Coal Age : devoted to the operating, technical and business problems of the coal-mining industry, Vol. 26, No. 25

James H. M cGraw, President . ,, „ r . R. Dawson H a l l E. J. M ehren,

Vice-President Problems Of the Coal-Mining Industry

Yolum e 26 N E W Y O R K , D E C E M B E R 18, 1924 N um ber 25

W a t c h i n g O u r O p p o r t u n i t i e s

I

says a letter from a large E n g lish jo b b in g house to a lis t o f A m erican coal producers, “the new conservative governm ent is going to get into trouble w ith our min- ers.” I f th a t tim e comes E n g lish coal production m ay be expected to be shut off again w ith conseąuent effect upon the im p o rta tio n o f coal by E nglan d . T his pros- pect adds another reason fo r the firm retention abroad of the trade representatives of the D epartm ent of Commerce. W hen there is any fore ign economic disturb- ance either in prospect or in process th is country needs to have a keen eye and ear on the spot.

P o o l i n g B r a i n s a n d E x p e r i e n c e

C

pany official claim s th a t the m anagers get together and interchange views on th e ir various problem s and go back to th e ir offices and carry out th e ir plans.

I f th is is all they do, it is easy to see w hy one com­

p an y is h ig h ly developed along some lines o f electrical ap plication and a laggard along m any others. W hen engineers themselves do not know w h at the other fellow is doing and cannot see where they themselves are progressive or unprogressive, how can they grasp the second-hand or third-hand in fo rm a tio n w hich m ay be transferred to them th ro u g h official channels?

The electrical engineer has too hard a task today m a k in g h is own president or generał m anager under- stand the problem s p e rtine n t to his own organ izatio n to hope to acquire in fo rm a tio n fro m another company by in d ire ct methods.

A good live society is needed, and the coal companies themselves should encourage its form ation .

F u m b l i n g a t t h e K n o t

C

I f they w a n t to tr a in practical men, they m ust get m en o f practice in th e ir college faculties. They m ust select electrical engineers who have worked at the bench, on the road, in the m ine. They m u st get min- in g engineers who have designed and erected tipples as m ining-com pany employees or as m a n u fa c tu re rs’

representatives. They m u st get as m echanical e n gi­

neers m en who can design and construct hoists, who can go in to the facto ry or the boiler shop and take charge.

T hat requires money. T h at involves a reconstruction o f staffs. Colleges are today too fre que ntly merely bricks, m arble, and stark intellect. O u r in d u s tria l colleges should be b u ilt on the r ig h t k in d o f b rains, on m en w ho have an in d u s tria l knack, rath e r th a n an

intellectual afflatus. Too often college heads have gone the rounds looking fo r m en at knockdown prices. They choose clever young men fo r fellow ships it is true, who are good experimenters perhaps, b u t are fail- ures as executives, designers and operating .officials.

Some day we m ay learn th a t the k in d of talen t th a t colleges m ust seek is talen t th a t w ill sell, th a t com- mands a h ig h price in the m arket.

The colleges m ust enter into com petition w ith in ­ dustry on equal terms, and when a college sees a m an in the forefront of in d ustrial progress it m ust offer him a salary th a t w ill lure h im to the classroom. There is no other way of c u ttin g the knot w ith w hich so m any colleges are still fu m b lin g . They get w h at they pay for, and the colleges do not grow. They become centers of research and of elementary education b u t not train- in g schools fo r the h ig h e r walks of industry. Today young men m ust go in to an apprenticeship in the shops and in the mines where they can be placed un d er tale nt of a kind w hich the colleges cannot attract because they are unw illing to pay fo r it. Let us hope th a t the collegiate atmosphere w ill come closer year by year to th a t of the mines, the m ills and the facto ry and th a t of the m illions given to educational in stitu tio n s more w ill be spent in the endowment o f adequate faculties.

The glory of a college is not in its b uild in g s b u t in its staff and in its students. L et th a t never be forgotten.

W h a t M a k e s f o r S t a b i l i z a t i o n ?

S

W h a t the stabilizers overlook is th a t the present wage is too h ig h . I f it were lower the excess of m in e workers w ould autom atically correct itself as it does in other industries. So long as wages are sustained by the same persons who desire to reduce the n u m b e r o f m ine workers there cannot be any correction o f the present situation. W here m en can get $7 to $15 a day it is not likely th a t they w ill leave the in d u s try perm anently.

Slow runs and short tim e m ay te m po rarily deplete an in d ustry w ith such a wage rate— w hether it w ill, is questionable— b u t it w ill not perm anently reduce the num ber of m en engaged in it. They w ill come back as soon as there is a dem and fo r th e ir services and even before they can be assured steady work. Low er wages w ill cure the excess and indeed little else w ill do it, except a restriction of the entrance of new blood into the in d ustry by re q u irin g previous experience in the m ines. T his latte r course makes w ork in the m ines a monopoly, and th a t surely is undesirable.

In m ost other industries, w ith the notable exception

856 C O A L A G E VOL. 26, NO. 25

of ra ilro a d in g , the wage is determ ined by supply and dem and. Conseąuently when the dem and is Iow, the supply falls off. In the coal in d ustry when tim es have been bad and w ork has been irre gular, the wage is raised by a fiat of the A d m in is tra tio n and of the public.

T hus the m in e r is compensated fo r h is past idle tim e, and the wage is pushed fu rth e r up above the norm al ra te ; th is is crystallized by an agreement. M ore men enter the industry. Business declines, and the m in e r soon suffers fro m short tim e.

