GENERAL ARTICLES

How Deep Is Down?

LESLIE McFARLANE February 15 1938
GENERAL ARTICLES

How Deep Is Down?

LESLIE McFARLANE February 15 1938

How Deep Is Down?

GENERAL ARTICLES

LESLIE McFARLANE

OW DEEP is down? In Canada, so far as mining is concerned, it’s 6,142 feet. In India it’s more than 7,000 feet. In Brazil it’s 8,000 feet. In South Africa it’s 8,250 feet.

And in each case, gold is the objective. No other treasure locked in the hard rock above the molten core of the globe lures men so far down. Oil-well drills go deeper but only gold takes man himself such distances beneath the surface of the earth. At the Quincy mine, in Michigan, they go deep for copper. A mile deep. But the very deepest mines are the gold mines.

The Bank of Commerce Building rears its bulk 473 feet above a Toronto street. The Empire State Building towers 1,250 feet into the clouds over New York. Imagine twelve more Bank of Commerce Buildings atop the original, imagine the Empire State extended to five times its present height. Then you will have, in reverse, a notion of the depths achieved by the deepest Canadian gold mine.

Teck-Hughes, at Kirkland Lake, in Northern Ontario, holds the record in tne Dominion. Its neighbor, Kirkland Lake Gold, is close behind.

The world record is held by the Robinson Deep, in

In Canada man’s deepest deep is 6,142 feet—The business of going down is thoroughly exciting — Here’s the story of how the McIntyre mine has delved more than a mile into solid roch

South Africa, where natives swelter in two-to-four-hour shifts and sweat five pounds of weight in the terrific humidity of 8,250 feet from daylight. The century-old Morro Velho gold mine in Brazil used to hold the record, and isn’t far behind the Robinson Deep figure right now. The Champion and the Ooregum gold mines in the Kola District of Mysore, India, are at 7,000 feet.

But the Canadian mines are young. There is no particular purpose to be served by achieving a deep-mining record merely for the record’s sake. The business of blasting holes in the earth to depths of a mile and more is highly expensive •—from $150 to $200 a foot in Canada—and the cost of equipping and maintaining a deep shaft is fantastic to the layman. A gold-mining company is a business institution. Every shaft is expected to pay its way. If it pays to go deeper, against the mounting costs and the operating problems peculiar to depth, they’ll go deeper. Mining men have a habit of taking the most formidable obstacles in their stride.

TT IS seven o’clock of a frosty winter night. Three hundred miners are waiting at the McIntyre shafthead to go on shift. Shovellers, scraper men, machine runners, timbermen, scalers, trammers, loaders, nippers, motormen, switchmen, helpers, chute loaders and just plain laborers. Men in hobnailed boots and overalls, each with a battery strapped to the back of his belt and an electric lamp clipped to his collar or the front of his hard hat. They wait in the draughty, lofty shafthouse, with its narrow-gauge railway tracks.

Deepest Porcupine Mine

Steel beams tower to the roof of the headframe 175 feet above. Steel cables glimmer black and slick, descending from the upper shadows into the shaft beneath. Metal gates and grills guard the mouth of the huge rectangular pit that has been hewn and blasted out of solid rock, straight down, down, down—Number Eleven, main shaft and lifeline of the McIntyre, deepest mine in the Porcupine gold country.

Mine Captain Bill DuFeu, a wiry, energetic veteran of the abyss, seems puzzled.

“You merely want to go down to the bottom? There’s a lot more to a big gold mine than just the shafts, you know.” “So much more that I’d probably find myself writing a book if I didn’t stick to one subject,” I reply. “Just now I’m interested only in depth. This is the deepest mine in the Porcupine. I want to know how deep you go, how you get there, and what it’s like at the bottom.”

“Maybe we should have started in the hoist-house,”

remarks Captain DuFeu. “It’s a separate building. You would see thousands of feet of cable wound on big motordriven drums. The cables run from the hoistroom on up through the air to the top of this headframe, see.” He gestures toward the shadowy roof. “They pass over wheels up there and then down into the shaft, into the various compartments—”

“Compartments?”

