Coal Age : devoted to the operating, technical and business problems of the coal-mining industry, Vol. 28, No. 23

M c G r a w - H i l l C o m p a n y , I n c . J a m e s H . M c G r a w , President E . J . M e h r e n , Vice-President

Devoted to th e O perating, Technical and Business

Problem s of th e Coal-Mining In d u stry R . D a w s o n H a l l Engineering Editor

Volume 28 NEW YORK, DECEMBER 3, 1925 Number 23

W hat D oes II Mean?

G

cite strike. From the public standpoint, the outstand­

ing featu res o f this program are the proposal to pro­

h ib it any increase in the price o f coal, a long-term agreem ent and an im m ediate resum ption o f operations.

That last proposal already has been invalidated by the declaration o f Mr. Lew is that resum ption w ill follow agreem ent— not the reopening of negotiations.

Mr. L ew is and h is associates, agreein g to nothing, prom ising nothing except a readiness to discuss the P inchot program w ith the operators, nevertheless em erge from the situ ation w ith the blessings o f Gifford and more public approbation than has been their lot at any tim e since the head o f the U nited M ine W orkers so brusquely ended . negotiations w ith the anthracite producers last A ugust. The operators, who have been g ath erin g favorable opinion to them selves because of the ju stice o f their cause, are again entering a cloud o f public disfavor. For this they have nobody to blame but them selves. T heir refusal to attend the governor’s H arrisburg party last Saturday, their plea for advance knowledge of w hat he would propose reveal anew a p itifu l incapacity for g a g in g public sentim ent.

A s for the Pinchot program, the more it is examined the less it appears in the public interest. The first pro­

posal is that there shall be no increase in price “by reason of th is agreem ent.” That provision contem ­ plates, in essence, a concerted m aintenance o f prices which is.clea rly illegal. Moreover, it is a denial o f the demand that the cost o f anthracite be lowered to a point enabling hard coal to compete w ith soft. In view of th at denial, the later provision for a study “to recom­

mend m ethods for in creasin g the efficiency and reduc­

in g the cost o f operation of the m ines” su g g ests no pub­

lic participation in the benefits of such a procedure. A s a m atter of fact, the attitu d e of the m iners has been th at those benefits shall be wiped out by w age increases.

In the lig h t o f w hat has taken place in the bitum inous regions, a long-term agreem ent w ith no m achinery for modification is not in the in terest o f either the m iner or the operator. N or is the public served if the inflexible w age basis fixed prove uneconomic, since the cost of industrial losses m ust ultim ately be absorbed by the public at large— indirectly, if not directly; T hat which the public m ost desires— an uninterrupted supply— is not guaranteed beyond the life of the new agreem ent.

A nother “stu d y” is to be added to the w earisom e bibliography on how to avoid strikes, but neither party is pledged to acceptance of the recom m endations made.

The only possible public gain promised by the gov­

ernor’s a ctiv ities w as an im m ediate resum ption o f op­

erations. Mr. Lew is has made it plain that that gain is h o t to be had. The other prom ises in the Pinchot program are too illusory to ju s tify enthusiasm .

Father o f Parliam ents

O

terned a fter it have had, of course, so long a life nor indeed so vigorous a one. Located as it is, the Coal M ining In stitu te of Am erica has been able to draw members as the city in which it m eets has been able to attract citizens. P ittsb u rgh is a convenient center for a live and flourishing in stitu te.

Many have frien d s and past acquaintances in P itts ­ burgh, and the annual m eeting accordingly serves for them as an “old home w eek” w here m any coal men who have not come in contact for years greet each ■ other once more and exchange confidences.

The P ittsburgh coal men have gone east, w est, north and south and som e have wandered into foreign clim es, but the Coal M ining In stitu te o f A m erica is th eir first love, even though they m ay have others, and whenever they have an opportunity they slip back to greet f a ­ m iliar faces and talk over old tim es and modern devel­

opments. A t its session s they are sure to find those who will welcome them a fter th eir travels and inform them as to the health and progress of th eir cronies.

Thoroughly practical the in stitu te has alw ays been.

Y et of late years it has kept a higher standard than in years past. In earlier days the budding politician occasionally found a chance a t the sum m er banquet to try out his ox-atory on the patient members, never being quite clear w hether he w as addressing the U nited Mine Workers o f Am erica or a technical society. B ut those days when we used to hear about Tubal Cain and K ing Solomon are gone. We eat our m eat today w ith better talent, and we ¡digest it w ith greater com fort.

No in stitu te, not even the A m erican In stitu te o f M in­

ing and M etallurgical E ngineers, has a better record for 100 per cent attendance at com m ittee m eetings.

No program s are prepared w ith more care. So long as th is condition obtains the life and vigor of the In stitu te will be assured.

The th irty-n in th annual m eeting assem bles next W ednesday. Let no consideration prevent the atten d ­ ance o f any coal man livin g w ithin reasonable distance.

Setting the H ouse in Order

H

nomic condition of the U nited States, show ing that the wealth and w ell-being of the average worker never stood any h igh er than today. The railroad improve­

m ent is m entioned as one o f the main underlying stones of the present economic structure. And here, we can­

not avoid alluding to bitum inous coal; the low price 755

756 C O A L A G E ^VOL. 28, NO. 23 throughout the year, too low all will admit, has been

kept from r isin g to undue levels by the excellent serv­

ice of the railroads.

Many of the inflations o f coal prices in years past have been due to the inability o f the roads to handle traffic. It has been said that the transportation u nits o f this country should not be planned to m eet the unrea­

soning demands of the public. That is true, but when the railroads come nearer to supplying the public need, the public ceases to become panicky and no longer orders goods for long periods in advance o f needs or annoys and hampers the railroads by com plaints about delayed shipm ents and losses. E x its at theaters are made large for use in case of panic, but w hen there are plenty of exits the panics do not occur. So w hen there are many railroad cars there w ill be less anxiety, and no duplication, triplication and other m ultiplications of orders.

