C o a l A g e
Established 1911 McGraw-Hill Publishing Company, Inc.
DEVOTED TO THE OPERATING, TECHNICAL A N D BUSINESS PROBLEMS OF THE COAL-M INING INDUSTRY S Y D N E Y A. H A D E . BdUor
N e w York, Decem ber, 1 9 3 5
The “Old Company
H a r d c o n d i t i o n s
breed strong men, lusty institutions and powerful traditions.
No better illustration of this fact could be asked than the history of the Lehigh Navi
gation coal developments. Started more than a century ago by Josiah White and his associates after two earlier groups had aban
doned the enterprise, desperate courage and bulldog persistence won success over difficul
ties which would have sapped the spirit of less sturdy souls.
I n s t i t u t i o n s ,
like men, however, either grow with the years or decay. To management at Lehigh Navigation, the her
itage of Josiah Whi te’s pioneering spirit and resourcefulness has been received as some
thing to emulate as well as to admire.
Throughout its long career, Lehigh Naviga
tion has shown a recuperative vitality that has kept it a leader in anthracite colliery practice and an eagerness to break new ground matching the zeal of its founders.
T h e RECORD
of pioneering develop
ments in Josiah Whi te’s day set new land
marks; the records of his successors have been no less significant. As part of the de
velopment of a system for recovering coal from heavily pitching seams, for example, Lehigh Navigation drove the first mining tunnel in the United States. Some of the earliest wet-cleaning processes were the brain children of its men. Again, at Hauto, Lehigh Navigation pioneered in mine-mouth generation of electrical energy.
S t r i p m i n i n g
at Lehigh Navigation properties is as old as the parent Lehigh company, for that method of recovery was employed at Summit Hill in 1820. Today, Lehigh Navigation stands as a leader in anthracite stripping practices. When big shovels were regarded as suitable only for bituminous open-pit work, the Navigation company demonstrated its faith in larger- capacity buckets at Cranberry.
W i t h t i m e
there are some institutions which grow richer in years and poorer in achievements. But Lehigh Navigation man
agement never has regarded great age as a passport to lasting fame or glorious tradi
tion as a justification for present inaction.
On the contrary, the company has taken such advantage of technical progress that today little remains but old rock dumps to attest its long years of existence. Buildings and plants suggest the most recent of develop
ments a product of the present decade rather than operations rooted in the early half of the Nineteenth Century.
T h e “ O l d C o m p a n y , ”
in truth, is old
only in name. While the record of its past
achievements, so sketchily indicated in the
preceding paragraphs, is impressive, the
manner in which it is meeting present-day
problems of production and merchandising
is still more inspiring. These methods of the
Lehigh Navigation Coal Co. are made the
theme of this issue — C oa l A g e ’s Fifteenth
Annual Model Mining Number.
S. D . W A R R IN E R J. B. W A R R I N E R
Chairman o f the Board President
L E H IC H
N A V I G A T I O N
C O A L
C O M P A N Y
FLASHBACKS
In O ld Company History
T
E N \ E A R S after the last gun in the R evolu tionary W ar had been silenced, a w eary hunter m oving through the d eepening shadows of P a n ther Creek valley stumbled over a strange black substance. Could P h ilip Ginter revisit the scen e o f h is 1791 d iscovery to
day he w ould find several thousand men busy m in in g that sam e black substance for shipm ent to m arkets w h ich then w ere w ildernesses. H e m igh t even see— to his eyes— lan tastic m achines takin g great bites out o f th e v e r y ground w here once he stumbled. F o r the triflin g m ishap o f this lonely N im ro d w as to lead to the commercial d evelopm ent o f the L eh igh anthracite field and th e lau nching o f a producing organ ization w h o se corporate history goes back to 1820.
W hile there is no record to indicate that P hilip G in ter’s visio n could leap the years, he did h ave a hazy idea that the substance m ig h t be som e o f the new
"stone coal” w h ich had been used by a few blacksm iths and a t th e C arlisle ar
senal during the late w ar. S o he show ed his find to h is frien d Col. Jacob W eiss, of Fort A llen , w h o w as interested enough to take it to P hiladelp hia, w h ere G inter’s guess w as confirm ed. T h e n ex t year, the colonel and a grou p o f associates w h ich included R obert M orris, financial angel to the R evolu tion, banded together in the Lehigh Coal M in e Co. and purchased between eig h t and ten thousand acres o f coal lands betw een M auch Chunk and Tamaqua. R iv er transportation costs ranging from S9 to $18 per ton for coal selling at th e m ines at SI to $2, the hazards o f that form o f tran sportation and deep-rooted consum er p referen ces for wood, B ritish and V ir g in ia coals caused the tem porary abandonm ent o f the p ro j
ect a few m onths after the n ew com pany had built a road from the m ines to the Lehigh R iv er near M auch Chunk.
A lthough som e im provem ents in n a v i
gation w ere m ade in 1798, the L e h ig h Coal M in e Co. did n ot resum e opera
tions until 1803. O n ly tw o o f the six arks floated tow ard P h ilad elp h ia that year, however, reached d estination, and great difficulty w a s exp erien ced in se llin g these cargoes. T h e n ew coal received its first real b oost w h en Ju d ge F ell in 1808 dem onstrated that it could be burned in an open grate. F u rth er im petus w as
given the in fan t industry during the W ar of 1812 w hen the A tlan tic coast ports w ere closed to V irginia and foreign coals.
Jacob Cist, Charles M iner and John Rob
inson w ere so im pressed w ith the p ossi
b ilities o f expansion that they negotiated a lea se w ith the discouraged" ow ners for the d e\ elopm ent of the L ehigh properties.
W h ile t i e n ew lessees escaped neither the perils o f n avigation nor, at the out
set, the indifference of consum ers, risin g p rices for charcoal spurred m anufac
turers to m ake a real attempt to use anthracite, and prospects for the venture brightened. W ith the end o f the w ar, h ow ever, the bottom dropped out of thé coal m arket and the business again w as abandoned.
In the m eantim e, fate w as preparing the w a y fo r th e entrance o f a n ew group o f p ioneers w ho w ould pick up the broken threads and w eave them into a m ore la stin g pattern o f success. E arly in life, Josiah V hite, a sturdy Quaker lad from M t. H o lly , N . J., had resolved that, if he could accum ulate $40,000 by the tim e he w as 30, he w ould retire from active business, becom e a gentlem an farm er and g iv e full p lay to h is suppressed in clina
tions for th in gs m echanical. A pprenticed to the proprietor of a Philadelphia hard
w are shop at fifteen and the ow ner o f a business in that lin e before he had at
tained h is m ajority, Josiah reached his g o a l at the age o f 28. H e bought h is farm,
but alm ost im m ediately becam e intrigued w ith the future o f w ater power and in
land w aterw ays.
