The pick-off line is essentially an assembly line except we didn't assemble anything - it was, after all, glass. Our job was to load the glass into boxes as it came down the conveyor belt.

It was gruelling work. The shifts were long and the labour entirely physical. It was monotonous and intellectually numbing. It was exactly the kind of job one stays in school to avoid.

It was also a chance to see the place where my father had worked for more than 30 years, longer than I've been alive. And it was an opportunity I'm glad I got when I did. A few months after my second summer there, the factory was shut down.

Making Glass

I work in an open room that's larger than a supermarket. The floor is dirt black. The walls are 40-feet high and made of grey concrete blocks. The innards of the ceiling - the support beams, the metal fans, the water pipes and electrical wires - hang exposed above us.

Glass dust is everywhere.

But the place was designed with function in mind, not looks. Everything is built around the production line, or simply "the line," which stretches a quarter mile from one end of the building to the other.

In a glass factory, there are many words for "glass." Besides the glass "ribbon," large sections of the ribbon are called "plates," panes of glass are called "lites" and broken glass is called "cullet."

At the beginning of the line is the "tank," a massive furnace the size of a school gymnasium. This is where sand, other raw materials and recycled glass are melted down at 1300 C.

I got a glance inside the tank once, on the tour they gave during orientation. Holding a flame guard in front of my face (in addition to my protective eyewear I had to wear everywhere except the cafeteria), I peered into one of the openings in the wall. Inside, waves of fire blew across a sea of what looked like boiling and bubbling molten lava. I could only bear to look for a short while, less than a minute, before the heat became unbearable. If there's such a thing as an eternal, burning hell, I imagine it looks something like the inside of the tank.

The tank spews an endless supply of glass called the "ribbon." It's long, thin and flat just like the ribbon you'd tie around a present except much bigger. The ribbon is about 12-feet wide and stretches for the length of the line in one piece until it's cut up into smaller sections.

Out of the tank, the ribbon floats on a bath of molten tin, which smoothes the bottom surface of the glass. Next, the glass is pulled up onto rollers that carry it on down the line. Cooling and heat are applied to maximize the strength of the glass.

Eventually the glass arrives at the washer, where water is sprayed on both the top and bottom surfaces before it's blown dry. Then a computerized scanner spots defects, such as stones, bubbles and distortion lines, and marks them with a dot of blue ink. When the pick-off men see a blue dot, they let it go by to fall into a chute.

Next the cutting wheel puts indentations along both the length and width of the ribbon. These indentations are used to snap the ribbon into smaller sections.

The glass then travels through three "stackers," giant machines equipped with suction cups that lift the glass off the line automatically if it's too large for human beings to handle. The machines stack the glass into piles that forklifts pick up with giant metal claws to carry off for shipping. If the pick-off men are doing the work, the stackers are turned off.

Finally the glass reaches the point where the line breaks into three legs, distributing the glass among the pick-off men so they have enough time to grab the lites before the next ones arrive.

This is where my work begins.

Life on the pick-off line

The dominant sound by the pick-off line is the constant "chucka-chucka chucka-chucka" of the rotating grinder that breaks up glass as it falls down the chute. It' s not the only sound in the enormous room. The truth is the whole factory hums with the clamour of rumbling motors, spinning wheels, buzzing lights and hissing air.

And the chucka-chucka isn't the loudest noise, either. Not by far. Nothing is as jolting as the unforeseen explosion of 8,000 pounds of glass crashing to the floor after accidentally slipping from the grip of a forklift. But as the panes of glass come down the line, I can't help being transfixed by the mechanical chant of rotating metal while standing at my post, executing the same moves again and again.

Grab lite. Tip it up onto one edge. Reposition hands and slide lite off line. Set lite down on pallet. Slide tight into place against previous lite, check for gaps between them and fix if needed. Grab next lite. Tip it up onto one edge. Reposition hands…

Repeating these motions for long hours gives me a lot of time to think. Sometimes I pass the time talking to the guy beside me. Other times I keep myself busy running songs through my head or thinking about who-knows-what.

The factory produced glass for buildings, furniture and the automobile industry. The thickness, which ranged from two to eight millimetres, depended on what the glass was being used for. Rear and side windows in cars are 4-millimetres thick. Windshields use two layers of 2-millimetre glass with a melted sheet of clear plastic in between for added strength. The glass used in tabletops is 8-millimetres thick. The glass used in hockey rinks is 12.

In a way, time rules the lives of the workers here. High up on a wall hangs a clock with a minute hand that turns six degrees every minute and seems always to have a witness when it does. When there's only half an hour left in a shift, all the guys have their eyes on it.

Being a subject to the clock doesn't end when the shift does, either. The glass plant is a 24-hour, seven-days-a-week operation, which means one thing for the people who work there - shift work. Regularly switching between day and night shifts quickly takes its toll.

When I come off a day shift, it's past 9 p.m. before I get home and I'm too excited about having days off to go to sleep. Returning to work is always a hassle because I have to force myself to sleep during the day when I'm not tired so I'll be able to stay awake all night. If I come off a night shift, the day is a write-off because I'm too exhausted to do anything. Going back to work is the same problem – too tired to stay awake or too awake to get any sleep.

The insomnia that shift work causes is like a case of perpetual jetlag.