Standardization and sim plification, as Mr. Hoover says, have done much to reduce w aste. In the indus­

tries which cater to the coal m ines standardization is*

difficult and makes slow progress, but it should be more rapid than it is. Greater standardization of the product of coal m ines would be o f great assistance. N everth e­

less, the advantage o f the movem ent is less in coal m in­

in g than in other lines, so th at such im m ense savings as are reported in other industries seem am azing. Some day when every one burns sm all sizes o f coal, savin gs like these will have been effected. B ut the process is slow as it involves large quantities of new consum er equip­

ment and is not determ inable on. an act o f w ill as is the size of a paving brick or the thickness of a plank.

The nation owes Mr. Hoover a debt of gratitude for h is continued efforts toward greater efficiency. We are all o f us laboring hard at jobs that sim plifications would shorten and make lighter. The m any item s of Mr. Hoover’s report will fu rn ish m any su g g estio n s to the industrial operator, be he in coal or in any other business.

B ringing T ools to the W ork

G

tion and m ining have not duplicated the econom ies of m anufacturing.

W ith m achinery, production is cheaper despite in creasin g w ages, but no such result has been possible where the tools have to be taken to the work. A t the m ines there are examples o f great economies o f opera­

tion. B ut hei-e in every instance the m aterial m oves to the tool. I f coal w ere carried on the backs o f packers up a 300 ft. sh a ft a ton per man per day would be a good day’s hoist, perhaps. B ut now one engineer can hoist w ith modern equipm ent 11,000 tons per day i f the m aterial hoisted is delivei-ed to it. Sim ilarly pumps receive their m aterial and effect prodigious economies, but w here m achines have to run around to g e t a chance to do th eir work no econom ies like those attained by the m anufacturer are possible, though such econom ies as are attained are certainly w orth-w hile. Those who

declare that they did well' in the old mule and hand- pick days exaggerate the resu lts attained under such conditions and fo rg et th at the m ines w ere sm all and near the tipple, th at hours were longer and m en worked harder and even then did not perform as much. To return to those days would double or triple the cost of our coal.

Safety the First Consideration

W

B ut as tim e wore on, the Federal governm ent gradually became w ealthy and found th at it could in terest itse lf in the technique o f industry, first w ith regard to farm ­ ing and then broadly through an extension o f the Bureau of Standards. L ater the Geological Survey form ed a technological branch w hich dealt largely w ith technique of coal.

So fa r nothing had been done federally for safety.

A t length a number o f d istressin g explosions caused Congress to urge th at the technological branch of the Geological Survey undertake an inquiry into the tech­

nique o f sa fety , a study m ore germ ane to the duties of governm ent than the development of m ining and m anu­

factu rin g processes. Surely the sa fety of the worker is a prim ary public interest, a form o f technique more consonant w ith the fundam ental purposes o f governm ent than any other. The U. S. Bureau of M ines w as form ed out of the technological branch largely because the need for sa fety had become im perative.

Had the Bureau taken up the m atter in any h a lf hearted, negligen t or insufficient m anner, its sa fe ty work m ight have been allowed to die w ithout protest. B u t it succeeded so well th at despite new hazards o f increased depth, more gas, greater production, m ore m achinery, more men in a sin gle m ine and larger and heavier tran s­

portation units, the grow th in accidents not only did not increase but actually declined. F or aw hile sa fety drove out the greater part o f th e other activ ities o f the Bureau. It became alm ost exclusively an in stitu tio n fo r the study and prom otion o f sa fety . It branched out into m ine rescue work. It trained men to perform the work o f first aid and m ine recovery.

The pubLc has confidence in its work. It questions whether, if th at w ork w ere le ft to each o f the m any states, it would be done as well. It notes w ith regret that state positions occasionally are held by men w hose qualifications are political and not technical. It is con­

fident th at the Bureau o f M ines is doing a m ore efficient work than the m any m ining sta tes would do if le ft to them selves. So excellent has th at work been th at some states have sought co-operation o f the Bureau in th eir inspectional a ctiv ities and every coal operator who has tried to m aintain good first-aid and m ine-rescue team s has sought th e Bureau’s aid in keeping them in a high sta te o f efficiency.

W e hope that the Bureau’s researches may some day be extended, but hold th at not a dollar should be taken from sa fe ty work for the study of coal or m etallurgical processes. It would be sad indeed if the Bureau should take as its m otto the slogan, “S a fety is not the first con­

sideration.” Such a decision would controvert the pur­

poses fo r w hich th at governm ental a ctiv ity w as estab­

lished.

De c e m b e r 3, 19 2 5 C O A L A G E 7 5 7

Conveyors D ouble Output per Man In Room W orking

R a ise A v era g e to 16.23 T o n s — F iv e-M a n U n its Can Cut, D rill, S h o o t and L oad F ou r F a lls a D a y and D o D ea d W o rk T o o

B y A lp h o n se F. B rosky

A s s i s t a n t E d ito r , C oal A g e , P i t t s b u r g h , P a .

I

centration and speedy recovery are facilitated by conveyoi’S in a room -and-pillar layout. T hese are the Telford m ine o f the T elford Coal Co. and the Jasahill m ine of the Jasahill Coal M ining Co. B y th is m eans an appreciable sa v in g in the production cost is effected.

Once started, a room is driven to its lim it and its com­

plem entary pillar brought back w ithout delay.

The cycle— in and out again

— has been completed in a m inim um of 16 and a m axi­

mum of 21 consecutive sh ifts o f 8 hr. each by five m en who cut, drill, shoot and load the coal, besides handling draw slate, se ttin g tim bers a n d m oving the conveyors. An average of three cuts from a room and as m any as four from a pillar are taken each s h ift. And despite the fa c t th at conditions are not the best, each m iner has produced an average o f 16.23 net tons per s h ift as again st 7.28 tons under the old system . It would appear, furtherm ore, th a t the lim it of productive­

n ess has not even y et been reached.