T h e record of w ater developm ent in P en n sylvan ia had been a sorry one. T w o canal projects had been abandoned and no public im provem ent by n avigation had y et succeeded” in p ayin g dividends in the State. D am m in g o f large stream s w as looked upon w ith su spicion and d is
trust. "H ere w as a ch oice,” h e said in h is y ellow in g diary, ‘'betw een applying m y m eans and m y talen ts in a w a y or singular u se to m y fellow m en and not im pair m y estate and not, as I thought, in volve m e in p lagu e or trouble. T h us m yself and others w ould be benefitted, es
pecially as I believed I had discovered the tru e plan o f m aking dam^ secure bv the manner of la y in g the stone or m aterial on it instead o f a g a in st it.”
S o Josiah W h ite made h is g reat d eci
sion. H is first ven ture in the n ew field w as the purchase o f th e F a lls of S ch u y l
kill, for w hich h e paid $14,000 in the sp rin g o f 1810, on ly to discover that he had jum ped out o f the fry in g pan into the fire and had jeop ard ized h is for
tune. E m barking into partnership w ith E rskine H azard in a nail factory as one m eans o f u tilizin g the falls, he w ry lv w rote that, w hen h e needed lo w w ater, “I usually had h igh w ater.” A lw a y s eager to experim ent, he paid $21 for a ton of anthracite from the first arkload floated F ive o f th e seven active o p eratio n s are co n cen trated in P a n th e r v a lle y
December, 1935 — C O A L A G E
485
down the L ehigh R iver for use in the fac
tory furnace. F ollow in g traditional methods w ith other fuels w ithout suc
cess, a workman closed the furnace door in disgust and started for h o m e ; return
ing some tim e later for a coat he had for
gotten, he found the hopeless fire red hot. A nd anthracite became irrevocably linked with navigation in Josiah W h ite’s dreams.
U nable to agree w ith the plans of those in control of the Schuylkill N avigation Co., Mr. W h ite, then teetering on the edge of bankruptcy, turned his thoughts to the L ehigh district. Late in Decem ber, 1817, riding a borrowed horse and ac
companied by G eorge F . A . H auto and W illiam B riggs, “my stone mason, who also w anted to ride som ew here,” he set out for his first inspection of Panther V alley and reached Bethlehem on Christ
mas Eve. A s a result of that trip it w as agreed that W hite, H azard and H auto would join in the developm ent of n aviga
tion and secure control of the L ehigh mines. “W e three at once set about to get a lease o f tw enty years on the Lehigh Coal M ine Co. coal lands of 10,000 acres for one ear of corn a year, if demanded, and from and after three years to send to Philadelphia at least 40,000 bu. of anthra
cite per year on our own account so as to be sure of introducing this coal into the market, by w hich means they would hope to make their m ines valuable, for thus far they had proved valueless to the L e
high Coal M ine Co.”
T h e necessary authority to improve the navigation of the L ehigh R iver w as granted W h ite and his associates by the State L egislature on March 20, 1818.
T he next month W h ite and H azard w ere at work, sleeping in the woods for a week and using levels borrowed from Benjam in R. M organ, “w ho had retained them as relics of the U nion Canal Co. W e knew o f no other level in Philadelphia, and, if th e re had been, w e w ould have been t o o poor to buy it.” In June, plans w ere
■completed for organization of the Lehigh N avigation & Coal Co., with a capital stock of $50,000, to im prove navigation and develop the m ines. Rebuffed by many who probably lived to regret their skepti
cism s and finding still other men of m eans chary either of the navigation or the coal prospects, W h ite and his part
ners agreed to tw o separate companies.
A s a result, the L ehigh N avigation Co., with a capital of $50,000, w as formed A ug. 10, 1818, and the Lehigh Coal Co., with a capital o f $55,000, on Oct 21,1818.
Less than tw o years later— on A pril 21, 1820— the tw o com panies w ere merged as the L ehigh N avigation & Coal Co.
T he n ext year the name was changed to the L ehigh Coal & N avigation Co. and
m ost con sp icu ous.” A nd in 1825, the com pany shipped 28,393 tons to market.
S tead ily in creasing demand, however, did n ot m ean that all the troubles o f this p ion eerin g com pany w ere at an end. In 1842 a great flood w iped out practically all of the canal w ork w hich had been built som e years earlier betw een W h ite H aven and M auch Chunk, and it cost yearly
$1,000,000 to repair the damage. A sec
ond and still m ore deadly flood occurred in 1863, but, inasm uch as canal traffic had been d eclin in g sin ce 1855, the m ana
gers of the com pany w ere ready to de
vote their m ajor transportation building to railroads.
T h eir first excu rsion in that direction had been made in 1827, w hen a 9-m ile g ra v ity road had been constructed be
tw een the m ines at Sum m it H ill and M auch Chunk. B etw een 1837 and 1846, trackage had been laid between W ilkes- B arre and W h ite H a v e n and joined up as the L ehigh & Susquehanna R .R . Several years later this lin e w as extended to M auch Chunk and P hillip sb urg, and in 1871 it w as leased to the Central Railroad of N ew Jersey. In 1904 the L ehigh Coal
& N a v ig a tio n Co. acquired a controlling in terest in the L eh igh & N e w England R .R ., exten d in g from S latington, Pa., to Campbell H a ll, N . Y ., and increased its stock ow nership in the L eh igh & Hudson R iver R .R ., exten d in g from Phillipsburg, N . J., to M aybrook, N . Y .
