] o a l A g e
A M cG raw -H ill Pu b l i c a t io n — Es t a b l i s h e d 1911
DEVOTED TO T H E O PER A TIN G , TECH N IC A L AND BUSIN ESS PROBLEMS OF T H E COAL M ININ G INDUSTRY
N e w Y o r k , J u l y , Î 9 2 Q
Vo l u m e 34___Nu m b e r 7
Hostages to Ignorance
W A S T E I N D I S T R I B U T I O N is still a m a jo r challenge to industry and to the nation. T h e engineering control which has m ade such g re a t headway against preventable wastes in production and manu
facturing processes has had little opportunity to function in the field of distribution. I h e basis of engineering, irrespective of the direc
tion its specific application may take, is factual. But the developed factual basis for an intelligent engineering study of distribu
tion in many industries is wholly inadequate
— and waste continues unchecked.
B I T U M I N O U S C O A L is representative of those industries in which the field of distribu
tion is shrouded in a fog of ignorance. I t is one of th a t group of commodities which, to quote from the address of Secretary of Commerce L a m o n t before the M e rc h a n ts’
Association of N e w Y ork last month, we practically lose sight of statistically once it is produced.” Published basic data on dis
tribution and consumption are either so old or so fra g m en ta ry th a t dangerous and costly guesswork too often must substitute for facts.
SO L O N G as this situation exists wasted efforts which increase sales expenses and eat into profits hard ly can be avoided. H eavy sales artillery will be wasted on lone consum
ing outposts and pop-gun campaigns di
rected against im portant m arkets. T ra v elin g salesmen will tre a d upon one a n o th e r’s heels begging the business of a plant which m ight better be left to a local retail distributor.
And, directly or indirectly, the public will foot the bill for all this lost motion and mis
guided energy.
I N T H E A B S E N C E <?f a common public reservoir of information a few of the largest companies can and will make p rivate surveys.
But the results of these studies will be jeal
ously guarded, and each independent survey means a duplication of effort and expense.
W h a t is needed is a b ro a d study th a t will take in all coal distribution and will m ake its facts available equally to all who care to examine and be guided by them.
S U C H A S U R V E Y could be m ade m ost suc
cessfully and completely by a governm ent agency working in close co-operation with the railroads. H e r e is a real opportunity to do a real job th a t would benefit both the coal industry and the vast coal-consuming indus
trial public. U n til this job is undertaken, workers in the field of coal distribution must remain hostages to ignorance, and the buyer must continue to b e a r the toll of pre
ventable waste.
QHANGE
in
M ining Layouts Is Now
]V ie c h a n iz a tio n ’s G rea test Need
By Alphonse F. Brosky
Associate Editor. Coal Age
H
A V E A m eric an m in in g m en accepted fro m th e ir a n te c e dents in th e ro o m -a n d -p illa r system a h eritag e w h ich is p assin g the stage of u se fu ln e ss? F ro m the standpoint o f m e ch a n iza tio n th is seemingly is so, fo r clash es a re co m mon in attem pts to d ovetail th e new with the old. T h e reaso n is n o t th a t the room -and-pillar system does not possess m erit— it does— b u t ra th e r that the principles u p o n w h ich it is based, the conditions w h ich it c re ate s and the dem ands w hich it e x a c ts are in general out of h a rm o n y w ith th e fundamentals o f u tm o st m a ch in e u tilization and th e ideals o f w o rk e rs ’ e f ficiency, sa fe ty an d g e n e ra l w ell
being.
Befitting th e ac h ie v em e n ts of th e ir fathers, the re su lts accom plished by mining men o f th e p re se n t g en e ratio n m applying m achines to ro o m -a n d - pillar layouts are cre d itab le. B u t, as gains verge closer to th e lim it o f p o s
sibilities of b e tte rm e n t in th is ap p li
cation, g reater im p ro v e m en t m u st be- come increasingly difficult. A s th e mechanical p e rfo rm a n c e o f th e m a chines is fu rth e r im p ro v e d th e ta sk capacity will be f u r th e r increased, with the resu lt th a t, d u e to th e lim bed task available, th e ra tio betw een me time of w o rk acco m p lish m en t an d
“}e time of idleness a n d m o v in g com - ,;n«l will decline r a th e r th a n rise.
T h e only o u tle t sufficiently e x p an siv e to em brace the g ro w in g needs o f m echan izatio n ap p e a rs to be a change to layouts g iv in g few er and b ig g e r w o rk in g places. T h is change w ill com e as th e in d u stry loses its lin g e rin g atta c h m e n t fo r th e old and gains fa ith in th e new m in in g sy s
tem s. I t will be fo rc ed by th e influ
ences of m o d ern tools, advanced k n ow ledge and developed directiv e capacity, an ab u n d an ce o f w hich the in d u stry alre ad y possesses.
C hanges need n o t n ecessarily be d ra stic a n d in ch a ra c te r m ay ran g e betw een th e ro o m -a n d -p illa r system an d panel-longw all m ining, co n d itio n s b eing th e g o v e rn in g fac to r. H o w ever. th e m o re th e n a tu re o f th e sys
tem d iffe rs fro m ro o m -a n d -p illa r m in in g and th e m o re it approaches panel-longw all m ining, th e m o re will it be in ag re em e n t w ith sound p r in ciples o f m ech an izatio n . I t is a lto g e th e r unlikely th a t tru e longw all m in in g will find a place in th is c o u n try . L ik e th e ro o m -a n d -p illa r layout, tr u e longw all d o es n o t adequatelv m eet m echanization dem ands.
T h is is m erely a sta te m e n t o f fact as to th e rela tio n o f m echanization p rin cip les w ith th e ch a racteristics of m in in g system s. I t does n o t m ean
th e a u th o r flatly p ro p o ses th a t every o p eratio n should be estab lish ed o n any one system . T o o m a n y fa c to rs, both econom ic an d physical, influence final ju d g m e n t to allow o f a n y d e cisive opinion. C o n d itio n s g o v ern in g th e m e th o d s o f w o rk in g th e N o . 6 seam in Illinois, likew ise th e d i f ficulty o f h an d lin g d ra w sla te ro o f in th e P itts b u r g h seam in P e n n sy lv a n ia , illu stra te th e n ecessity f o r a lib e ral view o f m achine ad a p ta tio n .
W
H E N longw all m e th o d s a r e bro ach ed in th e p rese n ce o f a d h e re n ts o f th e ro o m -a n d -p illa r school, th e la tte r alm ost in v a riab ly voice th e ir opinion by saying, “ I t c a n ’t be d o n e ; a t least n o t u n d e r o u r co n d itio n s.” V ag u e , indeed, is th e m ean in g o f "c o n d itio n s in th is r e jo in d e r. D oes th e rep ly r e f e r bro ad ly to co n d itio n s o b ta in in g in all th e coal fields o f th e c o u n try o r stric tly to co nditions in one seam o r one m in e :' H o w is it k n o w n th a t longw all w ill n o t w o rk ? Is th e opinion based on actual e x p e rie n c e ? W ith r a r e e x ceptions, it is n ot. S m ith h e a rs Jo n e s say longw all m e th o d s a re a lto g e th e r im p ra c tic a b le ; S m ith tells D o e ; D oe tells H an c o ck , a n d so th e opinion h a s sp re a d fro m m o u th to m outh.T h e tr u th is th a t longw all gives p ro m ise o f econom ical a p p lica tio n to
M'S,1929—
C O A L A G E 403
m a n y seam s in th is c o u n try . O p in io n to th e c o n tra ry should n o t be based o n th e re su lts o f sh o rt-liv e d a tte m p ts to ap p ly th e longw all system . It m a y ta k e m a n y y e a rs to ap p ly th e ro o m -a n d -p illa r sy stem su ccessfu lly to som e h ith e rto u n m in e d seam o f coal. A cc o rd in g ly o n ly ex p e rien c e is a f a ir basis fo r d e te rm in in g th e re l
ativ e m e rits o f longw all m ethods.
