When the Dust Settles

Introduction

Looking out over the small town of Britannia Beach, it can seem almost unbelievable that this now quiet community was once home to the largest copper mine in the British Empire. In fact, if it were not for the town’s location along the Sea-to-Sky highway, it most likely would have befallen a fate common of past resource towns – it would have been lost to history.

Largest vs. Highest Producing As early as 1916, Britannia was the largest copper mine in the British Empire. Largest refers to physical size. While Britannia was big, its production was overshadowed by the Anyox Mines. In 1925, Britannia still remained the second largest copper producer in the British Empire behind this mine. In that year, Anyox produced 38,207,434 pounds of copper compared to Britannia’s 28,600,000. Britannia claimed the title of highest producing copper mine in the British Empire in 1929.

Perhaps more remarkable is that even when this mine was a major copper producer it was largely unknown. In 1926, this Mine had already achieved the status of the largest copper mine and the second largest copper producer in the British Empire. In that year, the Mine’s General Manager gave a presentation to the Foreign Bureau of the Vancouver Board of Trade. An editorial on this presentation in the Mining and Industrial Record stated:

“One of the lamentable oversights in the public organizations of Vancouver is their ignorance and failure to obtain at first hand, reliable information concerning the industrial enterprises on which the Province depends for its progress and prosperity.”

The same conditions exist today. Mining is largely not thought about in our day-to-day lives. Yet, this industry continues to perform the same foundational role within civilization that it has for over 300,000 years.

What has changed is mining itself. It went through radical changes as a result of the industrial revolution. Building on those changes, Britannia demonstrated the ability to adopt and adapt as conditions changed from its beginning in the early 1900s through to its closure in 1974.

By the time the last whistle blew and the dust had settled at the Britannia Mine, it had repeatedly proven itself to be a ‘striking story of achievement’ (Mining and Industrial Record, 1926).

 

Background

The success of Britannia begins long before its first mineral deposit was discovered in 1888. The opportunity for Britannia to become a major mine, or a mine at all, began with the Industrial Revolution. Mining Britannia’s low grade ores profitably required fundamental changes. The first of these was an increase in demand for copper. The second was the technological innovation necessary to make mining Britannia’s deposits feasible.

Two major innovations occurred in the second half of the 19^th century – dynamite and air powered rock drills.

Dynamite was invented in 1867 by Alfred Nobel. Compared to black powder and nitroglycerine, which it rapidly replaced, it was safer to work with.

The first air-powered rock drills began to be deployed for tunneling purposes in the mid 1800s, but these first drills were plagued with issues. These issues were overcome through steady stream of advancements. By the turn of the century, air-powered drills had proven their worth.

They had also proven their risk.

Men working with these drills had a mortality rate far above the general population. One study performed in Colorado from 1902-1911 showed metal miners to have a mortality rate from lung diseases to be triple that of the remaining population (Industrial Revolution in the West: Hard Rock Miners and the New Technology, Mark Wyman). The issue lay within the dust, but it took many years for how the dust impacted people to become understood.

The story of the dust captures one element of the challenges faced by mining in the 1900s as it worked to meet the mineral needs of society as well as address the associated costs. This is the focus of 'When the Dust Settles'.

Being able to extract low-grade ores from the ground is only the beginning. The next challenge is separating trace amounts of valuable minerals from the rock which entraps it. This begins with crushing the rock into a sand-like material. This led to the development of new rock grinding machinery which could efficiently reduce rock to sand.

While Britannia employed these new rock crushing technologies, where it really led the way was in the adoption of a new mineral separation technology called froth flotation. This new method of processing low grade ores began in the mid-1800s. It was first used in a production environment at Broken Hill, Australia in 1902. It was in that same year that the first tests were carried out on ore from Britannia (The Kootenay Mail, July 11, 1902) using flotation, three years before the first ore was shipped from the Mine and ten years before flotation was in use at Britannia. The story of flotation is the focus of 'An Icon of Innovation'.

Working at Britannia

Hard rock mining at Britannia employed the mining cycle of drill-blast-haul. Holes are drilled into the rock for explosives. Explosives are loaded into the holes and then detonated. Lastly, the broken rock is hauled out of the mine.

While this cycle remained constant over the life of the Britannia Mine, several changes occurred to how drilling, blasting, and hauling occurred. This is the story of the major changes that impacted both the Mine's efficiency and safety.