S in c e Josiah W h ite relinquished the p residency of the L eh ig h Coal & N a v ig a tion Co. in 1841, n ine successors, includ
in g the presen t incum bent, have occu
pied the presidential chair. M any of them, like the founder, have been leaders not only in th eir ow n com pany but in the industry as a w h o le ; the lon g years of distingu ish ed service of S. D . W arriner, for exam ple, as official spokesman for the anthracite producers are still fresh in m em ory. Josiah W h ite saw production g ro w from the m odest in itial shipments of 1820 to 454,258 net tons in 1850; last year, the com m ercial output o f the L e
high N a v ig a tio n Coal Co. w as 3,657,688 tons and the op eration s had a capacity in ex cess of 4,500,000 tons. T o trace in de
tail the m any ch an ges in the structure and organ ization of the com pany which n ecessarily have accom panied this growth w ould exh au st a volum e. Em phasis in th is prelude has been deliberately placed on the earlier days because the pionering spirit then so d aun tlessly displayed has left a brand w h ich still burns. H o w 1935 m anagem ent is u sin g the rich heritage o f cou rage and resou rcefuln ess bequeathed it by J osiah W h ite and h is associates in m eetin g p resent-day problem s of produc
tion and sales is told in the pages which follow .
incorporated under that name by a special act of the State L egislatu re on Feb. 13, 1822. O ver a century later (in 1 9 3 0 ), the m ining and sales branches w ere sepa
rated from the parent organization to form the L ehigh N avigation Coal Co.
A lthough there are records of scat
tered production and shipm ents o f hard coal go in g back to 1807, the tonnage w as small and the real history of the com m er
cial shipm ents begins in 1820, w hen the L ehigh N a vigation & Coal Co. sent 365 gross tons to the Philadelphia market. In 1821, shipm ents w ere 1,073 ton s; “still,’
remarks Mr. W h ite, “the consum ption of fam ilies in P en nsylvania w as insufficient to take this small quantity, but the bal
ance was sold to factories.” Shipm ents o f 5,823 tons in 1823 resulted in a carry
over of approxim ately 1,000 tons the fo l
low in g spring, and the Philadelphia m anagers begged their M auch Chunk associates to lim it the 1824 m ovem ent to 2,000 or 3,000 tons. Instead, the Mauch Chunk m anagers insisted on sending down 9,541 t o n s !
T h is bold disregard of the recom m en
dations of the early sales agents had m ost fortunate repercussions for the com pany and for the industry. S eein g “so large a stock on hand” at a uniform price of
$8.40 per gross ton, public interest and inquiry grew apace. “S tove m akers and grate sellers now for the first tim e,” w rote Mr. W h ite in h is diary, “began to boast of h aving preferable patterns of grates and stoves for burning anthracite. Som e patriotic ladies also began their sample fires of a n th ra c ite: am ong them, the W id ow Guest in Sansom S treet stood the
N ig h t on Sum m it H ill
Strip sh o v els now w ork w h ere G in ter stu m bled over “sto n e c o a l” in 1791
*486 C O A L A G E — Vol.40, No.12
MANAGEMENT
+ A t Lehigh Navigation Coal Co.
M
a n a g e m e n t in its functional aspects is prim arily cereb ra l:organ ization for action and m anagerial thinking, h ow ever, con
sciously or subconsciously, are influ
enced or determ ined largely by the material conditions surrounding the property to be m anaged. M anagem ent organization in the L eh igh N a vigation Coal Co. m irrors the geograp h ic com pactness of its physical operations w ith five of its seven active collieries con
centrated in the P anther Creek valley—
a narrow basin betw een the L eh igh and Little S ch uylk ill rivers on the eastern edge of the S outhern anthracite field—
and the m ore distant of the other two properties, only fourteen m iles from operating headquarters at Lansford.
Such a set-up encourages sim plification in organization structure, and this the Lehigh m anagem ent has achieved.
T he L eh igh op eratin g organ ization is a com bination o f line and staff w ith functions clearly defined and authority definitely delegated. E xecu tiv e, sales, general p urch asing and accoun ting de
partment headquarters are in P h ilad el
phia ; operating departm ent headquarters, as stated in the p receding paragraph, are at Lansford. S u p ervision and control over all op eratin g departm ent activities are vested in the general superintendent, who reports d irectly to the president.
Jurisdiction o f this departm ent embraces mining, preparation, com pany and con
tract stripping, op eratin g plants and equipment, research, industrial relations and personnel w ork, safety, com pensa
tion and m edical service, h ousin g, w are
houses, supply depots, and forestry.
Im mediate su p ervision of various phases o f the w ork o f the op eratin g de
partment is allocated am on g a staff of fourteen officials (in c lu d in g s ix district su perin ten dents), all reporting to the general superintendent. T h e specific functional assign m en ts to each of these officials and the d ivision al breakdown of their subordinate staff organ ization s are shown in F ig . 1; the w ork o f these d if
ferent grou p s is d iscu ssed in detail in the articles w h ich fo llo w this over-all re
view. In addition to th is gen eral staff, the general superintendent also has an operating assista n t w h o not on ly handles the m any d etails com m only associated with the p osition of aide to a ch ief
operating officer but also has direct charge of public relations in the m in
in g area and, in cooperation w ith the district superintendents, participates in the handling of problem s in volvin g labor
^relations.
W h ile each m ajor staff official is co
ordinate in rank w ith every other m ajor staff official and— subject, of course, to direction and veto by the general super
intendent— is supreme in h is ow n par
ticular bailiw ick, the key position is held by the district superintendents. A ll the planning and all the activities of the staff organization as a w hole have a com m on ob jective: to produce a coal w hich w ill be acceptable to an exactin g m arket as econom ically and as safely as possible. T h is m ay mean a change in m ining methods, an im provem ent in preparation or sizin g, design of new equipment, a revision in maintenance practices or the developm ent of a new m arket outlet. S in ce direct responsi
b ility for production, how ever, rests upon the district superintendent, the po
sition he occupies in the m anagem ent set-up is readily understandable. H e m ust take the plans, the m aterials, the services and the equipm ent developed by the other d ivision s of the operating de
partm ent and translate them into low er costs and a m ore marketable product—
or know the reason w hy.
G enerally speaking, the straigh t-line system of reporting from subordinate in a d ivision to a staff d ivision chief and from the staff d ivision chief to the gen eral superintendent, w ho is the ch ief co ord in ating officer, predom inates in the L eh igh N a v ig a tio n organ ization plan.
B u t th is does not mean that each d iv i
sion o f th e operating department w orks in a sealed compartment. F ar from i t ! M oreover, the organ ization plan makes specific p rovision for certain official cross-reporting between the district superintendents and other d ivision s or d ivision heads. D istrict engin eers, for exam ple, are attached to the office of the m in in g en gin eer, but also report on op eratin g problem s to the superintendent o f the d istrict in w h ich they are sta
tioned. T h ere is a close tie-in between d istrict superintendents and the m echani
cal superintendent on questions relat
in g to equipm ent and m aintenance, and b etw een d istrict superintendents and
the superintendent of preparation and stripping on coal preparation.
