C o a l A ge
Established 1911 M c G r a w - H ill Publishing Com pany, Inc.
DEVOTED TO THE OPERATING, TECHNICAL A N D BUSINESS PROBLEMS OF THE C O A L -M IN IN G INDUSTRy
New York, November, 1931
V o lu m e 36 . . . . N u m b er 11
❖
Production Control and the Law
M o r e d i f f e r e n c e s
of opinion are evidenced in industry thinking on produc
tion control than upon any other one of the seven major objectives, except labor policies, in the bituminous stabilization program sug
gested in the September
C o a l A g e .The de
sirability of a reasonable balance between production and demand is universally con
ceded, but the methods by which that balance shall be attained are sharply debated. One group whole-heartedly approves modification of existing anti-trust laws; another cynically denies such modification would be of any help; a minority challenges both the efficacy and the soundness of any liberalization.
W i t h
the announced purpose of the Sherman law “to protect trade and commerce against unlawful restraints and monopolies,”
there can be no quarrel. At the time this act was passed, industry bursting into raw manhood, with social senses undeveloped and ethical concepts vague and muddy, needed some such corrective as the law implied.
Even today, when business is more keenly aware that socially destructive policies spell industrial dissolution, few would ask that the wholesome restraints imposed by the anti-trust statutes be abandoned.
T h e a t t a c k
today comes not from those who would foster unregulated mon
opoly or invite a revival of competitive prac
tices offensive to enlightened business ideals.
On the contrary, the strongest attack is launched by men who see in this body of law statutes twisted out of their original pro
tective purposes into instruments of oppres
sion. Fashioned as a shield to guard the weak from the jungle tactics of the power
ful, these laws compel the small and the weak to participate in jungle competition destructive economically and socially inde
fensible.
Su c h a c l a i m,
retort opponents of modification, distorts of the facts. What business should be permitted to do it can do now if it has the will; lack of genuine desire on the part of industrial leaders, not the law, bars effective action and constructive cooper
ation in remedying existing evils. The fan
cied prohibitions of the anti-trust statutes, says this group, are a smoke screen set up by business men who believe the lone wolf has the fattest hunting.
T h i s s h a r p c o n f l i c t
in opinion in itself is one of the strongest arguments in favor of modification. As was strikingly emphasized at the conference on anti-trust laws sponsored by the New York University last month, despite the fact that the Sherman law has been on the statute books since 1890, there is nothing approaching unanimity of opinion either in business, the bar or the bench as to what can and what can not be done under this act. Members of the Supreme Court of the United States have disagreed in interpretation and application in almost half the cases involving the Sherman and related measures decided by that court.
Certainly, where there is so much confusion of thought after all these years, clarification or modification is imperative. Even those who hold the law now permits reasonable production control can hardly object to a modification which does no more than give that same assurance to others still flounder
ing in doubt.
F ig. 2— S ig n al B uses and a C lea rin g C o n tacto r
i — C over R em oved to Show P lu n g e r. T o g g le , and S prings
F ig. 3— T w o -P o in t C o n tro l o f O n e -T ra c k Sw itch
F ig . 5— T w o E lectrified T ra c k Sw itches in the Y a rd
F ig . 9— E lectric Sw itch T h ro w er at N o . 8 P o rta l
C O A L A G E — Vol.36, No.1T
S I G N A L S Y S T E M
+ Yields Safety and Profit
W
H A T is said to be the m ost extensive installation o f a u to m atic tra c k signals and electric sw itch th ro w e rs in coal m ines of this co u n try is now in operation at the F o rd so n Coal Co., S tone, K y.
S a fe ty w as the principal considera
tion upon w hich the m anagem ent based its decision to m ake an initial installation. E x p erien ce of about tw o y e ars since th e first m ine w as so equipped has dem onstrated th a t the direct o p eratin g saving alone ju s ti
fies the investm ent.
T h ese m ines, controlled by the F o rd M o to r Co. and located on P ond C reek bran ch of the N o rfo lk &
W e ste rn R .R . about 12 m iles from W illiam son, W . V a., are d r if t op
eratio n s in a com paratively level seam and produce norm ally, as a group, ab o u t 8,000 tons p er day. T h e m ain haulage roads of M ines N o. 3, N o. 7, and N o. 8 are com pletely equipped w ith the autom atic signals and sw itch th ro w ers, and M ine N o. 4 is in the process of being so equipped. A t T w in B ranch, W . V a . , an o th er d iv i
sion, w hich produces about 2,000 tons p e r day, tw o sections of the m ain line in th e N o. 5 m ine are sim ilarly equipped.
W ith com plete signal protection and autom atic sw itching it w as found unnecessary to have brakem en on the m ain-line locom otives, th u s elim inat
in g th e m ost hazard o u s class o f w ork.
I n the N o. 8 m ine, w hich has the m ost elaborate system , the increased efficiency of th e haulage u n its m ade it possible to re tire one locom otive.
I n th is m ine th e w ages o f one m otor- m an, th re e brakem en, and th ree tra p p e rs a re being saved. A t the com paratively high daily w age paid by the F o rd in terests this rep resen ts an attra c tiv e e a rn in g on th e investm ent.
E q u ip m en t o f a sta n d a rd type w hich has p roved its w o rth in street
railw ay service an d has been tested in coal m ines, w as selected. T h e signal equipm ent, o p eratin g fro m th e 275- volt d.c. trolley w ith o u t batteries, affords fro n t and re a r pro tectio n to the train s. L am ps o f the signal and pilot indicators a re set an d cleared autom atically as the locom otive tro l
ley w heel engages contactors m ounted close to the trolley w ire.
T h e th ro w in g of tra c k sw itches is n o t full-autom atic, b u t instead is re
m otely controlled by th e m otorm an.
W ith o u t stopping, he s e le c ts'a n d e x ecutes the sw itch position desired by b rin g in g the locom otive co n tro ller to the “o ff” position o r by leaving it on a c u rre n t position as his trolley wheel passes th ro u g h a special contactor.
C om plete signal pro tectio n o f a section o f m ain line including a side
track and th ree branch roads to ac
tive sections is illu strated in F ig . 7.
Signal indicators, pilot indicators, and trolley contactors are show n in th e ir relative locations except th a t the distances are com pacted. T h e type S U D relay boxes a n d signal w ires are placed on th e d raw in g w ith o u t reg a rd to th e ir actu al locations. T h e directional clearing contactors on the branch roads are located a distance fro m the tu rn o u t som ew hat g re a te r th an th e length o f the longest tr ip ; this in o rd e r th a t an inbound locom o
tive will n o t “clear” th e lights o f th e block it is leaving b efo re th e last car of its train has m oved clear o f th e m ain line.
Blocks may. be a rran g e d to any length desired. O n e type S U D relay box is req u ired fo r each p oint o f entrance. Signal equipm ent is d upli
cated on the tw o sides o f th e passing track. T h is allows fo r m oving equip-
F<g. 6— T ra c k Sw itches A re O p e ra te d by M a n ip u la tio n o f th e C o n tro lle r H a n d le
m ent either direction on eith er track, w hich is of special advan tag e a t n ight w hen one tra ck m ay be blocked w ith slate. Signals fo r one w ay operation on each side w ere first installed, b u t la te r changed in fav o r of th e tw o- w ay scheme.
