Coal Age : devoted to the operating, technical and business problems of the coal-mining industry, Vol. 26, No. 13

M c G r a w - H il l C o m p a n y , I n c . Devoted to th e O p e ratin g , Technical and Business

J a m e s H . M c G r a w ,

President

E. J. M e h r e n ,

Vice-President

Engineering Editor

Yolum e 26 N E W Y O R K , S E P T E M B E R , 25, 1924 N um ber 13

L o n g W a y to B o t t o m O f W o rlc P s C o a l B in

T

The other is a vague uncertain apprehension, fostered m orę or less by w riters of popular and semi-scientific fiction, th a t the world is b u rn in g up its supply of coal faster th a n it should and th a t w ith in a compar- atively short tim e, say a generation or two, the fuel bounty w herew ith n atu rę has so lavishly endowed th is land of ours w ill have been exhausted and the peoples of th a t day and age w ill be compelled to seek some substitute means of heat supply or go cold and perhaps h un g ry as well.

As to the fu tu rę trend of prices so m any variables enter the eąuation th a t any attem pt to forecast it can be little more th an mere speculation. C ertain it is th a t the extent to w hich labor-saving m achinery is or can be adopted w ill play an im p o rta n t role in price determ ination.

E x h austio n of our coal resources is a possibility th a t is extremely remote. The period of tim e d u rin g w hich the w orld’s know n coal supply w ill be ade- quate to its reąuirem ents has been variously estimated by “experts” at fro m 500 to 15,000 years. This old planet, therefore, w ill not go cold fo r lack of fuel d u rin g the lives of men now livin g, nor w ith in those of th e ir children or th e ir children’s children. D u r in g 110 years of commercial coal production in the U nited States th is country has exhausted, in cludin g losses incurred in m in in g , appreciably less th an 2 per cent o f its known coal deposits. M ak in g all due allowance, therefore, fo r the increased demands of the fu tu rę it is certain th a t our coal supply w ill last for “ ąuite a spell.”

Y e t T h e r e A r e C o m p e n s a t io n s

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I t is good indeed to have the governm ent interested in h ig h prices in yo ur in d ustry . The B r itis h Govern- m e n t chuckles when the operator gets a good price ju s t a., iu rs does when the fa rm e r gets an increased re tu rn fo r 'w h e a t and corn. I t m u st seem good to have the governm ent w ith you when you boost your price and

look sad when you lower it. I t ’s not so here unless you are a farm er. They coddle the farm e r vote here ju s t as they do the m in er vote in G reat B rita in .

B u t then, and here’s the rub, when the operator increases the “f.o.b. p it,” the retailer raises his prices, which is, of course, to be deprecated. The governm ent hounds the retailers fo r this offense. However, th a t attem pt to s h ift the blame w ould not work i f the con- sumer was properly organized like the m iner. The government would take the snivelling retailer in hand ju s t as Charlie B ryan did. I t would establish coal de- pots on free non-taxpaying ground in the h e art of the city. B u t the consum er really doesn’t m atte r so m uch in Great B rita in . He is poorly organized. He votes on large national issues.

The m iner alone counts. He votes fo r him self, fo r his own wages and lets politics go at th at. So the government is glad when coal prices rise, especially as about one hundred m illions of tons, or over 33 per cent of the whole output, go abroad, and only one-third of the whole production is used fo r domestic purposes.

W hen the foreigner pays who should care? H e has no vote whatever and so is beyond the' pale altogether and has no righ ts th a t anyone respects. N o nation is really internationally minded.

U n io n M in e s A r e S a f e

I

Jo u rn al is a cartoon entitled “ He Changed H is T une,”

which is flavored, to say no more, w ith tru th . A m an is seen approaching a non-union m ine, w ith a pick in hand, saying : “ T his is the life ! The U nited M ine W orkers can’t tell me w h at to do.” In the next picture, the m an ’s pick is flying fro m the d r ift m outh in a m anner suggesting an extremely violent explosion, and in the th ir d the m an, who is greatly frigh te n e d, is ru n n in g fro m the m ine pursued by a dog m arked,

“Accidents due to poor w o rk in g conditions.” B y the way, the m iner has had tim e m eanw hile to p u t adhesive plaster on his face.

The flavor of tr u th in the story is th a t the un ion mines w hich do not w ork cannot well have accidents and therefore are ^safe. O n the whole the w o rk in g conditions are better in non-union th a n in u n io n m ines, some h avin g w onderful records and m any leading in protective devices, b u t the un io n m ines are w in n in g ju s t now in the com petition fo r safety, th o u g h n ot so m uch as the U n ited M in e W orkers w ould have us th in k . There are no accidents in in d u s try w hen there is no in d ustry to have accidents. The tin - m in in g in d u s try in the U n ite d States has less accidents th a n th a t in G reat B r ita in because in the fo rm e r no one is employed in th a t industry. However, the autom obiles a t union m ines are doing w h at m in e accidents cannot do. W he n the mines are idle, there are more fa ta litie s on the surface.

425

426 C O A L A G E Y o l. 26, N o . 13

as it is fo r the purchaser. In m ost cases the m aker, due to his knowledge and experience in his special line, could have furn ished a satisfacto ry m achinę had he been given the proper latitude in the specifications.

W hen purchasing new e ąuipm ent don’t h u n t fo r trouble. Include the necessary detail, p u ttin g it up to the m anufacturer to supply a m achinę w hich w ill accomplish a definite purpose. O n the other hand, avoid ordering duplications of old eąuip m en t th a t the m a n u ­ facturer has discarded. This practice is n either f a ir to the makers of m achinery nor to the purchaser. I t cannot yield the best results. Spare parts cannot be as cheap i f specially made and the com pany w hich gives an exact repeat order often finds its re p a ir p arts are more expensive and the efficiency of its e ąuipm ent lower, though it gains, of course, in the ą u a n tity of spare parts carried, in not h avin g in some cases to buy spare parts and also in the fact th a t its m en know how to handle the old eąuipm ent and it would take tim e to accustom them to the new. The gains, however, are fa r less th an the losses. In the interest o f m orale, no company should be buy ing new m achinery o f old type.