C lose ad h e ren ce to th e ro o m -a n d - p illar system u n d e r a v a rie ty o f con
d itio n s in th is c o u n try su g g e sts the p rev a len c e o f a f e a r o f th e ro o f in m o re e x ten d e d w o rk in g s. T h a t fe a r h a s been q u ick en ed by th e fre q u en c y an d re g u la rity o f ac cid en ts d u e to falls o f ro o f. S o long as th is fe a r re m a in s ro o f w ill co n tin u e th e m a s
te r o v e r m a n a n d d ic ta te to him w h a t sy stem s shall o r shall n o t be used.
I t sh o u ld n o t be fo rg o tte n th a t ro o f co n d itio n s th a t e x ist in th e ro o m -a n d - p illa r sy stem a re n o t th o se th a t w ill be en c o u n te re d in w id e r flung m ech
anized layouts. R o o f c o n d itio n s a re a lto g e th e r likely to be b e tte r in lo n g face layouts. L o n g w all m e th o d s will give th e w o rk e r co n sid erab ly b e tte r p ro tec tio n fro m ro o f falls an d o th e r d a n g e rs lu rk in g in p re s e n t m in e layouts.
T
H E claim is m ad e th a t m e ch an iz atio n b rin g s ab o u t g re a te r co n c e n tra tio n a n d yet in m a n y m e ch a
n ized layouts, m o st n o ta b ly w h e re co nveyors are used, only one o r tw o room places on an e n try a re w o rk e d a t a tim e. S u ch a rra n g e m e n ts do give g re a te r c o n c e n tra tio n o f m a chines a n d m en in each w o rk in g place b u t they do n o t p ro v id e a m uch g re a te r yield o f coal fro m th e e n try section. T h a t is n o t co n c e n tra tio n m th e tru e sense o f th e w o rd . C o n c e n tra tio n , being a rela tiv e te rm , is
best m e asu red by a co m p ariso n o f rates of p ro d u c tio n fro m a u n it o f developed te rr ito r y , th a t is, fro m a
w o rk in g section. If 200 tons of coal is ta k e n in tw o full shifts from s w o rk in g a re a which formerly pro
d u c e d 100 to n s w hen mining was co n d u c te d d u rin g only one shift and p e rh a p s a p a r t o f another, it cannot re a so n a b ly be said that concentration has been im p ro v ed 100 per cent. Con
c e n tra tio n in its relation to mining is n o t clea rly defined in the minds of all w h o a re plan n in g and developing m e ch a n iza tio n systems.
P e r h a p s no one factor has pre
v ailed m o re ag a in st enterprise in the d ev e lo p in g o f new mining systems th a n th e b elief th a t the pillar or frac
tu r e line m u s t be maintained on the c u s to m a ry an g le o f 45 deg., regard
less o f conditio n s. T h at disposition o f th e m in in g f ro n t is deemed advis
able in th e d riv in g of rooms even w h e re p illa rs a re not extracted. That in c lin a tio n is believed necessary re
g a rd le s s o f th e thickness of the seam, th e s tr u c tu re a n d hardness of the coal,
Longw all
Longwall la yo u t
_ _ _ _ _ _ _ _ _ _ _ _ _ _ Room- and-pillar. „ A - C om parison o f d is ta n c e s a ir tra vels Room- and- pillar- u _ _ _ _ _ _ _ _ _ _ _ _ _ _
lo n g w a ll B - Com parison o f e ffe ctiv e face fr o n ts Longw all-4
Room- and-pillar- -j
T h e s e C om pa rison s M e a n S o m e t h i n g
From layouts of the two systems under consideration, room-and-pillar vs. longwall, drawn to scale and each embracing a unit area, data were taken from which graphic comparisons were made. The area taken for each layout is roughly three acres, the tract measuring 250x500 ft. In each case the places were established broadside of the tract. The tract accommodates fourteen rooms, each 15 ft. wide on 35-ft. centers, in a concentrated room-and-pillar layout, or two faces, each 250 ft. long, in the long
wall layout. Interpretation of the graphic
comparisons follows: ,
A —Before rejoining the main current ot the split the air in the ventilation of the room-and-pillar layout by the shortest pos
sible route travels over three times the dis
tance covered by the air sweeping the longwall layout in an equivalent area. In the room-and-pillar layout only a small proportion of the air in the split reaches the faces; in the longwall layout all of the air is effective.
B—Granting that a cut can be taken from the full width of every retreating pillar and every advancing room in the room-and-pillar layout, and that a cut can be taken from the faces in the longwall layout each day, the combined length ot effective faces in the room-and-pillar day- out is one-half the combined length of faces
in the longwall layout. ,
C—The area of standing rooms and crosscuts in the room-and-pillar layout is three times as great as the open area along the faces in the longwall layout. In this calculation the writer allowed a roof span of 20 ft. to project over the longwall faces.
These are but a few of many compari
sons which can be made in favor of long
wall. Are not these three advantages alone sufficient to offset the higher cost of tim
bering in longwall layouts?
404
C - C o m parison o f o p en a r e a s * * * *
C O A L A G E — V ol.34 ,^°-
the nature and thickness o f th e cover, the character of th e ro o f, th e n a tu re of the bottom, th e w id th o f th e rooms and pillars a n d th e le n g th o f the rooms.
In rare instances th e p illa r line has been established a t an an g le o f 30 deg.
with the room e n try , a n d re su lts achieved are com parable w ith th o se that would be obtained w e re th e m o re acute angle used. T h e 45-deg. line was chosen years ago an d is accepted today for reasons th a t a re o p en to question. I t pro v id es ste p s o f coal .at the ends o f th e p illars, it is tru e , but does the th r o a t fo rm e d b y th e step between tw o a d ja c e n t p illa rs actually protect th e m e n w o rk in g in it any more than a s tra ig h t f ro n t a d e
quately tim bered?
The 45-deg. line ca u ses th e ro o f load to be im posed d ia g o n ally ac ro ss the face and b u tt cleats o f th e coal, but is that d esira b le ? C e rta in ly it causes roof loads to ac cu m u late and to ride over p illar edges, th e re b y in fluencing the o cc u rre n ce o f fails a t the face, a t th e en d o f th e p illa r o r back from these places a n d f r e quently on the e n try fro m w h ich the rooms are tu rn ed . T h a t, in a larg e degree, accounts fo r m a n y o f the fatalities from ro o f falls, E sta b lish ing the 45-deg. line is like b o rro w in g from P ete r to p ay P a u l ; th e benefits derivable from it a p p e a r f o r th e m o st part mythical.
Staunch advocates o f th e ro o m - and-pillar system d e fe n d it chiefly o n the ground th a t it d em an d s less timbering th a n o th e r sy stem s. T h e defense is w eak en ed by th e fact that tim bering p rac tice in th e room - and-pillar system h as n o t in g e n e ra l been sufficient to g u a ra n te e ad e q u ate protection fro m ro o f falls. A s mechanization pro ceed s th e ten d en c y ]s to use less a n d less tim b e rin g in room-and-pillar w o rk because tim b ers interfere w ith the m a n e u v e rin g an d moving of the eq u ip m en t. D a n g e rs rom roof falls c o n seq u e n tly te n d to increase.