Under the plan followed, each unit is composed of cer­

tain definite pieces o f equip­

m ent and the complement o f m e n necessary to operate them . Each crew is composed o f five men. The equipment con sists o f : A m ain con-

T h e h e a d p ie c e a c c o m p a n y in g t h i s a r t i c l e s h o w s tw o in d e p e n d e n tly - d r iv e n l a t e r a l c o n v e y o rs a r r a n g e d in t a n d e m to d is c h a r g e in to a m a in c o n v e y o r w h ic h e x te n d s f ro m a ro o m f a c e t o th e e n t r y . B y th e a id o f th e s e c o n v e y o rs f o u r m e n m in e th r e e 6-ft. c u ts , 35 f t. lo n g , f ro m a ro o m in 8 h r. T h is is 3 0 -in . c o a l in th e B s e a m , J a s a h i l l m in e .

Gravity Plane and Tipple at Jasahill Mine

I n a c c o r d a n c e w ith th e c o m m o n p r a c tic e w h e r e th e c o a l b e d lie s a b o v e th e r a i l r o a d t r a c k in c e n t r a l P e n n s y lv a n ia , a t th is m in e lo a d e d c a r s a r e u tiliz e d to p u ll th e e m p tie s b a c k u p h ill. A s a r e s u l t n o p o w e r is c o n s u m e d .

veyor, 250 ft. long made up o f 6-ft. sections. T his is extended in driving a room and shortened in draw ing a pillar. Two face conveyors, each 12 ft. long, discharge into the main conveyor (a complete description o f these conveyors, known as the “Suppes,” appeared in last week’s issu e o f th is m agazin e). One undercutting m achine; a d istrib u tin g or booster fan and canvas tubing; a 5-hp. h oist and the necessary w irin g and lig h tin g m aterials complete the outfit.

A stron g conviction t h a t long-face m ining involves d is­

advantages ou tw eigh in g its b e n e fits has fortified the

“Knickerbocker M ines” m an­

agem ent in the b elief that m echanization yields best re­

su lts in a room-and-pillar lay­

out. The sim p licity o f roof control in th is system o f m in­

ing as compared w ith th a t in longwall operations, especially when a room and pillar never attain a m onth’s age, is suffi­

cient justification fo r the re­

tention o f th is system . The m anagem ent holds th at tran s­

portation is the m ost impor­

tan t f a c t o r lim itin g the productivity o f any m ining method. L ight, sectional con­

veyors solve th is problem in one system as well as in another.

T he m anagem ent believes it is not w ise to concentrate m ining areas w ithout likew ise condensing the phases o f the m ining cycle. T hus it m ain- t a i n s that in non-gaseous m ines, at least, not only should every phase of a m ining cycle be completed in one s h ift but th at two, three or even four, such cycles should be con­

sum m ated on each face in th is sam e tim e interval. A

758 C O A L A G E ^VOL. 28, No. 23

-D istributing fan ■ C utting m ach in e|

■Canvas tu b in g C

{ M a m conveyor

m ining cycle, o f course, com prises those operations (phases) which are required to complete one cut—

undercutting, drilling, shooting, tim bering and loading out. T hese considerations dictated a choice of the mechanized room-and-pillar system .

The general layout is as fo llo w s: Room headings, con sistin g of two entries 25 ft. wide on 80-ft. centers, are driven at 90 deg. off the m ains leaving a 500-ft.

room-and-pillar territory or panel between them. Rooms on 53-ft. centers are turned rig h t and le ft or off both entries o f a room heading. T hese rooms are 35 ft.

wide and 250 ft. long, w ith 18-ft. pillars betw een them.

Room headings w ill be approxim ately 2,750 ft. in length or long enough to accommodate 50 rooms upon either side. It is the intention to drive the room headings to th eir lim its advancing and to m ine the rooms and pillars retreatin g. It is h ighly desirable that the rooms and pillars on one entry of the cross heading be mined advancing w hile those on the other shall be mined retreatin g. In closed-lamp m ines a triple-entry cross heading would be required where rooms are driven off both sides of a room heading. A nother modification, that could be worked successfully, would be th at of driving rooms off only one side of a tw o-entry heading, using only one conveyor unit to advance the headings to their lim its and to m ine the rooms and pillars on the retreat.

Inasmuch as entry driving precedes room-and-pillar

Loading Boom on an Entry

O ne m a n is s t a ­ tio n e d a t th e lo a d ­ ing: b o om . H e lo a d s a n d s p o ts m in e c a r s in t r ip s o f 25. F r o m 14 f t. to 2 ft. o f to p o r b o tto m m u s t be t a k e n o n t h e e n tr y f o r . h a u l a g e p u r ­ p o se s, in d ic a tin g th e th ic k n e s s , o r r a t h e r th e th in n e s s , o f th e s e a m . H o o f is a ls o b r u s h e d to g iv e h e a d ro o m fo r t h e lo a d in g b o o m w h ic h m u s t b e e le ­ v a t e d to c le a r th e c a r s .

F IG . 1

Conveyors in Entry Work

A f te r th e u p p e r e n t r y is a d v a n c e d fro m A to B th e e q u ip m e n t is m o v e d to th e lo w e r p a s s ­ a g e w h ic h is d r iv e n 220 ft. fro m C to D . T h u s th e d r i v ­ in g p ro c e s s is a l t e r ­ n a te d b e tw e e n th e tw o e n tr ie s . W h ile th e lo w e r e n t r y is b e in g m in e d ro c k is b e in g t a k e n to p r o v i d e h a u la g e h e ig h t in th e s t r e t c h fro m A to B . R o o m n e c k s (are d e v e lo p e d a lo n g w i t h th e e n tr y .

work, it is well to consider developm ent m ethods first, even though greater significance may attach to the mode of later recovery. In a sense, however, both plans are based on the sam e fundam ental principles of quick recovery by the use of conveyors, w ide places (w here conditions w ill perm it) and intensive m ining accom­

plished by taking at least three cuts from one place in each sh ift.