W h a t F o r e i g n T r a d e D e m a n d s

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I t is not possible to succeed if foreign trade is accorded less consideration th an domestic. In fact, it is necessary to tre a t it w ith more care. The foreigner knows next to n o th in g about Am erican coals, and Am ericans, know ing little about foreign boilers and firemen, cannot afFord to dismiss the problem of dis- trib u tio n as cavalierly as they sometimes successfully do in th is country. They m ust follow th e ir fuel to the boiler room ; they m ust note its behavior; they m ust ascertain w h at k in d o f coal w ill do the w ork best.

In this country a m anufacturer who has had success w ith the low-volatile coal of one producer can find where there is another m ine owner producing sim ilar fuel. H e can go to his dealer; he can ask his neigh- bors; he can consult a directory; he can look up the town on the m ap and seek another producer operating nearby or he can look in a trade paper and get some in fo rm atio n — no m atte r how meager— from the adver- tisements it contains. Then there are the publications of the B ureau of Mines. H is chances are one hundred tim es as good as those of a foreign buyer who, afte r much d iligent b u t ill-directed in ąuiry , m ay get a gas coal in place of a low-volatile or vice versa. Success in coal selling abroad is based on service and m utual confidence.

A nother necessity is a yard. F oreig n buyers are often smali consumers o f coal. Besides, they, like others, do not like to buy a large shipm ent u n til they' have tried out the coal. I f foreign trade is to be b u ilt up the shipper m ust be prepared to deliver in almost any ąuan tity . I t is well to be able to give the buyer a chance to see the coal. I t is p artly because this element of success in selling has not been observed th a t so fa r we have been unsuccessful in placing coal in large quantities in Europę.

W h y H u n t T r o u b l e ?

W

Too often the m in in g company h a v in g an elaborate engineering organization goes to unnecessary expense in p re p aring detailed specifications covering new e ąu ip ­ ment. L im itin g dim ensions and other essential details should of course be prepared w ith all possible care.

However, m ost specifications should stop here, in v itin g the m an ufacture rs to su b m it proposals covering a m achinę w hich w ill accomplish the desired result under the conditions set fo rth . O rd in a rily the reliable m an ufac ture r is only too glad to sell m achinery on such a contract, accepting fu li responsibility fo r satis­

facto ry performance.

M an y tim es it has happened th a t a purchaser, who w ent to considerable trouble and expense in calculating and p re p arin g elaborate specifications, found afte r in- sta llation th a t the new eąuipm ent was inadeąuate fo r the service intended. The m an u fac tu re r proves th a t he is not a t fa u lt because the m achinę conform s to the specifications w hich described the eąuipm ent b u t did n ot state the work to be perform ed. This sort of situ a tio n is about as unpleasant fo r the m an ufac ture r

•

“ K e e p C o o l w ith ” — C o a l

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W ho would not be happy to pay as little fo r reasonable coolness as fo r satisfactory heat? Too often we m iss our calculation and go away in a cool spell to shiver and return to face b liste ring heat. B u t i f we cooled our houses and offices we would m ake no m istakes of this k in d ; we would use our cooling a p paratu s when we needed it, even in the sp rin g or a u tu m n i f the conditions w arranted it.

The summ er holidays are grow ing longer and “week- ends” are g e ttin g more num erous and tim e consum ing.

True, vacationing has its value. I t clears the tire d brain of cobwebs; it w idens the scope o f one’s in te re st;

it gives the children a relaxation they need; it affords an opportunity to cast off c iv iliza tio n ju s t a little and go back to naturę, b u t still it is g e ttin g to be a drain on business activity and, moreover, some cannot go, and in the still heat o f city streets how greatly vitality is drained from those who have to stay at their desks!

In w inter we have sometimes to raise the te m perature of the a ir com ing in to our houses 60 to 90 deg. an d in summer all we would need to lower the tem perature would be 10 to 20 deg. The low ering m ay be inefficient as compared w ith the ra is in g of tem perature, b u t the rangę being so m uch less, the cost should n o t be exces- sive. This dissertation seems little germ ane to the subject of th is publication, coal production, b u t the use of power to produce cold would level the peaks of coal consum ption and the coal in d u stry m ig h t do well to advocate the practice o f the artificial cooling of

houses, offices and places of public resort.

S e p tem ber 2-5, 1924 C O A L A G E 427

Rockies Are Fuli of Ingenious Dusting Machines

L a c k i n g P e r f e c t e d A p p a r a t u s , M in e s A r e “ R o llin g T h e ir O w n ,” U s in g W h a te v e r E ą u i p m e n t I s a t H a n d — U n ifo r m F e e d D iff ic u lt t o A s s u r e — A t K e n ilw o r th , H ills id e D i r t I s B lo w n o n F r e s h l y W a t e r e d S u r f a c e s

I

The great problem “ H ow to rock d u s t? ” faces every m ine superintendent, and it is no sim ple problem . B u t every m an w ants his m ine made safe against the ig n itio n

of coal dust even i f he is not driven to do it by law as in U tah. As a result the m o u n tain region is fu li of home-made devices fo r ap p ly in g in e rt dust of one k in d or another and em ploying various principles. A t W attis, U tah, they are “m u d iz in g ” as described in a recent article. B u t m ost m ines are blow ing the dust in dry, usin g either adobe or native soil, ground or unground, or they are p ulv e rizin g shale or soft sand- stone. One com pany tries soaking the entries first.

Nobody knows all about the a rt of rendering coal dust in a m ine incom bustible, b u t the m en of the Rockies are find in g out a great deal by the cut-and-try method, based on all the in fo rm a tio n available. T heir greatest difficulty, ju s t now, is to produce a d ustin g m achinę capable o f a p p ly in g the m a te ria ł as they th in k it o u g h t to be applied. To meet th is shortcom ing they are in v e n tin g an d a d a p tin g — and g e ttin g th in g s done.

A t K enilw orth, U tah , fo r instance, the m en o f the Note— The rock-dust distributor in the headpiece was built for use in the Kenilworth, Utah, mines of the Independent Coal &

Coke Co. m ainly through the ingenuity of such men as Master Mechanic W . H. Woodhead (rig h t), and Mine Foreman K . F.

Lueder (le ft). I t reąuires three men to operate it, including a motorman whose locomotive pushes the duster and its accompany- ing car of dust. The operator of the machinę turns the discharge pipę about w ith the lever at the rear end of the car, as illustrated by Mr Lueder, and the third m an m ust shovel dust from the pit car into the hopper (posed by Fireboss Sam Westerfleld).