W he n tim es im prove he asks fo r more wages to com- pensate fo r the short w o rk in g hours of a previous year.

A g a in he gets an increase, and ag ain more m en enter the ind ustry . I t is a vicious circle. W e get nowhere by ado p tin g the p lan of g iv in g a yearly wage to the m iner. W e m ake it necessary to pay ever more and more. I t makes more idleness, more discontent. The wage th a t is given makes a h ig he r wage more neces­

sary. The path we are tre ad in g leads ever to a more aggravated condition of a deplorable evil.

M ore m en means large m ine capacity an d more m in e s; so th a t the other evil, too m any m ines, follows in the same tra in . F ig u rę the m in e r’s wage per day and not per year, and conditions w ill r ig h t themselves.

A n uneconomic theory is b earing the in d u s try fast to the rocks o f over-m anning and overdevelopment, and the stabilizers should realize th a t fact. B u t politics makes it necessary to talk stabilization and h ig h wages in the same breath, and who w ill say th a t the one does not negative the o ther? The stabilizers do not know w hether they are sin g in g bass or soprano.

L i n e U p w i t h t h e B e s t

H A T a confusing bąbel o f sounds one can expect to hear when the U n ite d M ine W orkers’ officials get together to plan legislation to cu rta il the use of electricity in the m ines, as they have declared it th e ir purpose to do at th e ir recent m eeting in H arrisb u rg .

In the an th racite region m an y companies do n o t know w h at the others are doing, electrically. One large com­

pany m ay pride itse lf upon its power plants and extensive use o f electricity, yet be fa r behind another and a sm aller com pany th a t has p u t more b rain s into its work. Each com pany has relied too m uch on its own a b ility to th in k out and devise new plans, and as a result is in some ways fa r behind others in the safe use of electricity.

The electrical hazards fo un d at some m ines are real an d m any. There are breakers w hich have no electric lig h ts b u t instead use open-flame oil lam ps w ith th e ir ever-present fire hazard. W ell-lighted s h a ft bottom s greet you in some m ines whereas others are d a rk and dam p death traps. A t some m ines only 440-volt m otors are used, b u t they are installed in such a m an n e r th a t they are m ore dangerous th a n the 2,300-volt m otors a t anoth e r m ine.

Crooked and tw isted trolley w ire supported on old- type hangers w hich leak and cause the trolley w ire to sp utte r sparks on powder cans, h ay and feed have ta u g h t some com panies serious lessons. Open-type c irc u it breakers instead o f closed types have caused dangerous flashes. S e ctionalizing trolley switches left closed d u rin g the n ig h t have been responsible fo r m ine fires. Leakage currents in h o is tin g cables and pipes have shocked the w orkm en.

I n every an th racite m ine some o f these hazards have been guarded against, b u t others have m ade no provi- sion a g a in s t them . D espite the need fo r concerted

effort the coal companies have never m et to fo rm ulate definite practices th a t would assure safety.

Perhaps the greatest difficulty of all lies in the fact th at the m ine forem an and not the electrical engineer supervises the work of the m en in the m ines who m ain tain , operate and re pair the electrical eąuipm ent.

Y o u r P la c e i n t h e C o a l I n d u s t r y

A

He th ough t th a t he had fo un d a good deposit and opened a m ine in it, spending a m illio n dollars before he got a single pound of coal. I t w ill be remembered th at in those earlier days a cool m illio n was regarded as a tremendous sum. H e found, however, th a t the coal he got fro m his new venture was fa s t in ju r in g his reputation. I t was altogether too volatile and had too m uch ash. He could have continued to sell it for w hat it was, a coal of m edium ąu ality , b u t he could not prevent it from low ering his sta n din g in the market.

Even had he organized another com pany to w ork the coal and sell it, there always would have been the assurance th a t the story would leak o u t th a t he was the principal owner, and the sale o f it w ould injure the excellent reputation he had acąuired o f m arketing n oth in g b u t the best, so he sold the m in e to other operators who could well afford to ship such coal, seeing th at they were already producers o f coal of only medium ąu ality and traded in a less d is c rim in a tin g market.

About the same tim e he purchased another field hav- in g a seam of excellent coal. Above the bed he bought was another con tainin g a coal of equally Iow volatile content, b u t it had more sulphur. H e d id not buy that bed, however. H e was determ ined to m in e n o th in g but the best.

In tim e the coal seam in the area in w h ich he first operated was exhausted, and he leased out the other seams below it. These seams had fa ir ly good coal, as has been stated, b u t he w ould not w ork them. They would have in ju re d his repu tation . H e concentrated his efforts on the good seam in the new area he had purchased and developed. N ow he is m a k in g an analysis survey of th is good seam so th a t he can m in e the best of it, and leave the rest.

The tim e m ay come when he w ill have to w ork what he is rejecting. Some tim e he m ay have to m ine this less desirable coal or perhaps m ay have to establish him self where the coal is still lower in h e a tin g yalue.

B u t he w ill m a in ta in his sta n din g by m in in g the best th a t is obtainable. To do otherw ise w ill m ean th a t he w ill be obliged to class h im se lf w ith those who are producers of only fa ir ly good coal. H e m ay wash it and table it, b u t it is likely th a t it w ill never be as good as th a t w hich he is now selling. However, he will see to it th at it is still the best on the m arket.

