C o al A ge
E stablished 1 9 1 1 — M cG raw -H ill P ublishing C om p any , Inc.
D E V O T E D T O THE O P E R A T IN G , T E C H N IC A L A N D BUSINESS P R O B L E M S O F THE C O A L - M I N IN G INDUSTRY S T D N E T A. H A L E , E d ito r
New Y ork, Ju ly , 1934
I R A ,
MllftMfllMIW
CODE
B a n
REGCTtAlBNNa3H5681934
Equipped for the Moment
M a n y m i n e s
can p ro d u c e coal w ith o u t
loss because th e ir hauls a r e n o t long, bu t the economical life o f such mines is, a t best, only one o r tw o y e a rs if t h e equipm ent is to o light fo r lo n g h a u la g e . O ne m ay “ g e t b y ” w ith light rail, n a r ro w -g a g e , sm all ca rs an d small locom o
tives f o r a while, bu t n o t f o r long, an d a mine thus equipped, if it has a la rg e a rea, has only a small p a r t o f it in the economic zone. A s it will h a v e to be equipped la te r, an d as ad e q u ate equipm ent w o u ld yield m o r e profit now th an i n a d e q u a te equipm ent, w hy n o t introduce it at once a n d h a v e th e p re s e n t benefit t h a t arises fr o m its u se ?
I t m ig h t be r e v e a lin g if, on the mine m ap, a line w e re ru led show ing th e limits o f econom ical o p e r a t io n w ith p r e s e n t equipm ent, fo r w ith out new eq u ip m e n t all th e coal beyond t h a t line is w o r t h ab solutely n o th in g except to someone willing to expend t h e m oney fo r reequipping the mine, a n d all th e m oney expended in tr a c k ing up to t h a t p o in t m ig h t j u s t as well be spent in a d e q u a t e tr a c k f o r th e future.
High-Speed Ventilation
T o o
L IT T L Eis b eing done to ease corners in th e tu rn in g o f air. A t only 900 ft. p er m in
ute, a s q u a r e tu rn resists t h e p ro g re ss o f air 2.33 tim es as m uch as a curve o f 3-ft. radius a t th e inner c o r n e r a n d a 12-ft. radius a t the o u te r c o r n e r in a h e a d in g 9 ft. wide, an d m o re th a n 4.82 tim es as m uch as a curve o f 6-ft.
ra dius a t t h e inner c o r n e r an d a 15-ft. radius a t t h e o u te r c o r n e r in a h e a d in g o f th e same w id th . W i t h a h ig h e r velocity o f c u r re n t even
g r e a t e r differences will be found. W h e r e velocities o f 5,000 ft. p e r m inute a r e used n e a r the fan, th e im p o rta n c e o f r o u n d in g curves seems ab u n d a n tly p r o v e d . T h e s e figures a r e based on th e findings o f H . P . G re e n w a ld a n d G. E . M c E l r o y , o f t h e U . S. B u re a u o f M in e s.
W i t h vanes, p e r h a p s even b e tt e r results m ig h t be o b ta in e d a t high velocities. W h e t h e r vanes a r e used o r o m itte d , a t least th e r o u n d ing off o f curves w o u ld seem to be desirable, especially as t h e re b y t h e s u p p o r t f o r th e r o a d w ay w o u ld be r e n d e r e d m o r e ad e q u ate, f o r t h e w id th o f the h e a d in g will n o t be increased a t th e bend as it w o u ld be by m a k in g its o u te r c o rn er square. T h e o u te r angle could be filled w ith rock, faced w ith concrete in fo r m s . P r e f erably, th e inner curve sh o u ld be cut to te m p le t an d faced w ith p ro je c te d concrete.
Must the Code D ie?
N R A
o f f i c i a l sfrequently, a n d with g o o d re aso n too, p o in t to th e bitum inous code as one o f th e shining achievem ents o f th e r e covery p r o g r a m . In c re a sin g m u r m u r s o f dis
co ntent o r w orse, h o w e v er, give rise to the disquieting th o u g h t th a t, unless t h e r e is a speedy re c a p tu r e o f the s p irit which a n im a te d the industry last O c to b e r, this l a n d m a r k m a y d is a p p e a r u n d e r a w a v e o f sectional jealousies.
T h o s e who voice this f e a r couple it w ith criti
cism o f the a d m in is tr a tio n f o r its seem ing u n willingness to com pel co m p ro m ise b etw e en th e w a r r i n g factions w ithin the industry.
T h e ro o ts o f these com plaints go bac k to
the w eaknesses stre sse d in t h e stu d y o f code
o p e ra tio n an d a d m in is tr a tio n which a p p e a r e d in
th e F e b r u a r y issue o f C oa l A g e ( p p . 6 9 - 7 2 ) ,
w ith p re s e n t em phasis ce n te re d upon price r e lationships. A d m i t te d ly these re la tio n sh ip s do n o t lend them selves to easy solution because o f th e com p etitiv e issues involved, but these very difficulties sug g est th e urgency o f N R A a d o p t ing m o r e th a n a passive role in t h e ir se ttle m ent. In a d d itio n , e n thusiasm f o r f u r t h e r N R A cost r e p o r t s is ebbing a n d one division has definitely declined to continue volu n tarily w ith this p a r t o f t h e p r o g r a m .
N ice a p p o r ti o n m e n t o f responsibility be
tw een N R A a n d th e in d ustry f o r t h e p re s e n t situation is v alu ab le only as it furnishes a guide for fu t u r e action. T h e essential p o in t is t h a t no sane o p e r a t o r w a n ts to c o n te m p la te r e v e r t ing to th e chaotic a n d ruinous conditions which p re v a ile d less t h a n a y e a r ago. T o p re v e n t such a re tu r n som e sacrifice o f individual p r e f erences a n d a d v a n ta g e s f o r t h e g e n e ra l good a n d even som e s u r r e n d e r o f cherished local au to n o m y m ay be necessary. B ut t h a t is n o t to o high a price f o r profitable stab iliz atio n .
A Paramount Consideration
Fe w p r o b l e m s
tra n s c e n d in im p o rta n c e
r o o f action. O n it depends, in Illinois, the possibility o f doubling the q u a n tity o f coal r e m o v e d fr o m th e mine, in m a n y places th e a d visability o f m ining coal u n d e r h ea v y cover an d th e o p p o rtu n ity f o r o p e r a t i n g intensively by longw all. In G e r m a n y seams a r e la boriously backfilled a n d in G r e a t B rita in pack-w alling is g en e ral. B o th o f these a r e expensive p ro c e e d ings. Shall we be obliged to com e to t h e m as mines g e t d e e p e r a n d one bed is w o r k e d above a n o t h e r ? C an th ey be a v o id e d by a k n o w led g e o f th e a p p a r e n t w him s o f th e r o o f ? Som e d e clare r o o f is so i r r e g u la r an d u n c e rta in t h a t no m a th e m a tic s will solve its pro b lem s. T h e reply is obvious.