T h e follow ing p a rag rap h s quoted from the coal com pany stan d ard s serve to explain the functions of the equipm ent and indicate th e m ethod o f o p e ra tio n :
1. A DARK signal indicates a CLEAR block.
2. A RED signal indicates a train in the block, entered from some other point.
3. A GREEN signal pilot indicates a train in the block entered from that point.
4. An operator shall not overrun a red signal pilot indication.
5. An operator shall not operate on a green signal pilot indication set by a pre
ceding train, but shall wait in the clear at the point of entrance until the preceding .train has cleared the block, which will be
indicated by the signal turning dark.
6. Operators shall not approach track switches or signal indicator stations at a speed greater than five (5) miles per hour.
7. On a dark signal indication, an oper
ator may advance to the setting contactor of the block about to be entered and, up-n obtaining a green signal pilot at this point, proceed through the block.
8. Should an operator receive both a green and red signal pilot on entering a block which indicates that a train has entered the block from some other point and has right of way preference over the train receiving both the green and red signal pilots; the operator receiving both the green and red signal pilots is to stop his train in the clear, using care not to run his trolley through the clearing contactor of the_ block in question, which would clear the signals in the block and leave the preferred train in the block without signal protection. Only after the preferred train has passed out of the block and cleared the signals shall the operator attempt to enter the block.
November, 1931 — C O A L A G E
571
L e g e n d T ro lle y w ire s
*S ig n a l w ire s (ID =Tvpe S U D re la y b o x
R * R e d fe n s W ^Whife o r d e a r le n s
6 *G reenlens
c d * D ou ble-face sin g te -u m t signaltnatccrfor O " Single-face chub/e-unit p ilo t in d ic a to r
- D ire c tio n a l c le a rin g c o n ta c to r - -M on-directiona! s e ttin g c o n ta c to r
"T h re e -w ire s ig n a l b u s
- E x te n t o f b lo c k , (ic o n ta in in g J u n its )
■■ E x t e n t o f b lo c k (c o n ta in in g 4 u n its )
l ie. 7— Illu s tra tin g E q u ip m e n t fo r T w o "B locks” o f M ain L ine In c lu d in g a S id e tra ck and T h re e B ranch R oads
9. O n fa ilu re to o b tain th e p ro p e r signal pilot indication w hen e n te rin g th e block, the o p e rato r is to sto p h is tr a in and call th e d isp atch er fo r o p e ra tin g in stru ctio n s. H e is n o t to o p erate w ith o u t th e p ro p e r signal o r telephone pro tectio n .
10. B lo ck sig n a ls sh all apply to loco
m otives, m in in g m achines, m ine c ars, push c ars, o r a n y equipm ent th a t m ig h t block th e trac k .
A s indicated by p a ra g ra p h N o. 8 the signal system provides protection against sim ultaneous entrance of tw o train s in to a block. B y a change of connections either end can be given preference over th e o th er entrances to the block.
T h e d raw ing o f a th re e -u n it block F ig. 8, is reproduced to show the equipm ent th a t is housed in the type S U D relay boxes an d to indicate the internal connections. N um erals be
low the signal and pilot lam ps indi
cate th a t these lam ps are in th e sig
nal boxes listed by corresponding num erals. C ontactors o f th e type S U D relay are oil-im m ersed.
Signal control circuits, including
the three-w ire buses connecting the S U D relays, are N o. 12 B & S single conductor double-galvanized solid iron w ire w ith triple-braid w eath erp ro o f insulation. T h e w ires are supported on porcelain knobs m ounted on roof or ribs, depending on clearance and local condition. A t th e le ft in F ig . 2 is a typical signal w ire support. A t the rig h t hand, clam ped to th e trolley w ire, is a directional clearing contac
to r. T h e heavy cable in th e center is not a p a rt of th e signal system b u t is a d.c. pow er feeder.
In order to convey some idea of th e installed cost of th is type of a u to m atic signal system , assum e a hypo
thetical case of a tw o-m ile m ain haul w ith one passing sidetrack and th re e junctions w ith bran ch roads. I f th ree signal blocks are provided fo r p ro tection of this layout, the labor and m aterial will am ount to about $3,000.
I n all of the F o rd so n m ines the gathering sidetracks are protected by signals, b u t fo r th e m ost p a rt these are of a simple h and-operated type.
In stallatio n , of autom atic signals to replace those o f m anual control is in cluded in a ten tativ e p ro g ram of f u
tu re im provem ents.
O ne of the solenoid-operated sw itch th ro w ers w ith cover off is show n in Fig. 1. A toggle m echanism w ith heavy leaf springs assu res a full th ro w of the sw itch points and ex erts a force to hold them in position.
I n F ig . 6 th e locom otive trolley w heel is ju s t passing th ro u g h a sw itch th ro w e r contactor. W h e th e r the track sw itch is unm oved o r is th ro w n to an opposite position d e
pends on w h eth er th e locom otive is coasted th ro u g h the contactor or is operated w ith pow er on. In terp o sed in th e electrical circuit betw een the trolley contactor and sw itch th ro w e r is a control box c ontaining relays and a m agnetic contactor w ith blow out.
T e rm in a ls a re provided fo r sw itch- position indicating lam ps.
I n F ig . 3, w hich is a view from n e a r the m ine portal and looking to w ard N o. 8 tipple, contactors a re in evidence on th e trolleys above the tw o nearest tracks. T h e se contactors are connected in parallel and serv e to operate one tra c k sw itch fro m tw o approaches.
E q u ip p in g u n d e rg ro u n d haulw ays w ith autom atic block signals and re- m ote-control sw itch th ro w s, as lias been done at the F o rd so n m ines, a p p ears to be th e n e x t logical step fo r general acceptance as a m eans o f in creasing the sa fety and efficiency of coal-m ine haulage.
T h e signal equipm ent in use w as fu rn ish ed by the N achod & U n ited S tates Signal Co., Inc., an d sw itch- th ro w e r equipm ent by the C heatham E lectric S w itching S ervice Co.