The m orał is short and p ith y . D o not go to the m arket w ith all kinds o f coal fo r all comers. Specialize on one kind of coal w ith preference fo r the best. Some of the present consolidations m ay n ot have been formed w ith this simple rule in m in d . I f a m an is know n to have a good and an only m ed ium coal, h is customers will be wary of b u y in g fro m h im , fo r they w ill hear on one side of hig h ig h e r price and on the other side th a t his coal is not of first q uality. Standardize, therefore, stan dardize!

Machinę Loads 377 Tons Into 2-Ton Cars

In 8 Hours

From Room Workings

T ra v e rsin g a C ro sscu t

A v e r a g e P r o d u c t i o n o f M a c h i n ę f o r a M o n t h , 289 T o n s — C r o s s c u t T u r n o u t s a n d T w o C a r- S h i f t i n g L o c o m o t iv e s F a c i l i t a t e L o a d i n g — B i g C a r A d v a n t a g e o u s —

P i l l a r C o a l I s B e in g L o a d e d M e c h a n i c a l l y By Al p h o n s e F. Br o sk y

A s s is ta n t E d ito r , C o al A g e, P itts b u r g h , P a.

T

Im pressed w ith the possibilities of saving in the labor of coal loading by the use of machines, the P ittsb u rg h

& E rie Coal Co. procured an Oldroyd loading m achinę fo r use in its S um ne r No. 2 operation. T his m ine is located at B raznell in the Monongahela d istric t of Pennsylvania. W h a t the company desired to ascertain was the exact degree to w hich the theoretical possi­

bilitie s o f lo ading m achines could be realized.

T his loader was p u t to w ork in the thick P ittsb u rg h bed under conditions th a t could not by any means be considered favorable. Sum ner No. 2 is an old and alm ost exhausted operation. No błock of coal of ade- ąuate size fo r experim ents in m echanical loading could be fo u n d in it, and fo r th is reason, tests o f the m ach in e ’s lo ad ing a b ility were somewhat desultory and inconclusive. I t was soon discovered, however, th a t even in the P itts b u rg h bed, w ith its troublesome draw- slate, loading machines possess more th an m ythical advantages. U pon one occasion the m achinę succeeded, d u r in g an 8-hr. sh ift, in loading 250 tons of coal into m in e cars o f 1.6 tons capacity.

Ne w a n d More Pr o m is in g Fie l d Provided D e s irin g to continue the experiments where they were discontinued, b u t under conditions s im ila r to those p re v a ilin g a t the Sum ner No. 2 operation, the P itts b u r g h & E rie Coal Co. closed negotiations fo r the p rivilege of m echanically loading coal in a sm ali section o f the R obert m in e near Clarksburg, W . V a„ th is m ine b e in g owned by the N ew Superior Coal & Coke Co.

In c id e n ta lly it m ay be said th a t d u r in g the recent w ar an atte m p t was m ade to produce coal in th is property

TiThnne-h th e lo ad in g : m a c h in ę s h o w n in th e h e a d p ie c e is 45 ft.

. w it b u ilt iń th re e sec tio n s o r seg m e n ts a n d as m a y be ju d g e d l 0n£ tb p illu s t r a t io n n o d iffic u lty is e x p e rie n ce d in t a k in g it th r o u g h

o L n U T hese p as sa g e s , h ow e v e r, are d r iv e n on a 45-deg.

a n ? le a n d th e tr a c k c u rv e s h a v e 35-ft. r a d li.

by stripping. This, however, faile d because the cover, which ranged from 40 to 75 ft., was too th ick fo r ordi- nary strip p in g eąuipm ent.

M achinę loading in the Robert m ine under the super- vision of T. F. W halen, generał superintendent o f the P ittsb urgh & E rie Coal Co., began about the m iddle o f Ju ly of the present year. Some tim e was reąuired, however, to prepare the sections and m ake the changes necessary fo r the introd uction of m achinę m ethods, and it was not u n til the latte r p a rt of A u g u st th a t the work approached the production stage.

D u rin g twenty-four 8-hr. sh ifts worked in September, one m achinę loaded 6,058 tons, or an average of 252 tons per day. Twenty-four m en in clud in g a m ine fore- man, mined, shot, loaded and transported all th is coal from the face to the railroad car. The daily o u tp u t per m an employed was th us 104 tons. The results achieved d u rin g 17 w o rk in g days of October, however, were fa r better. D u r in g th is m onth the same n u m b e r of men w ith one loading m achinę produced an average of 289 tons per sh ift, or a daily o u tp u t per m an o f 12 tons. Even th is perform ance is scarcely in dicative of the m achine’s possibilities, fo r on one day the crew m echanically loaded 377 tons o f coal.

The Oldroyd m achinę used at th is p la n t is 42 ft. long and weighs 22 tons. A lth o u g h its over-all h e ig h t is 54 in., it can operate in a 5-ft. coal bed. I t travels upon, and works from , the m ine track, its massiveness o f construction e nabling it to push itse lf under loosened coal and th u s to break out h a n g in g shots. The m ach in ę is not only pow erful, b u t it has also a reach th a t enables it to gather in the coal fro m the entire face w ith o u t leaving the track. I t is eąuipped w ith three conveyors, the m iddle one b e in g fixed to th e body, w h ile the fro n t and rear sections sw in g in e ith e r direction, horizontally as well as vertically. B oth m otions can be m ade sim ultaneously.