Explosives

The invention of dynamite tremendously improved the safety of mines by introducing an explosive less sensitive to physical impacts or abrasions. While dynamite contains nitroglycerine as its key explosive – a material which is very sensitive to shock and friction - the nitroglycerine in dynamite is stabilized.

But the inherent volatility of nitroglycerine meant that dynamite still posed safety concerns.

If the nitroglycerine separates from the binding agents and seeps to the surface of dynamite (a process referred to as weeping or sweating), the dynamite loses its shock and friction resistance, rendering it prone to detonation from impact or abrasion, both of which were possible to occur in the loading of blast holes.

Signs of Weeping When nitroglycerine wept to the surface of paper wrapped dynamite, it tended to form a white crystalline deposit. Dangerous, but potentially observable. To prevent the nitroglycerine from reaching the surface as well as making dynamite more water resistant, modern manufacturing processes seal the dynamite with a water resistant outer shell.

Further, dampness increases this risk of weeping, requiring it to be stored at a controlled temperature and humidity – conditions controlled within the explosives magazines.

To reduce the risk posed by nitroglycerine seeping from dynamite, ammonia dynamite was developed. It substitutes some of the nitroglycerine for ammonium nitrate, making it less sensitive to shock or friction. By 1915, Britannia had begun using Polar Ammonia Dynamite (produced by Canadian Explosives Ltd).

The Polar dynamite brought several other safety advances to Britannia. Its freezing point was lower than temperatures experienced at Britannia, eliminating the risk of it freezing. While frozen dynamite is stable, when it is defrosted the nitroglycerine will tend to weep.

It also gave off less gas and was more difficult to burn than ordinary dynamite.

By the 1950s, ammonia gelatin (Forcite), and semi-gelatin had replaced ammonia dynamite, which provided better water resistance. 

Report on explosives usage at Britannia in the 1950s.

 

 

Drilling

Drilling can be broken down into two categories – development and production.

Development drilling is the searching for and mapping of new deposits. Production drilling is for the extraction of deposits mapped by the development process.

Development miners work in tunnels and shafts, extending the mine into new territory. Production miners work at breaking and moving the ore bodies – their job is extraction. Of these two broad categories, development work required a higher skill set, and was paid accordingly.

Why are drills powered by air? The first powered drills ran on steam, but this was quickly abandoned in favour of air due to it being easier to convey compressed air over the distances needed. But air powered drills are not very efficient. Only about 15% of the energy input is converted to productive work. Also, compared to electric drills, they are noisier and heavier. Electric drills were not adopted as a solution though. This is because even though air powered drills are not energy efficient, they were still more powerful. While air powered drills are still used today, they have been replaced in larger operations with hydraulic drills. These drills, first introduced in the 1970s, provide better power utilization (45% is converted to useful work), higher drilling productivity, higher penetration rates, and lower noise compared to air powered drills.   One advantage air-powered drills provide is the simplicity of their mechanics. This means almost anybody can repair them.

The earliest development work performed at Britannia was performed with manual tools, similar to the single-jack drilling being performed in the image to the left (Harry Yaky, circa 1960s). This work was performed to determine if the mineral deposit at Britannia could potentially prove to be minable. Once it was established that Britannia was suitable for mining – that the mineral deposit could be extracted at a profit – infrastructure for mining was constructed, which included the first powerhouse to provide electricity and compressed air. Thus, by the time development of the Mine began in earnest in 1904, miners were working with air powered drills. A news snippet from the Mining and Scientific Press of November 18, 1905, one month before Britannia shipped its first concentrates to the smelter, claimed the Mine to be equipped with ‘400 rock drills of various types’. While this number is likely high given the size of the mine at the time, it does capture the reality that several types of air-powered drills were in operation when the Mine began extracting ore.