, Is this a f a ir basis f o r c o n d e m n ing longwall m e th o d s? T h e sy stem
™es require close tim b e rin g f o r its success; it does com pel m e n a n d m a chines to w o rk close to th e coal.
. l’t in so d oing it elim in ates w ide, inadequately su p p o rte d , d ead -en d Paces and in su res s a fe ty . U n til it
■^ established a f a ir basis f o r com parison, the in d u stry ca n n o t sit back complacently an d pro claim its a rriv a l a ,„ safest a n d m o st econom ical S>stem of m ining coal.
■j-hould not A m e ric a n m in in g m en ect on experiences a n d p rac tice s Iuh, 1929
— C O A L A G E
Longwall Characteristics Meet Mechanization Needs
o f fo re ig n co u n tries in reg a rd to lo n g wall m in in g ? T h e y can learn m uch fro m th e ir fellow m ining engineers across the sea, ju s t as E u ro p e an s can p ro fit in large d egree by considering ce rtain A m erican practices.
T h e holding fo rth o f E u ro p e an m in in g p ractices as an a rg u m e n t will d ra w p ro te st as it alw ays has. A g ain it will be said co nditions th e re are vastly d iffe ren t fro m those here. T h e m ain difference really is th a t geologic conditions in E u ro p e are m o re diffi
cult. notably in th a t th e seam s m ined a re th in n e r and lie a t g re a te r depths.
T h e sam e arg u m e n ts advanced to ju s tify ro o m -an d -p illar m ining here are applicable there. In E n g lan d , fo r instance, m in in g rre n know bo*h sys
tem s, as th e y use both, b u f w herever possible th e y give p referen c e to lo n g wall. T h e ir su p p o rtin g arg u m e n ts d eserv e close study.
M in in g m eth o d s on both sides of th e A tla n tic a re likely to u n d erg o a change as m o re m ach in ery is in tro duced u n d e rg ro u n d . T h e change will be w orked fro m tw o en d s to w a rd th e m id d le ; th a t is, th e re w ill be d riftin g aw ay fro m tru e longw all in E u ro p e a n d fro m ro o m -a n d -p illa r in th e U n ite d S ta te s in a convergence to w ard panel longw all. M achine a d a p ta tio n w ill com pel th ese changes.
I f ro o m -a n d -p illa r m in in g it m u st be, w hy n o t sim ultaneously d riv e up f o u r, six, eight o r as m a n y room s as desired on a fro n t p arallel w ith th e e n try and in th e sam e m a n n e r b rin g back th e com p lem en tary pillars ? T h a t a rra n g e m e n t w ill w ork sa tis
fac to rily u n d e r a fairly w ide v arie ty o f ro o f c o n d itio n s a f te r refined details a re d eterm in e d an d the w o rk e rs le arn th e ir jo b s by e x p e ri
ence. A f te r th e system h a s been trie d a n d fo u n d su ccessfu l, p ro g re ss will d ic tate a g ra d u a l in crease in th e w id th o f p illars, in w hich case th e room s w ill no lo n g e r be ro o m s b u t en tries, a n d l o ! th e re w ill be evolved ex p e rien c e an d p ractice in panel longw all m in in g o r som e m odification th e re o f.
O n e larg e co m pany has red e sig n ed th e layout of one o f its m ines to ta k e ad v a n ta g e o f th e su b sta n tia lly g re a te r co n c en tra tio n w h ich th is schem e gives. T h e p a rtic u la r m in e in q u es
tion is in one o f th e S o u th e rn m o u n tain reg io n s u n d e r e x tre m e ly heavy cover. T h e im m ed iate ro o f is fair. A s o rig in a lly w o rk e d ro o m s w ere d riv en long, n a rro w a n d in ac
co rd a n ce w ith th e 45-deg. f ra c tu r e line th e o ry . M uch tro u b le w as e x p erienced in g e ttin g coal b y th is system o w in g to th e c o n c e n tra tio n on th e p illa rs o f p re s s u re s re su ltin g fro m th e m ethod o f w o rk in g . T h e re su lta n t p re ssu re w as sufficient to cause occasional d im in u tiv e b u m p s o r o u tb u rsts o f coal fro m th e faces.
In th e red e sig n o f th e lay o u t th e room s w ere sh o rten e d to a len g th o f only 250 ft. N o t one ro o m is driv en " u n til a f te r th e room e n try is fu lly developed. T h e n all p ro je cte d ro o m s on th a t e n try a re sta rte d sim u lta n eo u sly an d d riv e n up on an even f ro n t to th e ir lim it. O n th e re tre a t all ro o m p illars on th a t e n try a r e a ttac k ed sim u lta n eo u sly an d b ro u g h t back on an even fro n t.
(Turn to page 412)
405
HORDEN
One of
England's Crack
Collieries
H
O R D E N C O L L I E R Y , C astle E d e n , C o u n ty D u rh a m , E n g lan d , is ow ned by th e H o rd e n C ollieries, L td . T o v isit it is a real p le asu re, b ecau se a m in in g m a n a t on ce senses th a t he is seeing th e best th a t b ra in s p lu s m oney can evolve. H e w ill im m ed ia te ly be im p re ssed w ith th e fine layout, th e su b sta n tia l c h a ra c te r an d a rc h ite c tu ra l effect o f th e s u rfa c e p la n t a n d w ith th e a b ility o f th e official p erso n n e l.
I t is p a rtic u la rly in te re s tin g to th e A m e ric a n m in in g m a n , fo r o f th e m ines I h av e seen a b ro a d it is one o f th e few th a t lends itse lf rea d ily to a c o m p ariso n w ith A m e ric a n m ines.
H e r e is a m in e open ed u n d e r th e p r e v ailin g E u ro p e a n m e th o d s o f m u ltip le s h if ts , u s in g sm all c a rs h o isted on d o u b le-d eck ed cages. H a d it been o pened in A m eric a it w ould hav e em ployed sin g le -sh ift h o istin g w ith larg e c a rs h o isted o n cages, o r p e rh a p s skips.
406
O n e finds ro o m -a n d -p illa r an d longw all w o rk in g s both in o p era tio n , o n e ,o f th e best w et-w a sh in g system s in th e w o rld bein g replaced w ith a ir tables, to g e th e r w ith coke ovens and d istilla tio n p la n t, all o f w h ich fe a tu re s ju s t now a re th e su b je c t o f m uch d is
cussion a m o n g th e m in in g fra te rn ity in A m erica.
T h e colliery is w o rk in g th re e seam s o f coal, th e M a in coal seam a t a d epth o f 858 ft., th e L o w M a in a t 1,080 ft., a n d th e H u tto n seam a t 1,209 ft.
T h e se seam s d ip a p p ro x im a te ly 3 deg.
to th e east a n d e x te n d f o r m iles o u t u n d e r th e N o rth S ea, a n d th e ir r e spective th ic k n esses a re 3 to 4 ft. 6 in., 3 to 3 ft. 10 in. a n d 4 to 5 ft. 6 in.
T h e colliery is opened by m eans o f th re e c irc u la r sh a fts , one o f w hich h o ists 2,800 to n s, th e o th e r 2 .000 to n s a n d th e th ird o r u p c a st s h a ft 1,200 to n s in tw o s h ifts , o r n in e tee n h o u rs.
T w o o f th e s h a fts a re 2 0 ft. in d ia m e te r an d se rv e as d o w n casts. T h e
E a s t S h a ft, w hich is the upcast, is 17 ft. in d ia m eter.