R o o f in n e a rly all regions is a c ting re g u la rly an d d ep e n d a b ly as w o rk e d , so it m ust be h o m o geneous enough to satis fy in all cases the m e th o d o f o p e r a tio n . I f a p ra ctical solution will w o r k infallibly, th e n a m a t h e m a t i c a l solu
tion sh o u ld be fr a m a b l e t h a t will m e e t the situ atio n . I f a r o o f t o d a y b re a k s a lo n g th e p illa r line, a n d then t h e r e a f t e r — o r f o r some tim e— “ r id e s ” th e pillar, t h e re m ust be a lack o f h o m o g e n e ity to explain t h e v a r ia t i o n ; b u t w h e re t h e r e is no v a r ia tio n , t h e r e m u st be ho m ogeneity, an d a m a th e m a tic a l solution is in o r d e r .
B ut such u n c e rta in ty does n o t seem to exist in practice. I f t h e r e a r e p ra c tic a l solutions, it will be said, w hy tro u b le a b o u t t h e m a th e m a tic s which explains t h e m ? A g a in , th e a n s w e r is obvious. A c o r re c t m a th e m a tic a l principle will enable a stu d e n t to d e te r m in e a t any mine w h a t m e th o d will afford a p ra c tic a l m e t h o d o f
•meeting th e r o o f ’s pro b lem s.
Words, Just Words
Ou r M IN IN G LA N G U A G E
g re a tly needs r e vision. T h e to n g u e o f th e m in e r is being d o u b t
fully enriched f r o m all q u a r te rs , a n d every region insists t h a t its w o rd s an d i n t e r p r e t a tio n s o f w o rd s m u st be accepted as t h e j a r g o n of everyone in th e m ining field. S ynonym s a r e needed, so no p u rp o s e will be s e r v e d by lo pping off duplicate o r trip lic ate nam es f o r any one th in g ; but e n d e a v o r should c o n c e n tra te on no t h av in g one n a m e f o r se v e ra l s e p a r a t e things which a r e e ith e r essentially unlike o r so pro- vokingly alike t h a t one m ay be m is ta k en f o r a n o t h e r w hen distinction betw een th e m is essen
tial.
M a n y hav e n o t m a d e up th e ir m inds w h a t any given p a r t o f a m ine should be na m e d , but use certain te rm s indefinitely to a p p ly to several p a r t s o f a mine. O n e a u th o rity , f o r example, insists t h a t longw all w ith o u t pack-walls is n o t
“ lo n g w a ll” b u t “ l o n g fa c e ” ; a n o t h e r g ro u p w o uld define “ lo n g w a ll” as a continuous face g r o w in g l a r g e r w ith o p e r a t i o n ; “ lo n g fa c e ,” a w ide w'orking betw een p a r a lle l ro a d w a y s.
Som e w o uld m ak e an e n try a g r o u p o f h e a d ings; o th e r s w o uld m ak e a h e a d in g a g ro u p o f entries.
“ S la t e ” is quite freq u en tly ap p lied to rock which consists a lm o s t en tirely o f silica, an d qualified only in a p p e a ra n c e as slate by re aso n o f its fine g ra in . Such n o m e n c la tu r e arg u es technical u n ce rtain ty . P e r h a p s “ schist” is a useful an d b r o a d e r w o r d w ith w id e r c o n n o ta tion, bu t it wrould a p p ly t o all m a te r ia ls be
tween coal beds. T e r m i n o l o g y studies will u p r o o t m a n y fallacies t h a t incorrect technique has c re a te d . “ M e t h a n e ” w as once ta b o o e d as to o scientific, an d th e w o r d f o r th e m ix tu re “ fire
d a m p ” was p r e f e r r e d as the b e t t e r n a m e f o r the p a r ti c u la r gas in question. B ut custom p a r tl y has c o rre c te d this, as it will o t h e r m isn o m e rs if a technical s t a n d a r d is established. G lossaries m ust give w a y to dictionaries, an d definite te rm s re p la ce w o rd s o f unce rtain m eaning.
258 C O A L A G E — Vol.39, No.7
WAGE RATES TREBLE
+ But Total Labor Costs Per Ton Decrease A t Union Pacific Mines
By E U G E N E M c A U L IF F E
President, Union Pacific Coal Co.
F O R T Y - F O U R Y E A R S A G O , the base h o u rly rates for inside la b o r in the mines of the U n io n Pacific Coal Co.
w ere 25 and 15c. T o d a y the base rate is 77.5c. p e r hour.
D espite this g r e a t increase in h o u rly rates, however, total lab o r costs p e r ton are low er than they w ere in 1890.
C o n tin u ally increasin g efficiency, m ade possible by in creasing c a p ital investm ent in eq u ip m en t for m e c h a n iz a tion and a le rt m anag em en t, w h ic h M r . M c A u liffe m o d estly glides over in this article, are responsible for this record.
I
N I T I A L D E V E L O P M E N T of the p ro p ertie s now co n tro lled by the U nion P acific C oal Co. sta rte d a t Carbon, W yo., w h ere 6,560 to n s w as produced in 1868. D u rin g th e sam e y ear, 365 to n s also w as m ined n e a r Rock S p rin g s, W y o . C arb o n ceased to be a p ro d u cer in 1902, b u t R ock S p rin g s has been m a k in g its a n n u al c o n trib u tio n to the o u tp u t of th e p ro p e rty fo r 66 years. T h e w ag es paid, h o u rs w orked per sh ift an d the cost of p ro d u ctio n in all d is tric ts a re a m a tte r of re c o rd w ith the com pany. T h e se reco rd s m ake it possible to co m p are w ag e ra te s a n d p r o duction costs in e a rlie r y e a rs w ith those of the p re se n t day.In 1890, fo r exam ple, the b asic w age paid w h ite la b o r w o rk in g inside th e m ine w as $2.50 fo r a 10-hour d a y ; O rie n ta l labor w as paid $1.50. T h e 10-hour day continued u n til S ept. 1, 1907, w hen the 8-hour d ay w as adopted. U n d e r the recent am en d m en t to th e Code of F a ir C om petition fo r th e B itu m in o u s Coal In d u stry , a 7 -h o u r d ay w as established effective A p ril 1, 1934. P r i o r to 1903, tonnage ra te s w ere on a g ro s s-to n basis, w ith ,a 30 p e r cen t deduction fo r slack.
A s a result, u n d e r a 70c. ra te p er ton, th e m in er actually received only 43.75c.
fo r each 2,000 lb. loaded.
L a st year, the basic m inim um ra te fo r inside skilled lab o r w as 67.75c. per h our.
N o tw ith sta n d in g th e g re a t increases in c u rre n t b asic ra te s ov er those p rev ailin g in th e ’90s and th e early y e a rs of the p resen t century, the lab o r cost in 1933 w as 9.1c. p er ton less th a n th e av erag e of the lab o r costs fo r the th re e y e a rs p reced in g th e ad v en t of the 8 -h o u r day.
T h e ex p lan a tio n of th is achievem ent is to be found in in creased capital in v est
m ent an d im proved technique.