Fig. 8— W irin g D ia g ram o f a T h re e -U n it B lock
BCD*
'E le c tric tra c k s w itc h a t tu rn o u t
E q u ip m e n t c irc u m s c rib e d is co n ta in e d in one SU D rela y box
572 C O A L A G E — VoI.36, No.11
P H Y S IC A L E X A M I N A T I O N + W o u ld Reduce Accidents
By R. R. S A Y E R S
I
N A L I S T o f accident rates by in d u stries, com piled by the N atio n al S a fe ty C ouncil from re p o rts o f m em ber establishm ents, m in in g w as second on the list in fre -Chicf Surgeon, U. S. Bureau of Mines Washington, D. C.
tw ice th e accident ra te o f those rated w ere A ccidents have very largely been re
duced w here protective m easures have been employed, b u t the n u m b er of accidents a ttrib u tab le to th e hum an
/¿to 1 n m n n n pquAti°n and caused by caielessness, as second class. T h ese findings wen
quency
(49.34 p er 1,000,000 m an- m difterence, and thoughtlessness a re obtained in spite of the fact th a t th ird h o u rs w o rk ed ) and w as first on the increasing an d co n stitu te to d ay th e W 1 W n r-,1 ^ , 1 list m severity rates (8 .9 4 days lost biggest problem in accident preven-p e r 1,000 m an -h o u rs w o rk e d ). In - tion.
d u stries show ing figures m ost com- A s the individual seem s to be the m ost im p o rtan t fa c to r in accident causation, in fo rm atio n as to the p arable to m ining fo r 1930 are
w oodw orking and lum bering, w ith a
freq u en cy rate o f 40.53 and a m eans o f correction m ust be sought by a critical ex am ination o f th e h u m an m achine, so th a t its deficiencies as to stru c tu re o r function will be severity ra te o f 3.3 1 ; and co n stru c
tion, w ith a freq u en cy ra te of 51.57 and a sev erity ra te o f 5.49.
H . W . H ein rich , in his book on
“ In d u stria l A ccident P re v e n tio n ,”
calls a tten tio n to the in accu rate p ra c tice of re fe rrin g to th e cause of an in ju ry as being the cause of th e acci
dent. A person is in ju re d by a fall, the fall is the accident, b u t w h at we need to know , in o rd e r to p rev en t falls, is w h a t caused th e fall. P e r haps instead o f calling th e fall the
“cau se” o f the accident, it w ould be b e tte r to call it the “occasion.” T he cause o f an accident is w h at actually produces it or b rin g s it a b o u t; the occasion is w hat, directly o r in d i
rectly, provides an o p p o rtu n ity fo r th e causal agencies to act o r serves to set them in m otion. W h e n a p e r
son is in ju re d falling d ow nstairs, the fall is th e d irec t cause of the in ju ry b u t n o t of the accident itself, w hich m ay be due to the physiological con
d itio n o f th e victim , w ho m ay have revealed. T h is principle is applied defective^ eyesight, epilepsy, o r m ay to every com plex device used in in- be su ffe rin g fro m som e o th e r disabil- d u stry b u t is neglected w ith reg ard
R. R . Sayers
class p ersons had been placed in oc
cupations involving low accident risk.
T h e relation o f certain physical d e
fects to accidents is ap p aren t to a n y one, such as loss of a n eye, an arm , a leg o r finger. M any em ploym ent m an w ork in g u n d er every lift he eye, b u t as they cannot see th e inside o f the h ea rt they h ire a crane m an w ho is a m enace to him self and every m an w ork in g u n d er every lift he m akes. T h ey tu rn dow n the m an lacking tw o or m ore fingers and hire th e m an w ith active tuberculosis, w hile failing to tak e p recautions to p rev en t th e spread o f th e disease.
T h e y will h ire a m an w ith tw o eyes th a t ap p ear sound, yet w hich are so defective th a t they do n o t enable th e ir o w n er to see the larg est letters on the te st ch art. A ccording to F . N . Schrem , th e re a re m any m ore m en applying fo r w ork in th e average in d u stry w hose eyes ap p ear all rig h t and y et w ho are alm ost blind in one eye th a n there are whose eye defects a re noticeable.
M ost w idespread o f physical d e fects is fau lty vision and, th erefo re, probably the one involved in th e larg est num ber of accidents. S tudies in P en n sy lv an ia have show n th a t m or th an h alf of the to tal accident claim s arise from in ju ries to th e eye. T h e re lty th a t causes him to fall w hen occa
sion p resen ts itself.
In an analysis o f 11,000 fatal and n o n -fata l cases, m ore th a n tw ice as m an y accidents w e re d ue to n o n m echanical ag en ts as w ere charge
able to m achinery in operation. T h is em phasizes the im portance o f th e hu m an fa c to r in accident prevention.
A b str a c t o f a r tic le on " R elation o f I lln e s s to S a fe ty in Mining:,” rea d b efo re th e N a - O ct 1 3 a C o n g ress C ouncil, a t C hicago,
is no m ethod fo r d eterm in in g the to the infinitely m ore com plex device percentage of accidents happening to th a t guides the m achinery. o th e r p a rts of th e body th a t m ight
S tu d y indicates th a t perh ap s man}’- have been avoided had the em ployees’
eyesight been raised to th e p oint o f highest efficiency. T h e fractio n of a second necessary fo r the norm al, healthy eye to com prehend th e c ir
cum stances o f d an g er m ay be all th a t is needed to avoid a blow. In such an em ergency, how ever, seri
ously defective vision is alm ost en
tirely helpless.
of the accidents now attrib u te d to the carelessness, indifference, o r m ental deficiency o f th e em ployee m ay be due to poor health o r to undiscovered o r unrealized physical defects. W h a t is the connection betw een poor health and physical defects and accidents?
T h e H o o d R u b b er Co. found th a t m en rated as th ird class had nearly November, 1931 — C O A L A G E
R . S. S im pson has stated th a t about 70 per cent of o u r m uscular activities are initiated in response to im pulses induced by o u r sense of sight. T h is fact, coupled w ith th e average d e
fective vision m ay, in large m easure, explain m any accidents w hich, fo r w an t of a definite u n d erstan d in g of th e ir causes, are a t present ascribed to carelessness o r heedlessness. I n some plants w here th o ro u g h exam inations w ere m ade it w as fo u n d th a t nine out of every ten w o rk ers had defects o f vision and th a t only a sm all num ber w ere correctin g these defects w ith glasses. In o th er plan ts betw een 60 and 80 per cent of th e to tal num ber em ployed had defective vision.
In some m ines in which the em ployees have been given a physical exam ination the percentage of eye d e
fects seems to be low er than in other industries. I n an exam ination of the eyes of 800 em ployees o f th ree mines of the St. L ouis S m elting & R efining W o rk s and the N atio n al L ead Co., only about 20 p er cent of the m en had defective vision. In an exam ination by the U . S. B ureau of M ines of 1,098 m iners, 21.4 p e r cent w ere found to have defective vision in one o r both eyes. T w en ty of 81 appli
cants w ho presented them selves fo r exam ination fo r certificates as hoist
ing engineers in U ta h h ad defective vision.
L ittle m aterial is available to show the connection betw een th e physical condition of an individual an d th e ac
cidents he m ay experience. H o w ever, in a study of accidents am ong m otorm en and bus operators, a can
vass of the com pany’s records showed th a t accidents did not d istrib u te th e m selves im partially am ong the m en by w hom the cars w ere operated. H a lf the accidents happened to less th a n a th ird of the operators. I n one group of 200 m en of am ple experience and m a tu rity in the service, half of the accidents happened to only one-fifth o f th e m otorm en.
W ith a realization o f the im paired physical condition of such a large p ro p o rtio n of in d u strial w orkers, th e im portance and economic value of health supervision in industry be
comes increasingly apparent. T h e w o rk of a plant physician should reach all d epartm ents and all activi
ties o f the organization. C oexistent w ith his curative and preventive ac
tivities should be a desire to see th a t m en are placed a t w ork fo r w hich they are physically qualified. T he only m ethod of a ttain in g th is end is th ro u g h the physical exam ination of w orkers and o f applicants fo r em ploy
m ent, to determ ine not only th eir physical condition b u t th eir m ental attitu d e as well.