Working on the pick-off line, each of us is responsible for his share of lites as they come down the line. The lites come in different sizes, from as small as a poster to as large as a store window. The big ones take two or three of us to load.

One time I was lifting the big lites off the end of the line with another student when the lite in our hands broke. But it didn't just shatter and spill on the floor. The break started with a crack in the bottom edge of the glass. The crack quickly shot up the middle of the lite about half way before splitting like a V in the road, continuing off towards both top corners of the lite.

In an instant, one lite became three. I held one in my hands and so did the other student, but nobody had control of the third. It came down at me before I had time to think about letting go of the glass I was holding and getting out of the way. It slammed down on my left hand.

The loose piece of glass and the one I was holding smashed at my feet. I grabbed my left hand with my right. The glass had slit through my rubber glove like it wasn't there. I tore it off to see how badly I was hurt, though I had an idea it wasn't good because I had screamed a profanity when it happened and now the pain was pumping up my arm.

The glass had cut through my skin and left a gap wide enough that I could see my muscle underneath. But the impact was so powerful I didn't start bleeding for at least five minutes as if my insides were in shock and had forgotten what they were supposed to do next.

I abandoned my post without a second thought to wash and bandage my hand. I look back and I know it could have been worse. I still have all five digits on both hands. But I also have a small scar on the back of my left hand between my thumb and index finger. I've had a dozen jobs in my life but the glass factory was the only one to leave me with a physical memento.

I like to think of it as my battle scar.

The dirtiest job in the glass factory

When the lites are too big for even a group of us to manage, we go on stackers, which do the work for us. This means we're given other work to do, such as being put on the manual glass cutter to fill small orders, or posted at the cardboard compactor or sent off to sweep up the garbage in the warehouse.

But the dirtiest job is beneath the production line where the cullet system collects defective glass that has fallen and broken up, carrying it off to be recycled.

The network of conveyor belts runs below every part of the line. Besides the drop chutes at various points of the line, there is a chute at the end of each of the three legs, which pick-off men allow defective lites to drop into. All of these conveyor belts merge at a place called "ten-eleven-twelve."

Ten-eleven-twelve is the deepest point under the line. From here the broken glass arriving from different directions lands onto three new belts that carry it up and out of the building. These three belts are numbered 10, 11 and 12.

The problem is that the cullet system isn't perfect.

As the glass falls it smashes into smaller and smaller pieces, which bounce off everything they hit, sometimes shooting right past the conveyor belt and onto the floor. These pieces can be as large as a kite or as small as a grain of sand. Over time this renegade debris builds up into piles and, if left long enough, would bury the tight walkways and crawl spaces under the line along with anything that occupies them. So every now and then a bunch of us have to be sent down there to shovel the mess up onto the conveyor belts before the belts themselves are buried.

This is where a couple of my fellow student workers and I come in.

To get to ten-eleven-twelve we descend a set of stairs so steep they might as well have put in a ladder. At the bottom there's a heavy metal door that's stuck halfway open because nobody has swept there in so long the dust has buried the bottom of it. But that's not a priority.

Past the door is a tunnel-like hallway that leads down at about a 30-degree angle to the left and up by the same degree to the right. The three conveyor belts run upwards to the light beaming in from outside. We head left.

The slanted floor pulls me down with every step. We pass through another door, but this one moves. It's heavy, resisting me as I hold it open for the next guy. When it shuts behind us we're almost entirely cut off from the sunlight. The light we're left with comes from a handful of naked bulbs.

We continue down about 50 metres until we reach the bottom.

The dust in the air is the thickest down here. It carries with it a chemical smell that compares with nothing in nature. Everything is covered in the grey, powdery glass dust - the walls, the floor, the ceiling, pipes, ladders, electrical circuits, hoses, scaffolding, even the brooms and shovels left behind from the previous excavation.

Broken glass falls from the machinery above but mostly in tiny, harmless pieces that sparkle like diamonds in the dim light. Every now and then cullet pours down the chutes like an avalanche, but when it does we hear it coming and have enough time to get out of the way.

We're not unprotected. Besides the safety glasses and construction boots that are mandatory on the line, we're geared up in plastic body suits, so our clothes don't get soaked with dust, and face masks so we don't breathe in the stuff. Helmets are optional. I left mine behind.

Shovelling is tough on the body - the turning and twisting of muscles - and I get sweaty fast because in the body suit my skin suffocates as if it's covered in plastic food wrap. Shovelling is hard work but it's a welcome change to have a task and to be left to do it.

Returning to the surface for the first time, I immediately realize that leaving the top of my head exposed was a mistake. My head is covered in glass dust which I discover turns into a disgusting, muddy paste when I try to wash it off. And my hair is filled with prickly pieces of cullet, sharp little balls that roll around scratching my scalp as I work to untangle them. Next time I tie an old rag over my head before heading down.

No matter how much cover I wear, I can't stop the dirt from seeping into every crevice in my face. The pits of my eyes are black and my nostrils are filled with the black, too - the same stuff that covers every square inch of the floor in the factory. It's not a comforting thought. I can also feel the gritty texture of sand on my lips and the taste of chemicals lingers in my mouth.

When I get home, I get into the shower and wash the stink off. It is liberating to be clean again and fulfilling to crawl into bed after a hard day's work.

Nothing feels like that.

Owen Wood, 24, works as a researcher for CBC News Online, his 12th job... so far.