T h e p rin cip al ch an g es th a t h ave m ade it possible to produce coal today w ith an hou rly lab o r cost 210 p er cen t above th a t of 1890 include the su b stitu tio n of electricity fo r steam h o ists an d pum ps.
E le c tric ity also m ade possible the present-day c u ttin g m achine, th e h a u l
age locom otive an d th e lo ad in g m achine.
E lectrically d riv en fan s located ov er e x h au st a irsh a fts m iles aw ay from th e boiler room also have added m uch to v en tilatio n and to safety.
In 1890, th e com pany had no electric pow er. Coal w as c u t w ith fo u r a ir -
d riv e n L eg g e chain coal c u tte rs an d a few a ir p u n ch ers. T h e m ine c a rs had a m ax im u m cap acity of 1,500 lb., as com p ared w ith the 3£- to 4 -to n cap acity of th e equipm ent now in use. T h e first elec tric locom otive, a 9 -to n te rra p in - back type u n it equipped w ith one 60-hp.
500-volt d.c. m o to r an d g e a re d to a m axim um speed o f 8 m iles p e r h our, w as n o t p u rch ased u n til M ay 16, 1892.
T h is w as one of th e first tw o electric locom otives built. A few y e a rs ago, it w as inducted into th e U n io n Pacific C oal Co. O ld T im e rs ’ A sso ciatio n u n d er the nam e of “ C h arlie S m ith ,” its fo rm e r o p e ra to r, a n d now occupies a position of ho n o rab le re tire m e n t in fro n t of th e O ld T im e rs ' B u ild in g a t R ock S p rin g s.
In c o n tra st to th is m eag e r equipm ent of 1890, th e com pany today is u sin g 124 electrically o p erated sh o rtw a ll m in in g m achines, 81 m ine locom otives, 49 m o to r-g e n e ra to r sets, 110 elec tric hoists, 145 m o to rized lo ad in g m ach in es and 183 elec tric d rills. O p e ra tio n of th ese m achines an d o th e r equipm ent such as tu g g e r h o ists an d blow er fa n s involves th e em ploym ent of o v er 1,300 m otors.
A n occasional b a ck -sig h t such as th a t tak en by th e m an ag em en t of th is com p an y su g g ests th a t so-called “ m ech a n iza
tio n ,” th e resu lt of scientific technique co n trib u ted v ery la rg e ly by th e m an u fa c tu re rs of m in in g m ach in ery and equipm ent, re in fo rc e d by th e U . S.
B u reau of M ines, plus su b stan tial ca p i
tal investm ent, h as m ade i t possible fo r the in d u s try to p ay w ages in 1934 e q u iv alen t to 310 p e r cen t of th e w age o f 1890. If th e m ethods em ployed in m in in g coal in W y o m in g in 1890 w ere follow ed w ith th e p re s e n t scale of w ages a n d h o u rs in effect, th e m a rk e t p rice of m in e -ru n w ould be a t least $2.25 per ton h ig h e r th a n the p re se n t code price. T h e a n sw e r is an obvious o n e : V e ry little, coal w ould be used.
July, 1934 — C O A L A G E 2 5 9
Undercut and Sheared, Cuttings Cleaned From the Kerf and Loaded,' and Two-by-
fours Placed in Correct Position.
Left H alf of the Face. JJeing
to W ithin a Few Inches of the U pper Binder.
W hile Loading Coal N o Shoveling Is Done Be
tween the 2x4 and the Face of the Lower Bench.
The Left H alf of the Face Has Been Shot and the Coal Has Moved to the R ight U ntil the K erf of the Shear Cut Is Closed and Appears
Only as a V ertical Line.
Both Halves of the Face Loaded O ut Down to U pper Binder. After This Binder Is Skinned Off and Cast Aside, the N ext Layer of Coal W ill Be Loaded. The Fines Be
tween the 2x4 and the Lower Face Are Shoveled to the Refuse After the Lower
Binder H as Been Skinned Off.
C O A L A G E — Vol.39, No.7
An Inspector Views the Coal From Each Car as It Passes by in a Thin Layer on an A pron Conveyor En Route Between the D um p and th e Shaker
Screens.
FACE PREPARATION
+ Stressed at A nchor Mines
A n d Pedigree of Every Car Recorded
I
O A D IN G clean coal an d o b tain in g the h ig h e s t possible p ercen tag e of larg e sizes u n d e r a g iv en n a tu ra l condition re q u ire s n o t only d e te rm in a tion a n d in stitu tio n of a m ethod best suited to th a t condition, acq u isitio n of necessary equipm ent to do the w ork, but also co n sta n t su p erv isio n of the loaders a n d re c o rd in g all th e facts th a t w ill help tra c e th e so u rce of a n y coal w hich m ay a ro u se com plaints. M ethods em ployed a t m ines of the A n c h o r Coal Co., H ig h co al, B oone C ounty, W e st V irg in ia , a r e illu s tra tiv e of a system w hich h as p ro v ed its effectiveness in p rom oting the lo ad in g o f clean coal a t the face, o b ta in in g m ax im u m lum p, and re c o rd in g a n a c c u ra te p ed ig ree of each carload shipped.T o ship clean coal is th e p rim a ry goal and, fo rtu n a te ly , m ost of th e e ffo rt d i
rected to w a rd lo ad in g clean coal a t the face can be c red ited w ith red u cin g cost.
Im p u rities n o t loaded inflict no loading cost, do n o t reduce m in c -c a r an d loco
m otive co al-h an d lin g cap acity , a re free from p o w er cost fo r g a th e r in g an d h au l
ing, an d in cu r 110 c h a rg e fo r pick in g out a t the tipple an d haulage to th e refuse dump.
T h e A n c h o r com pany o p erates tw o d rift m ines in th e D o ro th y seam served by a c en tral tipple. T h e coal, w hich lies p ractically level and a v erag es 90 in.
in thickness, is a m ulti-bedded splinty coal an aly z in g about 33 p er cent v o la
tile, ap p ro x im ately 4 p er cent in h eren t ash, an d w ell u n d er 1 p e r cent sulphur.
In som e sections th e ro o f is a sand rock an d in o th e r sections a d ra w sla te of suffi
cient thickness to be tim bered an d held in place. T h e bottom is h a rd shale.
T w o shale b in d ers, each ra n g in g be
tw een 1 an d 4 in. in thickness, occur n e a r the bottom . O ne is 12 in. from the bottom a n d the o th e r 24 to 30 in.
fro m th e bottom .
T h e bed is u n d e rc u t to a depth of 6 ft. w ith sh o rtw all equipm ent an d sheared on th e ce n te r line w ith a G ood
m an m achine equipped w ith sw ivel tru ck . T h e u n d e rc u t is positioned to leave 4 to 6 in. of bottom coal w hich is never tak en up, th u s elim in atin g the
p o ssibility of th e m in e r sc ra p in g up any pieces of the bottom sh ale w hen shovel
ing coal.