T h is co lliery hoists 6,000 tons per day, o r a n a v e rag e of 1,500,000 o >
p e r y ea r. T h e to n n a g e underlying j 5,373 ac re s in th e are a as origins ^ defined w as 110,000,000, indicating p la n t life o f 73 years. Due to ce ta in ch a n g es o f boundaries t e m a in in g life is figured at 60 y© - T h is b rin g s o u t th e first inter« | th o u g h t f o r th e A m erican n1"!' m an , nam ely , th a t European 1111 . a r e d esig n ed f o r a life approxima 2 ^ to 3 tim e s a s long as Amen
m ines. , htv
' A t H o rd e n C olliery this pro!»», can be ju stifie d , fo r the nunc located n e a r th e sh o re of the 0 S ea. I t is n ow w o rk in g under ^ se a a t a d istan c e o f tw o m th e sh o re line, a n d a fte r *Pr0C a n o th e r m ile th e royalty pa>me.
cease, a n d it w ill be possible to m o u t p ro b ab ly a n add itio n al two
C O A L A G E
— V o l 3 0 c]Headframe, Harden Colliery
By J. H . Pierce
Associate, Stuart, James & Cooke, Inc., New York dh
of coal ior which n o th in g will be paid.
In general, how ever, I believe th a t European mines a re d esig n ed f o r too long a life.
The determ ination o f th e econom ic life of a property m u s t c o n sid er so many factors, financial, te ch n ic al a n d practical, that one h esita tes to ta lk in generalities w ith o u t r is k in g criticism from those who h av e specific p r o p erties in mind. H o w ev er, it m ay be taken as axiom atic th a t so f a r as a n nual earnings are co n c ern ed th e economic life of a m ine in c re ase s w ith the increased cost o f p la n t a n d eq u ip ment. If we com pare th e p re se n t value of the series o f an n u a l n e t e a r n ings from p ro p ertie s h a v in g v a rio u s capitalizations p e r to n o f an n u a l o u t
put we get quite a clear p ic tu re o f th e most economic life.
On the above basis, a s su m in g a profit per ton th e sam e in each case, and that P e n n sy lv a n ia a n th ra c ite mines have a capital e x p e n d itu re o f
$8 per ton o f an n u a l p ro d u ctio n , Great Britain $5 p e r to n a n d A m e ri
can bitum inous m ines a t $ 2 .5 0 p er ton, it would in d icate th a t th e m ines in Great B rita in sh o u ld h av e a life midway betw een o u r a n th ra c ite and bituminous p ro p ertie s, if A m e ric a n practice is correct.
If in addition to th e financial and technical co n sid eratio n s w e consider the practical d isa d v a n ta g e s o f long- lived properties, such as excessive maintenance, increased h a u la g e and ventilation charges, th e w e a rin g o u t of initial plant e q u ip m en t o r its ob solescence due to m o re m o d e rn p ra c tice, we are forced to th e conclusion
Uses Both Longwall and Room O perations—
Longwall Preferred W here Coal Is Less T h an F our Feet T hick—Mines in E ngland Planned to Last Two or Three Times as L ong as O urs
th a t, b a rrin g u n u su al circum stances, p la n t life probably should n o t e x ceed 35 years, o r as a m ax im u m 40 years.
I t is in te restin g to note h e re th a t o f th e m any m ines figured by this com pany’s engineers, w ith a w ide ra n g e o f inv estm en t p e r to n o f annual p ro d u ctio n , none h as exceeded th e figures given. I t w as f u rth e r o f in te re s t to m e to note th a t m an y o f th e long-lived m ines in G re a t B rita in are now engaged in sin k in g new s h a fts to overcom e th e difficulties b ro u g h t about by excessive coal reserves.
T o re tu rn to a description o f H o rd e n C olliery, F ig . 2 w ill illus
tra te th e m ain roadw ays, h av in g tw o in ta k es a n d tw o re tu rn s. T h e m ain ro a d in th e H u tto n seam h as 30-m .
b rick w alls on each side, an d th e to p is su p p o rted by 8 x 6-in. steel g ird e rs on 36-in. centers. T h e clearan ce be
tw een w alls is 12 ft. 6 in. an d fro m rails to g ird e rs 7 ft. T h e tra v e lin g w ay w alls a re 9 ft. a p a rt w ith 6 ft.
6 in. v ertical clearance. T h e u n usually p e rm a n e n t c h a ra c te r o f th e se openings an d th e ir am ple size in d icate th a t th e m an ag e m en t o f th is p ro p e rty is fa rsig h te d in fo re sta llin g th e h ig h m a in te n an c e an d v en tila tio n costs th a t w o u ld o th e rw ise hav e to be m et d u r ing th e la te r y e a rs o f th e life o f th e m ine.
T h e m ain h au lag e system is an e n d less ro p e w ith a speed o f tw o m iles p er h o u r an d th e c a rs a re placed on th e rope in sets o f five. In asm u c h as th e en g in e ro o m is close to th e
Horden Colliery, County Durham,
England
hdy, 1929
— C O A L A G E
407
s h a ft b o tto m , elec tric-m o to r d riv e is p e rm itte d on th is ro p e system , b u t the a u x ilia ry m a in a n d th e tail haulages a re d riv e n by co m p ressed a ir because o f th e g assy co n d itio n o f th e m ine.
A s th e face is m o re th a n tw o m iles f ro m th e s h a ft b o tto m , a m a in la n d - ta il h au lag e h as been installed in the tra v e lin g w ay, a n d th e m en a re h auled to w o rk in special c a rs hold in g tw elve m en each. T h e re a re tw e n ty o f th ese c a rs eq u ip p ed w ith s a fe ty ch ain s and brak es. T h e tr ip r id e r a t all tim es can signal th e e n g in ee r by m e an s o f a c o p p e r f o rk w hich is placed acro ss tw o b a re ov erh ead w ires. T h is m a n h a n d lin g sy stem is a good inv estm en t as it sav es a con sid erab le p o rtio n o f each w o rk m a n ’s s h ift, w hich he w ould o th e rw ise co n su m e in w alking.
A s b e fo re m en tio n ed , both long- w all a n d ro o m -a n d -p illa r a re in o p e ra tio n . I n th e la tte r p illa rs a re cu t
132 ft. sq u a re a n d th e se p illa rs are th e n rem o v ed b y slabs 12 to 15 ft.
w ide on th re e sides u n til th e p illar is e x tra c te d . A rec o v ery o f 95 p er cen t is claim ed f o r th is m ethod of o p era tio n .
I
N th e lon g w all w o rk in g s th e g a te w ay s a re 87 ft. w ide, a n d lif ts a re ta k e n o ff on each sid e o f th e g atew ay.Sufficient ro ck is b ru sh e d to m ake p ack w alls 9 ft. w id e on each side o f th e ro a d g a te a n d 12 ft. w id e o n th e m o th e r g ate. A rec o v ery o f 97 p e r c e n t is claim ed f o r th e longw all w o rk in g s.
W h e re v e r th e coal thickens to n e a rly 4 ft. it h a s been fo u n d th a t ro o m -a n d -p illa r y ie ld s ch e a p e r coal th a n fongw all, d u e to th e ex p e n siv e tim b e rin g a n d m a in te n a n c e o f ro a d w ay s in th e la tte r sy stem . A t th is co llie ry th e o u tp u t p e r coal g e tte r av e rag es 5 to n s p e r day , a n d 1.51 to n s p e r to ta l w o rk e r em ployed, w hich rec o rd is 50 p e r cen t b e tte r th a n th e
Caging the
av e rag e of all o f G re a t B rita in . T h e a v e rag e w ages o f all w o rk e rs is $2.28 p e r day a g a in st a n a v e rag e th ro u g h o u t G re a t B rita in o f $2.32 p e r day.