Such exam ination should disclose in each case w hether th e w o rk er is fit fo r th e job fo r w hich he applies o r is occupying, o r w hether he should be given a different type of w ork because of some physical defect o r weakness, o r rejected if no suitable w ork is then available. M ore and m ore effort is being m ade to find w ork fo r all.
Physical exam inations are f r e quently m ade of w orkers b efo re tr a n s ference to m ore hazardous o r ex act
ing jobs. T h is o ften will prevent a fu tu re accident o r breakdow n in health. In m any cases a w o rk er w ith physical defects or suffering fro m some diseased condition, o ften u n know n to him self, is a cause of acci
dents to others as well as to him self.
Some of the sources of w aste a ris ing from the placem ent of all com ers on jobs w ithout any effort at a physi
cal selection fo r th e ir w ork a r e : (1 ) L abor tu rn o v er due to the em ploy
m ent of the unfit w ho later m ust be discharged because of inability to do th e w ork or who are forced to stop w ork due to advancing disease. T hese latter have been a source of loss d u r ing the entire period -of em ploym ent, on account of the grad u al decrease in th eir efficiency. (2 ) Increased in dustrial liability to accidents of those who, because of th eir physical con
dition, are subject to fre q u e n t acci
dents. (3 ) A bsenteeism due to ill
ness and lost-tim e accidents. (4 ) L iability to long disability com pensa
tion of those w ho suffer accidents th at ordinarily w ould not be serious but, because of coincidental physical conditions, cause prolonged disability o r death. ( 5 ) Loss of services of those who are healthy th ro u g h con
traction of contagious diseases. T h e acute contagious diseases are m ore common, but tuberculosis and syphilis also cause g reat loss.
Em ployers should n o t m ake p hysi
cal exam inations w ith th e sole idea of weeding out the unfit. I t should be kept in m ind th a t m en m ust w ork, and it is the duty of the plant p hysi
cian to place m en to the best of th eir abilities. H e should rem em ber th a t if a m an is, fo r physical reasons, a danger to him self, to his fellow man, o r to the job, he should be adjudged unfit fo r the position. O th e r th an this, a sincere attem pt should be m ade to place all persons.
F ro m an economic standpoint the w orker is the one w ho pays the g reater p a rt of the enorm ous cost of
in d u strial in ju ries. I n spite o f the com pensation law s, th e w o rk ers still b ear fo u r-fifth s of the econom ic b u r den resulting fro m in d u stria l in ju ries.
I f , as has been estim ated, 9 0 p er cent of th e accidents a re due to th e individual w orkers, and probably 90 p er cent of these w o rk ers have p h y si
cal im p airm en t o r d efects ran g in g fro m m oderate im p airm en t (re q u ir
ing some fo rm o f hygienic guidance o r m in o r medical, dental, or surgical tre a tm e n t) to serious physical im p airm en t or defect (u rg e n tly d em an d ing im m ediate atte n tio n ) an d th a t probably 75 per cent of these im p air
m ents o r defects could be cured or benefited by treatm en t, it is of the g re a te st advantage to th e individual th a t he find o u t his physical assets and liabilities.
I n addition to th e econom ic loss in w ages due to accidents, m entioned above, the w o rk er m ust count th e hours of physical su fferin g an d the inconvenience to him self an d his fam ily, as well as th e possibility of perm anent, partial, or to ta l disability w ith a loss in his earn in g pow er.
P ro b ab ly in m any cases th e y ears of m ental d istress outw eigh th e y ears of pain and suffering incident to th e im m ediate accident. I t is im possible to evaluate th e actual cost to an in ju re d person o f reduced earn in g pow er and inability to advance in position. B u t fo r th e resu ltin g h a n d i
cap he m ight have been advanced fa r up the ladder o f supervising resp o n sibility.
In accordance w ith findings o f physical exam ination, prospective em ployees m ay be ‘classed as fo llo w s : ( 1 ) T h o se physically fit fo r any w ork. (2 ) T h o se physically u n d e r
developed, or w ith som e slight an a tom ical d e fe c t; otherw ise fit fo r any w ork. ( 3 ) T h o se fit only f o r certain em ploym ent w hen approved and supervised by th e m edical d epartm ent.
( 4 ) T h o se unfit f o r any em ploym ent.
A large co rporation em ploying thousands o f m en fo u n d th a t 7 p er cent of those applying fo r w o rk w ere physically unfit, b u t th a t by sim ple operations and o th er corrective m eas
ures 75 p e r cent of those rejected on original exam ination w ere sufficiently resto red to norm al to w a rra n t th e ir em ploym ent; th u s the to tal net re je c tions w ere less th a n tw o p e r cent of all those applying.
A bn o rm al conditions of th e air, including th e presence o f d u st and insufficient illum ination, a re tw o health h azard s in the m ining in d u stry th a t m ay predispose an individual to accidents.
574 C O A L A G E — Vol.36, N o .U
M I D V A L L E Y B R E A K E R + Embod ies New Principles In Coal Cleaning
O N E of the o u tstan d in g e x am ples of m odern coal-clean
in g m ethods is the M idvalley B reak er of th e H azle B rook Coal Co., located in the W e ste rn M iddle a n th ra c ite field, n o t f a r fro m M ount C arm el, P a. M o u n t C arm el is in N o rth u m b erlan d C ounty, but the b reak er is in the ad ja cen t co u n ty of Colum bia. Coal is being cleaned by fo u r system s— the C hance sand flota
tion, H y d ro ta to rs, D eister O v erstro m diagonal-deck tables, an d W ilm ot re fu se jigs.
Coal is b ro u g h t to the b rea k er head up an incline w hich, u n d erg ro u n d , follow s closely th e inclination o f the heavily p itch in g seam , w hich ru n s fro m 35 to 40 deg. to the horizontal.
A bove g ro u n d the coal trav els over a stru ctu ral-steel plane on an inclination o f 35 deg. O n reaching the breaker head the coal is dum ped over a chute into a hopper. Tn the chute is a rock
Fig- 1— W a s h a b ility C u rv es fo r M ix e d R ice, B arley an d
S ilt B efo re W a s h in g
10
I
\
\ \
os\?
%
N,
\
. _\
\
C e n t A .sh
60 10
gate, by w hich the contents o f cars of rock can be d iverted to a rock chute.
T h is chute is located u n d er the in cline by w hich the cars a re b rought to the breaker, thus m aking the e x pense of a second trestle unnecessary.
Coal is fed from th e hopper to the bull shakers u n d e r the control o f a push feeder w hich consists of a plate pushed to and fro by tw o cranks which a re actuated by a belt-driven shaft.
O n the bull shakers the coal is sized into broken-and-over and egg-and- under, the openings in the screen being of 3Ty i n . diam eter. T h e larg er coal goes to picking tables and is cleaned by fo u r men. T h en ce it is led to 34x36-in. cru sh e r rolls, w here it is reduced to b ro k en -an d -u n d er.