“A shaft isn’t just an empty hole in the ground,” says DuFeu. realizing that he must begin at the beginning, get right back to kindergarten lessons in fact. “It’s walled off into compartments all the way down. One division, for instance, contains nothing but pipes and ladders.”

I can see them from where I stand. Big pipes for forced draught ventilation, pipes for compressed air, pipes for pumping, pipes for drinking water, for electric wiring, pipes carrying water to the drills. And the ladders, DuFeu explains, run zigzag fashion from platform to platform all the way downa manway, for purposes of emergency, for shaft inspection, for convenience between the various levels.

“Another compartment for the man-cage, another for the service cage.” Steel tracks run across the floor of the shafthouse right up to the gates at the shafthead. A small fiat car loaded with heavy timber is in readiness for transportation underground. The floors of the cages, DuFeu explains, are also equipped with rails. Tracks coincide with them at every level in the mine, so that whole carloads of heavy materials can be transported from surface to the farthest reaches of the mine with a minimum of effort.

“It’s quite a little railway system, what with the fleet of trolley locomotives and cars. Eighty miles of track,” DuFeu remarks negligently.

“Eighty what?”

“Eighty miles. Over at the Hollinger they have 250 miles.”

One begins to get the idea that there is considerably more to a mine than a hole in the ground with a few men shovelling gold nuggets into a pail at the bottom, although I hastily disclaim guilt of ever having entertained a notion so innocent. I try to imagine 250 miles of track. Lay all that steel end to end, as the statisticians are so fond of doing, and you could travel from Kamloops almost to Vancouver, from Regina to Prince Albert, from Toronto to beyond North Bay, from Halifax to Yarmouth.

“A mine,” says Captain DuFeu, who knows the intricate complexity of tunnels in the McIntyre as you know the streets of your own neighborhood, “can be a pretty big place. If I set out to visit all the locations where those 300 men will be working tonight, how long do you think it would take me?”

I know I’m wrong before I start, but I decide to be wrong on the long side anyhow.

“Until blamed near morning.”

“It would take me nine days,” replied DuFeu gently.

Vertical Traffic

HPHERE ARE two other compartments in the shaft. These, DuFeu explains, are for the skips.

It seems difficult to get away from mining terminology. “Skips?”

“They bring up the rock. Some of it’s waste. Some of it’s ore. Listen.”

From away below rises a hollow, rumbling sound, like a freight train rushing through the night. The racket becomes louder and louder. Then with an appalling clatter a monstrous steel box shoots up from the shaft, hurtles out of the depths, slams on straight up toward the distant roof.

“That,” says DuFeu, “is a skip. It dumps automatically at the top of the headframe. The other skip counterbalances it, and they run in separate compartments of the shaft, with timber guides all the way down to keep them from swinging.”

That, then, is how the ore gets out of the mine. The skips, DuFeu tells me, weigh 12Uj tons loaded, carry seven tons of ore, travel at a top speed of 3,000 feet a minute.

“They take an awful beating. Each skip travels 250 miles per twenty-four hours, and is completely overhauled every twenty days. They dump the ore into a bin, from which it is drawn off by conveyor to a crusher, then on a belt conveyor to a mill bin.”

It’s pretty hard to stick to one subject in a gold mine. Attempt to follow the ore after the skip hauls it from the depths, and at once you’re into the complex ramifications of milling and refining, the processes through which the ore passes after it leaves the shafthead. A great many things happen to gold-laden rock before it is reduced to bullion.

“To get back to the shaft—” I insist firmly.

“Well,” says DuFeu, “it’s like the elevator shaft in a thirty-one story building, but the floors are 125 feet apart. We call ’em levels. Mining goes on between the levels.” Slam-crash-roar—down comes the empty skip, plummetting on its way for another load. A few moments later, in another compartment of the shaft, the same hollow rumble, the same deafening clatter. The second skip shoots out of the mouth of the shaft like some demoniac projectile.

And so this swift noisy traffic continues between the heights and the depths. Away below, under the direction

of geologists and engineers and bosses, miners are drilling holes in the rock. At the end of the shift the holes are filled with explosive, the rock is blasted out. On the next shift men break up the rock, empty it down chutes into waiting ore cars, which in turn convey it down the subterranean tracks to the ore passes. It goes tumbling down these yawning pits, on farther into the depths to the crushers, where it is ground almost to the consistency of earth, and then it cascades still farther down to the ore pockets where the skips receive their loads.