In F ig . 1 is indicated the plan by which an entry face is advanced at the rate of approxim ately 18 ft. per sh ift. The two en tries o f a room heading are extended by one m ining unit, th at also m ines crosscuts through the chain pillar and develops the room necks.

The thickness of coal in both the Telford and Jasahill m ines is not enough to provide sufficient h eigh t on the en tries; consequently top or bottom, or both, m ust be taken. B rushing top and liftin g bottom are operations perform ed entirely apai't from th at of m in in g coal from an entry. H aving developed the upper entry from A to B (F ig . 1) the equipm ent is moved to the lower passage which is then advanced from C to D. The length o f each step, th at is, from A to B and from C to D, is about 220 ft. W hile the lower entry is being developed from C to D, rock is being taken down and the track extended in the upper entry from A to B as indicated by the herringbone hatching.

Sufficient rock is taken to provide from 54 to 6 ft.

o f headroom over the haulw ay which is about 9 ft.

Tem porary em pty) sto ra g e, tr a c k '

Hoist- ’

JffffJniBs i

Loaofs

/ ✓^{L -} / ^Lj / ^{L -} / ^L- /

Face conveyor

<Z'.Fresh c u t -i i—

I I

'Nota :-Room nacks are m in ed sim ultaneously w ith the

developing e n trie s.

The conveyors g re a tly a ssist in this work

De c e m b e r 3, 1 9 2 5 C O A L A G E 759 wide, leavin g the rem aining w idth or about 16 ft. of the

entry fo r gob space. Furtherm ore, a pot hole is made at the mouth o f each room neck to assure ample clear­

ance above the loading boom of the conveyor during the room -and-pillar m in in g operation. W here the bed pitches, room headings as fa r as possible are for obvious reasons driven on the rise.

E n try driving, like room and pillar m ining, is ex­

pedited by an adequate supply of m ine cars. These are m ade, up into trip s of 25, into w hich the conveyor discharges a steady run o f coal. In every second chain-pillar crosscut track is laid connecting the per­

m anent track of the entry being advanced w ith a tem porary track laid on the gob sid e of the parallel entry. A portable hoist, driven by a 5-hp. motor and rem otely controlled from the loading station, is used to spot the cars com posing a trip. The haulage arran ge­

m ent is clearly shown in F ig . 1. A s the direction of m ovem ent of the loaded cars during sp ottin g is toward the dip, brakes m ust be set to hold them . The h oist m oves the trip w ithout these brakes being released.

The conveyor equipm ent can be used advantageously for handling rock. It has been thus applied in the driving of a stretch of the Fourth Main heading in the Telford mine, w here bad roof w as encountered under a stream . H ere the entries, which custom arily are driven 25 ft. w ide have been narrowed down to 10 ft. A t this, point about 2 ft. of com paratively loose slate overlies the bed. T his slate is tem porarily .propped up w hile the coal in each cut is being loaded out, a fter which it is taken down, loaded onto the conveyor and delivered to m ine cars fo r outside disposal.

In panels A , B and C of F ig . 2 are indicated respec­

tiv ely the dim ensions of rooms and pillars and the m ethods followed in driving the rooms and draw ing the pillars. In panels B and C are shown also the arrange­

m ent o f the conveyors and other equipm ent which provides quick recovery. A s already explained room necks are turned and developed w hen the entries are driven. One m ining unit advances a room heading to its lim its; tw o such units, or one on either side, are utilized to m ine the rooms and pillars in a full retreat.

Ar r a n g e m e n t o f Co n v e y o r s i n Ro o m

Im agine fo r the m om ent panel B in the earliest stage or room driving. The room neck has already been m ined 10 ft. w ide and 30 ft. deep. A t the m outh of th is neck and extending over the entry track is placed the loading boom. Onto the rear end o f the loading boom are added as m any 6-ft. sections of m ain conveyor (about fou r) as are required to reach the face of the room neck. H ere the w idening-out operation com­

m ences. In three consecutive cuts, made in one sh ift, the room is flared out to its full w idth of 35 ft. In each s h ift th ereafter a t full room w idth the face is advanced a distance equivalent to the depth o f three 6-ft. cuts until its lim it, which is 250 ft. from the entry, is reached. A s each breakthrough projection (on about 105-ft. centers) is reached the room pillar is pierced in three consecutive buttoff cuts. M ining op­

erations here alternate betw een the room and the cross­

cut faces until the pillar is mined through. When the lim it o f the room is reached, the pillar is, of course, broken through at its extrem ity, com pleting the m ining of the room proper.

The m ain conveyor is so laid as to m aintain a clear­

ance of about 7 ft. from the pillar and extends alm ost to the face. The roof over the gob area is supported by

J

J

n

Fig. 2— Room and Pillar Layouts

P a n e l A s im p ly g iv e s th e d im e n s io n s o f r o o m s a n d p illa rs . P a n e l B s h o w s th e a r r a n g e m e n t o f e q u ip m e n t in a n a d v a n c in g ro o m , a n d p a n e l C in d ic a te s th e m e th o d b y w h ic h a p i l l a r is d r a w n .

m eans of props on 5-ft. centers in lateral rows 6 ft.

apart. The posts in the line flanking the main con­

veyor nearly touch it.

W ithin 2 or 3 ft. o f the shot-down face are se t in tandem the two 12-ft. face conveyors extending at 90 deg. to the main conveyor. The effective length of these tw o conveyors w hen in tandem is about 22 ft. so that they are w ith in shoveling distance from the fu rth er­

m ost corner o f the room. Where the roof show s w eak­

ness three sa fe ty props are set between the lateral con­

veyor and the face, w ith in 18 in. o f the coal. T hese tim bers are set in position in the wakp o f the under­

cutter before the cut is shot. T hey in terfere w ith loading to only a slig h t degree.

Four men out o f the 5-man crew work at the face, the fifth man being stationed on the entry to load, trim and spot cars. A s in entry driving, the sp ottin g of cars in conjunction w ith room -and-pillar m ining is accom plished by m eans o f a 5-hp. h oist rem otely con­

trolled from the m ain control panel in the room neck.