Independent Coal & Coke Co. have b u ilt a u n iąu e m a­

chinę and adopted a m ethod all th e ir own. A ro und K enilw orth, as at m any other m ines in the U ta h Wa- satches, there are th ick outcrops of rock deposits w hich lend themselves well to rock dusting. The m ate riał is a sort of sandstone w hich disintegrates rap id ly and completely under exposure to the weather. T his d ir t can be shoveled easily fro m the face of a b an k th ro u g h a sand screen and in to a m ine car and delivered in to the m ine as rath er finely pulverized rock dust.

There is difficulty in sta tin g exactly how fine it is, b ut ju d g in g it by its appearance and texture, a con- siderable portion would pass th ro u g h a 200-mesh screen as most of it is finer th a n m otor sand and crushes easily to talcum-powder fineness between the th u m b and the forefinger. R ecognizing th is as a h andy supply of rock dust, W . H . W oodhead, m aste r m e chanic; K . F . Lueder, m ine forem an, and others, o f the m in e force set to w ork b u ild in g a m ach in ę und e r the d ire ction of Superintendent W . F . C lark th a t w ould apply it.

They b u ilt a 1-yd. capacity b in of i-in. sheet steel welded at the jo in ts in the fo rm of an inverted p y ram id . A n am ple outlet a t the bottom of th is b in feeds the dust down in to a 12-in. pipę c a rry in g the a ir discharge of a blower, an ingenious com binatio n a g ita to r and feeder preventing the dust fro m c ak in g an d delivering it to the outlet. The p ipę is tapered so th a t the d is­

charge is of only 8 in . diam eter. Here a loose elbow m ay be revolved th ro u g h an arc o f about 45 deg.

428 C O A L A G E V cl. 26, N o. 13

This Is an Example of New Mexican Ingenuity The new machinę for blowing dry dust into manways, return aircourses and back entries in the Stag Canyon mines of the Phelps-Dodge Corporation at Dawson, New Mexico, consists of a 40-in. blower driven by an ordinary mining-maehine motor. Dust is fed by gravity from a sheet-steel hopper into the discharge line which terminates in an elbow that has been cut in two to give the dust stream only a slightly upward direction. This unit is attached to a mine car carrying the dust supply, and the whole outflt is moved by a locomotiye.

O f course, the men realized th a t the flow of dust from the hopper into the a ir stream m ust be un ifo rm . I t would not do to have the outlet at the bottom of the hopper so sm ali as to cause packing or arching. N either would it do to have the outlet so free th a t the dust flow would be too heavy fo r the air. A n d provision had to be made to prevent blow ing back th ro ugh the bin.

So along in the late summ er they rigged up th e ir feeding device, w hich was designed to overcome these difficulties and yet be simple and rugged. A section of 5-in. pipę suspended on an axle was set horizontally th ro ug h the outlet aperture a t the bottom of the hop­

per. E ig h t strips of ł-in. flat steel 14 in. wide were welded on edge to the outer surface of the pipę in parallel arrangem eht. This converted the pipę into a sort of paddle wheel, w ith the steel blades revolving th ro u g h an arc w hich extended upw ard about 2 in.

in to the dust bin. The rem ainder of this com bination ag ita to r and feeder was enclosed in a cylindrical hous- in g open a t the bottom.

The dust fed by gravity in to the spaces between blades, was revolved dow nw ard and dropped into the a ir pipę whence it was blown out th ro ugh the elbow nozzle. The steel blades successfully prevented the dust in the b in fro m arch in g over the outlet. The housing in w hich the feeder revolved was of sufficiently snug fit to prevent m uch back pressure of a ir should the exhaust pipę be p artially choked. The device pro- vided also a u n ifo rm ity of dust feed.

Roek-Dust Barrier at Dawson, New Mexico

This method of suspending V-troughs from crossbars is con- sidered, by the Phelps-Dodge Corporation, as the best way to support barriers in the No. 6 mine of the Stag Canyon group.

The roof is brushed high enough to erect 16-trough batteries, leaving a fu li 6 ft. of headroom. A battery covers the fuli widtli of the entry. Sixteen troughs when heaped have a capacity of 49.6 cu.ft. The dust used is tailings from a concentrator in the region. The roof and ribs are covered with wet adobe dust by a cement gun, even in the spots occupied by the barriers.

The upturned elbow at the discharge end of the pipę would revolve because the threaded jo in t was not screwed up tig h t. The dust stream could be directed from rib to rib at the w ill of an operator at the op- posite end of the m achinę. A n u p rig h t lever m ounted close at his hand was connected w ith a rod ru n n in g the fu li length of the m achinę and supported solidly on strap-iron rests eąuipped w ith p lain bearings. Op- posite the discharge end of the pipę th is rod was bent downward in a rig h t angle and connected, th ro ugh an 18-in. steel link, to an arm projecting from a collar clamped firm ly around the discharge elbow. B y this lever and its connections, the elbow nozzle could be turned.

A 5-hp., direct-current motor, operating at 1,750 r.p.m., direct-connected to the 24-in. blower was also used to revolve the feeding device in the hopper. To do this, a 4-in. pulley was m ounted on an extension of the fan shaft. A belt from this pulley to a 24-in.

One of the Original Union Pacific Dusters

. This direct-connected blower In inyerted position supplied the air and the smali conical hopper supplied the dust which was discharg-ed through the flexible-jointed pipę shown here in the hands of Supt. T. H. Butler of the H anna, Wyo., mine of the company. The outflt was mounted on a mine-car track.

wheel accomplished one speed reduction. F u rth e r re- duction was made by an 18-tooth p in io n on the belt wheel shaft m eshing w ith a 78-tooth gear on the shaft of the feeding device. Thus a speed of 67 r.p.m.

was im parted to the feeder. A li the gears and the motor were housed in sheet iron fo r safety.

About 100 ft. of lig h t cable was used to connect the motor to a source of power. T his cable was “hot- hooked” on the trolley w ire as the outflt moved ^ o w ly along, or the end of the cable was clipped to the tro l­

ley wire and the clip moved fro m tim e to tim e as the m achinę advanced. The m otor was grounded on the track thro ugh a truck axle.

