 6 tons, or the capacity of three m ine cars. Beneath the hopper is placed a reciprocating feeder w hich feeds the coal fro m the hopper to the belt. T his feeder is p e rforated and the slack coal goes to the belt first and the lum p coal is deposited on top of it. The belt has a capacity of 2,500 tons per day of 8 h r. A 75-hp. m otor drives th is conveyor as well as the reciprocating feeder. The ad- vantages of th is system are reduced cost of all tipple and head-frame structures, a lower op e rating expense, a smaller investm ent in h o is tin g m achines— a 75-hp.

m otor as against an expensive hoist of 500 to 700-hp.

capacity. B y re g u la tin g the feed a t the b ottom o f the slope coal can be fed to the shaker screen in the tipple w ith such re g u larity as to m ake the screening h ig h ly effective, and all danger fro m slope trip s is elim inated.

T his belt has been in operation about a year and no wear is noticeable. The m in e has n o t been b ro u g h t to its fu li capacity, b u t 1,100 tons have been handled over th is conveyor in one day w ith the belt sta n d in g idle about h a lf of the tim e.

W ith beds of such diversified thickness an d p itch as here prevail, m an y types of m in e cars are in use in the state. In the more recent developments, cars with-

578 C O A L A G E V ol. 26, N o . 17

out end gates, and revolving dumps with which to dis- charge them, are becoming the generał practice. At one operation, on a 25 to 35 deg. pitch, Griffith bottom- dump cars are being used with success. One type of tipple installed at a slope mine, and which well illustrates the use of revolving dumps and gateless mine cars, is shown in Fig. 24. This tipple handles about 2,000 tons per 8-hr. day with a counterbalanced haul of five cars per trip. The capacity of the cars is 3,500 lb., making about 9 tons of coal per hoist.

The coal is pulled from the loaded yard up a 30-deg.

slope about 1,100 ft. long by an 800-hp. Vulcan hoist.

The drums are 10 ft. in diameter with a 4-ft. 6-in. face.

The rope speed is 1,800 ft. per minutę. A 500-ton reinforced-concrete bin, located over two standard-gage railroad tracks, receives the coal from the gravity dump.

The bin is 39 ft. high on the approach end and 494 ft.

high on the hoist end; this gives an angle of about 8ł-

Fig. 23—Auxiliary Drive for a Mine Fan.

W hen the fan is down the mine is down. This layout shows a fan normally driven by belt from a motor. Should a mishap befall this motor or should the source of power fail a kerosene engine m ay be started and the fan driven by it. Both engine and belt pully are clutched to the shaft so that shifting drives is a matter of only a few minutes.

deg. in the gravity dump, and facilitates the prompt return of cars by gravity after they have been dis- charged.

Hoist operation is controlled by electric signals from the man on the tipple, when cars are ready to be re- turned to the mine, and from the man in the loaded yard, when the trip is ready to be pulled out. The coal is weighed in the underground yard and pulled into the dump which is released by the operator on the tipple. The dump is rotated by the weight of the coal.

As the cars empty, the dump returns to its normal position, and latches automatically. It is then ready for the next trip. As the coal leaves the cars in the dump, part of it is caught by sampling chutes in top of the bin.

Every precaution has been taken to make the tipple as fireproof and safe as possible, the main structure being of reinforced concrete and steel. At the top of the tipple, on the hoist end, a 20,000-gal. water-storage tank is provided for fire emergency.

INSTALLATION AND ADVANTAGES OF SAMPLERS

All mines in Alabama employ a dockage system whereby miners are penalized for loading excessive quantities of slate or rock. The method generally used to check up the miner is to pick a few cars at random, unload them carefully, a shovelful at a time, and inspect closely the entire contents of each car. The weak point in this method is that only a few cars can be inspected

during one day’s operation and the miner, knowing this, will take the chance of not being discovered.

Erskine Ramsay, first vice-president and chief engi- neer of the Pratt Consolidated Coal Co., has perfected a mechanical sampler that has made possible the testing and inspection of a large number of mine cars without actually unloading their contents by hand. The Ram­

say sampler has been used more extensively by the Woodward Iron Co. than by any other concern in this district. This company installed its first sampler in May, 1920, at Dolomite No. 1 mine. Since then, two additional machines have been installed at this opera­

tion, three have been installed at Dolomite No. 3, and four at the Mulga mine; this gives the Woodward com­

pany a total of ten samplers.

At Dolomite No. 1, the coal is hoisted in four-car trips and is dumped four cars at a time by means of two Ramsay, rotary, multiple, slope dumps installed in parallel. Messrs. Crockard and Best, of the Woodward company, made such changes in the usual design of these dumps (which are generally power driven) as to make them rotate by gravity. Installed under these rotary dumps are chutes having hoppers at the top.

Beneath the right-hand dump there are two of these chutes by means of which the coal is directed to a sampler room, in which one sampler is installed. Be­

neath the left-hand rotary dump, there are four chutes leading to a sampler room on that side of the tipple, in which are installed two samplers, each being served by two chutes. The chutes have a hopper arrangement at the top for receiving the coal samples and are equip- ped with rotary gates operated by cables passing over sheaves and extending to a position convenient for the sampler operator. This man is thus enabled to draw the samples one at a time as reąuired for convenienc operation (see Fig. 25).

At the sampler, as installed by the Woodward com­

pany, the operator releases the sample from the chute onto a double-deck shaking screen 24x42 in. in size.

This feeds slowly to a 24x38 in. picking table. The upper of the two shaking screens has 1-in. circular perforations and the bottom screen i-in. perforations.

The lump materiał that passes over the upper screen is hand picked. That from the lower deck is discharged onto the picking table through a smali gate and is like- wise picked. The fines passing through the lower screen go directly to the coal car and are not considered in the sampling. The removal of this materiał, however, facilitates the sampling operation and makes more care- ful and faster picking possible.

At Dolomite No. 3 mine, practically the same ar­

rangement has been installed. Here the coal is dis­

charged from the mine cars by two Ramsay rotary dumps in trips of five cars each, instead of four cars as at Dolomite No. 1. Chutes of the same design lead from beneath the coal dump to the sampler room in exactly the same manner as has been described and are eąuipped with gates so that the coal may pass directly to the sampler or, if desired, may be retarded to suit the convenience of the sampler operator.

Carriers Substituted for Sa m p l e r Chutes

At Mulga mine, four samplers have been installed.

These are arranged in two rows back to back, but stag- gered so as to allow sufficient space for the attendants.

This installation presented unsual difficulties because

of the smali space available for the equipment. The

amount of head-room was so smali that it was not pos-