Official contact between the operating department and the departm ents located in Philadelphia usually is through the general superintendent, but there are som e exceptions to this gen eral rule.
T h e general shipper, for exam ple, acts as a liaison m an betw een the sales d e
partm ent and the op eratin g department in handling orders for coal shipm ent.
B ecau se inspection of coal loaded for shipm ent is under the ju risd iction o f the operating department and not— as is the case w ith som e com panies— under the w in g of the sales department, th e superintendent of preparation and strip p ing reports on coal inspection directly to the president, to w hom the sales d e
partment also reports.
T h e research d ivision has tw o d istinct fu n ction s: ( 1 ) to m aintain standards of product and o f m aterials used in produc
tion, and ( 2 ) to effect reductions in cost of m aterials and procedures and to de
velop new sources of revenue. T h e first function is perform ed in a w ell-equipped laboratory w here coal inspection is con trolled by m eans of siz in g and ash tests and proxim ate analyses. In th e testin g of m aterials used in production, the laboratory w ork s again st definite stand
ard specifications w h ich are closely fo l
low ed by the p urch asing agent.
O n the research side, em phasis at the present tim e is b ein g placed o n : (1 ) new m ethods of m ining, ( 2 ) the handling of exp losives in such a w a y as to reduce exp losive costs and con serve prepared sizes, and ( 3 ) the adaptation o f various types of timber to the special conditions m et in th e m ines. T h e w ork on e x p losives is closely related to the super
visio n of ex p lo siv e practices on the part of the m iners. E ach of these three p ro j
ects is in ch arge of a separate en gin eer.
T he com pany has giv en , and still is g iv in g , e x te n siv e attention to the u tiliza tion of breaker w aste, of w h ich L eh igh N a v ig a tio n has m ore than its share in the anthracite region , in the m anu fac
ture of ceram ic b uilding m aterials. A great deal of study also has been d e
voted to w id en in g the m arket fo r very fine coal in pulverized form .
A ttach ed to the d iv isio n o f prepara
tion and strip p ings is a corps of service en gin eers w h o w ork in clo se con ju n c
December, 1935 — C O A L A G E 487
tion w ith the sales department. T h ese engineers handle consumer com plaints in the field. T h is d ivision also w orks w ith the sales department in service schools held at Lansford for retail d is
tributors and their “trouble shooters.”
M ajor forecasts for development at each colliery— covering production from each level, output from each vein, and the virgin or “rem ining” tonnage from each vein— are projected for ten-year periods subdivided into units of 100 w orking days. A ll coal recovered by stripping is classified as virgin. A t the end of each 100-day unit, colliery de
velopm ent maps are posted to show actual output and the number of feet of gangw ay and tunnel driven as com pared w ith the forecast for that par
ticular period. T onnage also is posted at the same time on the companion graphs to the development maps.
T h is system of forecasting affords both long- and short-range control of actual developm ent work and the e x penses incident thereto. U nder the ac
counting methods of the company, the cost of shafts, main tunnels and main openings for ventilation purposes are capitalized; other development expenses are treated as part of the cost of pro
duction. A ll production-cost item s are reduced to a per-ton b asis; authoriza
tions for capital improvem ents usually are coupled w ith a time element. Thus, w hile the money appropriation for de
velopm ent work m ay be authorized for a specific period, actual expenditure of that portion chargeable to operating costs is controlled by the production rate— i. e., the number of days actually
worked. U nder this system , the p ossi
bilities of inflated production costs in any period due to an attempt to catch up on delayed developm ent w ork are definitely elim inated.
T op m anagem ent at L eh igh N a v ig a tion believes that subordinate officials held directly responsible for th e results achieved w ithin the sphere of their activities should have m ore than a shadowy picture of w hat those results, m easured in costs and efficiency, actually are. E very m onth each district superin
tendent is g iv en the com plete break
down on costs in his district and for the operations as a w hole. T h e inside cost sheet covers 52 individual alloca
tions of expenses fo r: ( 1 ) M in in g and loading, subdivided for ( a ) narrow work, ( b ) rock work, ( c ) chamber work, and ( d ) reopening w ork in gs and recovering p illars; ( 2 ) strip p in g; ( 3 ) . inside transportation, subdivided for (a ) haulage, (b ) h oisting, ( c ) tracks, ( d ) w irin g, ( e ) stable exp en ses, and ( f ) m ine cars; ( 4 ) ven tilation ; ( 5 ) drain
a g e; ( 6 ) general inside exp en ses, and ( 7 ) supplies sold and sm ithing. T h e outside cost sheet, w ith 56 individual allocations, covers exp en ses fo r : ( 1 ) Breakers, subdivided for ( a ) dum ping,
( b ) preparation, ( c ) loading, and ( d ) refuse disposal; ( 2 ) transportation, sub
divided for ( a ) haulage, ( b ) h oisting, ( c ) tracks, ( d ) w irin g, and ( e ) stable exp en se; ( 3 ) general outside exp en se;
( 4 ) heat, ligh t and p ow er; ( 5 ) general colliery expense ; ( 6 ) adm inistrative e x p enses; and ( 7 ) reserves for local taxes, com pensation insurance, m in in g hazards, depreciation, am ortization of m ine de
velopm ents, depletion and am ortization of leaseholds.
T h is breakdow n is further subdivided to sh o w : ( 1 ) Labor costs for ( a ) operation, (b ) repairs and m aintenance, and ( c ) total labor costs per ton ; ( 2 ) m aterial costs sim ilarly subdivided; ( 3 ) com bined labor and m aterial costs, and ( 4 ) the in crease or decrease per ton for each o f the 108 individual allocations com pared w ith the sam e period in the p receding year. Com parative data also are g iv e n on the num ber of m ine cars loaded, a verage load, hours worked, com m ercial production and the percent
age of each size loaded out.
In sid e and outside section foremen also are furnished w ith sectional costs for each pay period at their particular colliery. T h e form con taining these data g iv e s the num ber of cars produced and total and per-car costs for m ining, repairs above ga n g w a y , starters and loaders, tim bering, narrow and rock w ork, total section cost, transportation, ven tilation, d rainage and m iscellaneous costs, w ith com parative and cum ulative total costs for each section of the mine.
T h e forem an ’s breakdown on outside costs sh ow s totals and per-car costs for transportation, breaker, m aintenance and m iscellan eou s. In addition, he is given sim ilar figures on heat, lig h t and power costs, gen eral colliery, and adm inistra
tive exp en ses. In th is w ay, each sec
tion forem an is as fu lly inform ed as to cost resu lts in h is particular field of operations as h is superiors are for their larger dom ains, and is enabled to work out exact production costs for each work
in g place in h is section.