A ll the coal th a t will go th ro u g h a screen w ith holes o f 3Ty i n . diam eter is then rem oved as egg-and-under, an d passes to the stream of coal of th a t size from the bull shakers. T h e broken coal then goes to 34x36-in.
egg-coal rolls, w here it is reduced to egg-and-under, a f te r w hich it jo in s the rest of the coal o f th a t size. T h e en tire p ro d u ct then goes to cone-feed shak ers w hich sep arate the pea-and- over from the b uckw heat-and-under, the fo rm e r going to the Chance sep
a ra to r and th e la tte r to tables and H y d ro tato rs.
A ll the pea, n u t, stove, and egg coal is w ashed in a single C hance u nit of 13 ft. 6 in. diam eter. T h e coal leaving the to p of the cone goes over a desanding shaker, all m aterial u n d er /it in. going to th e 15-ft. d iam eter sand sum p, an d all above th a t size to the sizing shakers w hich deliver egg.
stove, nut, and pea, w hich pass to the loading pocket. T h e small quantity o f fine coal which goes th ro u g h a
i i - i n . screen passes to elevators w hich ca rry coal of m any sizes. T h ese de
liver it to th e aforem entioned cone- feed shakers, w hich again sep arate it w ith the line coal fro m o th er sources fo r delivery to the H y d ro ta to rs and D eister O v erstro m diagonal deck tables.
R efu se fro m the C hance cone, which includes practically all heavy im purities, such as sand rock, slate, and m ost o f the bone, is screened into th ree sizes: (1 ) e g g -a n d -sto v e; (2 ) nu t-an d -p ea (p lu s b re a k a g e ), and ( 3 ) m aterial u nder / r-in. diam eter.
T h e first tw o are w ashed separately in W ilm ot T ype D refu se jigs. T h e fine m aterial and sand go to the 9 -ft.
sand sum p. T h e coal end of th e egg- and-stove re fu se jig goes to 24x34-iti.
rolls and is crushed to nut-and-pea.
T h e coal end of the n u t-an d -p ea jig goes to 18x30-in. rolls and is crushed to pea-and-buckw heat. T h e product from both sets of rolls, to g eth er w ith
Fig- 2— D e tail o f H y d ro ta to r O p e ra tio n
I I I
£
-7 /6
Refuse concenfrai/ng
November, 1931 — C O A L A G E 575
Push
fe e d e r fe eckr
Roll shaker * l ?*V , .
2'-6*x 1 2 -...^ Egg, stove, n u t c fyy~coa^ ro ^ s* 3 4
1% \mesh 6 x 2 4 ,1 $
1J$2* m e s h ' " ^ x 2 7 , % 1 1 t s . V-'Fggi stove.i K Er$ i ---- *1 Desanding shakers
I ---1— , r ~ % m es^ 'x lf
X T \Chance / ^ f s,h
\ cone j T T ^ 7! Sizing sh akers^ "
/ I l.,---2feyhe6ht 6'x24' i
/ * w c= = ^ Z , r . ^ / mesJ, * T s ‘==t = ^ - J * , r ix3i
5 . r
3 ' ~ -%7frnesh
£ r - * r % h ¿M7
==3-' 6x!a 1—
— 1 J.— !% ’m esh
* s k •*
- - % w ^ |
D eiste r Overs from d ia g o n a l deck fable A , FX \for¿> uck c o a l
■¡/¡¿'mesh
^Çdrvbfor^
m esh _________ I 6 x ld
■ft. H y d ro ta to r
Refuse
shakers
9'sa n d sOTñp
Hut ana Egq and pea sTove
D ei5 te r concentrator fa b le fo r re fu se
\je fu s e rolls
© W < § W
k L V o ta n d>->.ys,
f L w rfj © © If # * .» ' I
^ /h r andbuck' f/utandpea S ift a n d s lu s h to
s lu s h -tro u g h C o a l fro m r e fu s e ta b le s
to e le v a to rs S la te to re fu s e conveyor
Chestnut Buck No.4 buck B arley S tove
Rock gate \ ) Rock gate
P o c k e t P o c k e t
■Bull shaker Sx/2f ..-Picking tab le
lump, steam boat g— ^ [ an d broken
• Crusher rolls, 34*x56"to broken (3% 'd iam )
i: * E g g , s to v e , n u t a n d s m a lle r
E g g -c o a / r o lls , 3 4 "x 3 6 "to e g g a n d s m a lle r
___..¿ T " 1-6 '*2 4 ', l% fm esh\
, i n , " \C o n e -fe e d sh a k >
- —6 x 2 7 , % m tsh ) ( . V -F q n s to v e ,n u t a n d p e a
■ — % 2 m esh,6x74'
/ $ 4 mesh 6x?!'
Refuse conveyor-''
= = —^>-5/7/ andslush
| S ettling fank | W ater pum ped from ta n k -h tank on top o f breaker
Fig. 3— F lo w S heet S h o w in g Sand F lo tatio n , H y d ro tato rs, T ab les an d Jig s
the slush fro m the re fu se jig, goes to the elevator and is re tu rn e d to the coal stream above the cone-feed shakers. T h e sam e elevator handles the lip screenings and any condem ned coal th at m ay req u ire re-trea tm en t. It is th e only elevator in the plant, and it has little w ork to do, the coal as a whole proceeding dow nw ard from m ine-car dum p to railroad car, th u s reducing th e pow er and rep air bills m aterially. Slate from th e W ilm o t jig s is carried to a re fu se conveyor.
T h e pressu re of the w ater in the cone ru n s fro m 30 to 40 lb. p er sq.in., w a te r being provided from a tan k on the top of the breaker. T h e steam or a ir used to operate the slate gates of
the Chance cone is ad m itted by an electrically operated cam, a ir being used d u rin g the sum m er, w hen no steam is available, and steam in the w inter. T h e use of steam in cold w eather prevents freezing o f the valves. A B a rre tt-H a e n tje n s chrom e- iron sand pum p has been used to re place the fo rm e r cast-iron pum p. O u t of the chrom e-iron pum p 2,500 hr. of service w as obtained, w hereas a cast- iron u nit would last only th ree o r fo u r weeks a t lo n g e st; yet the fo rm er a t the end of the 2,500 h r. w as by no m eans spent, but w as kept as a spare f o r em ergency use.
A s already stated, the fines passing th ro u g h a J |- i n . screen go from the
cone-feed shakers to th e H y d ro ta to rs a n d D eister O v erstro m ta b les; but fo r this, f u rth e r sizing on a ^ - i n . m esh screen is necessary. T h e over
size, w hich is buckw heat, goes to tw o D eister O v erstro m tables. Slate from this table goes to th e re fu se conveyor and clean buckw heat to the a p p ro p ria te loading pocket.