A ll m achine c u ttin g s a re rem oved fro m th e k e rf a n d loaded in to a m ine c a r p rio r to b lastin g . A ll holes a re d rilled by th e m in ers a n d m u st be parallel to the line of sig h ts, so th a t th e re w ill be no g rip p in g shots fired.
H o le s a r e c h a rg e d w ith pellet pow der tam p ed w ith clay a ro u n d a needle, a n d th e blast is ig n ited w ith a com m on squib. T w o lig h t sh o ts a re used, an d th e second is n ev er fired u n til a fte r the m in er has cleaned o u t a space a t least 3 ft. w ide to full depth a lo n g th e sh e a r cu t a n d dow n to th e uppec b in d er. T h is in effect w idens the sh e a r k e rf to 3 ft., th u s p ro v id in g am ple ex p an sio n space fo r th e coal to be loosened by th e second shot.
T o keep o u t c e rta in im p u rities th a t m ig h t o th erw ise be loaded w ith th e sm all-sized coals, th e follow ing m ethods a re rig id ly en fo rced a t th e fa c e : P r io r to the sh o o tin g , th e m in er m u st lay w ooden 2 x 4 ’s on th e bottom p arallel to th e face an d a t a d istan ce fro m th e face equal to th e h e ig h t of th e h ig h e r binder.
Keeping the Pedigree
T h e " I n s p e c tio n T a b le R e p o r t”
fo r m ( l e f t ) Is m a d e o u t in tr ip li
c a te b y th e in s p e c to r a t th e in s p e c tio n c o n v e y o r in th e p r e p a r a tio n p la n t : o n e c o p y , p r in te d o n w h it e p a p er, g o e s to th e C le v e la n d office ; a s e c o n d , o n b lu e p a p er , g o e s to th e m in e fo r e m a n , a n d th e th ird co p y , on y e llo w p a p e r , is filed in th e m in e office. T h e s iz e o f th is fo r m is 5 x 6 in.
T h e " D o c k R e p o r t” fo r m ( r i g h t ) is filled o u t in th e m in e office a n d s e n t to th e m in e fo r e m a n , w h o m u s t n o t i f y th e o ff e n d in g lo a d e r , s ig n th e r e p o r t a n d r e tu r n i t to th e m in e office fo r filin g . T h is fo r m is p r in te d o n w h it e p a p er, s iz e 6 x 6 J -in .
A N C H O R C O A L C O M P A N Y
Inspection Tabic Report
DATE---
SLatV____ COAL S___________ SIZE---
GENEHM. REMARKS:
ARPEA R AN « COAL REGARDS SLATE
a nÖi o r c o a l c o m p a nP
R rp o fl Nrt. . . .
DOCK REPORT
Mine N o... D e«e...! 9 i ____
Ckrek N A M F. Om N<mtm¡
... ... ... :...
.
T k . , t ~ . ImWi i *f «I m c mI k*«r k*-»« w ttüw « k r mm mmAm m
M « F m »
July, 1934 ■ — C O A L A G E 261
Rules and Regulations for Loading Coal for Anchor Coal Miners
BLASTING
1. I i you are a new em ployee you m ust not start loading1 coal un til a foreman or coal inspector has accom panied you to your w ork
ing- place and explained THOROUGHLY our method o f loading: coal.
2. Before shooting: and after all dust has been loaded out, place a 2x4-in. across front o f coal to be shot, w ith in 3 ft . o f the face of the coal.
3. No more than one shot sh all be fired at any one tim e; the second shot m ust n ot be fired un til a space at least 3 ft. wide has been cleaned o u t above top dirty band back to the solid coal in center o f room, or the back o f the c u t made by the mining: machine.
4 . Previous to shooting in any place the machine cutting* m ust be cleaned out o f the cut made by the m ining machine back to the solid coal. All m achine cuttings m ust be loaded into m ine car or cars un less special orders are given by the foreman or the m a
chine has cu t into the bottom ; then the cu t
tings rhust be thrown back into the gob.
5. There m ust not be any holes drilled grip
ping; drill holes straight w ith line o f sigh ts.
IMPURITIES NOT TO BE LOADED 1. N orm ally there ex ist three bands o f dirt in the seam o f coal we are mining, commonly known to the miner as “dirty bands"; they are located all o f them w ithin about 2J ft. o f the
bottom ; these bands under no consideration arc to be loaded in the m ine cars w ith coal.
2. There is at tim es th roughout the coal seain, at tim es near the top, other tim es near the bottom , a streak o f dull gray substance w hich we class as “bone" coal; th is m ust not be loaded w ith other coal in cars.
3. If a t any tim e a fa ll o f roof slate occurs on top of the loose coal do not attem pt to load the coal u n til it is pronounced O.K. by the foreman or coal inspector.
4 . If a t any tim e the m ining m achine cuts into the bottom or up into the dirty band, the cu ttin gs m ust all be thrown back in to the gob.
5. We load dirt from tim e to tim e Into the mine cars and dump sam e over the dirt dump;
at tim es, especially when the dirt loaded is wet. there w ill be som e o f it cling to and re
main in the mine car after it h as been dumped.
When you receive an empty car from the motor- man look in to it before you load any coal into the car.
METHOD OF LOADING
1. A fter coal is shot begin your loading above the top dirty band, leave a strip of coal stick ing to the band about 4 in. thick, to shovel off o f; th is w ill prevent you from scraping any o f the band up into your shovel w hile you are shoveling.
2. A s long as you have coal above the dirty band to load do not shovel any closer to the front edge o f th e cut than the edge o f the
2 x4-in . that you placed there previous to shooting.
3. A fter all top coal above top dirty, band has been loaded, rem ove the coal le ft sticking to dirty band to shovel off o f together w ith the tw o top dirty bands and throw back into gob;
under no circum stances Bhall any part o f this be loaded as coal.
4. A fter two top dirty bands h a v e been re
moved and thrown back into gob, then clean out all coal that has accum ulated between the 2x4-in . and the face o f coal th a t can be loaded by hand and put it into the car as coal.
5. A fter thjs coal and dirt th a t has ac
cum ulated between th e 2x4-in . and th e face has had all the large pieces of coal picked o u t o f it by hand, then rem ove the 2x4-in . and shovel .a ll th is fine coal and dirt back into the gob.
If sufficient space i9 not available in the gob.
apply to foreman in charge for a car to load dirt into.
6. A fter the coal and dirt accum ulated be
tween 2x4-in . and face ha9 all been cleaned up. then load the next coal into th e car down to the third dirty band from top, then remove th is band.
7. A fter third band from top has been re
moved and thrown back, then the rem aining coal down to the coal le ft by th e m ining m a
chine as bottom coal can be loaded.
8. When loading the la st coal at the bottom be sure the m ining m achine has not cut into bottom fireclay and le ft sm all pieces o f dirt w hich w ill be shoveled up.
ANCHOR COAL COMPANY
A ll coal above the b in d er m u st be loaded b efore th e lo w er bench is touched, an d w h en lo a d in g out th a t u p p er bench no sh o v elin g is to be done in th e space betw een th e 2 x 4 a n d the face of th e lo w er bench. A n y coal loaded fro m th is space m u st be picked up by hand. W h e n lo ad in g the u p p er bench, 2 to 4 in. of coal is left on top of th e b in d er to p ro v id e a clean floor on w h ich to shovel. S p ecial c a re is e x e r
cised in liftin g th is re m a in in g lay er.