Fig. 1— T he straig h t-lin e system p redom inates in the L ehigh N a v ig a tio n C oal Co. o p e ra tin g d e p a rtm e n t o rg a n iz a tio n
A s ^ o _ c o a l J n _ s p e c H o n _ J{ p R E S , D E N T
G E N E R A L SUP ERIN TEN D EN T
M E C H A N I C A L SUPERINTENDENT
SUPERINTENDENT P R E P A R A T IO N AND STRIPPINGS
O PERATING A S S I S T A N T
D IR EC TO R OF RE SEA RC H AND
P E R S O N N E L
--- --- - ---
M e c h a n i c a l
E n g i n e e r - Co-Operated
S tri pping s C h i e f
C h e m i s t
E l e c t r i c a l
E n g i n e e r - C o a l
P r e p a r a t i o n R e s e a r c h E n g i n e e r s
C o n s t r u c t i o n
S u p e r in te n d e n t - C o a l
I n s p e c t i o n F i re
I n s p e c t o r
S h o p s C o a 1
S e r v i c e S a f e t y
E n g i n e e r B p - g si' ra
P l a n t R e ta il Coal
S a l e s Compensation
a n d Medical Service M a c h i n e r y
I n s p e c t o r s S t o r a q e
Y a r d Real
R o a d R e p a i r
D e p a r t m e n t Employment
B u r e a u
D I S T R I C T SUPERINTENDENTS
^As fp_prepaiyifion_
_As_t°jpjpçhjne ry_
I n s i d e F o r e m a n
. 0c -it 5<b
§•
_ i f . O u t s i d e
F o r e m a n
C o l l i e r y E l e c t r i c i a n
C o llie ry S t o r e k e e p e r
C o llie ry S h i p p e r
MINI NG E N G I N E E R
C o n t r a c t S t r i p p i n g s
D i s t r i c t E n g i n e e r s
L e a s e d P r o p e r t i e s
_ _ S t o r e h o u s e ! __
I n s p e c t o r
F o r e s t e r
G e n e r a l S h i p p e r
Mi ne I n s p e c t o r
L a b o r R e l a t i o n s
Public R e l a t i o n s
C h i e f o f P o l i c e
488 C O A L A G E — Vol. 40, N 0.12
MINING METHODS
+ A t Lehigh Navigation Coal Co.
W
I T H steep p itches and substantial coal thickn esses as the gen eral rule, the L eh ig h N a v i
gation Coal Co. em ploys a v ariety of m ining system s a t its seven active oper
ations. S upplem enting m ethods de
signed for application in steeply pitch
ing m easures is th e u se of m echanical m ining aids w h ere less than a sheet- iron pitch ex ists. W ith the exception of the C ranberry colliery, in th e E astern Middle anthracite field, L eh igh N a v ig a tion operations, h ow ever, are located in sections o f th e S outhern field w here folding w a s m ost se v er e; relatively flat areas, therefore, are the exception.
The seat o f th e com pany's m ining operations is in th e P anth er Creek v a l
ley, and b etw een th e L ittle Schuylkill and L eh igh rivers. A c tiv e collieries in this valley a re : N esq u eh on in g, L an s- ford, Coaldale, G reenw ood and T am a- qua. A llia n ce co lliery lies farther w est in the S outhern field near M iddleport.
M axim um w id th o f th e P anth er valley basin, w h ich spoons out and ends near Mauch Chunk, on th e L eh ig h R iver, is two m iles.
Compared w ith L e h ig h N a v ig a tio n operations in the S outhern field, pitches at Cranberry collier}', in th e H azelton basin o f the E astern M iddle field, are relatively flat. M axim u m pitch in local areas at C ranberry is 90 deg., varyin g from th is m agnitu de to flat. In general, how ever, th e p itch seldom exceed s 30 deg., and in the section s w ork ed at pres
ent no pitch steeper than 35 deg. is en countered.
T h e M am m oth is the th ick est bed worked a t Cranberry, a v era g in g 23 ft., against 2 \ to 8 f t fo r the other beds mined. P re sen t op eration s in th e M am moth, w h ich w a s first-m ined years ago, are confined to robbing pillars. A s a result o f cru sh in g and ca v in g in the bed, the M am m oth pillars are attacked from the F o u r F o o t sp lit beneath. F rom gan gw ays in th e F o u r F o o t, b ed -h eigh t chutes 10 f t w id e are d riven up the pitch on centers o f 8 0 to 100 ft. S tart
in g at th e tops o f these chutes, slants are turned to th e rig h t and left at in tervals to m eet sim ilar slants from ad
jacent ch u tes. F rom th ese slants, rock holes are punched through the 4 ft. ( a v
er a g e ) interval to strike the various M am m oth pillars.
O ther beds at Cranberry, from w hich m ost o f th e v irgin -coal output comes, are m ined by the breast-and-pillar sys
tem. F rom th e gan gw ays, chutes are driven up the pitch 15 ft. to start the breasts. B reast w idth is 24 ft. Centers as a rule are 50 f t , leavin g a 26-ft. pil
lar. P illars are robbed by cutting across the ends and then skipping them dow n to the gan gw ay. If, as occasional
ly happens, w id er pillars are left, they are split by pillar holes and w orked down from the top in much the same fashion.
S heet iron is used to transport the coal on pitches from 35 down to 12 deg. T o facilitate running' coal on in
clinations near the m inimum, galvanized sheets have been adopted. E xp erience has sh ow n that galvan ized sheets have double the life. T h ey also retain a sm ooth surface during idle periods and, therefore, are in better condition for running coal upon resum ption o f opera
tions. O n pitches under approxim ately 12 deg., 35- to 36-cu.ft. b u ggies w ere em ployed in the past, but are rapidly b ein g replaced bv scraper loaders
(p . 4 9 4 ).
V ith, at th e p resent tim e, a m a x i
mum bed thickness o f approxim ately 12 f t , A llia n ce colliery em ploys, in ad
dition to con veyor and scraper units, the
"full-breast” system of m ining. B reasts are driven 24 ft. w ide, in clu d ing m an- w ays, on 5 0 - ft centers. N o coal is drawn from the breasts as they advance, the excess resu lting from m in in g flow in g dow n the tw o m anw ays (o n e on each sid e o f th e b reast) to th e load in g chute. U p on com pletion o f a breast, a 6 x 6 - ft pillar hole, or chute, is driven on the bottom rock up the center o f the pillar. F rom th is pillar chute, slant chutes are turned at intervals o f ap
proxim ately 30 f t , startin g at th e top, and the pillar is w orked dow n from these slants. A s a rule, on ly sufficient coal is drawn from the breast to keep it level w ith the dow nw ard course o f p illar rob
bing.