Advances in Drilling   1900 to 1930 – a period of tremendous advancement in drilling In 1900, piston drills were heavy and capable of delivering 200 blows per minute to the rock face. In 1930, the drills were up to 1/5th the weight and capable of delivering up to 2000 blows per minute. Below are some drill weights and drill rates which exemplify the rate of change: Date and Drill Weight in pounds Penetration rate Prior to 1912, piston drills 250 3 inches per minute 1912, medium drifter 153 6.25 inches per minute 1928, medium drifter 144 20.3 inches per minute 1929, light drifter 117 16.2 inches per minute 1929, heavy drifter 179 23.5 inches per minute Source: Proceedings of the LSMI – Vol XXVIII – September 10 and 11, 1930, page 27 (Drifter is a general term for drills which use fixed mounts to manage their weight and power.) For comparison, the jack-leg drill (introduced in the 1930s) has a maximal penetration rate of 20.4 inches per minute while weighing under 100 pounds.   1930s - the shift to blast-hole diamond drilling  Long-hole drilling and its associated changes in mining methods brought several advances in both efficiency and safety. So desired were these advances, that diamond drills were introduced for blast-hole drilling even though they bore a higher operational cost. The penetration rates for diamond drills in blast -hole drilling are as follows. Drill    Penetration Rate    Penetration Rate per minute 5-15 horsepower, working in soft ground 200 feet in 8 hours  5 inches per minute 8 -27 horsepower, working in hard ground 40-50 feet in 8 hours  1-1.25 inches per minute   1940s - the shift to tungston carbide long-hole blast-hole drilling Advancing the penetration rates of the drills used in long-hole drilling came with the introduction of tungsten carbide bit tips. By the 1960s, the penetration rates had reached as high as 400 feet in eight hours (10 inches per minute). By this point, the drills themselves were capable of greater rates, but the Mine restricted the amount produced per day.

The first drills can collectively be referred to as piston drills. Due to their weight and power, they were mounted on tripods (as seen in the photo above, circa 1905) or bar and arm mounts. With these drills, the drill bit is attached to the piston which drives it. As such, the bit travels forward and back with the piston, delivering up to 200 blows per minute. With each blow, the piston turned to rotate the drill bit. But one of the issues these drills presented was a direct result of the drill bit being attached to the piston. When the drill bit bound up in the hole, the drill would kick back and hit the operator. For this reason, these early drills became known as ‘widowmakers’. By 1912, this drill design was being supplanted by hammer drills, which are lighter and faster than piston drills. With these drills, the piston is not attached to the drill bit. The piston acts as a hammer pounding on the bit in the same way a hammer is manually pounded on a chisel.

Kickback is not the only reason these first drills became known as ‘widowmakers’.

These drills produced significant amounts of fine dust. What was revealed over the course of the first decades of the 20^th century was the insidious nature of the impact of silica dust on human lungs. The condition, called silicosis, became a compensatable disease in 1936. Shortly after this, dry drilling – drilling without a dust suppression system – was banned in British Columbia.

Water for dust control was introduced to Britannia by 1916. But the use of water in general, beginning in the 1800s, was not driven by dust concerns. It was driven by the desire to improve productivity.

From a productivity standpoint there are a couple of issues all drills faced. First, drill bits dull. Secondly, rock chips can clog a hole. Both of these issues can be solved by flushing the hole. When water is injected into the hole, it not only washes material away, it cools the drill bit, extending its life.

Water was not the first method employed for flushing holes. Air was experimented with briefly, and proved quite effective at clearing the hole, but the amount of airborne dust created by this approach quickly led to complaints and a refusal to work with these drills by miners. While pumping air down a hollow drill bit to blow out the hole failed, it did pave the way for what became the standard – pumping water down the hollow drill bit to flush the hole. The use of water brought the second benefit of cooling the drill bit, which extended its life.

The holes most in need of flushing when it comes to productivity are downward holes. This is because without any method to blow the dust from the hole, it builds up at the bottom, preventing the drill from directly impacting the unbroken rock and thus slowing the speed at which the hole is drilled. In contrast, dust in upward holes more freely falls out.

In 1922, Britannia was employing wet stoper drills (pictured left: stoper drill circa 1960s) for upward drilling in the underground portions of the Mine while utilizing dry drills for the downward drilling in the above ground operations (pictured below, circa 1910s). This would seem to imply that the adoption of wet drills was driven to some extent by concern for the working conditions of the men. What it did not do is eliminate the risk of silicosis. 

