Evening Star Newspaper, August 23, 1925, Page 69

ILLUSTRATED FEATURES MAGAZINE SECTION he Sunthy Staf / FICTION AND HUMOR Part 5—8 Pages WASHIN GTON, D. L SUNDAY MORNING, AUGUST Washinston Miners Are Disging Tunnel Th E The Mammoth Conerete Tile ready for purial. Experienced Rock Men Cut Subterranean Passage Through Solid Mass Three-Quarters of a Mile Long—Modern Mining Methods Within Three- Miles of the White House. Water Supply From the New High-Pressure Reservoir Will Flow Through This Remark- able Tunnel. BY GEORGE H. DACY. HILE Washington sleeps or the Capital City pul with the activities business day ing is in pr of not far from Mighty machines i rockmen are attacking g of granite. The details of Washington's latest venture into rock drilling come from far underground—down where it chill on the warmest » Where water drips constantly from mighty walls of rock, where miners risk life and limb, and where all the hazards of cate tunneling are faced and ved. The writer, arrayed in hip boots, a capacious slicker and rubber hat, ac- companied by a photographer simi- larly garbed, clutched the side of the rock bucket as it dropped to the bot- tom of Washington's only mining mass of granite as Gibr: ar de- ted in true mining compressed-air hols Jumping from the muck car at the bottom of the shaft, we stepped into knee-deep wat and saw, stretching away in either direction, yawni erns, in which electric like sputtering candles, while the dull, almost muffled, thuds of steel beating on lid rock resounded tunnel is the cc which will join togethe service water reservo lands above Nebraska getts avenues and the line which will lead to the n, tion plant now under line red _along wk Creek oticed and the District As ) scenic 'h you have sive gr sheer from the highway along certain exposures. vou have mai veled at these semi-mountainous in this almost tableland region so happens that the granite vein which is most outstanding in the park that has been termed the “most nat- urally beautiful reservation of its kind in the world” extends to the peak of Nebraska avenue near American University, where the elevation is about 450 feet above sea level. When the Army engineers were routing the survey line of the water course which is to convey our filtered supplies to an_elevation where the water can flow by gravity to the high- est bullding in the District they came face to face with this granite vein They sunk shafts about 300 in_order to study the rock formation. These shafts r in depth from 40 to The subterranean d acquired in this nove basis of the tunnel specifications which they subsequently submitted to the commercial engineering public for rk construction | of near the intersection of Conduit road | chanical uses. the | which can edge 600 steels daily the mas- | the steel drills most | to 10 feet in length arid bore a hole competitive bids" on the wark. A Washington engineer, Allan Pope, sub- mitted the most acceptable bid and s awarded the contract. It was a 0,000 job to cut through that three- quarter-mile stretch of solid rock and to install the regulation concrete duct which was to carry the water supply. This explains why the year 1925 has seen a revival of mining in the Dis- trict—a sort of a throw-back to Wash- ington’s former mining furore, when somebody discovered evidence of low- grade gold on the Maryland side of the Potomac several miles from Great Falls and embarked in an unsuccess- ful commercial attempt to win a for- tune from the gold-bearing strata of that rugged neighborhood. have * X X % THE last days of 1925 wil faded before the tunnel-digging task is completed. Battling against guaranteed granite is almost as diffi-] cult an assignment as trying to con- quer the Arctic Circle ice floes. Mere man would find the job a superhuman task if he tackled it pick-and-shovel ashion. The work has been partially simplified by the use of mechanical fingers and by the disruptive effects of heavy discharges of dynamite. The task might well be likened to the | ations of each colossal order of pulling the earth's, molars, if there were such The first thing which Mr. Pope his aides did was (o .construct shops nd sheds and to mount thelr massive machinery on substantial foundations | at the central sector of the granite| vein the. equipment are tw zan compressors whic itated to deliver 1,000 cubic compressed air a minute for me-| “There is also a com arill sharpener, An nd temper | ange from 2 and | | In air pressed-air tool—a oil furnace is used to heat which 13, inches in diameter. Kach steel is heated to the temperature of 1,700 degrees. At this temperature stebl loses its magnetic qualities. A spe- cial electrical device is used to test each flaming-hot drill point, to make sure that it has lost its magnetiza- tion, which, of course, means that it has been heated sufficiently. The compressed-air supply is piped in galvanized casing to the tunnelway, where it is used to function efficient drilling machines, called “drifters.” The drill point, set in the ‘“drifter, rotates so rapidly that man's eye can- not follow its progress. It dulls one of the drills to“bore a hoe 12 to 18 inches deep where granite is the ob- structing material. Hence to drill a dynamite hole 8\feet deep, six to eight drills have to be'used. The crews dull from 200 to 300 steels daily, and keep the