All electrical taps are made on a duplex cable. This is carried overhead across the entry from the feeder to a cable reel of the m ining-m achine type set up in the room neck. Branch circuits lead from th is connection to the m ain conveyor drive and to a sm all fa n which by the aid of canvas tu b in g delivers air to the face.

A s the room face is advanced th e cable is unwound from the reel. The end o f th is cable term inates a t a junction box at the face. From th is point electrical connections are made to the cu ttin g machine, to the

760 C O A L A G E Vol. 28, No. 23 tw o independently driven transverse conveyors and to

a flood lamp which illum inates the face.

A fu se on th e m in in g m achine and another on the m ain control panel in the room neck join tly guard all th is equipm ent again st overloads. The m ain conveyor m ay be stopped w hen desired by th e m en at the face as well as by the operator at its heading end.

A snap sw itch on one o f the face conveyors and a no­

voltage release mounted on the m ain control panel pre­

vent restartin g. T his featu re is particularly valuable when the m ain conveyor is being used fo r transporting supplies and equipm ent from the entry to the face. It also serves as a sa fe ty precaution w hen work is being done on the conveyor unit.

The four face men work on th eir knees in low coal.

They are stationed at equal intervals along the face.

Shoveling is easy in th at th ey are enabled to load the coal by a sim ple toss o f the shovel; or the shovel, filled w ith coal, may be dragged back to the conveyor, lifted above the flare board and the coal allowed to slide off.

In no case is it necessary to throw the coal fa r upward or outward from the shovel. The men go through no unnecessary m otions and the exertion involved is less than a third th at required to load into the ordinary m ine car. T his point is im portant as has been proven by actual practice, fo r a man in 1 hr. loads w ithout task in g h im self as much coai as he could load into a m ine car in approxim ately 3 hr. o f heavy exertion.

The four men load a w idth o f face m easuring about 24 ft. from the left-hand side o f the room, leaving about 11 ft. on the rig h t side. T his la st one-third is loaded out by tw o men w hile the other tw o move the undercutter from its position a t A (panel B, F ig . 2) and start cu ttin g from le ft to righ t. B y the tim e the cu ttin g m achine reaches the center of the face the two shovelers have about cleaned up the previous cut. H av­

in g completed the clean-up the tw o shovelers become drillers and sta rt on the le ft side to drill and charge the shot holes, in the wake o f the cu ttin g m achine.

W hile cu ttin g and drilling are in progress the fifth man on the entry loads onto the m ain conveyor the supplies and equipm ent necessary to extend it, reverses the direction o f its travel and thus transports to the face the w herew ithal fo r its extension along w ith tim ­ ber and supplies. H e then goes to the face w here he join s h is buddies in len gth en in g the conveyor.

The tw o transverse conveyors are moved to an advanced position w ith in 2 f t. o f the new face. Then w hile three men add a 6-ft. section to the m ain con-

Conveyor in a Room

T h e ste p p e d b o tto m is a n in d ic a tio n o f a lo c a l r is e to th e c r e s t o f a ro ll. N o te t h a t th is c o n v e y o r a c c o m m o d a te s its e lf to th e r is e a n d d ip .

Looking Out of a Room

A n a v e r a g e o f th r e e r o lls a r e e n c o u n te r e d in th e d r iv in g o f e a c h ro o m in th e J a s a h i l l m in e , a n d th e c o a l v a r i e s fro m 23 to 44 in.

in th ic k n e s s . T h e p r o n o u n c e d v e r t i c a l b e n d in th e c o n v e y o r in th e b a c k g r o u n d is n o tic e a b le . T h is ro o m w a s s t a r t e d u n d e r th e old sy s te m o f m in e c a r lo a d in g a^. in d ic a te d b y th e w a ll o f r o c k t a k e n f ro m th e b o tto m .

veyor, the tw o others set a row of props behind the face conveyors. When these jobs have been completed the shots are w ired and the men retire to sa fe ty on the entry. From th is vantage point th e charges are detonated by m eans of a battery. W hile the face is being cleared o f gases and smoke by the d istrib u tin g fan the men usually eat lunch. T hus one o f the three cycles of room driving ordinarily com pleted in an 8-hr.

s h ift is finished.

Turn now to panel C o f F ig . 2, in which is illustrated the steps taken in draw ing a pillar. Since the pillar is 18 ft. wide, three buttoff cuts, each 6 ft. in depth will pierce it. T hese buttoff cuts are made 25 ft. long, leaving a 6-ft. stum p w hich is taken upon the comple­

tion of the adjoining buttoff place.

Three to four cuts are taken from a pillar in a sh ift.

The sequence of w orking is indicated in F ig . 2 by a num ber-and-letter notation, the num bers in d icatin g the places worked at one tim e and the letters th e sequence o f working. Thus during the first s h ift cuts 1-A, 1 -5 and 1-C are m ined; during the second s h ift cuts 2-A, 2-B and 2-C; during the third s h ift cuts 3-A, 3-B, 3-C and 3-D, and so on. A s shown, a room pillar can be com pletely drawn in six s h ifts. In m any cases only four sh ifts nave been required fo r robbing a pillar.

The pillar is w ithdraw n only as fa r as the entry stum p, which is le ft for later recovery w ith the chain pillar.

T hese abstract fa cts should be n o te d : The equipm ent com posing a m ining unit can be moved from a worked- out place to an adjacent room neck by five men in 12 hr. Toward the close of each s h ift it is custom ary to prepare at least one cut for loading a t the b egin n in g o f the follow ing sh ift. Each m ining unit has its own cut­

tin g m achine. All these arrangem ents lend them selves adm irably to double-shifting.