W hen the m achinę first went into the m ine it dis- charged the finely divided sandstone successfully, b u t not enough of it stuck to roof and ribs. The plan was then adopted of preceding the m achinę w ith a sprinkler hose. The entry in the process of d ustin g was thor- oughly washed down im m ediately ahead of the m achinę and the rock dust was sprayed onto surfaces saturated w ith water. The result was reasonably satisfactory The sprinkler washed the coal dust to the floor, and the rock dust stuck to the surfaces in a sort of plaster coat.

This plaster tended to let go its coarser particles

S e p te m b e r 25, 1924 C O A L A G E 429

A Booster Fan Does the Work Here

This simple machinę, which consists merely of a twelve-inch booster fan and a smali wooden dust hopper from which dust is expected to slide by gravity through a curved pipę into the air stream, represents one stage of experimentation with the dusting problems at the Bon Carbo mine of the American Smelting &

Reflning Co., near Cokedale, Colo. Charles Smith, mine electri- cian, appears in the picture.

and presented, w hen fu lly dry, a rather dusty surface.

The m achinę d istrib u ted about two tons of d ir t in completely d ustin g 1,000 ft. of 24-ft. entry w hich had a n unusually h ig h roof. The h eight sometimes ran up to 18 ft. The m achinę and an attached m ine car o f dust were handled by the h oistin g rope on slopes an d by a locomotive on m a in entries.

The m achinę was p u t in to operation in A u g u st of the present year. There were distin ct lim itin g features to th is m achinę in its early stages, b u t some of these can be removed. The m a in difficulty was th a t it re- ąuire d too m any men. W hen it was hauled by a loco- m otive a crew of fo u r were reąuired. One m an sprinkled ahead, a m otorm an handled the locomotive, a shovelman stood in the m ine car feeding dust steadily in to the hopper and the m achinę operator directed the dust, started and stopped the fa n and looked a fte r the power cab!e.

W hen the outfit hooked onto a haulage cable on a slope, of course no m otorm an was necessary, b u t the hoistm an should be accounted as p a rt of the crew, fo r haulage on the rope was obviously impossible w hile the dustin g was in progress. The shovelman could be elimi- nated only by increasing the size of the dust hopper, w hich would probably necessitate ch anging the feeding mechanism . B u t w hatever its lim itation s, the m achinę represented one m orę idea in the long list w hich the W est is developing. F rom experim entation w ith such ideas comes the finished m achinę of the futu rę.

A nother home-made dust d istrib u to r w ith m any of the same lim itatio n s was th a t w hich was b u ilt in A ug ust at the Bon Carbo m ine of the A m erican Sm elt­

in g & R efining Co., near Cokedale, Colo. I t consisted of a wooden bin to hołd about i yd. of dust. The feed was by g ravity assisted by suction from the a ir line.

The opening in the bottom of the b in was eąuipped w ith a pipę in the a ir line turned in the direction of the a ir travel. The necessary blast of a ir was supplied by a 12-in. booster fa n blow ing th ro ugh a pipę w hich tapered to a diam eter o f about 3 in. a t the outlet.

This simple and compact outfit was m ounted on a mine- car truck and was ready fo r travel in to the m ine, moved by a haulage locomotive and accompanied by a car loaded w ith dust. C. R. G arrett, m ine superintendent, and Charles S m ith , m ine electrician, are devoting a good deal of th o u g h t to the m achinę in the hope of developing it.

In experim enting w ith th is and th a t at the D elagua m ine of the Victor-Am erican Fuel Co., in Colorado, m en used th e ir in g e n uity w ith w hatever parts and eąuipm ent happened to be handy. The result was a blower made fro m a 10-ft. oblong steel ta n k and a low-pressure ro- tary blower capable of delivering a large volum e of air.

Holes were cut in the ends of the ta n k to p e rm it a large sheet-iron pipę to be inserted the fu li length of it.

The tan k was filled w ith dust and slots in this pipę were m ade to a d m it the dust. The stream of a ir passing fro m the blower th ro u g h th is pipę was intended to pro- duce such a volume of dust th a t a u n ifo rm deposit would be m ade th ro u g h o u t the area traversed.

Difficulty was experienced in g e ttin g a steady feed of dust th ro ug h the inlet slots, and the outfit was cumbersome and heavy. B u t it represented a trail- blazing effort w hich has led the com pany in to the use of m ore advanced d u s tin g devices. The Victor-Ameri-

This Is the Way They “Mudize” in

Stag Canyon A cement gun is used oy the Phelps- Dodge Corporation to apply tailings from a nearby m ili or adobe dust from the ground surface or a mixture of cement and sand, one to eight. W et tailings are sprayed on roof and ribs of all m ain haulage roads, the surfaces having already been gunited. The m a ­ chinę, with a crew of three men, can cover 600 ft. of such entry in a day. The train cou- sists of the supply car, cement gun.

air receiver, air compressor, water tank and locomo- tive.

430 C O A L A G E V ol. 26, N o. 13

Machinę Planned to Produce Large Volume of Dust

I t was built at the Delagua mine of the Victor-American F u e l Co. from various parts and old equipment which happened to be handy. The blower sent a stream of air through a sheet pipę running through a tank. Dust from the tank was expected to fali through slots in the pipę and thus be caught in the air and discharged in a cloud into the atmosphere without particular direction. Dust could be shoveled into the tank when a top lid w a s raised.

can Fuel Co. experimented w ith rock d ustin g at Delagua long before the rest of the country had waked up to the value of the practice. Its work began as fa r back as 1911 when General Superintendent Ben W . Snod- grass was superintendent there.

Experim ents in b u ild in g d ustin g machines have been steadily progressing in the m ine shops of the U nion Pacific Coal Co., at both H an n a and Reliance, W yo.

Such dusters as had been b u ilt by late sum m er were able to deliver the dust, b u t they, too, suffered handi- caps th a t had to be overcome.

A t H an na, Superintendent T. H . B u tle r first tried an ord in ary forge blower turned upside down and driven by a sm ali direct-connected m otor. T his blew a stream of a ir th ro ugh a 5-in. pipę on top o f w hich was m ounted a funnel-shaped dust hopper w ith a capacity of about i yd. A short piece of stout, flexible tu b in g connected the outlet w ith a 4-ft. length of galvanized iron pipę eąuipped w ith a hand hołd. W ith th is the dust could

One Motor Drives Everything on Kenilworth Car By means of a belt and a reducing gear on the opposite side of the machinę, a revolving feeding device, set in the bottom of the hopper delivers dust at uniform speed and without danger of choking into the 12-in. pipę from the blower. This pipę is tapered to an 8-in. discharge and connects with a loose elbow which can be turned from side to side by the operator. Roof and ribs are washed down w ith water immediately ahead of this machinę so that the dust sticks to all surfaces readily.

be accurately directed by an operator. The whole u n it was mounted on a truck and accompanied by a car o f unground surface dust.