A fte r th e u p p e r b in d er h as been skinned off a n d gobbed a lo n g one side o f th e room , the n e x t la y e r of coal is loaded an d th en th e b in d e r cast to the gob. T h e n e x t step is to dispose of th e m aterial, m ostly coal, th a t h as a c cum ulated betw een th e 2 x 4 an d the face of th e dislodged cut. L u m p s of coal th a t can be picked up by h an d a re loaded fro m th is space, a n d th e re m a in in g m a
terial, p rin c ip a lly fine coal, but c o n ta in in g som e b in d er, m u st be shoveled to the gob.
In o rd e r th a t a new ly h ire d m iner, if he is sum m oned fo r lo ad in g d ir ty coal o r o th e rw ise v io la tin g com pany re g u la tions, can n o t offer th e ex cu se “ nobody told me ab o u t th a t,” th e ac tu a l h ir in g of a n in d iv id u al is delayed u n til he is han d ed a copy of the “ R ules an d R e g u latio n s fo r L o a d in g C oal in A n c h o r Coal M in es,” allow ed tim e to re a d it, a n d th en w hen questioned says th a t he c an load coal a c c o rd in g to those re g u lations.
S in ce th e d eg re e o f en fo rcem en t of these ru les is th e tr u e m easu re o f a c com plishm ent, sev eral m eans a re p ro v ided fo r su p e rv isin g th e lo ad er an d p in n in g him to a s tric t a c c o u n tin g of th e
q u ality of coal he loads. B la stin g reco rd s a re one exam ple. K e p t on file in th e office is th e p erfo rm an ce of each m an as re g a rd s th e tons of coal he p ro duces p er pound of exp lo siv e used.
E a c h section forem an is h eld resp o n sible fo r q u ality of p re p a ra tio n of coal fro m h is m in in g section an d m u st keep av ailab le a re c o rd of th e nam e, check n u m b er a n d lo catio n of each coal loader.
In a d d itio n , a n inside coal in sp ecto r is em ployed to devote h is full tim e to p o lic
in g th e w o rk in g places a n d e n fo rc in g all ru le s an d re g u la tio n s affectin g face p re p a ra tio n .
A t th e tipple, w hich w as m odernized la st y ear, a n a p ro n conveyor is p ro vided to affo rd inspection of each c a r of coal in its m in e-ru n condition. T h is conveyor o p erates in co n ju n c tio n w ith a d is trib u tio n conveyor, b u t ru n s a t a h ig h e r speed so th a t th e coal is sp read th in ; th is decreases the chance of im p u ritie s b ein g concealed in th e la y e r of coal. A n o th e r coal in sp ecto r spends h is full tim e v iew in g th e coal p assin g ov er th is conveyor.
W h e n th is in sp e c to r d isco v ers a piece of d irt, he m akes n o ta tio n of a dock an d sig n a ls to the w eighm an, w ho fu rn ish e s th e check n u m b er of th e c a r involved.
F o r each check n u m b er re c e iv in g a dock d u rin g th e d ay th e in sp e c to r fills out in trip lic a te a n “ In sp ectio n T ab le R e p o rt.” A w h ite copy is sen t to the g e n e ra l office in C leveland, a blue copy is g iv en to th e m ine fo rem an , a n d a yellow copy is filed in th e office a t H ig h - coal. T h e m in e fo re m a n is also given a n o th e r “ D ock R e p o rt” form , w hich he m u st sig n a n d re tu rn to the office. T h is show s th e d ate he notified th e lo ad er of
th e dock an d is k ep t on file fo r fu tu re reference.
F o r each ra ilro a d c a r of lum p an d eg g loaded, the w e ig h m a s te r m u st tab u late the check n u m b ers an d w e ig h ts of all m ine c a rs th a t c o n trib u te d to th e lo ad ing. W h e n the lo a d in g of a c a r is com pleted, th e loading-boom o p e ra to r calls to th e w e ig h m a s te r th ro u g h a sp eaking tube, g iv in g the c a r in itials an d n um ber a n d co m m u n icatin g h is g e n e ra l opinion of th e coal in th a t ca r. T h e m an a t the inspection table likew ise notes his o p in io n of th e coal th a t w e n t to m ake u p th a t carload.
If a co m p lain t is received re g a rd in g a c e rta in ra ilro a d c a r, all of th e in fo r
m atio n n ecessary to d eterm in e th e re a sonableness of th a t co m p lain t an d to lo
cate a bad c o n d itio n o r p ractice, if one ex ists, is on file. F ir s t th e com m ents of the insp ectio n -tab le m an an d of the loading-boom o p e ra to r re g a rd in g th a t p a rtic u la r c a r a re noted. N e x t th e m ine fo rem an is called to fu rn is h th e ex act lo catio n s of th e w o rk in g places from w hich th e m en of th e listed check n u m bers loaded th e coal. F in a lly , if th o u g h t necessary , th e su p e rin te n d e n t of m ines w ill in sp ect all of those w o rk in g places before m ak in g h is final re p o rt of the co m p lain t to the g e n e ra l office.
T h e A n c h o r m ines a re now p ro d u c
in g a b o u t 1,500 to n s p e r day, b u t by re c e n t im p ro v em en ts a re equipped to step th e o u tp u t up to 2,400 tons. Offi
cials activ e in th e m an ag e m en t o f the c om pany a r e F r a n k L . H o rn ic k e l, C leve
land, p re s id e n t; G. H . H o rn ic k e l, H ig h - coal, g e n e ra l su p e rin te n d e n t ; an d V a n B. S tith , H ig h co al, su p e rin te n d e n t of m ines.
262 C O A L A G E — VolJP, No.7
LONGFACES AND ROOMS
+ In a Pitching Anthracite Mine A t Salem Hill Colliery
L
O N G F A C E w o rk in g s on a pitch of 30 to 40 cleg, w ith m echanical u n d e rc u ttin g up th a t steep face, and triple s h iftin g of m ine o p eratio n s a rc featu res of p ro d u ctio n a t th e H ad d o ck M in in g C o.’s S alem H ill m ine, w hich a re ra re ly found in th e U n ited States.T h is new ly opened m ine, th o u g h sm all, is rem ark ab ly w eil conducted. O n e of the u nusual fe a tu re s is the p ractice of ru n n in g the m ines in the sum m er on de
velopm ent a n d d u rin g the w in te r m ainly fo r coal g e ttin g , th o u g h in w in te r an d sum m er alik e developm ent proceeds triple shift.