DuFeu explains this to me as we wait. Ore goes down, then, before it goes up. One of the lesser paradoxes of mining technique. The greatest paradox of all, of course, is in the return to earth—the burial of the precious metal in underground vaults in the money capitals of the world.

The man-cage rises swiftly to floor level-a high, huge metal box with two sets of sliding doors, for this cage is a double-decker, carries men in upper and lower compartments. The iron gate at the shafthead slams open, so do the cage doors. Miners file into the lower deck.

“Carries sixty men on one trip, that cage,” says DuFeu. “Thirty men to a deck. Weighs ten tons, loaded.”

When the lower deck is crowded, a cage tender yanks sharply at a chain hanging outside the shaft. Bells clang; the signal is repeated from the distant hoistroom. The door clashes shut, the lower deck slips down out of sight and the upper deck is at floor level. More miners clump in, their lamps gleaming. Clash and crash of door and gate, clatter and clang of bells again. The big cage suddenly slides away, drops silently into the partitioned pit.

The moving cable glimmers in the electric lights. That black rope is lowering ten tons of steel and humanity.

“At 2,000 feet a minute,” remarks DuFeu. “Faster than an express elevator in a skyscraper.”

“And as safe?”

“Automatic controls and hydraulic brakes on the hoist drum, foolproof signal system, track limit switch above the shaft, safety dogs on the cage. The cable gets a Department of Mines test every six months. The shaft is inspected constantly, from top to bottom, in off-shift periods.”

Successive trips of the cage thin out the crowd of men. The roar of the hurtling skips echoes spasmodically in the shafthouse. Finally, when the cage shoots into sight again and jockeys to a stop, we step inside with half a dozen workers. The brilliant lamps illuminate the damp steel coll. The men call the levels to which they are bound.

The cage tender yanks the chain. Ctang-ctang-ctangetyctang-clang! A pause. The echo from the hoistroom. Clang-clang-clangety-clang-clang! The signal has been received and correctly repeated. Another pause, for ]x>ssible correction. We move.

Slowly we move at first, penned up in that steel box. We are leaving the world, slipping away into mystery. Not much noise, not much vibration. The timber guides in the compartment hold the cage true on its downward course, prevent it from swinging and smashing the shaft lining to atoms. But we’re dropping faster, racing ...

Underground Drainage

' I TIERE IS no sensation of falling. Swift as the cage

descends, you feel that it is being lowered, that its speed is under control. And although it is travelling faster than an express elevator, there is not the same “send-downmy-stomach-on-the-next-trip" sensation.

That’s because of the size of the cage, the consequently greater resistance of the column of air in the shaft. This swift displacement of air causes a fullness in the ears. You swallow and the sensation is gone for the moment, but it returns as you plunge deeper.

They say you could drop a mouse down one of these deep shafts and air resistance would pillow Mr. Mouse undamaged to the bottom, because his skin surface is enormous in proportion to his weight. He would, in effect, be a living parachute. DuFeu says he has never tried it. Dropping mice and things down the shaft is not an approved sport at the McIntyre or any other mine. Instant dismissal is one penalty. Boiling in oil may be another.

The cage slackens speed, comes to a gentle, springy stop, as if the cables were made of rubber instead of steel. The door slams open, some of the men get out, carrying their lunch pails, bound for work. I have a glimpse of a whitewashed cavern hewn out of solid rock, brilliant with electric light. This is a “station” on one of the levels. It narrows down to a broad tunnel, with a trolley line along the roofs, pipe lines along the sides, railway tracks leading right up to the line of track set into the cage floor.

The tender yanks the signal chain for the bottom level, gets the answering ring, slams the door shut. We move again.

Water drips and spatters on the roof of the cage. A mine, one learns, can be a very wet place. A lot of water is deliberately piped in for operating use, especially for the drilling machines, in any case. But thousands of gallons come seeping in through a thousand seams in the rock. Much of the McIntyre mine lies under Pearl Lake. And in spring and summer the melting snows and the rains add to the surface moisture.