To control the flow of dust and to prevent a back- draught of a ir from blow ing up th ro ug h the little hop­

per, a 4-leaf, revolving valve b u ilt on the order of a stove-pipe damper, was installed in the round pipę through which the dust descended into the a ir stream . This was first turned w ith a hand crank so th a t a m an had to walk along beside it to run the feed. T his extra m an m ay be elim inated by gearing or belting the rotary valve to the blower motor.

T hat company has experimentally dusted p arts of its properties w ith adobe dust from the exterior o f the mines, screening b u t not g rin d in g it. F in a lly it has been concluded th a t fineness is obligatory, so a pulver- izer has been installed.

The Phelps-Dodge Corporation a t Dawson, N ew Mex., the U tah Fuel Co. and the U nited States F uel Co., both in U tah, and several other companies have done m uch experimental work w ith d ustin g machines of th e ir own construction. Thus the Rocky M oun tain region has m any hands and heads busy and the 1924 crop of d ust­

in g devices is proving itself a “bum per.”

____l _________

Washing of Freeport Coals Studied At Pittsburgh Experiment Station

A study of the w ashing characteristics of coal from the thick Freeport bed in Pennsylvania has been com- pleted by the U. S. B ureau of M ines investigators working in co-operation w ith the Carnegie In s titu te of Technology. The tests were conducted at the P itts ­ burgh experiment station. Coal from th is th ick bed makes good m etallurgical coke except th a t at some mines the ash content is usually too high, and at other mines sulphur is present in the coal in excess o f the ąuantity permitted in m etallurgical coke. Therefore, washing to remove the ash and the su lp hu r is an im- portant and vexing problem to the coal-mine operators.

The coal is mined for byoroduct coking, steam-raising, domestic use, gas-mak’ ig and other purposes. The problem in washing is elim inate the frag m e n ts th at in m ining get into the coal fro m im pure bands present in the coal bed, as well as im p uritie s finely distributed in the coal from some layers.of the bed. I t was deter- mined that the best treatm ent fo r coal w ith bony fragments was to make three products— clean coal for coking, secondary coal fo r use in boiler plants, and refuse.

Salt Damages Walls of Coke Ovens

Salt is an im p u rity w hich occurs in m any varieties of B ritish coking coals. I t consists p rin cipally of sodium and potassium chlorides, and on account of its ultim ate effect on the brickw ork o f the oven walls it is desirable to elim inate it as fa r as possible. To do this, freąuent change of the w ashing w ater is neces- sary, as in course of tim e the accum ulation o f dissolved c orides in the w ater becomes excessive, and instead of washing reducing the salt content of the coal it actually increases it. The w ashing w ater itse lf there- ore must be as free as possible fro m these con- stituents. On account of its salty naturę, m ine water is freąuently ąuite unsuitable fo r w ash in g purposes.

— G. Stanley Cooper in Byproduct Coking.

S e p te m b e r 25, 1924 C O A L A G E 431

Elaborate Care Fails to Protect Gates Minę

P ip e s E x t e n d e d t o F a c e o f E v e r y W o rk in g P la c e — E le c t r ic D e t o n a t o r s a P o s s ib le C a u s e o f E x p lo s io n — M a n y S a f e t y P r e - c a u t io n s P r o v id e d — R e c o m m e n d B e t t e r S u p e r v is io n o f N i g h t S h if t

A

The Gates No. 1 m ine is in a gaseous territory.

The P itts b u rg h seam, w hich at this m ine is 8 ft. thick, is being worked. The location is on the east side of the M onongahela R iv e r about twenty-five miles south of Brow nsville. A s h a ft 250 ft. deep form s the m ain entrance to the m ine. V e n tilatio n is provided by a force or blower fa n driven by steam w hich produces a pressure o f 2.5 in. w ater gage. The inspector’s report here reproduced describes the details of the m ine layout and the conditions as observed by the committee.

The a ir is forced down a com partm ent of the m a in sh aft, the airw ay b eing separated fro m the h oistin g s h a ft by a concrete p a rtitio n . The a ir a fte r leaving the s h a ft is conducted fo r some distance along airw ays parallel to the m a in haulage roads b u t later enters these roadways w hich thereafter serve as intake a ir ­ ways. The a ir is conducted th ro ug h the w orkings and then returns to the surface a t outlets provided fo r th a t purpose. I t is prevented fro m m a k in g a short c ircu it to the h o istin g com partm ent of the m a in sh a ft by a series of doors on each m a in haulage road leading to the m a in shaft.

Ex p l o s i o n Co n f i n e d t o On e Se c t io n

The m ine is divided into three sections to one of w hich, the N o rth section, w hich is adjacent to the P alm e r m ine of the same company, the explosion was confined. A b o u t 51,600 cu.ft. o f a ir per m in u tę enters th ro u g h No. 6 B u tt entry and a parallel aircourse and is d istrib u te d th ro u g h o u t the w orkings of the section.

T his entry form s the longer side of the trian g le occu- pied by the area described. I t is also the roadw ay th ro u g h w hich all the coal in the section is b ro ug h t to the shaft.

O n one side are tw o parallel airw ays separated fro m the rest of the m in e by a b a rrie r p illar. These two parallel headings are the re tu rn airw ays fo r th a t side o f the trian g le , the other side o f w hich is bounded by a n old gob. A n o th e r p a ir o f adjacent headings, w hich are parallel to No. 6 B u tt and on the same side as the rooms turne d off th a t roadway, serve as re tu rn airw ays fo r th a t side next to the old gob and nearest to the h o is tin g shaft.

Room s have been turn ed off No. 6 B u tt and as a rule they have been driven n o rth on the face, u n til they reach a b oun d ary of the trian g le . The first rooms tu rn e d off No. 6 B u tt are short b u t they increase in le n gth successively u n til N o. 15 room is reached.

Thereafter each in its tu r n is shorter th an the one th a t precedes it, No. 24 room being the last room turned. No. 13 room is about 1,500 ft. long, extending from No. 6 B u tt to the apex o f the triangle.