Salem H ill C olliery lies ju s t outside the C ity of P o ttsv ille, to th e east. T h is section of the so u th e rn a n th ra c ite field has p erh ap s m o re coal seam s th a n any o th er in th e U n ited S tates. O n ly w hen one has dro p p ed below all th e seam s th a t a re o r h av e been w ork ed on the p ro p erty does one begin to recognize the nam es of the b ed s: L ittle T ra c y , T ra c y , L ittle D iam o n d , D iam ond, L ittle O rc h ard an d O rc h a rd . O ne w o n d ers if the seam s o p erated a rc n o t of th e D u n k ard S eries of the e a rly P e rm ia n . A s is often th e case in th e a n th ra c ite region, the iden tificatio n of th e beds is a little in doubt. In T a b le I w ill be found a list of the scam s in the so u th ern field of th e a n th ra c ite re g io n a rra n g e d in order.
M ost of these p robably w ill be found on the p ro p erty .
E n tra n c e to the m ine is m ade by a cro ss-m easu re d rift, a few feet above w a te r level in th e valley of th e S ch u y l
kill R iv er. T h is d rift ex ten d s n o rth about 1,500 ft. u n til it strik e s th e R ab b it H o le seam , in w hich a slope h a s been sunk w hich ru n s on a pitch of 30 to 39 deg., b u t p arallel in plan to th e e n te r
ing d r if t a n d only a few feet aw ay from it. In consequence, th e e n tra n c e of th e d rift an d th e end of the R ab b it H ole w o rk in g s a re v ery close to one an o th er, as seen in plan, b u t sev eral h u n d red feet a p a r t in elevation. A t equal d is
tances, levels h av e been laid off in the R ab b it H o le seam to th e left a n d rig h t
— th a t is, ro u g h ly east a n d w est— and from these R ab b it H ole levels on th e w est side of the slope have been d riv e n h o rizo n tal tunnels, a g a in doubling on the slope a n d ru n n in g parallel to the m ain cross-m easure d rift an d th u s fo rm in g the base of a le tte r Z, a sh o rt b ase indeed but lo n g enough to reach the T u n n el bed, w hich, as T ab le I show s, is the n e x t below th e R ab b it H ole. F ro m the intersections of these cro ss-m easu re tu n nels w ith th e T u n n e l bed, levels rig h t
TABLE I
Seams Found in Southern Anthracite Field
S t r a y s e a m B u r k e o r B r e w e r y S t r a y s e a m S o u th S a le m S a le m F a u s t R a b b it H o le T u n n el
G a te , P e a c h M o u n ta in or B la c k M in e (p r o b a b ly a ll th e s a m e s e a m )
L ittle T r a c y T r a c y o r S e lk ir k L ittle D ia m o n d D ia m o n d L it tle O rch a rd . S tr a y se a m
O rchard S t r a y se a m P r im r o s e
H o lm e s , C h u rch or 4 -F o o t F o u r F o o t
M a m m o th S k id m o re
S e v e n -F o o t or W h ite A sh R o u g h
S t r a y se a m B u c k M o u n ta in L y k e n s 1-6 in c lu s iv e
an d left— th a t is, east an d w est— are d riv en to w a rd the b o u n d ary of the p ro p erty . A ll th e tu n n els have a g r a d ient of i p er cent in fav o r of the load.
O p eratio n s of th e S alem m ine d ate back to P o ttsv ille ’s early days, a n d th e g an g w ay s ceased to be extended a fte r 1852. F o r a w hile th e developm ent of the so u th ern field lagged, b u t a b e tte r e ra daw ned about th e b eg in n in g of the cen tu ry . T h e Salem w o rk in g s still lie
full of w a te r to w ith in 20 ft. of th e m ain c ro ss-m easu re d rift. T h e y have g r e a t value as a so u rce of w a te r fo r the Salem H ill b re a k e r. Som e day the m ine w ill be pum ped d ry an d th e re s t of th e coal w ill be rem oved, fo r it has a c re a g e en tire ly undeveloped, probably som e developm ent h ead in g s d riv en but still w ith o u t cham bers, an d som e ch a m b er pillars. Below th e S alem lies the u n m inable F a u s t an d n e x t th e R ab b it H ole, p erh a p s not u n ju s tly nam ed, fo r it is only 2 ft. to 2 ft. 6 in. thick, w h e re a s the T u n n e l bed is 7 ft. in thickness.
B ecause the R ab b it H o le bed w as so th in , long-face m ethods becam e im p e ra tive. A lso, to save expense, th e levels w ere d riv e n w ith o u t re tu rn airw a y s,
•using an a u x ilia ry fan a n d fa b ric pipe.
T h e y w e re th u s ex ten d e d to th e bound
a r y of the p ro p e rty . T h e re w as no b re a k e r a t th a t tim e an d n o th in g b u t developm ent w as attem pted. T o d ay , w hen e x tra c tio n w ill adv an ce w ith de
velopm ent, the use of fan a n d pipe w ill be abandoned in fu tu re levels, and a ir w ill e n te r by a n a irw a y an d re tu rn by a level in th e o rd in a ry m an n er. A s in all a n th ra c ite m ines, th e c o n to u rs of th e seam a re ir re g u la r an d the levels h av e to conform them selves to th e co n to u rs, m ak in g the g an g w ay s som ew hat crooked an d th e d istan ce betw een levels q u ite irre g u la r. T h e c o n to u rs a re s tra ig h te r a t Salem H ill th a n a t m any m ines one m ig h t m ention, b u t th e long faces ru n , nevertheless, fro m 250 to 280 ft., som ew hat fu r th e r th a n the d istan ce betw een levels, fo r the lo n g faces a re c u t a little on th e bias, th u s le n g th e n in g the w o rk in g face.
In m any E u ro p e a n m ines, th e m a
chine c u tte r is held in place by a h o ist a t the u p p er end of th e long face, p u ttin g the co n tro l of th e h o ist in th e h an d s of a th ird m an, w ho is n o t only su p e rn u m e ra ry b u t also can be m ade to p erfo rm h is d uties only by sig n al. T h e G ood
m an an d S u lliv an longw all c u ttin g m a chines c a rr y th e ir d ru m s on th e ir backs, and the m achines a re held in place and m oved up th e pitch, w h ich is th e d ire c tio n o f c u ttin g , by w in d in g on ropes atta c h e d to ja c k p o sts set betw een ro o f
July, 1934
— C O A L A G E 263
an d floor. T h e re a re tw o d ru m s on each cu tte r. C onsequently, th e re a re tw o m eans o f su p p o rt sh ould a ja c k pipe d ra g loose, w h ich it ra re ly does, and th e re is a m eans o f su p p o rt w hen a ja c k p ip e is b ein g m oved to a po in t f u r th e r u p th e face. W ith th e d rum m ounted on th e back of th e m achine, th e c u tte r is n o t 12 in. h ig h b u t a b o u t 18 in., b u t th e seam h as been thick enough th u s f a r th a t th is in creased h e ig h t is n o d e trim e n t.
2 5 0 to 2 8 0 F t. P e r S h if t T h e crew co n sists solely of tw o m en, a c u tte r an d a helper, b o th o f w hom u su ally a re y o u n g hig h -sch o o l g ra d u a te s an d of m o re th a n a v e ra g e intelligence.