A ta b le is a p p e n d ed g iv in g g e n eral in fo rm a tio n as to p ro d u c tio n sta tistic s an d co st fo r v a rio u s d istric ts in G re a t B r ita ir an d in to ta l fo r th e th ird q u a r te r o f 1928, an d it w ill be noted th a t th e n et loss fo r th is perio d w as 34c. p e r ton.
W ith th e low w age scale now in effect, w ith la b o r e x tre m e ly d is
satisfied, w ith a loss p e r tu n a m o u n t
in g to 7 p e r cen t o n th e ir in v ested capital, w ith deep a n d ex p e n siv e m ines w hich are costly to la y idle d u rin g p erio d s o f dep ressio n , th e coal o p e ra to rs o f G re a t B rita in a re indeed in f a r g re a te r d istre ss th a n th e A m e ri
can m in e o p e ra to r, w h o is en title d to w h a te v e r little c o m fo rt m ay be d e riv e d fro m h a v in g a com panion in m isery.
I t is in te re s tin g to n o te th a t in th e face o f these a d v e rse co n d itio n s th e H o rd e n C ollieries, L td ., m ad e a p ro fit in 1928, a n d p aid a d iv id e n d o f 2 \ p e r cent.
Mine Cars
F ig . 1 indicates how the coal from th e N o r th a n d S o u th shafts »re as
sem bled to th e tippler house. The coal fro m th e th ird shaft comes in fro m th e e a st side, and the full cars fro m all th re e s h a fts run by gravity th r o u g h th e w eig h in g machines to the r o ta ry d u m p s, thence by gravity to ch ain h au ls w hich raise them su - cien tly to co n tin u e by gravity to t e h y d ra u lic d ec k in g gear at the sha t.
E ig h t c a rs, o r fo u r cars per deck, a re h o isted a t each trip, and the ) d ra u lic d ec k in g device, which is in re a lity tw o a u x ilia ry cages on eac side o f th e s h a f t so arranged as to . ' raise d a n d low ered by a vertica raffl.
se rv e s to p e rm it th e eight empty ca*- sim u lta n eo u sly to discharge the eig loaded ca rs.
T h e loaded c a rs pass to six rotor) d u m p s w h ich d istrib u te the coa >•
th e sh a k in g screens, and all coay !' e‘
l f - i n . size p asses to th e picking i->
w hile th e u n d e rsiz e , w hich consti u ab o u t 34 pei" cen t o f the input, P^ss to tw o S im o n -C arv e s washer box each o f 4 0 to n s hourly capacity.
A f te r b ein g cru sh e d , th e coal is store
Fig. 1— Tipple at Horden Showing Car Handii.
and Manual Cleaning Equipment
■South p it hoist house
408 C O A L A G E
— V o lM $ eJin a 2,000-ton concrete h o p p e r a n d is then sent to th e coking p lan t.
The coking plan t co n sists of 120 Koppers regenerative ovens w h ich a re fed by an electrically d riv e n top- charging machine. T h e g ases fro m these ovens pass to th e b y p ro d u c t
m o re po w er th a n these g en e rato rs d eliver it pays th e cen tral statio n 11 m ills fo r th e first 250,000 kw .-hr.
u se d in a th ree -m o n th s period, 5£
m ills fo r th e n e x t 1,250,000 kw .hr.
an d 4.5 m ills fo r an y additional. I f th e colliery com pany m akes an y ex -
equipm ent, because I w ish to d escribe a final fe a tu re o f th is p la n t o f g re a t in te re st. H o w e v e r, th e accom pany
ing illu stra tio n s w ill in d ic ate th e splendid ty p e o f c o n stru c tio n . O n e illu stratio n show s th e su rfa c e la n d in g
T i
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— i _ < -
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1 1
f
j-:-...-264-...H
r/ain_ 1
¡¡-rrvahna wa
F n (jmeplane-UnisJssX- --- --- -
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L
, G o a f
Fig. 2 -B ig Pillars Make for Safety and High Recovery. Quite a Commentary on American Small-Ptllar Legislation
plant N o d escrip tio n w ill be given of this plant d u e to space lim itatio n , but the p ro d u cts d e riv e d fro m th e coal treated a re se t f o r th in th e ac
companying ta b le :
Output Per Ton From Horden Colliery Ovens
Gm... I1,000 cu .it. , „ Coke... 1,624 c u .tt.@ $ 4 .50 p er ton $3.26 Ammonium
sulphate.. ,. 32 cu.ffc. 52.00 per ton .74 J " ... 105 c u .it. 7.75 p er ton .36 Ben*ol... 2.8 gal. .25 p er gal. .70 Value of byproducts exclusive of gas... $5.06
About 40 p e r ce n t o f th e g a s p r o duced is used to h e a t th e coke ovens, the surplus being u tilize d in th e m a n ner now to be described.
The pow er schem e a t th is colliery is unique. T h e e x h a u s t steam fro m Horden and S h o tto n collieries is used to drive tw o 1,000-kw . g e n e ra to rs, snd the su rp lu s g a s f ro m th e ovens is used to d riv e tw o 3,000-kw . g en e r- ators, all o f w hich a r e con n ected to the common m a in s o f th e N ew castle Electric S upply C o., w h ich ow ns {he generators m e n tio n e d , a n d it ln turn sells back to th e colliery co m p l y the p o w er a t 3 \ m ills p e r kilowatt-hour. I f th e colliery uses
cess po w er th e ce n tral statio n pays f o r it a t th e r a te o f 0.6 null p e r k ilo w a tt-h o u r. T h e n e t re su ltin g p o w er cost to th e coal com pany is 6 m ills p e r k ilo w a tt-h o u r.
S pace w ill n o t p e rm it a descrip tio n o f th e fine h o istin g a n d g en e ratin g equipm ent, th e m o d e rn w ash h o u se an d o th e r a u x ilia ry b u ild in g s and
a rra n g e m e n t a t one o f th e sh a fts . A n o th e r the ty p e o f h e a d -h o u se co n stru ctio n an d th e th ir d show s th e coke ovens, screen-house, w a sh e ry , sto ra g e pocket and b y p ro d u c t p lant.
A lth o u g h th e colliery h as a p e r
fectly sa tisfa c to ry w et w a sh in g p lan t, a new a ir clean in g p la n t is being designed by th e B irtle y I ro n W o rk s , w hich uses th e O ’T o o le p a te n ts , b u t w ith d istin ct ch an g es in table design.
I
T S reaso n fo r th is is th e d e s ire to give its coke ovens coal o f low m o istu re c o n ten t. I n o rd e r to u tilize all th e fine coal a n d a t th e sam e tim e elim in ate th e d u s t co nnected w ith a ir cleaning, th e fine coal fro m th e tables is collected f o r th e firin g o f B abcock& W ilc o x p o w d e re d -fu e l boilers.
I p re d ic t th a t a ir tab les w ill m ake th e ir g re a te s t p ro g re ss alo n g th e line b ein g follow ed a t th is colliery. T h e u tiliza tio n o f th e d u s t u n d e r boilers is a com m endable fe a tu re . I n th is re g a rd a n d in th e u tiliz a tio n o f th e e x h a u s t steam th e E n g lish m ine m a n a g e r
is th in k in g a h e a d o f th e A m eric an m in e m a n a g e r. I t h a s been m y ob serv a tio n th a t p o w e r co sts th ro u g h o u t G re a t B rita in ’s m ines a re co n sid e r
ably low er th a n w ould b e o b ta in ed in A m eric a u n d e r sim ila r conditio n s.