The rooms are crossed at fre ąu e n t intervals by cross- cuts and entries so th a t the tria n g le resembles some- w hat a p a rt of a huge checkerboard except th a t it is crossed by several diagonal entries w hich have been disregarded as a p a rt of the p lan of m in in g the coal in the area being described.

A t the head of each room the process of e x tracting the room pillars has been g o in g on fo r several m onths so th at a gob extends along tw o sides of the trian g le m akin g two gob lines w hich meet a t an apex a t No.

13 room. The accom panying m ap shows the layout of the triangle.

Two parallel entries w ith brick-and-cement stoppings connect this tr ia n g u la r section w ith the m a in return aircourse of the adjacent P alm e r m ine, w hich is venti- lated by an exhaust fa n w ith a w ater gage of about 3 in.

Sm o k e Is s u e s f r o m Ai r s h a f t o f Pa l m e r Mi n e

A bout 7:3 0 p.m . on J u ly 25 smoke was discovered issuing from the a ir s h a ft o f the P alm er m ine, and it was supposed a t first th a t the smoke was caused by a fire or by an explosion in th a t m ine. U pon investiga- tion it was discovered th a t the smoke was the outcome of an explosion in the Gates m in e in the section adjacent to the P alm er m ine. One o f the 13-in. brick- and-cement stoppings w hich had been b u ilt in these entries to separate the tw o m ines was to rn down by the force of the explosion and th u s the smoke noticed at the Palm er a ir s h a ft was carried in the a ir current from the Gates m ine.

In ad ditio n to the broken stopping in the entry lead­

in g to the P alm e r m ine the inspectors fo u n d evidence o f m uch violence extending over a large p a rt of the section. There was n o t m uch evidence of heat n or violence noticed along No. 6 B u tt entry nor in th e first few rooms turne d off No. 6 B u tt, altho ug h a n um ber of b rick stoppings were dem olished along th a t entry.

The violence was considerable in the central p a rt of the tr ia n g u la r area and tow ard the apex of the trian g le opposite No. 6 B u tt entry. The he at seemed to increase tow ard the western corner of th e tria n g le as was evidenced by the fused coal d ust th a t was plastered on posts and other surfaces.

The forces and flame traveled in different directions b u t seemed to radiate fro m the neighborhood of No.

21 room, where six dead bodies were found. N e a r the end of th a t room one n arro w place d r iv in g w estw ard tow ard the gob h ad recently been cut by an electric shortw all m achinę. A n o th e r s im ila r place 25 ft. far- ther back fro m the head of the room was p a rtly cut and evidently th is cut was being m ade w hen the explosion occurred. On the roadw ay o f the room, between the place th a t h ad ju s t been cu t and th e place th a t w as b e in g cut, m an y tangled detonator w ires were foun d, indicat-

432 C O A L A G E V ol. 26, N o . 13

in g th a t about one hundred electric detonators were assembled together there, the leather case in w h ich the detonators were carried by the shotfirers b eing found em pty and in good condition a t the head of the room.

M ost o f the detonators were found to be destroyed.

Sh o t f i r e r a n d As s is t a n t s Fo u n d i n Sa m e Ro o m

Close by the bundle of detonator w ires a place was fo u n d where a ą u a n tity of perm issible powder had been burned. A ppare ntly it had lain on the ground in the space between two ties in the track. The room was tim bered w ith legs and crossbars at th is place, and these tim bers were deeply charred. Three flame safety lam ps were found extinguished at th is p oin t also, in d ic a tin g th a t the shotfirer and his two assistants were together here when the explosion occurred. One of the safety lam ps and three exploded detonators were fo un d under a piece of slate th a t h ad fallen from

the roof. This safety lam p was found ly in g on its side w ith its glass broken, b u t the evidence indicated th a t the slate fell a fte r the explosion had started. There was no evidence th a t any shots had yet been fired in the w o rk in g places.

I t appeared from all the evidence available th a t w hile the shotfirer and his assistants were at th is p o in t in No. 21 room a rra n g in g th e ir detonators and powder fo r convenient use a flame approached fro m some source w hich exploded the detonators and burned the perm is­

sible powder, although it m ay be th a t the detonators themselves in itia te d the explosion.

In ad ditio n to these three men, a cutter and his helper and a tim be rm an were fo und dead in th is room.

A driller and his helper were fo u n d a t the head of No. 19 room. A noth er cutter and his helper were fo un d near the head of No. 12 room.

A n accum ulation of gas m ig h t have taken place in

Car blown from hare-

to here —

No. 1 -Machina runnar No. 2- Shotfirer's helper No. 3 - Machinę runner's helper No. 4- Sprinkler

No. 5- S h o tfire r No. 6 - Timberman No. 7 - DrillerS helper No 8 - D riller No, 9 - Machina runner No.lO-Machino runner’s helper Stopping

/ n c Stopping with door B.S.-Brick stopping W.S.-Wood stopping

Door W.D Wooden door

--- Mine cars, number denoted by ad jacent numeral T.-Track

Dm-Demolished Dg.-Damaged N.Dg.-Not damaged

* Man M O N ON GA H E L A R l V i

Map of the Northern Section of the Gates Mine of H. C. Frick Coke Co. Where an Explosion Occurred July 25, 1924 The explosion blew out a 13-in. brick- ping and Demolished) near the left side of wires of about one hundred detonators, and-cement stopping in a heading leading the plan. The explosion seemed to center mostly exploded. Close by a place was throue-h the laree barrier pillar between the from the neighborhood of No. 21 room, noted where a large ąuantity of i owder Pnim pr and the Gates mines. This w ill be where six dead bodies were found., On the had burned, charring the legs and cross- seen marked B S and Dm (Brick Stop- roadway of the room were the tangled bars by which the place was timbered.

S e p tem ber 25, 1924 C O A L A G E 433

Room 21 where the six men were found, due either to a sudden outburst of gas caused by a heavy fali or to a gradual issue coupled w ith a disarrangem ent of the ventilation, w hich accum ulation could have become ig n ite d by an electric arc, or possibly by the accidental firin g of the detonators. T his explanation seems the m ost reasonable to the inspectors, b u t the evidence was insufficient to m ake th is opinion positive.