Controlling the Dust The first water suppression systems used in mechanized rock drilling were developed in the late 1800s. These first systems involved spraying water onto the rock face as the drill operated. This presented two issues. Unrecognized at the time, these water systems were not well suited to suppressing the finer dust particles which presented the greatest health risk to miners. Also, as these systems were operated independently from the drills themselves, miners often chose not to operate the sprays either because of the added work or simply out of a desire to not get wet. The later was influenced heavily by the immediacy of sickness from dampness compared to the slow onset of the various lung diseases caused by dust exposure. The first dust suppression systems employed for drilling at Britannia suffered from these same issues. While Britannia’s systems involved injecting pressurized water into the drill hole through the drill bit, the first drills enabled the drill to be operated without the water activated. These first systems also suffered from the ability of air to mix with the water. This allowed dust to be blasted out of the drill holes and become airborne. A new drill introduced in 1944 overcame these issues. A description of this advancement included in the Report of the Minister of Mines for that year read as follows: Ventilation and dust control received great attention throughout 1944. The greatest advance in the year was the introduction of aluminum-powder therapy for the prevention of silicosis. All the active dry-rooms were equipped with aluminum-dispersal units, and each man receives a treatment before going on shift. A satisfactory dustless Leyner machine was developed and put in use at the property during 1944, and is giving good results. The dust concentration in headings using this machine is below the dangerous limit. The machine was equipped with standard tappet chuck frontend and a New York backhead. A large water-needle is used with a small clearance in the tappet and hammer to prevent any air from passing into the drill steel with the water. The New York type backhead prevents any dry-drilling as the air cannot be turned on without the water being turned on automatically. The average dust-counts all over Britannia mines was lower in 1944 than in any other year.

In 1934, the Metalliferous Mines Act was amended. Dust suppression requirements were extended from ore body extraction to all drilling operations for mines where rock dust was deemed a potential health risk. This was followed in 1936 with silicosis becoming a compensatable disease, which led to more stringent standards and monitoring of dust levels and ventilation.

The following reports are examples of the monitoring required and studies performed at Britannia following the new legislation.

Dust investigation, 1936
Dust Report, 1936
Ventilation Report, 1939
Drilling Water Supply Report, 1939
Dust Report, 1940
Dust Report, 1944
Dust Report, 1947
Dust Contentrations, 1949
Stoper Testing, 1948
Leyner vs. Stoper, 1948 - a study on the feasibility of replacing the stoper drill with the lower dust producing Leyner.

Around this time a new drill brought a major change to the mining operations – the jack-leg drill. The larger drills at Britannia required mounts. The stoper did not, but was of restricted functionality. The jack-leg (pictured left) brought the smaller, lighter, single-person operation benefits of the stoper to all angles of drilling. The versatility of this drill is why it is still commonly used in mining where it is impractical to employ larger drills. 

Starting is the Hardest Part The most difficult aspect of drilling a hole is starting it, which is referred to as collaring the hole. Sometimes, although strictly forbidden, miners would take the risk of using a hole left behind from the previous blast to ease collaring the hole. The risk was that these old holes, called bootlegs, could still contain explosives. Using a bootleg came with the risk of injury or death caused by detonating those explosives. Because of this serious risk, the Company had a policy requiring miners to not collar holes within three feet of a bootleg.

The drill itself consists of two parts – the pusher leg and the drill. The drill can be operated without the leg attached, working like a jackhammer. The leg provides support and helps push the drill into the rock face.

The jackleg requires not just skill, but physical prowess. It is the strength of the operator which keeps the drill going straight, and this is accomplished while the drill vibrates through the operator’s entire body. Work is still being done to reduce the level of vibration experienced by these drills. Repetitive strain injury, sometimes called ‘white knuckle’, is a risk when working with these drills.

While there were always roles for small, versatile drill such as the stoper and jack-leg, producing the volume of copper ore necessary demanded different drill technology. The first advancement was increased drill penetration depth. Deeper hole depths began with the Britannia Method of mining in the early 1930s, which allowed for holes up to 22 feet deep. This was followed up with the introduction of blast-hole diamond drilling in the late 1930s, which introduced blast holes up to 100 feet deep. ('The Innovators' contains more information on these methods)  Improving on this in the early 1940s was the introduction of drills capable of drilling the same depth, but using tungston carbide tips rather than diamonds, which reduced costs and increased drill rates. These drills enabled another new method of mining at Britannia – sub-level caving.