Coal thickn esses are considerably less a t Cranberry and A llia n ce than in the P anther V a lle y area and, w ith the e x ception o f the M am m oth pillar w ork at Cranberry gan gw ays, therefore, are driven in th e bed at th ese co llieries. In the valley, on the other hand, d rivin g has been transferred, as a rule, to the rock or a thinner bed u n d erlyin g the bed to be mined, as com pared w ith the gen eral p ractice in earlier days w h en m in in g w as confined la r g ely to the up
per portions o f the M am m oth and Prim rose beds ( F ig . 1 ) , w h ich u sually w ere developed by slopes and ga n g w a v s driven in the beds them selves. U nd er th is system , breasts w ere d riven as the
Fig. 1— Plan and section of the Panther Creek valley, showing relation of the various coal beds encountered
December, 1935 — C O A L A G E 489
g an gw ays advanced and robbing w as deferred until the gan gw ays had reached their lim its. W ith the great coal thick
nesses prevailing, output from a single breast w as large and its advance cor
respondingly slow . A s a result, gan g
w ay life w as greatly lengthened, w ith corresponding liability to deterioration.
A s m ining w as extended to lower levels, deterioriation of coal gangw ays started earlier and increased in m agni
tude, w ith consequent increases in m ain
tenance cost. T o reduce this cost, g an g
w ays w ere removed from the coal to the rock or the thin veins underlying the bed, particularly in the case of the M am moth. From these main haulagew ays, panel tunnels w ere driven to the bed at intervals of 1,000 to 2,000 ft. From these tunnels, short gan gw ays were driven in the bed, thus perm itting m in
in g and robbing in the panel sections before gangw ays required m ajor repairs.
Further im provem ent in drilling equip
ment and explosives has been reflected by a strengthening of the trend toward rock or thin veins for development work, w ith the result that now gan g
w ays and airw ays usually are placed be
low the bed, w hich is tapped by rock chutes.
Shafts are em ployed exclu sively in the Panther Creek valley. Levels are es
tablished 200 to 225 ft. apart, measured vertically, and from each level cross
measure tunnels are driven to intersect the various beds. Only occasionally, however, are gan gw ays turned off these tunnels in the beds them selves. U sually, the connection is made to a haulage gangw ay in the Skidmore bed under the Mammoth. W here the Skidmore is too close to the Mammoth or is in bad con
dition, the Seven F oot bed is used if not too far aw ay; otherw ise, the g an g
w ay is driven in rock. Occasionally, a haulage gan gw ay is driven in the leader above the Buck Mountain bed, but only w here the Buck Mountain is vertical and gan gw ays in the bed itself cannot be held open. A s a rule, however, main haulage gan gw ays on each level are driven under the .Mammoth, and other beds, if mined, are developed from panel tunnels turned off the main gangw ays at
1,000- to 2,000-ft. intervals.
In drivin g rock tunnels, prim ary haul
age gan gw ays and subsidiary openings, post-m ounted w ater leyner drills are em ployed— two in rock tunnels and one in Skidmore or other thin -vein gan gw ays.
Rock work, including m ucking, g en erally is contracted. D rillin g crew s usually consist of a chargem an, driller and one or tw o helpers, w ho drill and shoot the face on one shift. O n the n ext shift, a mucker boss and four men load out the broken rock and prepare the face for drilling.
W ith hand m ucking, drilling depth is adjusted to g iv e a daily advance of 1.8 lin.yd. in an 8 x l2 -ft. place, y ield in g ap
proxim ately 8 cars of m uck at 115 cu.ft.
per car, level full, w hich provides a full sh ift’s w ork for a m ucking crew . T o reduce the cost of rock work, three M yers-W h aley track-m ounted loading m achines are em ployed at the Lansford, Coaldale and G reenwood collieries.
W ith these m achines, 12 to 16 cars can be mucked per shift, and their use al
low s m ucking tw o 6x8-ft. rock chutes in addition to the face on a sin g le shift.
A ctual shovel output is lim ited by con ditions in the gan gw ay, and to enable it to perform m ost efficiently, at least tw o faces must be m ucked per shovel shift. D riv in g of rock chutes sim ul
taneously w ith the tunnel or g a n g w a y face offers still another ad vantage in that the rock chute n ext to the face can be blasted first and the m aterial thus yielded used as a barrier to confine fly dirt from the face rounds to a com para
tively short area n ext to the face. Still higher m ucking records are possible in d rivin g double-track tunnels, w hich are made by drivin g a standard-sized tunnel and then slabbing one side to th e re
quired width. W ith one face and one slab, or skip, to load from , one loader at L ansford colliery averaged 23 cars
T a b le I— R e s u lts , in P a r t, o f th e 1925 C e n s u s of I n s id e M in e T im b e r ,
P a n th e r C r e e k V a lle y
L ength, tu n n els and g a n g w a y s, f e e t 522,986 L ength, tu n n e ls and g a n g w a y s tim
bered, fe e t ... 224,880 Num ber o f ste e l tim b er s e t s 2,403 T otal, a ll tim ber sets, in clu d in g ste el 66,252 W ood tim ber se ts lo st by sq u eeze . . 13,417 P er cen t o f to ta l ...,. . 21.0 W ood tim ber se ts lo s t b y w e t r o t. . 3,821 P er cen t o f to ta l ... 6.0 W ood tim ber se ts lo st b y dry r o t. . 46,611 P er cen t o f to ta l . . . .,... 7 3.0 A verage life, w ood tim ber set, y e a r s 5.5
T a b le II L o s s o f T a g g e d P ie c e s o f T im b e r b y C a u se s in P e r C e n t o f T o t a l P ie c e s I n s ta lle d as D i s c lo s e d b y I n s p e c tio n s in 1932 a n d 1 9 3 4
T amaqua Greenwood Coaldale
Treated Untreated Treated Untreated Treated Untreated
1932 1934 1932 1934 1932 1934 1932 1934 1932 1934 1932 1934
Total failed...
Failed, dry rot...
Squeeze...
Robbing...
Sealed off...