Two

Coal is fed in to the fo rw a rd conveyor by m eans o f a revolving dipper. T his consists o f a roli o f sm ali diam eter on w hich are cast tw o plate paddles spaced 180 deg. ap art. T his fe e d in g device is d riven by tw o cutter chains provided w ith p ick b its w h ich cut a p ath in the coal pile fo r the be arin gs as the m a c h in ę

858 C O A L A G E Vo l. 26, N o . 25

advances. The m a in body of the loader is supported by two sets of swivel trucks w hich enable it to round curves w ith ease.

F ive m otors are utilized to give independent yet correlated m ovem ent to the various m achinę elements.

A s fa r as possible, chain drives have been elim inated, transm ission being made by means of gears and worms.

Two m en operate the m achinę. One Controls its for- w ard movement, the s ta rtin g and stopping of the dipper and the sw in g in g of the forw ard boom. The other starts and stops all three conveyors and Controls the positio n o f the rear boom. This two-man control is analogous to th a t of the ordinary steam shovel.

The layout of the Robert m ine where this m achinę is employed is shown in F ig . 4. Rooms are driven 400 ft. long and 20 ft. wide on 30-ft. centers. They are necked on a 45-deg. angle in order to provide a tu rn o u t of greater radius th an is norm ally provided fo r g a th e rin g locomotives. T his is necessary to facil- itate m ovem ent of the loading m achinę. F o r the same reason crosscuts are turne d on a 45-deg. angle in one direction only. The inby crosscut, placed at a con- Y enient distance fro m the room faces, is tracked to

Fig. 1— Loading Machinę Used in Robert Mine

I n th is illu s tr a t io n th e lo a d e r is in w o r k in g p o s itio n a t th e e nd o f a c o a l p ile . I n a s m u c h as th is m a c h in ę o p e ra te s fr o m a t r a c k th e s p a n o f u n s u p p o r te d ro o f is o n ly s lig h tly g re a te r t h a n th e d e p th o f c u t p lu s th e t r a c k gage.

expedite haulage and to p e rm it of the m ovem ent of the loading m achinę fro m one room to another w ith o u t the necessity o f trave rsin g the b u tt entry. As a m atte r o f fact, only one of the crosscut tu rn o u ts is of sufficient ra d iu s to enable the loadin g m achinę to pass between th e rooms th us connected. I t is the in te n tio n to install tu rn o u ts o f 30- to 35-ft. radius eąuipped w ith a No.

2 frog.

The track is la id up the center of the rooms. On each side of th is room track is set a row of props on 5-ft. centers. The coal is cut to a depth of 8 i ft.

at a h e ig h t of 6J ft. above the floor, leaving 1 ft. of top coal to proteęt the roof. F ig . 6 shows a circular cut be in g executed by an Oldroyd U niversal m achinę w hich also shears the coal in the center o f the face. One long shothole on either side o f the shearing cut and one short hole in each r ib are employed to break down the coal.

He a v y Sh o o t in g Assu res Ea s y Lo a d in g

I n th is m ine, shotholes are charged rath er heavily fo r tw o reasons: F irs t, the coal on reaching the out- side m u st be carried to a railroad sid in g on the fa rth e r b an k o f a stream by an aerial tram w ay, the buckets of w h ich are too sm ali to hołd large lum ps. Second, the c ircu lar cut m ade by the m in in g m achinę in a w id th of 20 ft. leaves tw o t ig h t corners, w hich reąuire two lig h t r ib shots.

S atisfacto ry shooting fo r m echanical loading pre- sents problem s all its own. In th is p a rtic u la r m ine,

Fig. 2— Breaking Down a Hanging Shot

R u g g e d c o n s tr u c tio n a n d m a s s iv e w e ig h t e n a b le th e m a c h in ę to d is r u p t m asses o f s ta n d in g c o a l as s h o w n . T h o u g h th is process is slo w e r th a n s h o v e lin g loose c o a l fr o m th e m in e floor i t a ffo rd s a co a rse r p ro d u c t. T he h a n d s h o v e le r seen in th is illu s tr a t io n saves the m a c h in ę m u c h tim e b y g a t h e r in g u p s tr a y pieces o f c o a l t h a t the m a c h in ę c o u ld r e c la im o n ly w ith d ifflc u lty .

as has been stated, the coal is undercut an d center sheared to a depth of about 8J ft. The two lig h t rib shots already m entioned are sufficient to b rin g the coal away from the sides and roof, b u t they do not break and roli it out on the floor. They result rath er in a true h an g in g shot, m ost of the coal re m a in in g in two blocks upon either side of the shear cut. These are broken aw ay fro m the roof and show some evidence of a slig h t separation and m ovem ent along the cleavage planes.

A n attem pt to load out these blocks shows th a t this apparent sh atte ring does not extend th ro u g h o u t the entire mass, as certain portions stubbornly resist, although they finally succumb to the pow erful action o f the revolving dipper. T his shooting, however, gives a product w ith a Iow percentage of slack, the ąuan tity o f coal less th an | in. in size m a k in g a prop ortion of the whole product fro m 7 to 10 per cent less than th a t obtained w ith hand loading. Center sh e arin g and lig h t shooting, altho ugh not extensively practiced, has m any strong advocates am ong present-day m in e man- agers. Lum ps w e ig h in g alm ost 200 lb. each are successfully handled by th is m achinę. In fact, the size of the in d iv id ual pieces loaded appears to be lim ited only by the w idth of the dipper and the conveyors.