Continued on page 28

How Deep Is Down?

Continued from page 9—Starts on page 8 -

The water is encouraged to seep. If it collected in subterranean reservoirs the weight of the water would ultimately cause floods, collapse of the workings beneath. The subterranean drainage system in a “wet” mine, therefore, is elaborate and important. The McIntyre is a wet mine in comparison with the Dome, for instance, where underground you are struck by the comparative dryness of the air and the rock. This is partly on account of the Dome’s age. partly on account of its nature. There is no lake on the Dome property. Over a period of twenty-five years the mine has dried out.

Go to the bottom of the year-old Number Five shaft at Creighton Mine in the Sudbury district. It is a new shaft. The water pours down the ladderway like April rain, its torrential spatter drowned by the deafening cough and gasp of the pumps. And yet, in comparison with other parts of the w'orld. Ontario mines are considered dry. At the Hollingerand as the biggest gold mine on the continent, the Hollinger is the place to go for the biggest statistics-they will pump out an average of nearly two million gallons of water a day in late April. In a year’s time they will pump out more than half a ton of water for every ton of ore milled. But don’t go getting the notion that Ontario gold mines are really wet.

However, it’s just another mining paradox. If the pumps stopped and you couldn’t get out, you could drown a mile below the earth.

But to get back to Captain DuFeu. The cage plunges on into darkness, slows down, bobs to a stop once more. The door clashes open. We thank the cageman, impassive in oilskins, and step out.

Under Pearl Lake

WE ARE 3,875 feet from the surface, but not at the bottom of the shaft. The skips go a little lower still, to the loading pocket, and the extreme bottom of the pit is a “sump” or well for the falling water. We are as far down as the Number Eleven cage can take us, but we aren’t yet at the bottom of the mine.

Down is deeper still.

“The mine,” says DuFeu, “is 5,375 feet deep. To get there we had to sink another shaft.”

"Why not sink Number Eleven deeper?” “They don't sink ’em much deeper than

Change of Address

Subscribers who are changing their addresses should advise us at least five weeks in advance so that no issues may be missed.

Mailing lists have to be prepared considerably in advance of actual mailing date. If notice of change of address has not reached us before mailing list has been prepared, change cannot be made until next issue.

4.000 feet. Why? Do you know how much that cable weighs when the cage is at the bottom? Ten tons. Just the cable, mind. And the loaded cage weighs another ten tons. So the hoist is pulling cable weight equal to the burden weight. When you’re so deep that you’re pulling as much cable as cage, it’s time to quit.”

So we take a little walk down the track. Down a long, eerie tunnel, electrically lighted at intervals, with the trolley wire along the roof and the pipes along the sides. Captain DuFeu calls it ThirtyEight-C crosscut, and says we are walking under Pearl Lake. The reflection that there are several billion tons of rock above the craggy roof could easily induce qualms and jitters in an imaginative person.

The tunnel is whitewashed, and the absence of any timbering by way of support seems a little surprising until DuFeu explains that the tunnel is virtually cemented with a preparation called gunite. This is a McIntyre specialty, is now used in mines in other parts of the world, and won the Leonard Medal for Superintendent Dan Keeley, who invented it.

Occasional tunnels, curving off into darkness, intersect the crosscut. We investigate some of these, come upon two men—a drill-runner and his helper— drilling into a face of rock. Their lamps shine on the bleak wall. The big drills, operated by compressed air, create an unholy uproar. A fine haze of mist and a small amount of dust fill the cavern in spite of the ceaseless flow of water through the drills. Long bars of sharpened steel whirl and bite their way into the rock, boring out deep holes for the reception of the explosive that will shatter that wall into fragments.

In another tunnel we come upon two men loading ore cars from a chute. The broken rock comes roaring and tumbling down the invisible chutes at the side of the tunnel roof. The cars are filled, an electric locomotive hooks onto them and hauls them off down the tracks, awakening roaring echoes in the darkness.

We visit four men laboring with huge timbers in a stope—up between the levels where the ore is mined. The sulphides gleam golden when our lamps shine on the rocky roof. We meet a man, his lamp gleaming like a Cyclopean eye, trudging out of a black tunnel on some prosaic errand that the setting imbues with vast mystery.