14.9 0 . 0 9.4 5.2
33.7 1.3 1 1 . 2 20.9
51.7 42.8
6.5 2.4 71.551.2 10.9 9.4
14.6 3.8 4. 1 5.9 0 . 8
* 34.5
0 . 2 7.4 18.7 7. 1 1. 1
6 - 11 45.3 2 2. 1 14.0 9.2
64.0 46.1 17.9
28.3 1. 1 19.5 0.7
49.1 2.7 26.2 10.7
47.7 1 2 . 0 2 1 . 2 0.9
82.8 33.9 26.9
9.5 Average life of tim
ber failed by dry rot, years, months *
0.3
5-2 * 4-3 * 4-11
7.0
* 9.5
6- 11 13.6
* 12.5
5-1 included the and untreated «mber tagged is installed at the three collieries
*No compilation of average life made in this year.
490
S h a k e r c o n v e y o r d r iv in g c o a l g a n g w a y at A llia n c e c o llie r y
per sh ift for a lo n g period. Company m ucking is the rule w ith the loading m achines.
T im b ering, w here required in tunnels and g a n g w a y s, also is done by the com
pany. T h ree-p iece sets (collar and two le g s ) u sually are installed, although, de
pending upon con d itions, one le g only m ay be em ployed w ith th e opposite end of the collar h itched into the top or bot
tom rock, or le g s m ay be replaced by hitches en tirely. T o reduce loss of tim ber by decay, the com pany started installation of treated tunnel and gan g
w ay tim bers in 1925. N o w approxi
m ately 10,000 sets are in service in nearly ten m iles of op en ings in the P anth er V a lley . P reservatives include W olm an salts, A czo l, zin c chloride and zinc-m eta-arsenite, w ith zin c chloride lead in g in num ber of p ieces treated.
Standards in the valley call for treated sets in all op en in gs w here loss through m echanical dam age or abandoment of op en ings before th e exp ected life of the tim ber can be realized is n ot a lim iting factor. B efore adopting treated timber, every op en in g w as surveyed to de
term ine the num ber and type of sets and the causes of failu re of untreated tim bers then em ployed. T h is survey, sum
m arized in T ab le I, show ed that in a substantial num ber of cases the char
acter and life of th e op en ings would ju stify adoption of p reservatives to in
crease tim ber life over the average of 5-j- years revealed by the investigation.
T reatm en t is restricted to legs and collars, w h ich are purchased already fram ed from w ood -p reservin g com
panies. S h ort-leaf (S o u th ern y ellow ) pine is used e x c lu siv e ly . In the case of zin c-ch lorid e treatm ent, the specifica
tio n s include th e fo llo w in g :
T im ber sh a ll be o f sp ecie, q u a lity , etc., a s n oted in L. N . C. Co. S p ecification G-2 w ith th e fo llo w in g a d d itio n s : tim ber m ust h a v e a t le a s t 20 a n n u la r rin g s in th e 4 in.
fro m th e first a n n u la r r in g out, co n ta in a t le a s t on e-th ird su m m er w ood, h a v e n ot oyer 13 in. o f ta p e r in 9 ft. and n o t over 2 in.
of b ow in 9 ft. o f len g th . P e e lin g o f tim ber sh a ll be don e im m e d ia te ly a fter cu ttin g.
C O A L A G E — Vol.40, No.12
ta ? k m u V t 'b V r» 1 5 0 J er cen t of the inner carefuU v a t a e ^ m0Vei i - T im ber m u st be a fter D e e l i n ^ t n l L a n ? ?e Parated sh o rtly a lter p eelin g to p erm it a ir circu lation .
S ea so n in g sh a ll not cover period of over
™ °n th K' and if, a t the end of th a t fn S ’» *ls n ot s e a s oned su fficien tly
H b ° f ptlon specified it m u st then n^ Sjason ed to ta k e am ou n t of trea tm en t sp ecified. M ixed se a so n ed tim - f-erw L ,is ’. g r \ eil and p a r tia lly season ed timber m u st n ot be placed to g e th er in the tank for trea tm en t, a s it is im p ossib le to secure un iform trea tm en t w ith m ixed s e a soned tim ber. T rea tm en t sh a ll be fu ll-cell with a 3 -p er-cen t so lu tio n o f zin c chloride, w ith m inim um v o lu m etric ab sorp tion o f 40 per cent, or 3 lb. o f dry s a lt per cub ic foot.
Species included in Specification G-2 a r e : sh ort-leaf pine, loblolly pine, spruce pine or lon g-leaf pine. On quality and manufacture, the specifications provide the f o llo w in g :
L ogs m u st be cu t fr e sh ly from sound living tim ber and h a v e good d en sity , butt c u t s ; m ust be free from rot or a n y other defect th a t m a y im p air th eir service ; saw ed off sq uare a t both e n d s ; reason ab ly s tr a ig h t; free from crook s and k n ots ; and closely trim m ed. H e a v ily tapered tim ber is not accep tab le.
notably the “ slant-chute” and “tap” sy s
tem s, to m eet certain special conditions.
B reasts gen erally are driven 24 ft. w ide on 60-ft. centers, although in some cases either the w idth or the centers, or both, m ay be reduced to 18 or 50 ft. respect
ively.
T he breast-and-cutback system (F ig . 2 ) usually is em ployed in the thicker beds. F ig . 2 also show s the hip chute w idely used at Panther valley collieries, w hich elim inates sh oveling in running coal from the m anw ay opposite the bat
tery side of the breast w here the hip chutes are driven in coal, as in F ig . 3.
T h e pitch of the chute also facilitates running m aterial from the face to the loading point in driving. H ip chutes are driven either along the bottom rock in the coal or in the rock im mediately beneath, the latter method being em
ployed w here there is a possibility that
breast, also 15 ft. high, is started up the pitch on the bottom rock. W h en this second breast has been driven the proper distance, the first cutback is started and driven back to the top rock, the loose coal fallin g dow n into the space already excavated. T h e p rocess of exten d in g the breast and d rivin g the cutbacks is then repeated until the old w ork in gs on the upper level are reached, whereupon the pillar is robbed down from the top.