U nd ersize fro m the aforem entioned screen falls on a tV-in. m esh screen, the oversize going to a 5-ft. H y d ro - ta to r, w hich thus receives rice, barley, and N o. 4 buckw heat. T h e coal end of the H y d ro ta to r passes over a double-deck shaker, and the rice, o r plus -^5-in. coal fro m the to p deck, goes to the loading pocket. B arley and N o. 4 buckw heat fro m the second deck are recleaned in a second H y d ro ta to r and are separated into th e ir re
spective sizes a f te r cleaning. T h e slate ends o f both m achines go to a D eister C oncentrator Co. table fo r recleaning, from w hich table the coal end is sent back into the b rea k er feed, and the slate end is sent to the re fu se bank.
T h is com posite system o f cleaning has long been recognized in m etal con
cen tratin g plants w hen sep aratin g m inerals fro m gangue. In such con
c e n trato rs a com bination of tw o o r m ore m ethods is used to obtain the desired results. I t is only at a com p arativ ely recent date th a t an y o f the an th racite o p erato rs have recognized the possibilities of such a m ethod. In the past a choice has been m ade o f a single one of several possible m ethods, w ith no th o u g h t of a com bination of som e tw o o r m ore system s of sep ara
tion.
I n th e M idvalley b reak er th e - tw o m ethods of cleaning the sm all sizes supplem ent each other. T h e principle used in th e H y d ro ta to r is th a t o f h in dered settling. A v ery close specific- g rav ity sep aratio n is m ade giving a low -ash coal, b u t th e re also is a c e r tain classification of s iz e s ; conse
quently th e re is som e tendency fo r the oversize coal and good bone to sink w ith th e slate. O n th e concen
tra tin g table w hich recleans the H y d ro ta to r re fu se th e principle is re versed in th a t th e above-m entioned oversize coal and bone a re easily sep
arated from the slate and re tu rn e d to the breaker, w hile the re fu se end of the table contains su rp risin g ly little coal. T h e H y d ro ta to r, because of its g re a te r capacity, takes precedence in the flow sheet.
In one m onth 24 consecutive cars of barley w ere tested f o r ash content.
T h e average of these contained 10.2 p e r cent ash. A com posite sam ple
576 C O A L A G E — Vol.36, N o .l 1
o f barley slate w as m ade fro m daily sam ples and w as analyzed once a w e e k ; it show ed an average fo r the fo u r w eeks o f 68.6 p e r cent ash.
T h ese analyses w ere m ade by the H a zle B rook Coal Co. w ith o u t any know ledge th a t they w ere to be used except in. the daily ro u tin e. F ro m a com posite sam ple o f feed the ch art (F ig - 1) w as m ade show ing the coal and re fu se d a ta as m ade from float- an d -sin k tests.
It can be seen how closely the theo
retically possible resu lts correspond w ith the actual. S ta rtin g w ith a 10.2 p e r cent ash coal (F ig . 1 ), th e v e rti
cal dotted line intersects the curve at a p oint show ing 69.5 p e r cent recov
ery o f coal. T h e horizo n tal dotted line intersects the re fu se curve at a point show ing 68 p e r cent ash in the refu se, indicated by the vertical line a t this point. T he. actual refu se, as already stated, ra n 68.6 p e r cent ash.
T he, operation w as practically a u to m atic. N e ith e r the slate gates o f the H y d ro ta to r n o r the o p e ratin g condi
tions o f the D eister O v erstro m con
ce n tra tin g table needed regulation a fte r they w ere p ro p erly adjusted.
T h e part-tim e services of only one m an w ere needed fo r the en tire in
stallation.
T h e w ash w ater of the entire b rea k er goes to a settlin g tank, fro m w hich w ater is pum ped to a ta n k at the top of the breaker. T h e u n d e r
flow fro m th is tank, containing silt and slush, is taken to a settlin g pond which has been co nstructed by d u m p ing cars of m ine rock and breaker refu se aro u n d its periphery.
A m o tor-driven belt drives the line sh a ft, w hich in tu rn actu ates th e bull shakers, th e p u sh er feed, the one ele
v ator, and the cru sh ers. T h e cru sh ers are connected up by a rope drive, because the d istance betw een centers is long and a belt w ould in te rfe re w ith o th er m achinery. T h e breaker w hich cleans and p rep ares 1,000 tons daily em ploys th re e m en on the dum p, fo u r m en on the picking table, a boss in charge o f this table, one picker for the rem oval o f discolored coal, one cone te n d er and tw o helpers, one m an
o p eratin g the tw o H y d ro ta to rs and the tw o No. 1 buckw heat tables, one m an supervising the re fu se tables and jigs, th ree m en loading coal below the b reak er (o n e being a car cleaner and the o th e r tw o lo a d e rs), tw o b reak er cleaners, one m an ta k in g care o f the condem ned coal and the lim e n e u tra l
izing plant, fo u r m en on re fu se bank, one refu se locom otive engineer, one rep air m an, one oiler, one inspector, and one breaker boss— 29 m en in all.
T h e refu se is handled by six W estern cars and one locomotive.
T o neutralize the w ater, 1,000 to 1,300 lb. of h y d rated lime is used daily, as m ost of the w a te r used in the b reak er is pum ped fro m the mine.
T h is lim e is fed in m easured q u an tity to the w a te r by a G au n tt feed er m an u fa c tu re d by the H . J. Savage Co.
T h e b reak er is boarded and battened.
T o keep the plant w arm six larg e hot- air heating units have been provided by the A m erican B low er C orporation, and tw o small units. T h ese keep the e n tire plant w arm in the coldest of w eather.
M id v a lle y B re ak e r
November, 1931 — C O A L A G E
577
N A T I O N A L S A F E T Y C O U N C IL + Lays Stress on Individual’s
Proneness to Accident
T
H A T th e tru e cause o f m any accidents is n o t carelessness or ignorance o r occupational hazard but th e physical condition o f the w orkm an, w as the gist of the paper by D r. R . R . Sayers, chief surgeon, Ü . S. B u reau of M ines, a t the T w en tieth A nnual S a fe ty C ongress o f the N ational S a fe ty Council w hich m et a t Chicago, O ct. 12-16.
A n ab stract o f the article m ay be found on pp. 573 a n d 574.
In opening th e m eeting o f the m ining section as chairm an, O ct. 13, R . X. H o sier, su p erin ten d en t. Coal M ining Section. P ennsylvania Com pensation R a tin g a n d Inspection B ureau, H a rrisb u rg . P a ., said th a t one-seventh to one-eighth o f the en
tire labor cost is accident expense.
T h is is an op eratin g problem an d m ust be solved as such. E xcellent records m ade in m ines o f all kinds and conditions proved th a t bad roof need not resu lt in a high accident record. H is conclusion w as th a t natu ral local conditions have so little to do w ith accidents th a t sa fety can be obtained in th e face o f adverse conditions equal to th a t attained w here conditions a re favorable.
D aniel H a rrin g to n , chief safety engineer, U . S. B u reau o f M ines.
W ashington, D . C.. rep o rted on acci
d en t statistics fo r W . W . A dam s, accident statistician fo r th e sam e organization. H is findings a re em bodied in the rep o rt o f the B ureau know n as Serial No. 3126. M r. H a r rington, in m aking his re p o rt as secretary, said th a t if the present record fo r 1931 to d ate w ere con
tinued th ro u g h the y e a r th e fatality record fo r coal m ining w ould be 400 t j 500 less than th a t o i any other y e a r du rin g the present century'. T o date only one state, Indiana, h ad failed d u rin g the p resen t year to low er its accident record.