I d e sire to e x p re ss th a n k s to J . P . H a ll, ch ief m in in g a g e n t; C. A . P a t- teson, colliery m a n a g e r, a n d A . B . C h a rlesw o rth , ch ief m echanical engi
n eer, fo r th e ir c o u rte sy d u r in g m y v isit a n d th e ir aid in en a b lin g m e to o b ta in th e fo re g o in g d a ta .
O u tp u t, C osts o f P ro d u ctio n , P roceeds and P r o fits o f t h e B r i t i s h Coal M in in g I n d u s tr y f o r the Q u a rte r E n d e d S e p t. 30, 1 9 .8 .
-M ining D istric te -
10
C ost of Production per T on of P ro d u ct , 2 3 4 5 6 7 8 9
Disposed Commercially __________ _______ —________ _________ •
" «■> K t i «I 11 96 $2 58 $2.41 $2.39 $2.61 $3.08 $2.63 $2.37
... H l l * ¿ 1 7 0 « 0!50 0.2 9 0 .32 0.4 3 0.45 0.4 2 0.3 9
S t o r e s and tim ber... 0 ‘ 56 0.71 0^74 0 .6 6 0 .6» 0 .6 2 0.6 4 8.9 7 8.6 7 0.69
fitnnrposts ... 1 • m n i l ? 0 02 0 02 0 .0 2 0 .0 2 0 .9 2 0.0 2 U.Ux w.UZ
? i “ e re fw e lfa re F u n d c o n tn b u t.o n ... . t . 0 2 0.0 2 0.0 2 O.U? ^ ^ ^ 8.14 0 J 3 0.13 ... I T 2 6 I T « *3^25 $3793 $3.51 $3.44 $3.79 $4.66 $3.87 $3.60
T o ta lc o s ts ...V ... e o 2 ••• 0-®^ ® 0 .0 2 §.02 n«w W t oroceeds of miners coal... D eductproceed. _ _ _ _ _ _ _ ^--- --- ---^ ^ ^
Proceeds . 2 96 2 71 2.98 3.49 3.16 3.22 3.61 3.97 3 .5 0 3.25
CoMinercial disposals... ■ __ ;---
Balance: jo 28 $0.33 $0.27 $0.41 $0.33 $0.20 $0.17 $0.66 $0.35 $0.33
D ebit*... ... * • • • C red its... .. . . . • ■ • • • ■ - • • • ■ ■ • ‘ , 4 s th and M onm outh (A ugust, Septem ber a nd Oot-
e g Average for G reat B rita in .
409
§1^1929—
C O A L A G E
BAD TOP and PARTING
No Bar To Use of
E. R. Ogle, Vice-President;
IVillington O'Connor, General Superintendent, and Dale Ferris, Mine Foreman.
Discussing a Problem
Loading Machines
B y J. H . Edwards
Associate Editor, Coal Age
I
N sp ite o f u n fa v o ra b le m in in g conditions, co n sistin g o f to p w hich m u st be su p p o rte d above th e m ach in es a n d a p a rtin g several inches thick, o v er one m illion to n s h a s been loaded m echanically a t N o.28 m in e o f th e O g le Coal Co., n ea r C ass, S u lliv a n C o u n ty , In d . T h is w as accom plished d esp ite a sluggish m a rk e t a n d u n se ttle d la b o r co n d i
tio n s, b o th o f w h ich h av e prev ailed m u c h o f th e tim e since th e a u tu m n o f 1924, w h en th e first tw o loading m achines w ere in stalled .
T h e m in e is now com pletely m ech an ize d an d is sh ip p in g a n av e ra g e o f 1,000 to n s p e r day. B ecause o f th e prese n ce o f a p a rtin g c o n sistin g o f 4 to 5 in. o f fa irly h a rd m a teria l located ab o u t 2 ft. fro m th e b o tto m , c a re fu l pic k in g is n ec essary on th e tipple, b u t th is e x t r a p r e p a ra tio n w ith m e ch a n ical lo a d in g is in n o w ay h a m p e re d by eq u ip m en t lim ita tio n s, f o r th e rea so n th a t th e tip p le w as b u ilt fo r 4,800 to n s p e r d ay w ith h a n d loading.
A p ic k in g crew o f seven m e n r e m ove re fu s e to ta lin g 8 1/ 2 p e r ce n t o f th e to n n a g e h o isted . I t is estim a ted th a t in m ach in e-lo ad ed to n n a g e th e tip p le w ill su c ce ssfu lly h an d le 4 0 p er ce n t o f its r a tin g f o r h an d -lo a d ed coal.
P e rh a p s d e sc rib in g th e m in e ro o f a s “ u n c e rta in ” is a m isn o m er. I t m ig h t p ro p e rly be sa id th a t th e 5 to 41 0
10 ft. o f sa n d y shale o v erly in g th e coal is “ c e rta in ” to com e d o w n in a sh o rt tim e if n o t su p p o rte d . P r a c tically all o f th e m ain e n try is p r o tected by tim b e r se ts o r b y com bina
tion tim b e r a n d steel sets, a n d a t room faces th e m en an d m achines a re p ro tec ted b y tw o o r th re e 6-in.
steel beam s o f " H ” section 20 ft.
long.
T h e coal, w h ich is th e N o . 4, has a n a v e ra g e h e ig h t o f 66 in. I n th e m ining, J o y ty p e 5 B U lo a d in g m a chines a r e used exclusively. R o o m s a re d riv en 24 ft. w ide a n d 270 ft.
deep on 3 6 -ft. ce n te rs. B a rrie rs 20 ft.
th ic k a re le ft b etw een room fac es a n d th e 1 ,600-ft. pan els a re sealed w ith th e p illars le ft sta n d in g .
F
O R th e m o s t p a r t o n ly tw o H -b e a m s a r e u se d p e r face. I n o rd in a ry o r f a ir to p th e r e a r b eam is m oved to w ith in 3 ft. o f th e face a f te r th e lo a d in g o f a c u t is co m pleted . F o u r w ood p o sts a r e set u n d e r th e beam , w h ich is n o t m oved d u r in g th e c u ttin g , sh o o tin g o r loading. I n th e w o rs t places th e fo rw a rd beam is placed as close a s w ith in
18 in. o f th e clean ed -u p face.
B e g in n in g rec en tly th e 9 -ft. c u tte r b ars o f th e sh o rtw a ll m a ch in e s a re b ein g sh o rte n e d to 7 y 2 f t. W ith th is la tte r c u tte r b a r th e beam s a r e a b o u t 7 ft. a p a r t w hen tw o a r e used. F o r
each c u t o n e beam has to be rnove*J;
e x c e p t w h en th re e beams are used p e r face, in w hich case two are m o v ed p e r cut.
M a k in g u p th e cost o f this steel- beam p ro te c tio n , labor is the greatest item . T h e m e th o d requires two tim- b erm e n p e r lo a d in g machine instea o f one. A lth o u g h th e beams cost ap
p ro x im a te ly $15 each, the fixed c h a rg e s h a v e n o t been large because c o m p a ra tiv e ly few have been lost by rea so n o f h eavy falls. N o accurate check o f th e n u m b e r has been kept, b u t W illin g to n O 'C o n n o r, genera su p e rin te n d e n t, says th a t it does no^
to ta l o v e r tw e n ty in th e 4 t0 3 y e a rs o f use.