The method of h a n d lin g cars in the R ob e rt m ine is plainly shown in F ig . 4. A tr ip o f em pties is stored in room 4, adjacent to room 5 where coal is being loaded. A tu rn o u t connecting the tracks in a d jo in in g

Fig. 3— Cutter Chain Driving Feeding Deyice

P ic k b its c a rrie d b y t h is c h a in e le a r a p a s s a g e in th e coal p ile fo r the co nv e y o r b e a rin g s . T h is c h a in , to g e th e r w ith a s im ila r one on the opp o site side o f th e m a c h in ę , ro ta te s th e r e v o lv in g d ip p e r on the g a t h e r in g h e a d .

rooms is laid in the crosscut most conveniently located to the face. T his facilitates the storage of a tr ip of em pties inby and provides clearance beyond the turn o ut sw itch in the room being loaded out. In order to accom plish its purpose m ost effectively, such a crosscut tu r n o u t should be from 7 5 to 150 ft. fro m the work- in g face.

Tw o L o c o m o t i v e s C h a n g e C a r s Q u i c k l y

Two 5-ton storage-battery locomotives constantly attend the loading m achinę. B a rr in g delays arisin g fro m ch an g in g trips, fro m fa u lty track or ro llin g stock, the only tim e consumed in ch an g in g cars is th a t re- quired by a loaded car in clearing the tu rn o u t in the crosscut, or th a t necessary to push an empty from the tu rn o u t to the loading m achinę. The ease w ith w hich cars m ay be changed m ay be traced in rooms 4 and 5 of F ig . 4.

The m otor A w ith a loaded car clears the tu rn o u t in room 5 on its w ay to the b u tt entry where the loaded cars are stored. M otor B pushes an empty car to the loading m aehine. W h ile th is is being filled, m otor A

Table I— Time Study of Loading Machinę in Room 4

T im e of T im e of

C ar C a r

Car- L o ad in g Sh iftin g

N um ber Seconds Seconds

1 55 35

2 35 40

3 30 40

4 45 25

5 40 35

6 40 25

7 30 35

8 45 35

9 45 35

10 45 45

11 45 20

12 55 85

13 55 25

14 65 20

15 115 25

16 80 20

17 90 35

18 125 35

19 150

T o ta l... 1,190 615

A verage.. . 63 34

Lost Tim e Seconds

230 55

310

595 31

R em arks

Locom otive derailed Defective m ine car

C h anging trip

C leaning u p room

A d ju sting headlight on m achinę C leaning u p room

C leaning u p room C lean in g u p room

Table II— Time Study of Loading Machinę in Room 5

T ime 0f Tim e of

Car Car

Car- Loading Shifting Time

N u m ber Seconds Seconds Seconds Rem arks

1 65 15

2 45 45

3 50 15

4 50 30

5 40 30

6 45 70

7 40 20

8 75 150 C h a n g in g trip

9 50 35

10 60 20

II 70 30

12 60 65

' 13 55 20

14 60 30

15 100 25 C lean in g u p room

16 80 25 140 C a r derailed

17 160 45 C lean in g u p room

18 140 C le an in g u p room

T o ta l... 1,245 670 140

A verag e.... 69 39 8

uncouples its loaded car on the entry in the elear of room 4, goes in to th is room, couples onto an empty and w a its in the crosscut fo r its tu rn at the m achinę.

A side fro m a short backswitch while dropping a loaded car on the entry and coupling to an empty car in the room, th e two m otors move in closed circuits.

I tim ed w ith a stop watch the perform ance of the load in g m achinę in rooms 4 to 7 inclusive (see F ig . 4 ).

M y observations extended from 9 :0 4 a.m., when loading began in room 4, u n til noon, when w ork ceased afte r nine m in e cars had been loaded in room 7. They thus extended over a period of 176 m in. I n to ta lin g the stop-watch readings a m inus error o f H m in . was noted T his arose fro m protracted periods being read in whole m in ute s and not in m inutes and seconds. The error am ounts to less th an 1 per cent and conseąuently m ay be neglected.

R e adin gs show ing the operation of the m achinę, load­

ing- periods, tim e necessary to s h ift cars and tim e lost in rooms 4 to 7 respectively, are shown in Tables I to I V F ive m inutes were taken to move the m achinę fro m room 3 to room 4, and an equal length of tim e was consumed in m a k in g ready for the m achinę. In

4 1 9 cars co n ta in in g a total of 43 tons were 1r0° , , in 40 m inutes. F ive m inutes was consumed in

0 3 V)(r the loading m achinę to the face of room 5,

m0fi ;

-tance

Fig. 4— Room Layout in the Robert Mine

W h e n m a c h in ę lo a d in g w a s s ta rte d in th is m in e it w a s t h o u g h t t h a t ro o m c o a l c o u ld be lo a d e d m u c h fa s te r t h a n p illa r coal.

E x p e rie nc e h a s sh o w n t h a t th e re is litt le d iffe re n ce in th e tim e re q u ire d to p ro d u c e c o a l fr o m e ith e r o f these tw o sources a n d c o n s e ą u e n tly in s te a d o f d r iv in g 20-ft. ro o m s o n 30-ft. ce n te rs i t is th e in te n tio n in the f u t u r ę to m a k e th e p illa r th ic k n e s s e ą u a l to the d e pth o f a t le a s t tw o cuts.

eighteen cars con taining 40 tons of coal were loaded in a period of 34 m in . The loading m achinę was moved to the face of room 6, a distance o f 700 ft. in 6 m in., and again 5 m in . was required in m a k in g ready fo r loading. Here eighteen cars c o n tain in g 40 tons were