T h e y can cut th e full 250 to 280 ft. in a single sh ift, e n o u g h to sa tisfy th e lo ad in g re q u ire m e n ts fo r tw o sh ifts, w hich is as m an y sh ifts a s h av e been w orked h ith e rto in th e lo n g face o p eratio n s. S ix - o r e ig h t-in c h d iam eter posts a r e se t on 4- o r 5-ft. cen te rs to su p p o rt th e roof, w hich, th o u g h co m p risin g on its u n d e r
side 2 to 4 ft. o f clod, holds fa irly w ell fo r a w hile, b u t a fte r a m a tte r o f a few weeks, so m ething, possibly th e lim e
stone, in th is clod sw ells a n d forces it dow n. B y th a t tim e, h o w ev er, th e face h a s m oved along, an d th e fa ilu re of th e clod c re a te s n o difficulty. I t falls am o n g th e p o sts an d fu rn ish e s som e su p p o rt a s th e ro o f lo w ers an d th e bottom rise s to m eet a n d c a rr y the b u rd e n of th e m a in roof. N o deep holes a r e m ade in w h ich to sin k th e posts, b u t a little o f th e san d y sh ale is scuffed off w ith th e pick b efo re a p o st is set. T h e se roof s u p p o rts a re erected a few inches out of a n o rm al to th e bed, th e u p p er end b ein g th e fu r th e r up th e pitch, so th a t a n y m ovem ent of th e ro o f tends to m ake th e posts m o re n e a rly a t rig h t a n g les to th e floor, th u s tig h te n in g ra th e r th a n lo osening them . T h is is g e n e ra l p ra c tic e in p itc h in g seam s ev e ry w h e re in th e a n th ra c ite region, a n d is m entioned h ere only because, in c e rta in B ritis h m ines w ith longw all an d soft bottom , it h a s been fou n d th a t the bottom m oved dow nhill re la tiv e ly to the top, so th a t th e le a n in g post, in stead of tig h te n in g , fell over.
W ed g ed cap pieces a r e set, ru n n in g up a n d dow n th e p itch . T h e se a re 12 o r 14 in. long, 6 to 8 in. w ide, so as to c o v er th e post, a n d ab o u t H in. thick.
T h e y a re m ade of m ill scrap." P o sts a re n o t pointed. T h e coal seam is c u t in the b ottom close to, b u t above, th e floor.
F o rtu n a te ly , th is section of th e seam is re a d ily cut. K e rfs a r e m ade a b o u t 54 ft. deep. S o m etim es th e coal w h en shot w ould fall a lo n g ex cessiv e le n g th s of face, an d to p re v e n t h a v in g coal falls th a t w e re so b ig th a t th e y could n o t be re a d ily red u ced to su itab le lo ad in g p ro p o rtio n s, w ood w edges, o r sp ra g s, h ad to be in se rte d u n d e r th e c u t a t in terv als, so th a t sh o ts w ould n o t b rin g dow n an v m o re coal a t one tim e th a n read ily could be handled. T h e face in m an y cases
Fig. 2—Section of the Longface W ork in Rabbit H ole Seam.
w as w illin g to fall w ith o u t b ein g shot, if no sp ra g s w e re used to hold it up.
B ro k en coal a t th is m ine h a s h ith e rto refu sed to slide read ily dow n the face on sheets o f iro n , even th o u g h g a lv a n ized sh eets a re u sed e v e ry w h e re a t th is colliery. S u ch sheets a re fav o re d to p re v e n t c o rro sio n as m uch a s to a ffo rd m ore easy m ovem ent of th e coal on th e p itch . A s th e coal w ould n o t ru n , b ein g h in d e re d by th e b u g dust, w h ich is slu g g ish on an y b u t a p itch ex ceed in g 35 deg., 35-hp. d o u b le-d ru m h o ists h av e been p ro v id ed a n d th e coal is aided in its d escen t by sc ra p e rs, th e w o rk of d is
lo d g in g th e coal by lig h t sh o ts s ta rtin g a t th e u p p e r end. A s soon as a section of th e coal face is cle a re d of coal by th e sc ra p e r, p o sts a re erected to re ta in
th e roof. T h e face is k e p t a t th e top in adv an ce of th e bottom , so th a t coal, in fa llin g dow n th e pitch, w ill keep n e a r th e face, a n d coal fa llin g aw ay fro m the face w ill tre n d b ack to it a n d be col
lected by th e sc ra p e r. T h is also is the sa fe r w ay to o p erate.
T h e sc ra p e rs, th o u g h sm all in th e m selves, b rin g dow n a b o u t 30 cu.ft. of coal in each trip , fo r m uch coal is d riv e n ah ead of th e scoop. S o m etim es the clod, in places w h ich h a v e b een sta n d in g a lo n g tim e, h a s been fo u n d to h ave fallen . In th e w o rk in g s h ith e rto op
e rated , ch am b e rs w e re d riv e n up be
tw een levels a t in terv als, a n d w o rk w as sta rte d on th e rib s of th ese places, usually re tre a tin g b u t som etim es ad v an cin g . I n such places, it w as n ecessary to clean Schuylkill
River
Fig. 1—Cross-section of Measures at Salem H ill (some saddles recently dis
covered are not show n).
7 seam y '5.5se a m
264 C O A L A G E — Vol.39, No.7
up the clod b efo re th e c u ttin g m achine could g e t to w ork.
F ro m now on, th e w o rk w ill be w holly on th e ad v an ce, a n d no tro u b le p robably w ill be ex p erien ced w ith the clod. T h e p itch is expected to be heavy enough h e re a fte r, th a t the coal w ill ru n dow n w ith o u t th e help of a sc ra p e r. N o t only does th e clod fall in a confused m ass, b u t th e b o tto m also heaves, an d the ro o f descends to m eet the clod.
T h u s, th e w e ig h t of th e ro o f is taken by th e floor. In no case does th e h eav in g of th e floor cause tro u b le w ith m ethane, of w h ic h th e bottom is entirely
free. T h e g re a te s t in clin atio n th u s far h as been 39 deg., b u t in th e im m ediate fu tu re it m ay be n ecessary to c u t faces ru n n in g as steeply as 44 deg. H o w ev er, no difficulty is a n tic ip a te d on th is score, an d , even if it w e re to cause trouble, th e in clin atio n could be suitably reduced by m a k in g th e cut m o re on th e bias.