P relim inary to robbing, a 6 x6-ft. p il
lar chute is driven off the top of a rock chute connecting to the ap ex of the hip chute. A pp roxim ately 30 ft. b elow the top of the pillar, a pillar breast w ith straight battery is started off the pillar chute and cutbacks are made substan
tially as in the regular breast. T h e final operation is drilling the thin p il
lars on each side of the pillar breast
Chain-and-flight conveyors permit operation on adverse gradients at Alliance
To obtain accurate data on life and causes of losses, installation of treated timber w as accom panied by ta g g in g of both treated and untreated types. T h is tagging extended to every individual piece in a set, and w as supplem ented by a record sh o w in g ex a c t location o f each piece both in the op en in g and in the set, type o f treatm ent, date o f installation, date of failu re or loss and cause of fa il
ure or loss, as d eterm ined by regular in
spection. U p to the end of 1934, 39 per cent o f the treated tim ber had been lost from variou s cau ses ; the loss o f u n treated tim ber w as 73 per cent. T able II show s losses by causes at three co l
lieries in 1932 and 1934 and indicates the exten t to w h ich dry rot has been checked.
W ith g a n g w a y s and prim ary airw ays
— in m ost cases— below the M am m oth or other bed, and therefore protected by substantial th ick n esses of rock, com plete extra ctio n o f the coal on the ad
vance is n ow the rule at P an th er valley collieries. U su a lly , the b reast-and-pil- lar system or som e m odification is em ployed, supplem ented by special system s,
chutes or batteries w ill be difficult to m aintain if placed in the bed itself.
D riv in g hip chutes below the bed also m akes possible entire elim ination of the battery, as the short rock chute acts as a battery in con trolling the flow of coal from the breast.
W ith the hip chutes below the bed, as in F ig . 2, the first step in breast-and- cutback m ining is d rivin g the m ain rock chute through w hich coal is w ithdraw n from the breast, as w ell as tw o sm aller chutes con n ectin g w ith m anw ays in the breast under the first cutback. T h ese m anw ays are spaced to giv e a breast width of 18 or 24 ft. Then, starting at the top of the rock chute, the opening in the coal is gradually enlarged to both full breast w idth and h eigh t— 15 ft. in th e latter case. T h is breast is driven to the top rock. Sufficient coal is drawn off through the rock chute from tim e to tim e to m aintain a level in the breast w h ich w ill enable the m iners to reach the face w h ile stand in g on the loose m a
terial.
U p on com pletion o f the first breast the coal is draw n off and a second
at Cranberry colliery
(from either or both the pillar or reg- ular-breast m a n w a y s), as w ell as the stumps on each side of the battery, and blasting them d ow n into the pillar chute.
T h e m iners then drop back another 25
° r 30 ft. and start another pillar breast.
W h ere th e bed is vertical or nearly vertical, the pillar chute m ay be z ig zagged from bottom to top rock alon g the center lin e of the pillar to keep the pitch in the variou s section s dow n to approxim ately 35 deg., w h ich eases travel and at th e sam e tim e perm its flow of coal.
In case bed thickn ess d oes n ot exceed breast h eigh t, on ly the one breast alon g the bottom rock w ould be driven, al
though connections to the hip chute w ould be the sam e. I f the coal is thick, how ever, the cutback system is em ployed, and if excep tion ally thick or if the lift to the upper g a n g w a y is lon g, the breasts m ay be driven on ly half length. In “ sp littin g the lift” in this manner a chute is driven up the S k id m ore bed to a point h alf w a y betw een the upper and low er levels, w h ere the usual con n ection s to the bed are driven
December, 1935 — C O A L A G E 491
Fig. 2— W h e re coal thickness is g re a t, th e breast-an d -cu tb ack system of m in in g is em ployed. Sketch show s G reen w o o d co lliery p lan i
Fig. 3— D e ta ils o f th e ju g u la r b a tte ry used in the P a n th e r C reek valley
F ig. 4— M in in g w ith h ip chutes on 120-ft. centers, T am aq u a co lliery
in the rock in preparation for m in in g in the sam e m anner as from connections directly off th e gan gw ay. U p o n com pletion of operations in the upper half the low er half of the lift is m ined in the usual m anner.
A t N esq u eh on in g colliery, hip chutes usually are driven in the coal and are connected to ga n g w a y s b elow the bed by rock chutes. Coal ga n g w a y s are used in the thinner v ein s at th is colliery, w hich, how ever, contribute on ly a rela
tiv ely sm all tonnage. In con trad istinc
tion to the usual p ractice at other valley collieries, breasts are driven off the apex of the hip chutes. P illar breasts are em ployed in robbing in the thinner beds. In the M am m oth and other thick beds, on the other hand, the pillar chute is em ployed.
From this chute slant chutes are turned at 25- to 30-ft. in tervals, startin g at the top, and the pillar is w orked dow n from these.
W ith the hip chutes in coal, batteries are necessitated at N esq uehon in g. T he type usually installed is know n as the
“ju gu lar battery” ( F ig . 3 ) , w h ich is w id ely used in steeply p itch in g beds to facilitate th e ru n nin g of coal from the breast and at the sam e tim e furnish an adequate bypass for air. In this system , the hip chute is w id en ed about 4 ft., startin g about 15 ft. from the point w here the battery w ill be located. T he m axim um w id th is carried for ap proxi
m ately 15 ft., at w h ich point the chute is narrow ed to norm al w id th in the space of about 5 ft.
O ne lon g tim ber set is placed on the stump side of the breast op en ing and another on the opposite side. B etw een these tw o sets a short interm ediate set is placed, the three serv in g to support the stump pillar over the chute. N e x t a row of h eavy props, or jugu lars, is set w ith the props skin to skin in line w ith the bottom le g of the interm ediate set and parallel w ith the bottom rock.
T h e op en ing opposite the battery (S e c . B -B , F ig . 3 ) is then closed off w ith plank or poles, depending upon the w eig h t of m aterial to be supported.
T h e battery itself (S e c . A -A , F ig . 3 ) is form ed by p lacin g vertical props skin to skin to narrow the w id th of the open
in g betw een the ju g u la rs and the bot
tom rock to approxim ately 2 ft., and lik ew ise enough h orizontal props, w ork in g from th e top down, to reduce the h eig h t of the op en ing also to 2 f t . . F lo w of coal through the battery is controlled by the loose coal dn the load in g chute, w ithdraw al from th e chute b ein g re
flected in a corresp ond ing flow from the battery.
Tam aqua is another colliery w here hip chutes are d riven in the coal, in this case from rock chutes 120 ft. apart.
T h ese hip chutes also act as the prim ary airw ay. T w o breasts are driven off a hip chute, one ( A , F ig . 4 ) from the top of the rock chute and the other ( B ) from the ap ex of the hip chute. T h e latter breast is equipped w ith a jugu lar