Three u n its are installed in the T elford m ine. H ere the E seam being worked has an average thickness o f 42 in. and is overlaid by 5 in. o f draw slate w hich comes down or is pried loose and gobbed before the coal is loaded. N ear th e bottom o f the bed is a 2-in.

binder which is loaded w ith th e coal. T h is breaks in big pieces which are ea sily detected and removed on the tipple. The coal is so ft and friable.

One of the u nits here installed produced 17,371 net

De c e m b e r 3, 1 9 2 5 C O A L A G E 761 tons of coal in the first 214 consecutive s h ifts (includ­

in g the tim e required to m ove the equipm ent from place to p la ce), m aking an average of 81.17 tons per s h ift or 16.23 net tons per m an-shift. In m ining one room in which the draw slate w as only 1J in. thick th is unit m aintained an average production o f 95.76 n et tons per s h if t or 19.15 tons per man per s h ift. It m ined another room and its com plem entary pillar, y ield in g 1,377.6 tons in sixteen 8-hr. sh ifts at an average rate o f 17.2 n et tons per m an per sh ift.

Ot h e r Un i t s Sh o w Hi g h Av e r a g e s

The second unit installed in th is m ine in the first place worked, w hich w as a 25-ft. entry, m ined 1,072.96 tons in 18 sh ifts, an average o f 11.92 n et tons per man per sh ift. T his sam e unit n ext m ined a room at an average rate o f 17.09 n et tons per man per sh ift. In the third place m ined by th is unit, a room and a pillar, it produced an average o f 16.01 net tons per m an per sh ift.

The third unit installed in the T elford m ine, w ith four men in the crew, m ined 1,019.2 net tons from its first room in 16.8 sh ifts, or a t an average rate o f 15.16 tons per man per sh ift.

A t the Jasahill m ine the B seam varies in thickness from a m axim um o f 44 in. to a m inim um of 23 in.

Rolls, extending in any direction, are encountered at the average rate o f three to a room. N o draw slate occurs but a th in band o f so ft slate comes down w ith the coal.

One unit is in operation in th is m ine. In the second place worked it produced from a room and pillar 1,258.9 n et tons in 18.6 sh ifts at an average rate o f 13.53 tons per man per sh ift. The average thickness o f the bed in th is room and pillar w as 38 in.

S ixteen room -and-pillar places, five rooms w ithout pillars and four entries (each o f the latter being 220 ft. long) or 25 places in all, had been mined by the mechanical system up to Nov. 1. N eith er the equipm ent nor the methods, therefore, is experim ental.

Top Works at Jerome Nos. 1 and 2 Mines, Hillman Coal & Coke Co. at Jerome, Somerset County, Pa.

Jerome No. 1 Tipple Has Special Bin for Storing Crushed Refuse

J e r o m e N o. 1 is o n e o f tw o o p e r a tio n s a t J e ro m e , P a ., o f th e H illm a n C o a l &

C o k e Co. T h e c a p a c ity o f t h i s tip p le is 2 ,0 0 0 t o n s p e r clay, th e c o a l c o m in g fro m th e C - P rim e se a m . I n th e b in s u p p o r te d b y s te e l le g s , to th e l e f t o f th e tip p le s t r u c ­

t u r e a n d to th e r i g h t o f th e b rid g e , is s to r e d c r u s h e d p ic k in g - ta b le r e f u s e w h ic h is b u r n e d in a s te a m p la n t. A f te r p a s s in g t h r o u g h a c r u s h e r in th e tip p le th e r e fu s e is r a i s e d a n d d u m p e d in to th e b in b y a b u c k e t e le v a to r . M in e c a r s c a r r y t h i s fu e l

f ro m th e b in to th e b o ile r p l a n t w h ic h is lo c a te d b e h in d th e tip p le . T h e c r o s s a b o v e th e b in is n o t a p a r t o f th e d e s ig n o f th e s t r u c t u r e . I t is fo rm e d b y a te m p o r a r y h o r iz o n ta l w o r k in g p l a t f o r m su s p e n d e d fro m th e b u c k e t e le v a to r h o u s in g .

Tipple at Jerome No. 2, Where 2,000 Tons are Prepared Daily

T h is tip p le p r e p a r e s a b o u t 2,000 to n s of c o a l p e r d a y . T h e s h a f t is 225 f t . d e e p . D u r i n g th e w in te r o f 1924 m u c h o f th e c o a l f r o m th is p l a n t a n d t h a t f ro m th e J e r o m e N o . 1 p l a n t o f lik e c a p a c it y w e n t to E a s t e r n a n d N e w E n g la n d m a r k e t s In c o m ­

p e titio n w ith a n t h r a c i t e f o r d o m e s tic u se . T h e c o a l c o m e s fro m th e lo w v o la tile , s m o k e le s s C - P rim e s e a m o f C e n tr a l P e n n ­ s y lv a n ia . T h e s la c k c o m in g fro m th i s p l a n t r a n g e s In siz e s u p to 2 In. a n d th e r e f o r e m a k e s e x c e lle n t s t e a m c o al. S in c e t h i s

p i c t u r e w a s t a k e n th i s p l a n t h a s b e e n r e ­ m o d e le d . S h a k e r s c re e n s , p ic k in g t a b le s a n d lo a d in g b o o m s w e r e i n s ta lle d in th e f a ll o f 1924. A lso th e p l a t f o r m c a g e s in d ic a te d b y th e h e a d f r a m e c o n s tr u c tio n in th is p ic ­ t u r e w e r e r e p la c e d b y s e lf- d u m p in g c a g e s .

762 C O A L A G E Vol. 28, No. 23

Harmar Mine Raises Quality of Its Product By Overcutting in Impure Coal

“C a p tiv e” M ine S h o w s In flu en ce o f S te e l In d u stry — S h ip s by E ith e r L and or W a te r — P ro b lem o f H o u sin g in L im ited S p a ce I s S o lv e d by B u ild in g T erra ces

Bv A lp h o n se F. B rosk y

A s s i s t a n t E d it o r o f C o a l A a c . P i t t s b u

W

sid iary of the W heeling Steel Corp., one of w estern P ennsylvania’s m ost outstanding coal properties. Sev­

eral details both of surface design and operation differentiate th is m ine from the average run o f the common herd. Thus, top cu ttin g of the coal is prac­

ticed in preference to undercutting; the design of its houses differs radically from that usually adopted by m ost coal com panies; the m ine product is crushed before it leaves the tipple and can be shipped by either land or w ater. It is one of the m ost thoroughly rock- dusted m ines in the country. The extrem ely in terest­

in g subject of rock-dusting practice will be treated in the Dec. 10 issue.