Table I I I — Time Study of Loading Machinę in Room 6

R em ark s T im e of T im e of

C a r C a r L ost

Car- L o ad in g S h iftin g T im e ■

N um ber Seconds Seconds Seconds

1 60 40

2 35 30

3 55 35

4 85 40

5 40 190

6 50 30

7 60 50

8 55 30

9 45 45

10 50 40 25Ó

11 35 55

12 60 25

13 60 40

14 45 35

15 90 50

16 70 25

17 180 20

18 250

T o t a l... 1,105 580 250

A v e ra g e ... 61 34 14

C h a n g in g trip

A d ju s tin g m achinę

C le an in g u p room C le a n in g u p room C le an in g u p room C le an in g u p room

860 C O A L A G E Vo l. 26, N o . 25

loaded in a total tim e of 34 m in., the loading m achinę was then moved to the face of room 7, a distance of 500 ft. in 5 m in . In 9 m in . the m achinę was made ready fo r loading operations in th is room, and in 22 m in . th ereafter n ine cars con tain ing 20 tons of coal h ad been loaded.

“ M a k in g ready” included inspection, m in o r adjust- m ents and lub ricatio n of the loading m achinę, also re p a irin g track when necessary and sum ping into position. Coal in the face of room 6 was shot down in better shape fo r m achinę loading th an th a t in any other ro o m ; th a t in the face of room 7 was in the worst shape. Because the face of room 7 was not sufficiently shot, the rate of loading was lower by over 30 per cent, th an in room 6.

The wisdom o f using two locomotives is readily dis-

T a b le I V^— T im e S t u d y o f L o a d in g M a c h in ę in R o o m 7 T im e of T im e of

C a r C ar Lost

Car- L o adin g S h iftin g Tim e

N u m b e r Seconds Seconds Seconds R em arks

1 ^{60 30 205} C oal on track

2 80 30

3 55 35

4 60 30

5 60 30 130 A d ju stin g track

6 135 35

7 55 35

8 115 30

9 90 25

T o ta l... 710 280 335

A verage.. . 79 35 37

cernible fro m an inspection of Tables I to IV inclusive.

R e a d in g down the car-shifting colum n in these tables it w ill be noted th a t the tim e consumed in ch anging cars generally varies fro m 15 to 35 sec., depending upon the distance of the tu rn o u t from the face. I n a few cases as m uch as 70 sec. was consumed in th is opera- tion. N a tu ra lly when trip s were changed m ore tim e was required. L ong periods consumed in car s h iftin g in any one table arose fro m the use of old m ine cars th a t were in poor repair. R o llin g stock in proper condition and well-kept track should m ake it possible to rely on being able to change cars in 30 sec.

In Table V are shown the totals fo r each phase o f the loading operation fo r each room as well as a grand total fo r all rooms. F ro m it the follo w in g facts m ay be derived: A ctu al loading o f cars consumed 40.6 per cent o f the total tim e observed; s h iftin g took 20.6 per cent; m o v in g the m achinę reąuired 12 per cent;

m a k in g ready, 14.2 per cent; the tim e lost was 12.6

F i g . 6— S t a r t in g a C u t in a R o o m

T he top is c u t a n d the ce n te r sh e a re d w it h a U n iv e r s a l m a c h in ę a t th is m in e . A b o u t 1 ft. o f to p c o a l is le ft u p to p ro te c t th e ro o f.

C e n te r s h e a rin g m a k e s m o re b u g d u s t b u t g iv e s m o re lu m p co a l per ro o m cut, t h a n c o u ld be o b ta in e d w it h o u t it.

per cent of the whole tim e. D u r in g 176 m in. 64 cars containing 144 tons of coal were loaded a t the rate of 39.1 tons per hour. T his rate of production i f con- tinued thro ughout a fu li sh ift, would yield an output of almost 400 tons. I t is not m a in ta in e d th ro ug h o ut the w orking day, because the m ine cars are old and not fitted fo r the work they are called upon to perform . They were constructed o rig in ally to hołd 14 tons, b u t by the addition of sideboards th e ir capacity has been increased to 21 tons. A nother obstacle th a t interferes

T a b le V — T o ta ls o f T a b le s I to I V I n c lu s iv e

T im e of T im e of T im e of

M o v in s M a k in g N u m b e r L o a d in g N u m b e r S h iftin g Time

Room M ach inę R eady Cars T im e C ars Cars Lost

N um ber Seconds Seconds Loaded Seconds Shifted Seconds Seconds

4 300 300 19 1,190 18 615 595

5 300 360 18 1,245 17 670 140

6 360 300 18 1,105 17 580 250

7 300 540 9 710 8 280 335

T o t a l.. . . 1,260 1,500 64 4,250 60 2,155 1,320

Average.. 320 400 66* 36*

* Per car.

w ith the attain m e n t of th is 400-ton o u tp u t is the aerial tram w ay shown in one of the accom panying illustra- tions which transports the coal fro m the dum p to the railroad cars. T his means of tra n sp o rta tio n has a m axim um capacity of 375 tons in 8 hr. I t is responsible for m uch of the tim e lost.

Table V I, covering seventeen w o rk in g days in

F I G . 5 A S la b C u t W h e n t r a c k is m a in t a in e d a l o n g th e f u l i le n g th o f a s la b c u t th e co al ro lls o u t o ve r it m a k in g th e w o r k o f th e s h o v e lin g m a ­ c h in ę d iffic u lt. T he p re s e n t p r a c tic e is to a d d s h o rt sec- tio n s to th e tr a c k a s th e m a c h in a ad- v a n c e s , th u s allow - in g th e re v o lv in g d ip p e r to w o r k on a n u n o b s tru c te d b o tto m . T h e o p e r a ­ tio n o f th e m a c h in ę is th u s fa c ilita te d , a n d d o u b tle s s som e d e g r a d a tio n o f the c o a l a ls o is a v o id e d .