Sub-level Caving   Sub-level caving enabled the Mine to extract ore at a far greater rate. This was accomplished through the blasting of larger areas at once compared to previous methods. With this method of mining, tunnels, called sub-levels, are driven through the ore body. From these tunnels, long holes are driven which reach from sub-level to sub-level. It is these long holes which are loaded with explosives for the main breakage of the rock. After detonation, the rock is extracted from below. With this method of mining, the development of the next level to be mined occurs concurrently with the production (extraction) process. Drawings of sub-level caving method (including image above)

This new method allowed for a more efficient extraction of the ore from the Mine by drilling and blasting larger quantities of rock.

The second advancement brought combo-drill rigs to the mine for specific applications in the 1920s, although not widely used until the 1950s (pictured to the left, man in front is Ron Baverstock, who eventually became Mine Superintendent, circa 1950s). Now, multiple drills were mounted on one machine. This change further enhanced the speed at which the Mine could operate.

The combo rigs were followed with the jumbo rigs. With a jumbo, one person operated multiple drills simultaneously.

But drilling speed or depth alone will not make a mine more efficient. Efficiency is obtained through coordination of multiple activities within the mine. For the drillers, this coordination was obtained through areas to be drilled and primed for detonation being clearly marked out by ‘miner’s bullseyes’.

Production miners would report to their work area at the beginning of shift, locate a bull’s eye, and proceed to drilling the holes needed for blasting. The number of holes was dependent upon the strength of the rock and the size of the blast area. Once all the holes were drilled, explosives were moved in from the magazine and loaded.

Blasting is the most dangerous element of mining. Risk exists from the shockwave of the blast, flying rock, consumption of oxygen from the blast, as well as the potential release of toxic gases. For these reasons, blasting was performed when an area was evacuated. For production work, the most efficient time for this to occur was between shifts.

With the Hours of Work Act of 1934, the Mine shifted from operating seven days a week to operating Monday through Saturday. Prior to this change, blasting occurred after the third shift of the day. After the change, blasting occurred following the end of the Saturday evening shift. This change had the benefit of providing a full 24 hours for dust to settle and gases to evacuate from the Mine prior to the next shift entering.

Production blasting schedules account for the major blasts, but there still remained small blasts which did occur during the shift.

The first type was by development miners. The second type was in bull doze chambers.

For development miners, changes in blast patterns reflected the growing understanding of the impacts of dust on health. As such, as the air quality regulations improved, beginning in the late 1930s, more consideration was given to where the dust from a blast would travel to, eventually leading to a requirement that the dust not enter into any area where men were working

Bull doze chambers (pictured to the left) are rooms within the mine through which broken rock is checked to ensure it is broken to a small enough size for transportation. The rock enters from above and passes through a grate, called a grizzly. Oversized pieces are then broken down either by drilling or blasting. These blasts could occur at any point during a shift, so as dust control regulations advanced, so did the requirements for these chambers. The essential change for these chambers was better ventilation, which was accomplished largely through better overall ventilation within the mine.

Ventilation Ventilation has always been a concern in underground mining, for there is always a risk of suffocation without sufficient airflow. Ventilation took on another important role as the risks of dust in the air became understood. To achieve good ventilation, Britannia used fan-bags (bags through which air is blown, as seen above), fans (seen below), and doors which controlled the airflow through the Mine.

A Year of Major Change: 1946 Slushers Replace Bull doze Chambers In 1946 the shift to sublevel caving began the phase-out of the bull doze chambers. In their stead came the slushing machine (seen above). These machines drag large scrapers to move the broken rock to their draw holes. Detachable Drill Bits are Introduced This one small change had a tremendous impact on mining operations. Prior to their introduction, drill steels, which consisted of steel rods with affixed cutting tips were routinely resharpened in the steel shops. This required the movement of rods which ranged in length from three feet to twelve feet. It also was a source of dust in the steel shops. In contrast, the detachable bit tips were not resharpened, eliminating both issues. Once dull, the tips were recycled. Electric Lights for All The transition to cap mounted electric lights began in 1933. Thirteen years later, all underground workers were equipped with Edison P-3 electric cap lamps, bringing an end to the use of carbide lamps.

Loading

The rock broken by a blast is referred to as muck. The loading of the muck for transport is referred to as mucking.

Mucking changed in tandem with drilling. In the first years of Britannia’s operation the loading was done by manual labour. While it was slow, it was capable of meeting the needs of the day.

In those first years, manual loading did not contribute significantly to decreasing the air quality within the mine. The slower manual loading meant less dust was stirred up than after mechanical loading was introduced in 1920 .