No great groups of men toiling in subterranean caverns. A man here, two men there, half a dozen elsewhere, hidden away in the drifts and stopes of the mine. A silent, lonely place.

Underground World

AND SO we come to the head of - Number Twelve, a third of a mile from big Eleven. It is an internal shaft in the heart of the mine, 1,500 feet deep, making McIntyre the deepest mine in the Porcupine district.

Here, out of the solid rock, they had blasted room for a headframe ninety feet high. They had blasted a huge chamber for the hoistroom, with a slanting tunnel— a rope raise— for the cables from the drums to the top of the headframe, 147 feet away.

In the brilliantly lighted hoistroom with its concrete floor and whitewashed walls, we exchange a word with the hoistman, enthroned on his railed platform before the great 800 horsepower motor and the gigantic drum. He is in shirtsleeves; an electric fan is whirring. Not until then, so excellent is the ventilation system that forces air through shafts and crosscuts, drifts and raises, have I noticed that it is perceptibly warmer at this depth than on the surface.

“Seventy degrees,” says the hoistman. It is zero weather on surface. “Temperature goes up about one degree

for every 200 feet.” remarks DuFeu. It is not, he assures me earnestly, the heat so much as the humidity that matters. Cut down the ventilation and the place would be like a steam bath.

The big drum rolls in well-oiled silence paying out, winding in fat black cable. Arrows on great black dialsshift from number to number, indicating the levels, as the skips and cage hurtle up and plummet down under the hoistman’s control. A glass-cased recorder jiggles seismographically as it charts the minute-by-minute story of the cage’s movements over the eight-hour shift.

So we make our way to the station and ring for the cage, waiting in the electric brilliance under the whitewashed rock. It is very quiet down there in the depths, almost three quarters of a mile from the sprawl of humming buildings on surface under the Northern sky.

My mind plays with the notion of a man asleep, transported to these underground caverns and then awakened. Certainly in that efficient hoistroom with its Gargantuan machinery, in this solid station with its timber and steel concrete, he would not realize for a while that he was underground. Not, perhaps, until he noticed the absence of windows.

The cage arrives with a clang, a crash of the opening door. It is much smaller than the cage in Number Eleven. It will held nine men. A word to the cageman and we step inside; he yanks the signal chain. The familiar clangety-clang as the signal is given for the bottom level, the echoing ring from the hoistroom. The door closes. We plunge into the pit.

And down there? Down where men have probed deepest into the heart of the Porcupine?

Well, what did I expect? The McIntyre is a vast network of burrows and caverns in the rock. Here is merely another cavern, another tunnel into dark mystery, another line of railway track. It is a little warmer, a bit more humid.

Superficially viewed, it is not very wondrous down there. Essentially, it is miraculous.

Foot by foot, by patient, incalculable labor, by the expenditure of vast sums of money and human energy, men have created those two shafts to reach gold more than a mile beneath the earth’s surface. DuFeu tells me something of what they did. How they drilled, how they blasted out the rock and mucked it out, how they toiled in water and rock, how they lined the big shafts with timber as they burrowed deep, from six to eight feet a day. How all those tunnels and caverns for eighty miles of track were achieved by the same slow, gruelling labor. How the shaft-sinkers are the pick of the all-round miners.

A shaft is much more, I learn, than a deep hole in the rock. A big shaft is an epic. The new shaft at Lake Shore, when they had to start by sinking a cement foundation through seventy feet of oozy waste and mill tailing and blue clay in a lake bottom. The new internal shaft at Dome. The big Number Five at Creighton, that took two years to sink. The depths at Teck-Hughes, 6,142 feet, deepest mine in Canada. The jobs of fireproofing, the colossal tasks of timbering. The costs. The immensitiesof hoisting equipment . . .

But of these things, as the old-fashioned novelists used to say, more anon. Now that we have been to the bottom of one deep mine, they will, perhaps, be more readily comprehended.

In the second and concluding part of “ How Deep is Down?” which will appear in an early issue, Mr. McFarlane describes some of the big shafts sunk by Canadian mining men, and ventures an answer to the question: “ How deep will they go?”