The sh a ft o f th is operation is 134 ft. deep, extending to the bottom of the Thick Freeport bed and h oistin g is perform ed by m eans o f 10-ton skips. P resen t pro­

duction is at the rate of about 3,000 tons per day but the equipment has been designed for an ultim ate

•The h e a d p ie c e a c c o m p a n y in g t h i s a r t i c l e is a g e n e r a l v ie w o f th e u p p e r w o r k s a t H a r m a r v ille . T h e o u t p u t o f t h i s m in e c a n b e s h ip p e d b y e i t h e r r a i l o r r iv e r. A n a r t i f i c i a l h a r b o r h a s b een d r e d g e d to a c c o m m o d a te b a r g e s o f 1 ,0 0 0 to n s c a p a c ity in to w h ic h a r e lo a d e d .600 t o n s o f c o a l w h ic h is a ll t h a t th e o r d i n a r y s ta g e o r th e A lle g h e n y R i v e r w ill a c c o m m o d a te . T h e s e b o a ts a r e th e n flo a te d d o w n th e A lle g h e n y a n d O h io r i v e r s to th e b y p r o d u c t c o k ­ i n g p la n t a t S te u b e n v ille , O hio.

•gh, P a .

capacity of 6,000 tons and th is output will doubtless be attained eventually. The property com prises no less than 3,300 acres of coal which is enough to fu lly ju s tify such large capacity.

T his plant is all the more in terestin g because it is

“captive,” producing fu el solely fo r use in the parent com pany’s byp'*oduct coke works at Steubenville, Ohio.

B ein g thus closely affiliated w ith the in terests of another industry the operations at Harm ar bear stron g im print o f the influence which the steel works have exerted upon them . T his is evidenced both in m ining operations and in transportation. It is so marked in some respects as to render a number of the practices followed at Harm ar distin ctly different from those of neighboring operations.

The average thickness o f the cover above the work­

in gs is about 450 ft.; the maxim um about 650 ft.

The rbof directly over the coal is decidedly w eak and has presented perhaps the m ost difficult problem encountered in m in in g the Thick Freeport bed, which in th is mine, is about 86 in. thick and not all clean.

E n tries are driven 12 ft. w ide on 50-ft. centers. The m ain heading lies on a butt course and is composed of six entries protected by 200-ft. barriers upon either side. Cross headings, o f four entries each, protected by 175-ft. barriers, are laid out at 2,490-ft. intervals.

D ouble-entry room headings are turned every 400 ft., center to center, leaving 350-ft. strip s o f coal which

De c e m b e r 3, 1 9 2 5 C O A L A G E 763

Rotary Dump

S o lid c a r s , t u r n - o v e r d u m p s a n d s k ip h o i s tin g a r e a ll r a t h e r o u t o f th e o r d i n a r y in P e n n ­ s y lv a n ia m i n e s.

T h is d u m p is c a p ­ a b le o f d is c h a r g in g s ix t h r e e - t o n c a r s o f c o a l p e r m in u te w ith e a s e . I t is a c t u a t e d b y c o m ­ p r e s s e d a i r , th e o p e r a t i n g c y lin d e r s b e in g f a s te n e d to th e ro o f i n s te a d o f t h e flo o r a s is g e n ­ e r a l l y th e c a s e . T h e d u m p is on a p e r c e n t g r a d e so t h a t th e c a r s p r o c e e d a c r o s s i t b y g r a v ­ ity w ith o u t lo s s o f tim e .

are mined by 21-ft. rooms 300 ft. long pitched on 80-ft.

centers.

The demand for steel from the plants of the parent organization is reflected in the demand fo r coal on the Harm ar m ine. And as the coal company is not engaged in any com mercial business, w hen tim es have been dull in steel, the m ine has worked in term itten tly or not at all. T his fact, coupled w ith a bad roof condition, a c c e n t s for the adoption of a la5rout of w ide rooms in a region where pillars are seldom tw ice as w ide as the openings betw een them.

These pillars are being m achine-m ined by an 18 ft.

w ide buttoff place protected by a 10-ft. w in g which is recovered partly by m achine and partly by pick. A 6 x l0 -ft. stum p is le ft at either end of the w in g, to be drawn later by pick, and the coal between the two stum ps is m achine-m ined. Under better-than-average conditions the entire w in g m ay be m achine-cut.

W here tw o men work on a pillar, which is the com­

mon arrangem ent in th is m ine, each m iner has a place to h im self. Consequently, two places in one pillar are worked sim ultaneously. When the buttoff place nearest the inby end o f the pillar is ju st through, the m iner there employer, sta rts back w ith the w in g pillar w hile the other m iner sta rts a second buttoff place outby o f the first. A concentration system of three such places on a sin gle pillar is being experim ented w ith and may prove successful if the roof is not disturbed to any great degree, thereby causing undue pressure on the isolated pillar coal.

Se v e r a l La y o u t s Co n s i d e r e d

To avoid the danger ju st described a proposed lay­

out o f 22-ft. rooms on 60-ft. centers is now being con­

sidered. B y this plan the pillar would be drawn by two men im m ediately follow ing the com pletion of the room. Still another layout is being schemed, in an attem pt to arrive at the best. T his provides for 18-ft.

rooms on 40-ft. centers. Concentration would be obtained by driving a se t of six rooms sim ultaneously on an even front, w orking as m any sets as are required to m aintain a stra ig h t break line on an angle o f 45 cleg, to the headings. P illars would be drawn, w ithout interruption, follow ing the com pletion of the rooms.