This can be appreciated by how much more capable the mechanical loaders, called mucking machines, were. Where a mucker working by hand could load 8-10 tonnes per 8-hour day, a machine could do this in 30 minutes.

As with the drills, there was a delay between the introduction of mechanization and dust control. In the 1940s, wet mucking was mandated. It required all rock be sprayed down before it was moved. While ventilation had improved the air quality of the mine, it became recognized that dust which was stuck to broken rock became airborne when it was moved. Wetting the rocks beforehand reduced this risk.

 

On a Lighter Note

For all the dust within the mine, the miners could at least sigh a breath of relief that there was no potentially explosive dust released from the rock as it was broken down.

This allowed open flames to be used within the Mine for lighting.

The first form of light used was the candle. Due to the risk of candles going out, miners always carried matches with them.

Candles were replaced with carbide lamps in 1920. The carbide lamp improved lighting tremendously. Not only was it brighter, but it also could be worn on the miner’s cap, providing hands-free operation. Carbide lamps came with their own issues, however. A lamp could hold enough fuel (calcium carbide) for four hours of operation, requiring the lamp to be refilled mid-shift. They also required routine cleaning to ensure reliable operation.

In 1933, the Mine began replacing carbide lamps with Edison electric cap lamps. These lamps provided enough charge to last entire day, were brighter than carbide lamps, and required less maintenance than the carbide lamps. The trade-off was the batteries, worn on a belt, weighted 6.5 pounds.

The first people to be equipped with these lamps were people working with explosives.

In 1946, the Company completed the transition to electric cap lamps.

In Closing

Over the course of Britannia’s operations, working conditions and productivity improved.

Late to see change however, was the noise control. The Mines Regulation Act (1967) introduced a noise control rule which read ‘every rock drilling machine used underground in any mine after the 1^st day of July, 1968, shall be equipped with a device to give a noise attenuation satisfactory to the Chief Inspector’.

As with the first forms of dust suppression, not all miners appreciated the new noise suppression devices. There are stories of miners removing the ‘mufflers’ from the drills because they reduced a drill’s power.

Today, the Mine is silent, having closed in 1974. Over Britannia's life, its vibrant enterprise was a major contributor to the Canadian economy and a major contributor to meeting the need for copper. In the story of this Mine is the story of all mining - the story of overcoming challenges while also evolving to meet the changing needs of its workers and society, and how this occurs for the most part outside of the public eye.