The section of the m ine under consideration is known to generate some explosive gas, b u t the ventilation had been restored when the inspectors explored the scene of the explosion on Monday, and they fo un d no gas except at one place. Here it was issuing from the floor. There had been no explosive gas noted on the m ine report books fo r th is section of the m ine sińce Dec. 14, 1923.

The H . C. F ric k Coke Co. has spared no pains nor expense to m ake and keep th is m ine in a safe condi- tion. Sufficient a ir was supplied to give adeąuate ventilation. A system o f s p rin k lin g w ith pipę lines and hose had been provided so th a t all the w o rking places m ig h t be sprinkled w ith w ater before the shots were fired. A m an accompanies the shotfirer fo r this

Engineers Study Needs of Industrial Centers in Coal Storage Report

S

“ F ro m the standpoint of consumers in both large and sm ali com m unities,” according to the analysis, “the first reąuisite is th a t the supply should be freed from irre g ularitie s h a v in g th e ir o rig in largely in artificial causes. There is a negligible am ount of in tentional m a n ip u la tio n of the m arket, but flurries and near panics are freąuent. Consumers often are responsible.”

Es t a b l is h Av e r a g e Mo n t h l y St a n d a r d

The E n g in e e rin g Com m ittee has established a storage practice in leading in d u s tria l centers, using as a stand­

a rd an average m o nth ly shipm ent plan. As to th is the analysis said:

“E v id e n tly it is essential th a t the consumer storę coal. The ideał practice would be fo r h im to storę d u r in g the sum m er a large portion of the am ount con- sumed d u r in g the w inter. B u t such an ideał is too m uch to expect, hence the committee has set up as a sta n da rd an average m o nth ly shipm ent plan.

“ Com pliance w ith such a standard would m ean th a t the consum er would storę a m in im u m am ount of coal and such would not be in storage fo r a great length of tim e ; the tran sp o rtatio n agencies w ould be relieved of the in o rdin ate peak dem ands and would be enabled to move coal a t less expense th a n now ; the producer, k n o w in g w h at his m o nth ly demands w ould be, could

purpose. The coal is sprinkled by the loaders as they load it. I t is cut and shot on the n ig h t s h ift.

Perm issible powder only is used fo r shooting. Electric cap lamps are used exclusively except by the officials and shotfirers who use flame safety lamps b u t one such lamp is furnished to each cutter in ad d itio n to his electric cap lamp. B u t, considering the q u a n tity and character of the work being perform ed in th is section on the n ig h t sh ift, the supervision was insufficient.

The inspectors close th e ir report w ith certain recom- mendations suggested by th e ir in v e s tig a tio n : 1. That the ventilation be arranged so as to reduce to a m in i­

m um the chances of short-circuiting the a ir current.

2. That proper exam inations be made and efficient supervision be provided fo r the w orkings on the n ig h t shift. 3. That the Federal B ureau of M ines w ithhold its approval of electric detonators unless the type sub- m itted fo r approval provides ag ainst th e ir being exploded accidentally by electricity. 4. T hat greater care be exercised in the h a n d lin g o f detonators and explosives. 5. T hat all electric wires and eąuipm ent be installed, m ain taine d and operated so as to reduce the danger of arcing to a m in im u m .

so arrange his operation schedules as to produce coal a t a much lower cost per ton.

“Eventually, should such a practice become generally and regularly followed, the am ount of storage reąuired would be m aterially reduced, b u t th is cycle of improve- m ent can be in itia te d only by consumers.”

The Chicago com m ittee of the CounciFs m a in com­

mittee, it was said in an aly zin g conditions in th a t city, based its conclusions on d ata fro m fourteen representa- tive industries h av in g a consum ption o f 4,640,000 tons, representing 15 per cent of the total coal m ovin g into the Chicago district.

“ Only 6.7 per cent of the an n ual consum ption of these industries should be stored i f all of the users were purchasing coal on the basis of u n ifo rm m o n th ly ship- m ents,” th is committee reported. “T his is a larg er percentage th an th a t p e rta in in g to P h ilad elp h ia, b u t in comparison w ith m ost of the m edium to large cities of the country it is a very Iow percentage.

“ I t means th a t i f users generally in th is d is tric t were purchasing coal on a contract basis w ith eąual m o n th ly shipments, the aggregate storage b ill w ould be b u t a smali am ount when d istrib u te d over the entire year’s supply. U ndoubtedly some in dustrie s w ould be obliged to storę a larger percentage, b u t the typical estab­

lishm ent is in a fo rtu n a te condition in th is respect.”

The u n ifo rm m o nth ly shipm ent p la n recommended by the engineers fo r Chicago, would, it was said, result in m onthly shipm ents of 386,550 tons to 14 consumers, seasonal storage of 295,500 tons, a m o u n tin g to 6.4 per cent o f an n ual consum ption, reserve storage 7.1 per cent of annual consum ption and total storage 13.5 per cent of an an n ual consum ption of 4,638,600 tons.

Ta r Yie l d o f We s t e r n Li g n i t e s.— A larg e n um be r of assay re to rt tests o f samples of lig n ite taken fro m public lands in the W estern states have recently been m ade by the oil-shale lab oratory of the B u re a u of M ines, Boulder, Colo. The Colorado lig n ite s so fa r tested yielded fro m 8 to 10 gal. of ta r to the ton.

Sam ples of W y o m in g lig n ite yielded as h ig h as 20 gal.

to the ton.

434 C O A L A G E V o l. 26, N o . 13

Why Not Use Approved Eąuipment in Place o f Open or Half-Safe Type?

E le c tric ity Causes M a n y Disasters a n d Fires— T o D a te N one H as Been C aused b y Flashes from Perm issible A p p a ra tu s — Lists Large

V a rie ty o f E ą u ip m e n t B u re a u H a s A p prov ed

A

B ureau of M ines. T his paper starts by com paring the b u y in g of approved eąuipm ent follow ing a disaster to

“locking the stable door afte r the horse is stolen,” then goes on to discuss some recent accidents and th e ir effect.

“A n open type of electric coal d rill was used in a gaseous m ine in W est V irg in ia . T his was the probable cause of the death of twenty-seven men. A half-safe type of electric coal-cutting m achinę was used in a gas­

eous m ine in Pennsylvania. T his was probably the cause o f the death of thirty-six men. A n unapproved, unsafe type of flame safety lam p was used in a gaseous and dusty m ine in U tah. T his was the alleged cause o f the death of 171 men. A ll three disasters happened w ith in the last six m onths, and it would seem would have been avoidable if proper eąuipm ent had been used.