shopmen busy sharpening the tools. Thee 60 miners whom Mr. Pope is using in his tunmel-cutting enterprise work in three shifts of eight hours each. An engineer, acting as Govern. [ ment inspector, keeps tab on the oper- shift to see that the work is done exactly as stipulated by the contract. Under present tions about 10 feet of tunnelway being cut daily. Ordinarily two shots are fired. Each shot is responsible for 5 feet of rock- ribbed passageway. Usually 16 holes are bored with the compressed-air rock drills. Suppose that these holes are each 5 feet deep. They are charged with 33 pounds of dynamite. The miners retire about 400 feet from the heading to be shot. The charge is then fired by electricity. Some- times the rock flies 200 feet down the tunnel from the scene of explosion. The detonation is deafening. Residents of Washington know prac- tically nothing about these tunneling operations in that elevated district above Wisconsin avenue. Hence it was not at all surprising one fine Summer day when an expensive auto- mobile passed that way to have the driver stop the machine and descend with his two lady companions to gather wild flowers in the neighboring meadow. Fate placed the choicest flowers directly above the subter- ranean digging enterprise. The trio of nature lovers, all bending over and picking sweet-scented blooms, of a sudden arose, as though by order, looked inquiringly at one another, and then turned and fled precipitately to the motor car. Pell-mell style, they scrambled aboard. The driver stepped on the starter with alacrity. The car sped away as though pursued by sa- tanic demons. If you know anything about the vi- is brations produced by the discharge offc,¢yrated. a powerful underground dynamite shot you will understand immediately what caused the wild-flower pickers to flee. It so happened that 40 pounds of explosive were discharged exactly 35 feet below where they were stand- ing. A very perceptible tremor re- sulfed. Probably the erers imagined that a California earth- quuke had gone astray 1 centralized Its energies close to the City of Pre dents. Anyway, they decided t mediate flight was the best pi tion of discretion for such a cuse they fled. rip- % e NORTHODOX explosions in Wash ington’s deep-seated tunmelway have to be explained. The dangers of ve-in and disaster are as dire though the rock-lined passagew were 100 times as deep. Loose rock. detached from iis anchorage by the concurrent vibrations and concussions of daily explosions and further und il water action is liable to z ift as the bolts of Jove, and maim or kill the miners who chance to be below. A cave-in would block the tunnel and shut off actess to the shaft. It would shut off the ventilat- ing air supply. The imprisoned men caught in such a catastrophe might die before succor could reach them. That is why all irregular nolses, flames or other agents of potential explosion have to be accounted for. Our photographer used an extra heavy charge of flash powder when he exposed the first negative under- ground. The miner who had charge of firing all the shots was at the op- posite end of the level, and did not know that picture-taking was in prog- ress. All of a sudden we heard the splashing and floundering steps of a man who was in a desperate hurry. The sprinter, incumbered by heavy hip boots and the knee-deep water, wallowed our way. He sounded like the start of a dozen thoroughbreds sent away from the barrier at Pim- lico when track conditions were super- condi- | blossom-gath- | at im- | en at %‘na[ neer, consulls with su Loading Rock Cdr af £ endvance. periniendeat/ 'l,"\ )~ \X ter explosion— The runner rushed for- ward and gasped out the question: “Where was the explosion?” The mine superintendent quieted his fears by pointing to the camera and saying, “Pletures.” The man working 400 feet aw seen the flash of the photo; powder. 1 knew that extraordinary was on fool. sumed that it must he an untows explosion. He dashed forward to s certain the r and laughed wit | the rest of us when he found out the {real cause of the bright light. This serves to illustrate, however, the nerv- ous ten; s wark: ing below the grade line live. Une: without an instant’s may be called to shake h A narrow-gauge railr {1aid along the:pathway [to aid in the transy {and muck from the he above- nline tractor, 1 locomotive nething He son on under which min ad track i of the tunnel m of rock ne of explosion round rock crusher. A provided with sp attachments, is used cars from the tunnel headings to the central hoist. Trouble is experienced in running the gasoline vehicle so far underground. The temperature and jmoisture conditions make it difficult to start the motor machine. Tie-ups occur ‘through this refractory . steel steed. However, it is the most satis- factory source of transportation power for such an .enterprise, and hence is used. The shots are fired in alternation. An explosion is set off in the heading at one end of the tunnel. While ma- chinery is being used to load the rock debris on the tram cars in that sector, the drill crew works at the opposite end of the tunnel, preparing to make a second shot, which will wreck the rock barrier in that vicinity. Thus the work is continued night and day. When one of the rock cars is loaded—each car carries one cubic yard of myck—the tractor