F ra n k B. D u n b ar, general m an
ager, P ickands, A lather & Co., M ath er, Pa., read a paper on “ D iscipline in R elation to A ccidents.” H e declared th a t safety discipline w as m ore im po rtan t than low coal cost, and low coal costs are not possible w ith o u t safety discipline.
W ald o H . C om ins
A t t h e . aftern o o n session, th e officers fo r th e new y ear who had been nom inated a t the m o rn in g ses
sion w ere elected unanim ously. T he)' w ere as follow s: G eneral chairm an, W . H . Com ins. local m anager. N a tional Lead Co.. S t. F ran co is, M o. : first vice-chairm an. T hom as E . L ig h t- foot, engineer fo r accident p revention a n d com pensation. K oppers Coal Co., P ittsb u rg h , P a. ; second vice-chair
m an, F . W . A lt, chief safety engi
neer, C alum et & H ecla C onsolidated C opper Co.. Calum et. M ich .; th ird vice-chairm an. M r. D u n b a r: fo u rth vice-chairm an, P . M . A rth u r, directo r o f personnel, A m erican Z inc Co. of Tennessee. M ascot. T enn. : secretary an d new s-letter editor. M r. H a r r in g ton.
T h e d rift o f th e paper by W illiam
C onibear, assistan t su p erin ten d en t, Clevelarid-Cliffs Iro n Co., Ishpem ing, M ich., on “ E ducation P ro ce ss in A ccident P re v e n tio n W o rk ” w as th a t m en could not be tru ste d to educate them selves as th e resu lts o f th e ir ow n experiences. E x perience, he said, m ig h t be th e best teacher, w hich is at least debatable, b u t it is also the dearest an d th e slow est.
I n response to C. W . Gibbs, g en eral m anager, H a rw ic k Coal & Coke Co., P ittsb u rg h , P a ., M r. C onibear said th a t educative processes w ere supplem ented a t th e C leveland-C Iiffs m ines w ith all the aids d ram atizin g safety . A flag flies a t every m ine w henever not a single m an is absent because of a lost-tim e accident.
E v e ry m an in every m ine th a t goes a y ear w ith o u t a lost-tim e accident is given a gold b u tto n .
M u ch has been said about th e excellent m in in g record in 1931. I t h as been ascribed to th e fact th a t d is
cipline has tig h ten ed d u rin g th e d e p ression in th e coal in d u stry , b u t M ilton H . F ies, vice-president in charge of operations, D e B ardeleben Coal C orporation. B irm ingham . A la in his p ap er on “ T h e S a fe ty P la n of the N atio n al Coal A ssociation" said th a t in o th er y ears o f depression fatalities h ad increased. T h e irre g u larity o f operations h ad h ith e rto acted u n fav o rab ly to safety.
I f the U n ited S ta te s produced m ore to n s p e r fa tality th a t w as b e
cause to n s w ere m ore easily produced.
T h a t fa cto r had little to do w ith safety . I t w as largely due to m o re favorable op eratin g conditions. I f th ere is less blood on o u r coal, he said, th e re is m ore d esp air in th e h e a rts of th e m iners. I t did not lessen th e ir h a rd fate w hen th e fa ta l
ities p e r ton w en t dow n if th e reco rd p er m an -h o u r rose. M r. H a rrin g to n rem arked th a t the E m p ire m in e o f the De B ardeleben com pany a t one tim e had ru n tw o full v ears lacking one day w ith o u t a lost-tim e accident and w as well on its w ay to w a rd establish
in g an o th e r record.
A t th e W ed n esd ay a fte rn o o n ses
sion. A . C. Calien, p ro fe sso r o f
57S C O A L A G E — V 01.36, N o .l 1
C. W . B e rg q u ist
m in in g engineering, U n iv ersity of Illinois, U rb an a, 111., discussed the
“ Inspection o f E lectrical E q u ip m en t in th e M ining In d u s try ” and declared th a t th e m a tte r o f such inspection had been generally overlooked in m ining.
P en n sy lv a n ia had a t one tim e fo u r electrical inspectors and now h ad only one.
L aw s, said P ro f. Callen, g re atly needed extension to cover electrical hazard s. O n ly th e bitum inous law o f P en n sy lv a n ia filled the re q u ire m en ts o f adequate legislation, b u t he believed th at, even in th e absence of f u rth e r legislative enactm ent, w ith a co rre c t yet b road in te rp re ta tio n of the pow ers alread y co n fe rre d on inspec
to rs, enough au th o rity lay in ex ist
in g law s to p erm it them to in sist on sa fe electrical installation and m ain te
nance. Som e state inspectorates are doing so now ; notably A labam a. W . B. H illhouse, chief, d e p a rtm en t of m ines, B irm ingham , A la., has indi
cated to his insp ecto rs w h a t co rrec
tio n s in electrical installation and m aintenance his m en a re ju stified in dem anding.
I n the discussion o f the paper, M r.
H a rrin g to n said th a t his inquiries in the last fo u r y ears had show n th a t o u t o f 897 fatalities caused by ex p lo sions th ro u g h o u t th e U n ite d S tates, 74.8 p e r cent had resulted directly from electrical ignitions. In A labam a in 5}j y ears 71 m en h ad been killed by contact w ith w ires, b u t d u rin g the p re se n t year, no electrocutions had occurred, because o f M r. H illh o u se’s active cam paign fo r s a fe r electrical conditions.
G. X . M cC lellan, sa fe ty engineer, B u tle r C onsolidated Coal C o., W ild wood. P a ., said th a t in his m ines a m achine w h ich stalls m u st be m oved o u tby the last cro sscu t b e fo re inspec-
tion. I f it can ’t be m oved, inspection o f th e m achine m u st a w ait the a rriv al o f the assistan t forem an. W h en be has tested the place fo r gas and found the place clear, the inspection m ay be m ade.
G eorge M artin so n , sa fe ty engineer, P ickands, M a th e r & Co., H ibbing, M inn., presided over the question box
“W h a t A re th e A d v an tag es and D is
advantages o f Physical E x am in atio n s B e fo re E m ploym ent and a t S ix - or T w elve-M onth In te rv a ls D u rin g E m ploym ent ?” M r. M artin so n said we a re slowly em erging fro m th e tim e w hen the forem an insisted th a t he should do his ow n h irin g , because “he knew a stro n g back w hen he saw it.”
L a te r the m en o b jected to physical em ploym ent, b u t la tterly the principle had been generally accepted on the Iro n R ange. J . J . F o rb e s advocated physical ex am inations. W h y should anyone give a m an w ith a leaky h eart a tim b er jo b ?
O. F . M cS hane, in d u stria l com m issioner, S alt L ake C ity, U ta h , said th at no m an fo u n d by th e doctors needing reh ab ilitatio n is en titled to a job if he re fu se s to receive tre a tm e n t, b u t h e should be tre a te d free.