T a b le V I — S u m m a r iz e d R e c o r d f o r S e v e n te e n W o r k in g D a y s in O c to b e r

W o rk in g T onnage H ours H ours

D a y Produced W ork ed D elay ed R em ark s

215 5 3 R ep airing loader

2 377 8 ...

325 7J j R e p a iring loader

5 3 2 5 8 ;; ;;;;;;;;;;; i;;;;:;;;;;::;

6 167 4J 3J D e lay not caused b y loader

275 6| l j D e lay n o t caused by loader

8 307 7 1 R ep airing loader

9 370 8 ...

10 305 8 ...

11 285 6J 1 $ D e lay no t caused by loader

12 160 5 3 D elay not caused by loader

13 157 2$ 5$ D elay not caused by loader

14 370 8 ... ..

15 325 8 ...

16 220 6$ IJ D elay not caused by loader

17 275 6§ l i D e la y n o t caused by loader

T o ta l... 4,913 I I 3* 22*

A v e ra g e ... . 289 6.68 1.32

October, lists the tonnages obtained, hours worked, tim e lost and the reasons therefor. On an average day dur­

in g th is period 16$ per cent of the w orking tim e was lost because of miscellaneous delays arisin g from equip- m ent. Less th a n one-fourth of this loss was occasioned by trouble w ith the loading m achinę.

The loading-machine crew consists of three men, two runners and a th ir d m an stationed beside the forw ard

cut. O f course, if th is coal contains a large ą u a n tity of smali pieces it would be as hazardous to shoot the coal over it as it is to fire a shot over a pile of bug dust.

It should be remembered th a t the ratio of operating tim e to tonnage obtained is the chief factor governing the efficiency of a loading m achinę. Because a tonnage equivalent to the capacity o f the m achinę d u rin g a period of at least five m inutes is lost in g ath erin g stray lumps, two men w ith shovels m ig h t be employed profitably to relieve the m achinę o f th is duty. I t is probable th at no loading m achinę w ill ever be bu ilt th at will perform all the functions of a hum an loader, or be sufficiently flexible to m atch the co-ordination of m an’s brains and muscles. A ll th at any m achinę can ever do is to approach th is ideał. The deficiency of the coal loader m ust be made up by m uscular effort.

T w e n t y - f o u r M e n M i n e 289 T o n s D a i l y

The follow ing men were employed both inside and outside the Robert m ine in order to produce the tonnage shown in Table V I : One forem an, two loading-machine runners, one loading-machine helper, two motorm en, one trip rider, two cutters, fo u r tracklayers, tw o tim- bermen, one blacksmith, fo u r tipple men, one elec-

F I G . 7 Room Face

T h is is th e fa ce as i t a p p e a rs a f te r th e m a c h in ę h a s c o m p le te d its lo a d ­ ing-. I t is unproflt- ab le to e m p lo y the m a c h in ę to c le a n u p th e la s t b it o f c o a l in a ro o m . T he la s t tw o ca rs p r o ­ d u ce d f r o m th is p la c e to o k a s m u c h tim e t o lo a d a a d id th e fir s t s e v e n.

W h a t c o a l r e m a in s a t th e fa ce w ill be lo a d e d o u t w ith t h a t fr o m th e n e x t cu t.

conveyor who shovels up coal missed by the machinę.

Occasionally a fo u rth m an fo r cleaning up would be desirable, as the tim e lost in operating the loading m a­

chinę at a slow rate when gath e rin g up stray lum ps of coal, m ig h t be more profitably spent at points where the coal is deeply bedded. A n inspection of Tables I to V I w ill show th is fact conclusively.

R e a d in g down the car-loading column in each of these tables, it w ill be noted th a t m ine cars (capacity

2

Nevertheless, the loading period per car attain s a maxi- m um o f 250 sec. I t is tru e th a t a p ortion of this excess tim e is consumed by the loading m achinę m dislod ging tig h t coal, but more th an h a lf of it results fro m the necessity of m aneuvering the m achinę about in order to gather up sparsely strewn lumps. This especially is noticeable when loading the last tw o or three cars from a room. Even then a sm ali ą u a n tity of coal is le ft fo r recovery w ith the next cut. Because o f the long tim e necessary fo r loading the last few tons o f coal fro m a room, it would appear advisable to leave m uch o f th is m ateriał fo r recovery w ith the next

trician, tw o shotfirers and one w atchm an. These twenty-four hands loaded an average of 289 tons per w orking day d u rin g October, or 12 tons per m an. O f course, no development was attem pted when rooms were being worked. Conseąuently the o utp ut was h ig h as compared w ith w hat m ig h t be expected i f both rooms and headings were being driven sim ultaneously. The additional labor necessary fo r development work in th is mine, would not lower the daily ou tp u t per m an to less th an 10 tons. W ith a 5-ton car, the daily tonnage per m an employed in m in in g operations w ould probably rangę from 10 to 15 tons.