“ I t is understood th a t more rig id reąuirem ents w ill be enforced in W est V irg in ia . The com m ittee of state m ine inspectors made definite recom m endation fo r im- p roving the conditions in the Pennsylvania m ine to w hich reference has been made. The In d u s tria l Com- m ission of U tah has already issued new orders which w ill prevent the use o f unsafe lam ps in th a t state.

“These acts and recommendations are all good and w ill help to prevent accidents in those states in the fu tu rę . Is it not a p ity th a t such recom mendations and orders were not made a little earlier before the toll of life had been exacted? Is it not un fo rtu n a te th a t other states w ill not take these lessons to heart and safeguard th e ir m ines before and not afte r disasters take place?

“ Electric current can cause accidents in five generał ways as follow s: (1) By shock to persons; (2) by ig n itin g pow der; (3) by ig n itin g gas; (4 ) by ig n itin g coal d u st; and (5 ) by setting fire to flam m able m ateriał such as tim b e r and coal. M any accidents fro m these causes are preventable if proper care is taken. Most o f the accidents caused by sparks and flashes fro m elec­

tric a l ap paratus would not take place i f approved elec­

tric a l eąuipm ent was used. B y approved eąuipm ent is m eant eąuipm ent th a t has been tested and form ally approved by the B ureau of Mines. So fa r as known, up to the present tim e, no disasters have been caused by sparks or flashes fro m eąuipm ent h av in g the Bu- reau’s approval.

“ The table accom panying th is article and compiled by M . W . von B ernow itz from records of the B ureau of M ines covering the period 1910 to 1924, shows disasters an d fires caused by electrical apparatus and circuits.

“ The table shows th a t in the twenty-six accidents re- ported, 499 lives were lost and 86 other m en were in ju r e d ; besides there was m uch dam age to property.

“D u r in g the past fourteen years the B ureau o f M ines has. in co-operation w ith m an ufacturers of electrical m ach ine ry and e ąuipm ent fo r m ines, conducted thou- sands o f tests on various m achines and apparatus sub- m itte d by the m an ufac ture rs to determ ine w hether the device is safe fo r use in explosive atmospheres. I f the

machinę, or any p a rt of it, is not safe, the bureau an d the m an ufacture r work together to elim inate the u n ­ safe features. W hen the m achinę finally passes the b ureau’s test, it is form ally approved fo r use in coal mines where hazards fr o m gas and dust occur. Several classes o f eąuip­

m ent have been tested, and there is a steadily grow ing list of approved eąuipm ent recommended fo r use wher- ever such eąuipm ent is needed.

“The electrical eąuipm ent so fa r fo rm ally approved by the B ureau of Mines includes five storage-battery

Disasters from 1910 to 1924, Inclusive, Attributed to Electrical Apparatus and Circuits

Fatal- Injur-

Sfcate P robable Cause of Ig n itio n ities ies

W ash. Arc from booster-fan m otor ignites g as... ; . 10

111. A rc from short-circuited trolley wire sets fire to ventil- a tin g d o o r ... 31

Ohio Arc from bare cable sets fire to “su lp h u r” b a n d (a)... W ash. Arc from trolley wire ignites gas... 16

Pa. Arc from trolley wire ignites gas... 8

W . Va. Arc from ta ilin g cable ignites gas... ... 82 . .

W . Va. Arc from filam ent of electric-light b u lb ignites gas . . . . 6 3 K y. Arc from trolley wire ignites pow der... 2

M o. Arc from office-fan m otor ignites g a s ... 3

Pa. A rc from pum p-m otor controller ignites gas... I Pa. Arc from trolley wire ignites g as... 19

A la. Arc from switcn ignites g a s... 18

Pa. Arc from trolley wire ignites g as... 14

W . Va. Arc from trolley wire ignites gas... 4

In d . A rc from defective cable ignites gas (6 )... W . Va. Arc from trailing cable ignites gas... 7

U tah A rc from shoj*t-circuited wire ignites tim b e r (c )... Pa. Arc from hoist motor ignites g a s... ...^ Ala. Arc from electric wire caused b y derailed trip ignites coal d u st... 90 70 K an. Arc from batte ry of storage-battery locomotive ignites powder... ... . . 13

N . M . Arc from electric-power wire caused b y runaw ay trip ignites coal d u s t... 120

O kla. Arc from short-circuited power wires sets fire to coal (d) W . Va. Sparks from electric-drill m otor ignites gas... 27

Pa. Arc from electric m in in g m achinę ignites g as... . 36 Pa. Arc from short-circuited trolley wire sets fire to ventil-

ating door (d) ...

Pa. Sparks from electric coal-cutting m achinę ignites gas (d)

499 86

(a) M ine sealed for m onths. (b) Several acres of workings sealed for m o n th s.

(c) Besides being closed for m onths, m u ch dam age was done to w orkings. (rf) P art of mine sealed.

locomotives, one power truck, two coal drills, n ine short- wall m in in g machines, one arcw all m in in g m achinę, fo u r cap lamps, two hand and tr ip lam ps, and tw o single-shot blasting units. A complete list w ith m ore detailed Inform ation can be fo un d in B ureau of M ines Technical Paper 364. This paper is in course of p ublicatio n and a copy of it can be obtained free of charge by w r itin g the D irector o f the B ureau of M ines, W a s h in g ­ ton, D. C.”

Coal and Coke in House-Heating Plants

Accurate data on the effectiveness of com bustion of bitum inous coal and coke fo r g en eratin g steam under hand-fired low-pressure cast-iron boilers of a type actually used in h e a tin g large b u ild in g s have been obtained as the results of a study a t the P itts b u rg h station of the B u re au of M ines. The experim ental work has been under way sińce early in 1922. The effectiveness of different m ethods of firin g the different coals tested was determ ined, as well as the relative value of the different fuels used. The results showed th at the b itum in o u s coals fro m the P itts b u r g h and Lower K itta n n in g beds, o f Pennsylvania, and the coke were of about eąual steam ing value a t the lower pres- sures b ut at m ed ium and h ig h e r pressures perm issible w ith th is eąuipm ent, the coke had about 90 per cent of the steam ing value of the b itu m in o u s coal.