hauls it to the hoist. The body. of the car is de- n as the motive power to haul the rock | tachable. The hooks of the hoist are snapped into place and the car body with its load of rock is elevated about 6 feet and dumped automatically into the special hoist car. The workmen then signal to the surface to hoist the load. It is elevated to platform chutes that are to 40 feet ahove the ground.: The load Is dumped into one of these chutes and flows by gravity to the rock-crusher After the rock is crushed it is livered to a belt conveyor which | ries_ it _to the surplus rock pile. | erushed rock is sold and used in pay- [ing city and suburban streets and alleys. * K %k %k vou visit, the Washington:tunnel and - spimsh and splatter | sround in- the muck, mud and mire, be better able to .visua in leading mines under- [yon winl {the conditions | tunnels of the universe, wiiere located. A certain amount of imbering—a total of about 500 feet— has had to be installed to prevent the potential downpour, of loogened rock, whose masses might choke up the tun. nel before the water duct could be completed. The framewotk of this timbering consists of mammoth pieces, 10 inches square, in cross-section. The 3-inch planking supported by these braces consists of strong and durable oak. A water pipeline extends the length of the subterranean passage carved out of solid granite. It carries a water supply under a 100-pound pressure, which is utilized in .cleaning out the drill holes as they are bored. A sys- tem of electric -wires, which provides light in the dungeon-like catacombs, as well as the force for discharging the dynamite, parallel, the course of the pipeline. The fresh-air supply is circulated in a waterproof, durable duct about 16. inches in djameter, which extends along the top of the tunnel. It provides 25 cubic feet of fresh air per minute for each miner, The compressed-air supply for operat- | came | eartn. ing the rock drills is carried in 2%;- inch piping that abuts the railroad track. If you ask for a cup of drinking water you will be given a tumbler and told to fill.it from a spring which flows downhill. The ' water which seeps from the rock-ribbed ceiling has been clarified and filtered by its jour- ney through 30 to 50 feet of granite- lined i It is as cold as If it from a refrigerator, pure as the finest water 1 will find in any spring in nearby Virginia or Maryland The chill, dank temperature ‘of the twmel - makes you think that Jack Frost and his- delegation of ice-coated days ave heading toward Washington. The night crew in particular are dressed for_ chilly weather when they ate lowered into the bowels of the Corduroy breeches, woolen shirts*and sweaters and other habili- ments of cold-weather costumes are requisite even while the population of, our National Capital is sweating and ‘sweltering under the sun’s light or the'moon's smile. When the tunnel is completed the concreté water ‘duct, of. horseshoe shape, which will be about 6 feet wide and of similar height, will be built. A portable steel form, which will be mounted on wheels and provided with collapsible attachments, will be util- ized in 15-foot sections for supporting the mass concrete until it hardens. As soon as one section of duct is com- pleted the form will be moved to a new place of set-up and another seg- ment of the tunnelway will be laid. ‘The concrete plant is an interesting subsurface feature of this mechanical equipment. The sand, cement and crushed rock ‘are delivered in auto- matically measured quantities to the concrete mixer, functioning by elec- tricity, which is mounted in a cave- like recess 20 feet below the surface. Water, of course, is also piped to the mixer from the surface. After the concrete is mixed in proper propertion it flows by gravity.to the powerful Cornerete Tile used 1n piping water to veservoirs | concrete gun at the base of the shatt. | A 4-inch portable pipe shoots the con- | crete under mighty air pressure to the most distant part of the tunnel. The concrete is delivered from the gun at the crown of the duct. Wark- men with tamping bars and shovels assist in packing the binding material into place above the metal forms Logically, the floor of the duct is laid first. Then the temporary track line is placed directly on.the floor of the | concrete duct when it hardens suffi-| clently. 'The concrete forms are| moved from station to station along| this tramway -as desired. Manhole {entrances into the tunnel are left at | each end. Thus workmen can enter | |in future year the need for such | | action develops, in order to repair the | | curious waterwa { The ventilating air for the tunnel is | forced underground by a special 36- { inch ventilating fan, which is kept | { going continuously ‘he electrical power at the plant consists of current which aggregates 13.000 voits, and| which Mr. Pope transforms to serve| | his. many mechanical purposes. ©ne of these is to operate the fan | * x % 1 r}”i huge granite deposit which is | Lin that wedge of land bordered by | | Massachusetts, Wisconsin and Ne-| | braska avenues is being blasted to | depths of 35 1o 125 feet below the sur- | face in order to provide a smooth course for our future water spply t flow from the second high-pressure | reservoir. The total fall of the rock- cut tunnel will be only 12 inches in 3,960 