Silicosis - an Industrial Disease Air-powered drills introduced a major dust issue to mining. Compared to the manual drilling techniques which they replaced, these drills introduced more dust due to their increased drilling speed, as well as finer dust to the working environment of the miners. Early on, miners began to complain of health issues which appeared after the introduction of air-powered drilling, but little was done as a direct link between the drills and the illness had not been established. Complaints of dust did lead to some mines introducing water spray suppression systems as early as the late 1800s, but they were not eagerly welcomed. For miners, it meant more equipment to manage, and it also meant getting wet. The immediate risk of developing pneumonia far outweighed the potential risk or discomfort posed by the dust - a dust which was not fully understood yet. As it turned out, those early water sprays, even if used correctly, would not have solved the most significant of issue with the dust. The serious risks were posed by the smaller dust particles introduced by mechanical drilling, as well as what the dust contained. Over the course of the first decade of the 1900s, the understanding of the issue began to unfold. In 1900, a specific form of lung disease, called at the time a fibroid form of phthisis (phthisis was a general term covering several conditions of the lungs), was linked to silica dust in an article in the Journal of the American Medical Association. The next major leap happened when the results of studies in South Africa led to the identification of Silicosis as a distinct lung disease and in 1912 South Africa becoming the first country to recognize it as a compensatable disease. It was more than two more decades before the same recognition came to British Columbia. In the meantime, understanding of the issue and methods to address it advanced. In 1918, the British Columbia legislature introduced a new bill which called to amend the Metalliferous Mines Inspection Act with provisions to protect workers through the prevention of rock dust. Ahead of the legislation, Britannia had drills equipped with dust suppression systems in operation in some areas of the mine by 1916. Of particular note, dust suppression was in use for upward drilling at this point with the stoper drills – two years before provincial legislation was introduced that would require its usage. The upward drilling performed by stoper drills produced the most significant dust issues, but the use of water to suppress the dust brought about another significant issue – pneumonia (or the perceived risk of it). This is due to how the dust control works. Water is pumped through a hollow drill bit into the hole, where it mixed with the dust and then flows back out of the hole – a hole located above the miner. There was always the potential of becoming very wet. In 1934 British Columbia’s metaliferous mines regulations, now called the Metalliferous Mines Regulation Act was amended such that the rule which required drills used in stoping ‘where the ground is of such nature that dust is caused by drilling, shall be equipped with a water jet or other approved appliance to prevent the escape of dust’ was expanded to include all drills used in such mines. From this point forward, all drilling at Britannia was required to employ water suppression. In 1936, silicosis became a compensatable disease in British Columbia. Building on the research of the 1920s, including a better understanding of the dust particle size which was deemed most detrimental to health (between 5 and .25 microns), new regulations were introduced as well as the requirement for ventilation engineers – people responsible for ensuring dust counts remained below set standards. As the 1930s came to a close, the disease itself was still not fully understood, but its impact was of paramount concern. This led to the development of a new form of silicosis prevention, called aluminum prophylaxis. Research conducted in part at the Mcintyre Mine (Ontario) in 1937 revealed that rabbits exposed to a dust mixture of one percent metallic aluminum dust and ninety-nine percent quartz dust did not develop silicosis. Subsequent animal research conducted by other researchers found further support for aluminum providing protection against the development of silicosis.  In December 1943, aluminum powder was introduced as a preventative measure for silicosis at the McIntyre Mine. It was rapidly adopted at mines in Ontario, Quebec, British Columbia, Manitoba, United States, Mexico, and the Belgian Congo (W. D. Robson, Brief on silicosis and aluminum therapy to the Minister of Mines of Ontario. November l, 1945, referenced in Paterson, John F., Silicosis in Hardrock Miners in Ontario, p.36)The aluminum powder and the application standards were developed and marketed by the McIntyre Research Foundation – a company formed, in part, by the researchers at the McIntyre Mine. It was implemented at Britannia in 1944. The solution it provided was to protect the lungs from silica dust by coating them in aluminum dust. Before going on shift, miners would inhale aluminum dust impregnated air for 10 minutes. How it was reported to work is that the aluminum would react with silica when inhaled producing a solid which rather than binding to the lungs as silica does, would be exhaled. The question remained as to whether the treatment process was effective for preventing silicosis in humans. That research was never carried out to conclusion, but even though the treatment was not scientifically proven, mines and miners believed it to be effective. In 1952, for example, it was noted in the British Columbia Worker’s Compensation Board review of silicosis that the miner’s unions desired it be mandated for all mines within the province. It was employed for over a decade at Britannia. The last year it was employed at any mine in British Columbia was 1963 (based on Minister of Mines Reports). It was still available at Britannia in 1965, but no one was using it. The last year it was employed in Ontario was 1979. While aluminum prophylaxis slowly disappeared from mines, other methods of prevention advanced. Improved ventilation, improved dust suppression, changes in mining methods, and screening for silicosis all contributed to the decrease in silicosis rates following it becoming a compensatable disease. Today, while it is out of the public eye, silicosis prevention remains important. This is due to there being no treatment for exposure to the dust. Diligence in preventing exposure is the only solution.   From the Archives: Aluminum Prophilaxis at Britannia:   Equipment and Procedure to Disperse Aluminum Powder The Procedure for Dispersing Aluminum Powder, 1945 Ventilation Report - Condition in Drys during Aluminum Application, 1944 Report on Status of Aluminum Prophylaxis, December 28,1948

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photo Gallery

A dry is a change room, and where aluminum dust was administered while it was in use. Note the clothes hanging to dry from the ceiling.

Several advances in safety occurred over the life of the Mine. In the 1950s, rock bolting and screening became mandated to protect workers from rock fall.

For most of Britannia's history, everything ran on rails. In 1970 this changed. The introduction of trackless machines reduced operational costs.

Most of the drills were too heavy or powerful to be hand held. The large drill rig in this image was used for driving one of the 9 foot by 13 foot haulage lines (circa 1920).

A slushing machine drags rock out of a blasted area. To control dust, all broken rock was watered down, or wetted, prior to movement beginning in the 1940s.

A bull doze chamber worker prepares to break an oversized rock with a jackhammer.

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