T
H E beam s a re raised into place by th e tw o • tim berm en withou th e aid o f ja c k s, b u t o ften they are aid ed b y o th e r m en w ho may be w o rk in g n e a r by. A s th e cutting, an la te r th e lo ading, is done, one post a a tim e is rem o v ed tem porarily or m oved to a new location under t e beam by th e m ach in e crew s to w a j room f o r th e o p era tio n . A s the stee beam s a r e ad v a n ce d w ith the face, f o u r ro w s o f p ro p s a re set behin th e m in th e o rd in a ry w ay.A t all tim es one loading machine h a s been k e p t in re se rv e fo r substitu
tio n in case a n o th e r is undergoing rep a irs. A r a th e r te m p o rary shop'
C O A L A G E — Vol.34, No -7
Two H-Beams in a Room Just Being Widened; at Left Is a Breakthrough
Creosoted Pine Posts Moved from Where They Were Installed S ix Years Ago
% f - C 0 A L A G E
Post Removed from End of Front H-Bcarn, Allowing Loader to Clean Up the Corner
Section Repair Shop; the Substation Equip
ment Is in a Connecting Room at the Left
Showing How the Sandy Shale Top Keeps Coming; Here About 9 Ft. Has
Come Down
but one eq uipped w ith re p a ir p it, is located n e a r th e c e n te r o f each lo ad in g -m ach in e te rr ito ry . T h e shop location to g e th e r w ith th a t o f a su b sta tio n in connection is advanced w h en ev e r th e f a r th e s t loading m achines g e t a p p ro x im a te ly 2,000 ft. aw ay fro m it.
D ire c t c u r r e n t is used on th e load
ing m achines an d a lte rn a tin g c u rre n t on th e m in in g m achines. A typical su b sta tio n co n tain s one 150-kw. syn
c h ro n o u s co n v e rte r w ith its tr a n s fo rm e rs, also th re e 25-kva. tr a n s f o r m e rs fo r su p p ly in g th e u n d e rc u tte rs.
F iv e J o y lo a d in g u n its w o rk d u rin g th e d a y a n d th re e a t nig h t. O f th e five u n its , tw o cu t an d load n a rro w Work. O n e o f th e se e n try -d riv in g u n its is d o u b le -sh ifted . T h e o th e r J o y m achines ad v a n ce th e ir ow n n a r row w o rk a f te r bein g s ta rte d in a te rrito ry .
F
A C E p re p a ra tio n b e fo re sh o o tin g th e m a in body o f coal co n sists of sh o o tin g lig h t pop sh o ts a n d p u llin g th is p o rtio n o f th e coal o u t in fro n t o f th e face b y h an d m e th o d s. C u ttin g o u t th e p a r tin g an d sh e a rin g th e face w ith a co m b in atio n m a ch in e w as trie d b u t w as fo u n d to o costly. P a r t o f th is difficulty w as because o f th e divisio n o f w o rk re q u ire d b y the u n io n la b o r c o n tra c t w h en th e m anual la b o r w as red u c ed to th e p o in t th a t th e re w as n o t ste ad y w o rk fo r all o f th e m en.
E a c h lo a d in g m a ch in e c a rrie s tw o, o r a s m a n y as f o u r " lo a d e r sp lic e rs”
fo r c o n n e ctin g th e sh o rt ex ten sio n ra ils to th e e n d s o f th e room track s, w h ich a r e laid w ith 16-lb. steel. T h e se splicers, w h ich a re sh o w n in o n e o f th e p h o to g ra p h s, a r e th e in v e n tio n o f L loyd P ric e , m in e black sm ith . T h e y a r e m a d e b y sp littin g a piece o f d o u b le
s tre n g th 2-in. pipe, th e n flatten in g it -so th a t it w ill slide o v e r th e base o f th e ra il section. T h is device is v ery m u c h lig h te r a n d is o th e rw ise m o re s a tis fa c to ry th a n th e su p e rse d e d and cu m b erso m e p la te ty p e sh o w n a t th e b o tto m le f t in th e sam e p h o to g ra p h .
W h a n th e m in e w as on h a n d lo a d in g th e ca rs c a rrie d an av e ra g e o f 4 ,5 0 0 lb. W ith m a ch in e lo a d in g th e ca p ac ity d ro p p e d to 3,600 lb., in c lu d in g th e e x t r a re fu s e h au led o u t o f th e m in e a n d rem o v ed a t th e tip p le.
M e n tio n w as p re v io u sly m a d e o f sealin g th e w o rk e d -o u t p an els. T h e p lace f o r each seal is defin itely lo
c a te d by th e m in in g e n g in e e r a n d th e e n try is n a rro w e d d o w n fro m th e u su a l 10 ft. w id th to 7 o r 8 ft. a t th is p o in t. B e sid es th e sa v in g in cost o f c o n s tru c tin g th e seals, th is m eth o d
412
Splicers of the Old Plate Type and of the N ew Tube Type
h as th e ad v a n ta g e o f being e q u iv ale n t to m ak in g a tig h te r a n d stro n g e r w all.
T h e se seals a re b u ilt 4 ft. th ic k ; m ade u p o f a 4-in. brick w all on th e inside, an 8-in. brick w all on th e o u t
side an d th e cen ter space filled w ith
ro c k a n d concrete. Stoppings along th e m a in en tries are 3-ft. rock walls.
C re o so tin g o f timber has provd its, v alu e a t this mine. When the s h a f t w as sunk in 1918 creosoted oak p o sts w e re p u t under the steel beams tn a t w e re installed to protect to m a in b ottom . A s yet these posts show no sig n s o f decay. About six years ag o a s ta r t w as made in the use oi cre o so te d pine posts for supporting th e steel crossbars on the mains. This tim b e r w as treated at a plant in Terre H a u te , w hich is about 35 miles dis
ta n t. O n e o f the accompanying p h o to g ra p h s show s a few of these o rig in a l 6 - to 8-in. posts that were m oved to th e present location after th re e y e a rs o f service at another place. T h e six years in the mine have n o t caused th e posts to show any sig n s o f decay.
T a k e n a s a whole the methods at N o . 28 m in e show c o m m e n d a b le p ro g re ssiv e n e ss considering the ob
stacles th a t h av e been met at almost ev e ry tu r n . T h e m ine has been kepi w o rk in g a la rg e p art of that time d u rin g w h ich th e active u n d e r g r o u n d m in e s o f th e sta te could be counted on o n e ’s fingers.
for v era l y e a rs. _
A p a ra d o x in mechanical nunw th a t tw o schools of endeavor w ith r a r e exceptions developing d ia m e tric a lly opposite directions.