A t T h u rs d a y ’s session o f th e m in ing section, O. U . S im pson, safetv inspector, A labam a B y -P ro d u c ts C orporation, D ixiana, A la., read a p ap er by W . B. H illhouse, chief, d e p a rtm e n t of m ines, B irm ingham , A la., entitled “ P re v e n tio n of F a ta l
ities F ro m R o o f F a lls.” M r. H ill
house show ed th a t in 1927 th e re w ere 61 fatalities from th a t cause in th e S ta te o f A labam a an d th a t in 1931 up until A u g . 1 (sev en m o n th s) th e re w ere 5 fatalities. I n th e first o f the tw o y e a rs m entioned, th e re w as one fa tality to 330,999 to n s„ a n d in th e second, one to ab o u t 1,300,000 tons.
“ System atic tim b erin g ,” said M r.
H illh o u se, “ has becom e gen eral p ra c tice th ro u g h o u t the sta te .” H e added th a t long wall m in in g in A labam a h ad been rem arkably free from ro o f-fall fatalities, d ue en tirely to th e em ploy
m ent o f re g u la r tim b erin g crew s and to con tin u o u s supervision by th e w all forem an.
K . S. H u g h es, colliery su p erin tendent, H u d so n Coal Co., S cran to n , P a., said th a t w ith h is com pany th e re had been few er rock falls in long- wall than in o th e r m ine w orkings.
B ecause the places trav eled fo rw a rd m ore rap id ly w ith sc ra p e r m ining th an w ith h and m ining, th e ro o f did n o t have tim e to slack an d fall. W ith steel jack s, th e placing o f su p p o rts had to be system atized, and th is in itse lf m ade fo r safety.
M r. D u n b ar declared th a t no ro o f
W . H . C am eron
could be tru sted except w hen p ropped. K ettle bottom s o ften fell o u t a t points w hore, p rio r to the fall, the u nderside o f th e ro o f w as so u n d istu rb ed as to give no evidence o f th e ir presence. In fact, w h ere the ro o f is good is ju s t w here accidents h a p p e n ; th e m in er takes care to p ro p a bad roof. A t his m ines all cap- pieces are delivered duly w edged, th u s saving m any accidents from the m ishandling of axes. A m an is not allow ed to use an ax e w ith a long handle. T h e handles m ust be cut dow n so as to be n o t ov er 18 in.
long. M r. D u n b a r’s sta n d a rd fo r cap-pieces req u ired th a t they be 1 in.
thick, 4 in. wide, and 12 in. long.
M r. H u g h es said th e H u d so n Coal Co. h ad a plan fo r every seam , b u t on every plan the com pany w as c a re ful to o rd e r that, though th e in stru c tions m u st be followed, m ore tim b er th an ordered m u st be used if e ith e r m in er o r forem an deem ed it neces
sary.
M r. Com ins led the discussion on th e question-box problem “W h a t Is th e B est and S a fe st M ethod o f Illu m ination in M in es?” M r. H a r r in g to n said th e U . S. B ureau o f M ines had an e x p e rt len t by th e U , S.
H ealth S ervice and an en g in eer fro m th e B u reau stu d y in g th a t subject.
T h e y had ascertain ed m an y th in g s ; am ong them th a t th e coal m in er in his o rd in ary w o rk is receiving only o ne-tw entieth to o n e -th irtie th o f the lig h t re g u larly afforded a clerk in a W a sh in g to n office.
A t the b a n q u et it w as announced th a t C. W . B erg q u ist, su p erin ten d en t, public relations, W e ste rn E lectric Co., Chicago, w as re-elected p resid en t fo r th e en su in g y ear. W . H . C am eron also w as re-elected m anaging director.
November, 1931 — C O A L A G E
579
SECOND OF A SERIES OF ARTICLES ON BEST M ETHODS I N M E C H A N IC A L LOADING
OIL &
H A U L A G E P R O B L E M S + In Mechanical Loading
By K. E. C A I N E
M in in g E n g in e e r Jo y M a n u fa c tu rin g Co.
A
P R O M I N E N T railro ad executive recently m ade th e state
m ent th a t th e wheels on rolling stock w ere m ade ro u n d fo r th e p u r
pose of m oving c a r s ; th a t w hen they w ere standing still, no productive re sults w ere being obtained. H a d the significance o f th is sim ple statem ent been fu lly realized, in coal m ining, mechanical loading undoubtedly would be fa r ahead o f its p resen t statu s of achievem ent. F o r w ithout a steady supply o f cars to th e m achine te r ri
tory, m aintained by accu rate dispatch
ing fo r ihe avoidance o f traffic congestion and a tte n d a n t delays, car wheels w ill stand still and m achines w ill stand idle w hen they should be m oving in productive w ork.
I f capital investm ent in m achinery is to be kept at an economic m ini
mum , and every dollar sp en t fo r roll
in g stock is to continue productive, avoidable delavs cannot be counte-
F ig . 2— G ay M odified L o n g w all L ayout Is Id eal fo r H a u la g e in M ech an ical L oading
nanced. B u t n o t alw ays can the vagaries of an old haulage system easily be reconciled to a new o rd er of operation involving perhaps a change of layout and, fo r economic reasons, continued use of the equip
m ent at hand. T ra n sp o rta tio n read ju stm en ts present a big problem and should be considered accordingly.
S tripped o f its details an d ram ifi
cations, the problem o f tran sp o rta tio n in mechanical loading boils dow n to one m ajo r o bjective: to reduce or elim inate completely the delays caused by the sh iftin g of cars. T h e problem is faced everyw here in th is country, because the room and p illar system is here alm ost universal and because the use of conveyors as takeoffs fro m loading machines has n o t yet been developed. Soon, th ere will come this
F ig . 1— S lab b in g P e rm its th e L oad in g o f C ars in T rip s
developm ent of equipm ent an d m eth
ods f o r continuous loading, w hich is th e necessary n e x t step in th e p ro g ress o f m echanization. I n fact, e x perim ental w ork is now being done along these lines.
W h e n tra c k is elim inated from room s it can be reasonably expected th a t a m achine u n it will average from 700 to 1,000 to n s p e r sh ift. T h en th e p roduction records o f today, g ra tify in g as th ey are, will appear sm all indeed.
M eantim e, th e m ines m u st continue, as they have in th e past, to m ake the m ost of the equipm ent and m ethods available fo r use. I n this th e p ro gressive plants have done rem arkably w ell, considering the lim itations w ithin w hich they have been com pelled to w ork. Y e t th ere is a possi
bility o f im provem ent in individual cases, b o rro w in g fro m th e experiences o f others. T h e w rite r has k ep t this possibility in m ind in p re p a rin g this article, w hich w ill devote considerable space to review ing th e m ethods used by vario u s com panies.
In re tre a t w o rk th e tim e req u ired fo r changing cars can be reduced to a m inim um by slabbing along the open end o f pillars, w here a ro o f span can be m aintained to allow fo r track ou tby the sh o t coal. B y this a rra n g e m ent (see F ig . 1) cars can be filled one a f te r an o th er in trip s of th re e o r four.
A t the m ine o f th e Gay Coal &
Coke Co., W e st V irg in ia, a m odified
580 C O A L A G E — Vol.36, N o.11