L iv es o f m a n a g e rs in th e a n th ra c ite re g io n w ould be m ade m uch h ap p ier if th e beds w ould tra v e l dow n the pitch w ith o u t th e in tro d u c tio n of saddles o r rolls. U n fo rtu n a te ly , a bed ra re ly goes s tra ig h t dow n th e pitch. O nce in a w hile, th ese beds w ill h a v e a fold and th e u p p er level w o rk in g s com e up a g a in s t such a saddle, w here, instead of a p itch o f 30 to 39 deg., th e re is a sh o rt dip o f v a ry in g inclination, in one place re a c h in g 85 deg., w hich upsets all calc u latio n s b u t serves, nevertheless, to m ake th e m an ag e m en t ap p re c ia te the m ore th e con d itio n s o b ta in in g w h e re the dip is u n ifo rm . A s th e dip ru n s n early south, th e saddles, a n d th e re a re a t least th re e th u s fa r, ru n east an d w est. A lso the beds occasionally a re lo st o r reduced, as if p re s s u re h a d squeezed them w hen still in th e p la stic state, fo r th ey usually re a p p e a r la r g e r th a n ev er. I n th is mine, a p p a re n tly , n o tr u e fa u lts h av e been found, a n d n o n e o f th e coal losses have n ecessita ted le n g th y p ro b in g s o r long tu n n els, b u t th ey a r e v ex in g , n e v e rth e less.
H e re a fte r, a s stated , th e longface w o rk w ill be developed b y a g a n g w ay
an d a n a irw a y jo in ed a t 25-ft. in terv als by crosscuts o r chutes w h ich w ill be a b o u t 15 ft. long, as show n in F ig . 4.
A t a point about 7£ ft. from th e g a n g w ay, the chutes w ill w iden rig h t an d left— except the first one, w h ich w ill w iden only inbye— a t a n angle of 45 deg. T h e longfaces w ill be directed a t a n angle depending on th e dip of the seam an d experience. T h e coal, w hich w ill ru n on th e floor, w ill tra v e l th ro u g h one of these chutes an d be d irected to th e d isch arg e p o in t by th e inclined sides of th e chute. A s soon as the coal face has m oved fo rw a rd sufficiently th a t the
broken coal can no lo n g er use th e chute it has ju s t recen tly been trav elin g , th a t chute w ill be stopped w ith a tile b r a t
tice w h ich w ill be covered la te r w ith cem ent on the side of positive p re s su re
— in th is case, th e a irw a y side. W h en th u s coated, th e cem ent m o rta r is forced into a n y open crev ice an d fills it in stead of b ein g forced out. T h is is g en eral p ractice a t th is m ine. I t m akes the b ra ttic e m o re leakproof.
L evels a re show n 225 ft. a p a rt, b u t th a t distan ce w ill v ary . P ro b ab ly a sm all p illa r a b o u t 10 ft. w ide w ill be left betw een th e top of the w o rk in g s in th e level b ein g o p erated and th e level above it. T h a t level is also p ro tected b y a line of c rib s on th e u p p er side, so it is expected th a t th e a ir w ill continue to find it sufficiently open fo r en try . Some a ir w ill flow dow n th e face and som e w ill trav el th ro u g h the unclosed go af back of th e face. T h u s it w ill trav el p a rtly up th e a irw a y and p a rtly th ro u g h the chute dow n w hich th e coal is tr a v eling. O f course, th is plan is p red icated on p re se n t conditions w ith about 500 ft.
of cover. W ith g re a te r depth a new p a tte rn m ay h ave to be devised a n d fol
low ed an d th is plan m ay n o t p ro v e e n tire ly feasible even today an d need m in o r revision. H o w ev er, th e re w ould seem to be no reaso n to believe th a t it w ill n o t prove a t least as sa tisfa c to ry as th e m ethod o r m ethods it replaces.
W ith 7-ft. coal in th e T u n n e l bed, the m anagem ent fav o red th e use o f th e
ch am b e r-a n d -p illa r m ethod. T h e coal in th e bed is a little disposed to be d is
lodged w ith o u t shooting, b u t as th e in c lin atio n is only a little ov er 30 deg., th a t ten d en cy is n o t likely to g iv e m uch trouble. Y et 26 lin e a r feet of coal a fte r s h o o tin g have d etac h ed them selves o r been d etached by g a s p re s su re in one place, an d th e po ssib ility of such slide sh u ttin g dow n th e g a n g w ay , im p riso n in g m en o r s h u ttin g off th e a ir in the g a n g w ay is w o rth g u a rd in g a g a in s t, so ch am b e rs a re not opened all alo n g th e g a n g w ay b u t in g ro u p s of fo u r, an d in th e deepest level in g ro u p s of th ree, by le av in g one room o u t in ev ery five o r in ev ery fo u r, as th e case m ay be.
T h e w ide blocks of coal th u s left a re a t th is m ine d escribed as “ re se rv e p il
la rs.” T h is p ra c tic e also p re v e n ts a squeeze once sta rte d fro m co n tin u in g u n o b stru cted all ov er one side of the m ain slope. I t m u st be rem em bered th a t the p illars a re to be left fo r some tim e. N o n e h av e been as y e t w ith d ra w n . T h e y hold up th e roof, w hich c o n stitu te s th e floor on w hich o p e ra tio n s a re b ein g conducted in th e R ab b it H o le seam above. H o w e v e r, as the b o u n d ary of th e p ro p e rty is approached, th is p re c a u tio n is n o t taken, as less an d less of th e te r rito ry needs protection.
R oof in the T u n n el seam is never good. L e ft to itself it w ill cave to a h e ig h t of 8 ft. in a n a rro w place. Its p ro n en ess to fall is in h e re n t a n d is not the outcom e o f chem ical action, d ry in g o r m oistening, th o u g h it responds to som e such actions, fo r q u ite u su ally it w ill d estro y the first sets o f tim b ers an d re q u ire re tim b e rin g . T h e cham bers a re w idened a t a p o in t a b o u t 10 ft. above th e a irw ay , an d , if th e ro o f w ill p e r
m it, th ey a re m ade 20 ft. w ide, but som etim es it is n ecessary to u se heavy co llars acro ss th e ch am b er w ith la rg e tim b ers an d to p u t la g g in g o v er th e co l
lars. R oom w id th also h as to be n a r row ed. N o s ta n d a rd m ethod of tim b e rin g h as been adopted. T h e ru le is to tim b e r as m uch as is n ecessary . T h e coal in th e T u n n el bed is not u n d e r
cut, b u t sh o t off the solid.
C h u te s a t 5 0 -F t. C e n te rs A ll th e g an g w a y s h av e an a irw a y , an d a t each ch am b er a c ro s sc u t o r chute is provided, so th a t th e c h u tes a r e a t 50-ft. cen ters, a chute b ein g provided a t th e cen te r of each re s e rv e p illa r as if it w ere g o in g to serve a ch am b er like the o th e r chutes. G alvanized sheet iro n is used in th ese places. T h e ch am b e rs a re fro m 275 to 300 ft. long. S c ra p e rs a re n o t used in a n y of th e ch a m b ers. W h e n saddles d istu rb th e re g u la r in clin atio n , 40-cu.ft. steel b u g g ies a re provided, an d th e coal is shoveled into these, a n d th e c a r ru n do w n o r pushed u p on tra c k s to a p o in t in the ch u te w h e re th e in clin atio n w ill suffice to c a rr y th e coal aw ay . T h u s fa r no c o u n t
e rs h ave been d riv e n to c u t off th e room s a t th e p o in t w h ere th e roll o r
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Fig. 3—Section of the Chamber-and-Pillar W ork in Tunnel Seam.
July, 1934