The advantages of a large m ine car when used in conjunction w ith m echanical lo ad in g are ap pa re n t to the officials of th is m ine. General S uperinte nde nt W halen intends to adopt a 5-ton car w ith a 48-in. track gage as standard fo r a new m echanically operated m ine th a t his com pany contemplates opening. W ith cars of th is capacity, the Oldroyd m achinę o u g h t to load 500 tons in 8 hr. under conditions s im ila r to those e x istin g in the R obert m in e and w ith the same n um b e r of employees. To produce 500 tons, the coal fro m twelve

862 C O A L A G E Vo l. 26, N o . 25

F I G . 8

Tipple and Tramway

T h is m e th o d o f t r a n s p o r t in g t h e c o a l fr o m th e d u m p to th e r a ilr o a d c a r a lr e a d y is b e g in n in g to li m i t th e capac- it y o f th e lo a d in g m a c h in ę , fo r as a t p re s e n t o p e ra te d It c a n n o t c a r r y m o re t h a n 375 to n s in 8 h r . F u r th e r m o r e it

■ c a n n o t h a n d le la rg e lu m p s .

room cuts w ould have to be loaded into 100 m ine cars.

Table V shows th a t a 2^-ton car m ay be loaded in an average tim e o f 66 sec. A t th is rate of loading, a .5-ton car could be filled in 138 sec. or 100 cars in 13,800 sec. T his represents 48 per cent of an 8-hr. day. I t is calculated also fro m an analysis of the facts set fo rth in Table V, th a t about 11 per cent of an 8-hr. day would be spent in s h iftin g cars, and not over 12 per ,cent in m oving the m achinę, leaving 29 per cent of the tim e fo r miscellaneous delays. T his would appear to be an am ple allowance.

L ittle success has been reported thus fa r in d raw in g pillars w ith m in in g m achines. Possibly the slow progress attain e d in th is phase o f m in in g operations is a ttrib u ta b le to a lack of persistence and official super- vision in m a k in g the necessary experiments. There is little doubt, however, b u t th a t some day p illars w ill be draw n thus, and inasm uch as they can be removed

m uch more rapidly w ith loading m achines th a n by hand, the retreat w ill be rapid, lessening the danger fro m fa llin g roof and rendering p illa r extraction safer th a n it is today. I t is possible, also, th a t less slate w ill have to be handled.

Pil l a r Coa l Must Be Slabb ed

I t is h ighly probable th a t w hatever m ethod of m in ­ in g is adopted, the loading o f p illa r coal by m ach in ę w ill involve slabbing. Several reasons dictate the adoption of this method. In the first place, a slab cut produces more coal th an any single cut m ade in d riv in g through a pillar, leaving one or more stum ps th a t m u st be recovered before the next c u t is started. Conse­

ąuently a slab cut expedites recovery and assures safety. I t also elim inates sharp curves in the track and provides a more sui'"ible w o rk in g place fo r the loading machinę.

Pillars are being extracted by loadin g m ach in ę in the Robert mine. The results thus fa r achieved have been highly successful, and the w ork has progressed to such a point as to prove th a t the practice is entirely feasible.

Thus Mr. W halen states: “ T his w ork has proceeded w ithou t any difficulty whatever and the m ach in ę has never been forced to retreat because of unfavorable roof conditions. W e feel th a t we have already demon- strated conclusively th a t it is possible to d raw ribs w ith this type of loading m achinę in m ines where w h at m ig h t be termed a m edium roof prevails.”

Though at the in itia tio n o f its experim ents the com ­ pany was hopeful of recovering p illars by m echanical loading, it anticipated th a t greater difficulty w ould be encountered in loading p illa r coal th a n in lo ad in g th a t obtained from room faces. A ccordingly, rooms were driven wide on as narrow centers as the roo f would allow. Twenty-foot rooms on 30-ft. centers were there- fo ie adopted as standard, 10 ft. o f p illa r b e in g taken as the m inim um w id th th a t safely w ould hołd the roof.

The w ithdraw al of these p illa rs is illu strate d a t A in F ig. 9. The track is first s h ifte d as near to the rib as possible, so as to fa c ilita te the w ork o f both the cuttin g and loading m achines, w hich operate fro m it The pillars are m ined by slab cuts on the in by end.

The length of such cuts varies fro m 10 to 30 ft., depending upon the condition o f the roof. A n 84-ft.

cut leaves a rib about 14 ft. th ick, w hich, though freąuently shattered by shooting and roof pressure, generally reąuires some p ick m in in g . Some hand shoveling also is necessary in order to place the coal f i om this rib w ith in reach o f the lo a d in g m achinę.

The closed end of a p illa r cut is sumped on a 45-deg.

to facilitate m a c h 'M,% n m n f

A B

F ig. 9— Recovering Pillars by Machinę Loading

P i l l a r s a re d r a w n b y s la b b in g w it h o u t s tu m p p ro te c tio n . T he m e t h o d n o w use d is s h o w n a t A . T h e 10-ft. p illa r s a re s la b b e d

* o a d e p th o f 8 J ft. th e r e m a in in g c o a l b e in g recovered b y p ic k m in in g . T h e p ro b a b le f u t u r ę m e th o d o f p illa r d r a w in g is sh o w n a t B . T he p illa r w id t h w i l l be in c re a se d to 14 ft. p r o y id in g fo r tw o 7-ft. s la b b in g c u ts. T he flr s t o f the se w ill be re co v e re d in a m a n n e r s im ila r to t h a t n o w e m p lo y e d , b u t th e lo a d in g o f the se c o n d w i l l r e ą u ir e a c u rv e in th e tr a c k t h a t w ill e n a b le th e m a c h in ę to ta k e a p o s itio n close to th e cu t.