feet. Granite, as you may know, is one of the hardest rock materials to cut through that the rock miners usually meet. It breaks in great seams, 5o that large rocks are show- ered over the bottom of_the heading after each dynamite shot¥s fired. The new District water system will be fully completed and ready for ac- tive service by January, 1927. It will constitute one of the best municipal The total cost will be $9,000,000. ‘Phe supply will be handled by the old and new conduits which convey the water from Great Fails to the new filtration plant at Dalecarlia, near the District line. 9 miles, so that the combined length of the major water ducts amounts to 18 miles. ~After the water is filtered at this new, rapid, sand fiiter plant, which is to 'cost $2,500,000, it will be carrled to three special reservoirs. The first high-storage reservoir, | with a capacity of 15,000,000 gallons, |is being built of reinforced concrete near the Interscction of Ridge road and Reservoir street. This plant will cost $300,000. The second high reser- voir, of similar capacity and cost, is being constructed -above Nebraska avenue and Van Ness street. The old Reno reservoir, of 4,500,000 gallons capacity, will be used as the third | bigh reservoir. A battery of nine centrifugal pumps which will be installed at the new fil- tration plant will be used to pump the purified water from Dalecarlia to the three storage reservoirs, whence it will flow by gravity, as needed, to the high-elevation sections of Wash- ington. The filtration plant is on the old Dalecarlia plantation of 300 acres, which the District purchased about 1853, The nominal capacity of the| new filtration plant will be about | 80,000,000 gefions daily. In time of emergency it could handle as much as 100,000,000 gallons dafly. The slow | sand filter plant in MeMillan Park near Soldiers’ Home, with a capacity | water supplies in use under the sun. | This is a distance of | of 80,000,000 galléns dafly, will con- tinue to be wsed to purify the water the low-elevation sections City This filtration d the period supply for of our Capital plant was built from 1903 to 1306, Washington has been threatened by a water famine now for several vears and, strangely, the maximum use of water occurs during cold weather when houscholders let their water fa cets run to keep them from freezing The peak consumption of water in the District coincides very closely with the present maximum supply. If a break should occur in the old conduit which was built before the Civil War, a serious water shortage would occur, unless the damage could expedi tiously repaired. Our existent storage supply is only adequate for the con sumption of about hours. How ever, the gravity of the situation will be effaced when the new conduit from Great Falis to Dalecarlia is put into ervice, the latter early in September completion will permit of the ready repair of the old conduit at any time when such emergency should develop. These mammoth pipe lines can be used inter changeably IX miles of water duct will conve ' the water from the new filtration plant to the three high-storage reser voirs. Huge joint pipes, 4 feet in diameter and 12 feet long. are being used in the construction of the -mile waterway from Dalecarlia to the second High-storage reservoir. Com petitive bids are being considered at present to determine what style of duct will be built to the other high storage reservoirs. These mighty tiles, made of mass concrete, with a central jacket of steel, are manufactured in an interest ing plant near the District line out, Conduit road way. The steel jacket is made and riveted in true boller fask ion. Electric_riveting machines r: like musketry and do the work of many hundred workmen. After the cylindrical jacket is made concrete is poured around it in such a fashion that the great water pipes result Traveling cranes, functioning locomo tive style, are used in handling these enormously heavy concrete pipes After they have cured thoroughly they are transported to the trench in which they are to be interred as a link in_ Washington's waterway chain Washington's newest oasis includes a total of 13 miles of main water and branch duct line, which was cut through solid granite. In the vicinity of Great Falls a stretch of 2, had to be cut through the r granite-cored hills of that section tunnelway is as far as 200 feet beiov the surface of the ground at some points. This tunneling work was com pleted more than one vear ago, and the concrete duct. 10 feet in diameter has now been installed If you remember that hill which e: tends upward along Conduit road from the intersection of District gnd Mar: land soil, you will have located an- other section of underground passage- way which was cut through solid roc! This particular stretch is 800 feet ir length. The three-quarter-mile sector which is now being tunneled in_the neighborhood of Nebraska and Wis- consin avenues is the last link in the tunnel chain. The operations in that tunnel have been described in detail They are typical of the subterranean digging and blasting performed in the other sections mentioned. The $9.000,000 water service struction is being supervised by Al mnor, District engineer, and When the watcr system is completed, it will be turned over to the Distriet of Columbia for operation and maintenance, * % %