Loaded Mine Cars at the Shaft Bottom

T r ip fe e d e r s h a v e b e e n e lim in a te d fro m t h i s m in e b y p la c in g b o th lo a d e d a n d e m p ty s t o r a g e t r a c k s on a g r a v i t y g r a d e . T h u s th e l o a d e d . t r a c k s a r e on a n in c lin a tio n o f 1$ p e r c e n t. H e a v y c o n c r e te p ie r s p r o te c t th e t u r n o u t p o in ts.

W ithin a section, m ining would be pushed in a full retreat, which is the plan being applied to all the ex istin g sections in order th at sp lits of air m ay sweep the live w orkings first and then the goaf.

Twenty-five-pound rails are laid in rooms and butt entries. Coal is hauled in 3-ton steel cars to side tracks by storage-battery locom otives. F ifty-pound rails are laid in cross and main entries and from the gath erin g partings the coal is hauled in trips of 35 cars to the sh a ft bottom by tw o 13-ton locom otives. The max?' mum haul is about 14 m iles. If present plans m ate­

rialize the main haulw ay w ill soon be laid w ith 60- or 70-lb. rails. T his im provem ent will be in accord w ith the modern tendency toward heavier track.

Coal is discharged from the mine cars by a 2-car, air-operated rotary dump which has a continuous- perform ance capacity o f 6 cars per m inute. Inasmuch as the dumping cycle is only 6 sec. in duration, 14 sec.

are available between dumps for changing cars, which is ample tim e. The gate equipment under the dump is capable of handling the contents o f eig h t cars per minute. It thus will be seen that w ith the skip hoist-

764 C O A L A G E Vol. 28, N o. 23

M an a n d supply siopei Materia/ «SjwMA

rMain intake \

I®!?.' house-.

\ircompr.

■vrTrack '-'loading:

wafer ¿ms

^S~a-a£ saaSgS rfarftrt gfrgft^

B arge loading point;

\Supply

house _{/ ,Fan}

■'shaft Top o f fiank'

in g at the capacity rate o f 6,000 tons per day the dum ping and loading equipment would operate in a com paratively leisurely manner.

A ll of the shaft-bottom equipm ent is operated by com pressed air under 80-lb. pressure. From the dump the coal is discharged into 4-ton w eigh-baskets and from thence into a 38-ton bin. F ly gates, controlled by the dump operative, allow rock to be bypassed into a 30-ton rock bin. One such fly gate is arranged under each car so that one car of rock' and one car o f coal can be dumped sim ultaneously, as well as tw o cars of either rock or coal. A ir gates on both bins regulate the feed from them to either of tw o m easuring pockets.

Manually-controlled air gates govern the passage of the coal from the m easuring pockets into either o f the 10-ton skips.

Un c o m m o n Sh a f t Bo t t o m

In several respects the sh a ft bottom in the Harm ar mine is out of the ordinary. The loaded and empty storage tracks are not parallel, as is often the case w ith cage-hoisting where end dump cars are shunted by a kickback from the loaded track through a shoofly to the em pty storage track. A kickback layout is always a source o f trouble, which m ight well be avoided where possible. T his difficulty is surm ounted in this mine by estab lish in g the em pty storage, as shown in F ig . 1, as a continuation o f the loaded track but, of course, beyond the rotary dump.

Both tracks are double. Cars are fed to the rotary dump by gravity and taken aw ay in the sam e manner.

The loaded side has a storage capacity o f 225 cars and is on a grade o f l i per cent. The em pty side can hold 250 cars. It is on a grade of l i per cent w ith in the lim its o f the runoff from the cage, and on a more gentle inclination from there on. In th is w ay w orries

a risin g from inopportune breakdowns o f car hauls or feeders are elim inated.

Where the m ine output is dumped w ith in the m ine the danger, and detrim ental effect o f the coal dust upon the health and efficiency of the crew, is ever pres­

ent unless some m eans is provided to abate th is nuisance. T his is accomplished in the H arm ar mine by a rather ingenious control o f the v en tila tin g current in the v icin ity of the m ain bottom.

The m ain intake is a concrete, m an-and-supply slope which is 580 ft. long on a pitch of 14 deg. In th is passage a brick curtain separates the m anw ay from the supply com partm ent. The exhaust sh a ft is about 800 ft. from the m ain sh a ft, w hich is, o f course, neu­

tral, being neither a downcast nor an upcast.

A t E in F ig . 1 is located an old sh a ft w hich form ed a part of an earlier operation w ith in the property and w hich is now being u tilized as an au xiliary intake.

The air drawn in through th is sh a ft travels as indicated by arrows, to join that o f the m ain intake. H owever, part o f th is air is separated from the m ain course, passes through crosscuts at A and B and returns along the em pty track in a direction toward the h o istin g sh a ft to a point F. H ere a hole in the concrete en try wall, practically adjoining the sh a ft, connects w ith a cross­

cut which is on a secondary return to the fa n sh a ft.

In p assin g through th is hole and crosscut in its return to the fan, th is air carries w ith it any coal dust th at m ay be raised in the dum ping operation. A large part o f th is dust settles in the return betw een F and D. A t the latter point a regulator is located.

T his arrangem ent does not rob the m ine o f needed air as the fan is now producing only about 118,000 cu.ft. at a 2-in. w ater g age as ag a in st its rated capacity o f 300,000 cu.ft. at a 3-in. w ater gage. W ith the fa n w orking at capacity it would be possible to attain

Fig. 1— Layout of the Shaft Bottom at the Harmar Mine, Harmarville, Pa.

T h is is a g ra v ity b o tto m a n d th e tra c k a rra n g e m e n t, a cc o rd in g ly , is v e ry sim ple. A sm a ll q u a n tity of in ta k e a ir tra v e ls p a s t th e s h a f t foot, th u s c a rry in g a w a y th e d u s t ra is e d b y th e r o ta r y dum p.