Mechanization’s Greatest Ned
( Continued from page 405)
1 he p illa rs a re m ined by d riv in g be m o re easily won. r0°’
places a t rig h t an g les to th e room s, co n d itio n s w ould prevail ana o r “ b u tt-o n ” a t th e end of th e ch in ery cou ld be p u t to more ^ pillars. H a n d m e th o d s a re em ployed, nom ical u se. T h e w riter has
1 his system has been in use f o r a d v o c a tin g tria ls of this system o v er eig h teen m o n th s and h a s g iv e n se v eral y e a rs
re su lts exceed in g ex p ectatio n s. I m p ro v em e n t in all p h ases o f th e m in in g o p era tio n h a s been ex p erien ced since
th e change in th e m ine layout. O f d ia m e tric a lly opposite
m o st benefit hav e been th e re g u la rity lo a d in g m a ch in e is eliminating a w ith w hich b rea k s o cc u r in th e w ake d u o u s la b o r b u t it is not surmounts o f th e re tre a tin g p illar line an d th e th e tra n s p o rta tio n problem. T e ^ p erio d ic re lie f fro m a c cu m u latin g v e y o r is o v erco m in g transportau-- p re s s u re w hich resu lts. A s e x e rte d difficulties a n d , it m u st be gra"ted. j th e p re s s u re fa c ilita te s easy w in n in g lig h te n in g th e b u rd en of labor> j-,
o f th e coal. it is n o t w h olly eliminating
A sy stem o f th is so rt, p e rh a p s o n shovel. T h a t system which wi a sm aller scale, w o u ld fa v o r m e ch a n i- co m m o d ate th e o p eration of i za tio n in m a n y w ays. M o s t n o ta b ly m ach in es in com bination is a ^ 1 it w o u ld p ro v id e a h ig h d e g re e o f to g ro w in fa v o r. T h a t system in ^ c o n c en tra tio n . A ll ro o m faces o r p ro b a b ly w ill be characterize . p illa r en d s a t a n y tim e bein g eq u i- lo n g fa c e a tta c k e ith e r by cuts.
d is ta n t fro m th e e n try , u n if o rm ity in th e end o f th e p illar o r by sa _ th e daily o u tp u t w o u ld be p ro c u re d th e rib s. W h e re v e r possible, a to a d eg re e n e v e r a tta in a b le w h e re tern o f th is s o rt should be a op^
places a re step p ed . A b e tte r q u a lity a s it g iv e s p ro m ise o f greater e o f coal fro m th e sta n d p o in t o f size tu a l success th a n m ore con‘ ’ w ould be p ro d u ce d . T h e coal w o u ld lay o u ts.
C O A L A G E
— V o U i ^IPE Lowered Into Borehole
On Bed of Sand
By Ivan A . Given
Editorial Staff, Coal Age
P
I P E fo r siltin g p u rp o se s m u st be h ard an d re s is ta n t to a b ra sio n or it w ill h av e to be replaced frequently. A t th e P ro s p e c t colliery of the L eh ig h V alley C oal Co., W ilkes-B arre, P a ., it w a s decided in 1927 th at a h a rd w h ite -iro n p ip e o f high silica co n te n t sh o u ld be used to line a 16-in. hole su n k th ro u g h the B altim ore a n d S k id m o re beds to the Red A sh, in w hich bed w ere are as to be filled w ith silt.An effort w as m ad e to low er th e entire pipe fro m th e su rfa c e b y in serting a plug, o r h o istin g b u tto n , on which th e b o tto m end o f th e pipe would rest, le n g th s o f p ip e being added as th e pip e w as low ered. A rope w as coned a n d a tta c h e d to th e button w ith an eyebolt.
The rope th u s se cu red passed u p through th e pipe an d o v e r a sheave at the su rfa ce . A f t e r th e pip e h ad been low ered a len g th , clam ps w e re put on the ro p e to h o ld it in place above the hole, th e ro p e w as lifte d off the sheave, p assed th ro u g h a n other length o f pip e a n d th ro u g h a loose sleeve a n d ag a in p u t o v er th e sheave.
T he rope, a f te r b ein g faste n ed to the low ering h o ist, w as unclam ped and the new pipe le n g th w a s placed over th e to p le n g th in th e hole, th e sleeve to co n n e ct th e tw o being brought o v er th e jo in t a n d held in place by asp h altu m ap p lied h ot.
The strain w a s co n sid erab le, as the pipe w alls w e re 1 in. thick, th e interior d ia m eter 8 in . a n d th e o u te r diameter 10 in. E a c h section w as
10 ft. long an d w eig h ed 1,000 lb.
From the s u rfa c e to th e B a ltim o re bed th e re w e re 50 le n g th s a n d be
tween th e B a ltim o re a n d th e R ed A sh beds th e re w e re to be ab o u t 3 6 lengths. T h e to ta l w e ig h t w ith o u t sleeves w ould hav e been 85,785 lb., or about 43 to n s. A p p ro x im a te ly 35 tons had been lo w ere d b y rope w hen July, 1929
— C O A L A G E
th e la tte r pulled loose from its socket, le ttin g th e pipe fall dow n th e hole, b u t a t a p o in t several feet above th e R ed A sh bed it jam m ed an d w ent no fu rth e r.
T h e d rille rs w ho h ad u n d erta k en to place th e pipe trie d in vain to fre e it by fishing tools, b u t it w as too tig h tly w edged. T h ese m ethods fa il
in g th e y trie d to d riv e th e pipe dow n fro m above, b u t in th is also they
failed. F in ally they attem p ted to cu t th e pipe w ith a sh o t d rill, b u t fo u n d it to o h a rd . T w o m o n th s passed an d they w ere still vainly en d eav o rin g to find som e solution o f th e difficulty.
P a u l S terlin g , m echanical engineer o f th e L eh ig h V alley Coal Co., seeing th a t no p ro g re ss h a d been m ad e and recognizing th a t th e pipe w hich p r e sented so m uch resistan ce to c u ttin g tools w ould yield q u ite read ily to a fra c tu rin g shock, decided to b re a k th e p ip e " by explosives. A seven- ca rtrid g e ch arg e w as raise d fro m th e bottom o f th e borehole on a stick and th r u s t in to th e pip e a n d fired, t h e pipe w as sh a tte re d in th is m a n n er an d th e b ro k en pieces fell o u t in to th e
R e d A sh bed. I n tw o d ay s th e e n tire hole w as cleaned.
A f te r clean in g th e hole, p ip e w as placed by th e ro p e m e th o d fro m th e B a ltim o re to th e R e d A sh . B u t fo r th e long section fro m th e s u rfa c e to th e B a ltim o re , M r. S te rlin g decided to let th e pip e do w n on a bed o f sand in o rd e r to elim in ate th e d a n g e rs o f th e ro p e m ethod. T h e hole w a s plugged a t th e B a ltim o re bed a n d filled w ith sand. S om e th o u g h t th a t it w ould be possible to lo w er th e sa n d bed a n d th e pipe re stin g o n it by b leed in g th e san d th ro u g h a v alv e in th e p lu g a t th e b o tto m o f th e hole, b u t, as M r. S te rlin g knew , th is w as n o t feasible, fo r th e sa n d w ould a rc h in th e hole. T o o b v iate th is possi- iblity, as each, le n g th o f p ip e w as placed in th e hole th e displaced sand w as rem oved by a “ sa n d p u m p ” o r bailer, w hich, a s is w ell k n o w n , is a lig h t steel p ip e o f sm all d ia m e te r w ith a clack valve a t th e b o tto m open in g u p w ard .
W h e n th e b ailer w as lo w ere d in th e pipe d o w n to th e level o f th e sand, th e w a te r a n d sa n d en te re d th ro u g h th e clack valve a n d filled th e bailer. O n th e b ailer bein g raise d th e clack valve closed in resp o n se to the g re a te r p re ssu re on its u p p e r side.
T h u s th e san d an d w a te r w e re bailed o u t o f th e hole.
S om etim es it w as n ecessary to bail d ow n 8 o r 10 ft. b e fo re th e siltin g pipe w ould budge, b u t u su a lly it w ould trav e l do w n an inch a t a tim e as th e sa n d w as rem oved. A s th e sin k in g o p era tio n s w ere conducted f o r o nly eig h t h o u rs in 24, th e san d aro u n d th e pipe te n d e d to pack h a r d d u rin g th e p erio d o f idleness. A c cord in g ly th e sk in fric tio n som etim es w as sufficient to hold up th e pipe ag a in st th e w eig h t o f 10 o r 15 to n s o f siltin g pipe, even w h en th e san d below it w as rem oved.
W h e n th e packed san d could n o t
