Overview:
This paper provides a comprehensive overview of the U.S. Geological Survey’s extensive investigations conducted during the early 1900s. The study aimed to improve safety in coal mines, explore the use of more efficient and safer explosives, and find ways to utilize lower-grade fuel sources effectively.
The paper emphasizes the alarming number of fatalities in U.S. coal mines compared to European countries. The Survey’s research focuses on developing permissible explosives that do not ignite gas or dust mixtures in mines, thus reducing the risk of explosions. It also examines the use of electricity in mines, the safety of mine lamps, and the development of artificial breathing apparatus for rescue operations.
The paper further delves into the investigation of structural materials, including concrete, building stones, and clay products. The study focuses on understanding the properties of these materials, testing their fire-resistance and durability, and developing methods for efficient construction practices. The paper concludes with a detailed examination of fuel investigations, exploring different coal types, their efficiency in combustion, and the potential of using lower-grade fuels like peat and lignite.
Key Findings:
- The U.S. had a significantly higher coal mine fatality rate than European countries.
- The use of permissible explosives, tested and approved by the Geological Survey, significantly reduced the risk of mine explosions.
- The investigation revealed the importance of dampening coal dust to prevent explosions.
- The study found that many low-grade fuels, previously considered worthless, could be efficiently utilized in gas producers for power generation.
- The investigation identified the need for better fire-resistant materials and more efficient construction techniques in buildings.
Learning:
- Permissible Explosives: These explosives are specifically designed to minimize the risk of ignition in the presence of mine gas or dust. They are tested and approved by the U.S. Geological Survey, ensuring a higher level of safety in coal mines.
- Coal Dust Control: The paper highlights the significant role of coal dust in mine explosions. The study demonstrates the importance of effectively dampening coal dust using water, humidification, or other methods to prevent ignition.
- Fuel Efficiency: The investigations into fuels showed that lower-grade fuels like peat and lignite could be efficiently converted into producer gas, offering a valuable alternative to higher-quality fuels. This finding highlights the potential for utilizing previously overlooked resources for energy production.
- Fire Resistance in Buildings: The paper emphasizes the importance of fire-resistant materials and construction techniques to minimize fire losses. The investigations into the fire-resistance of various building materials provide valuable information for designing safer structures.
Historical Context:
This paper was written in 1910, a time when coal mining was a major industry, and mine safety was a growing concern. The publication highlights the urgent need for scientific research to address the challenges of mine explosions and the waste of natural resources. The U.S. government was beginning to invest in systematic research to improve safety and efficiency in these industries.
Facts:
- Coal Mine Fatality Rate: The average death rate in the coal mines of the United States is three times that of France, Belgium, or Germany.
- Coal Production and Waste: By 1907, nearly 7,000,000,000 tons of coal had been mined in the United States, with nearly an equal amount wasted.
- Coal Exhaustion: If production continues to increase at the rate it has over the past 50 years, a significant portion of the more accessible coal supply will be exhausted before the middle of the next century.
- Timber Supply: The Forest Service estimates that at the current rate of consumption, the timber supply will be exhausted within the next 25 years.
- Fire Losses: Fires in combustible buildings cause over $200,000,000 in damages annually in the U.S.
- Mine Fatalities: 28,514 men have been killed in the coal-mining industries over the last 19 years.
- Coal Dust: Coal dust, when fine enough, becomes highly explosive when mixed with air.
- Humidity Control: Maintaining a relative humidity of 90% at 60° Fahr. for 48 hours can prevent coal dust explosions.
- Explosive Flame Duration: The flame of black powder lasts 3,000 to 4,000 times longer than the flame of permissible explosives.
- Explosive Strength: Permissible explosives are one and one-fourth to one and three-fourths times as strong as black powder.
- Permissible Explosive Use: The use of permissible explosives should be considered supplemental to and not as a substitute for other safety precautions in mines where gas or inflammable coal dust is present.
- Explosive Gas Production: With equal quantities, black powder and permissible explosives produce roughly the same amount of noxious gases.
- Electric Fuse Safety: Tests show that enclosed electric fuses can safely be used in mines, as they do not ignite explosive mixtures of air and gas when blown out.
- Mine Water Corrosion: Acid mine water can damage electrical wiring insulation.
- Safety Lamp Testing: Safety lamps are tested in galleries with air and gas mixtures to determine their ability to withstand explosive conditions.
- Breathing Apparatus: Various artificial breathing apparatuses, primarily of European manufacture, are tested for their safety and efficiency in rescue operations.
- Rescue Training: Miners are trained in the use of breathing apparatus and rescue techniques to prepare them for mine emergencies.
- Concrete Construction: The U.S. Government spends approximately $40,000,000 annually on building and engineering construction.
- Alkaline Soils: Alkaline soils and waters can cause disintegration of concrete structures, especially in arid regions.
- Peat Fuel: Peat deposits throughout the United States, covering over 11,000 sq. miles, hold potential as an alternative fuel source.
Statistics:
- Coal Mine Fatalities (1907): 3,125 men died in U.S. coal mines in 1907 alone, while nearly 800 died in metal mines and quarries.
- Coal Waste: For every ton of coal mined in the U.S., nearly a ton is wasted, totaling 3,500,000,000 tons by 1907.
- Coal Production (1907): Nearly 7,000,000,000 tons of coal had been mined in the U.S. by the end of 1907.
- Annual Coal Production: The U.S. produced approximately 415,000,000 tons of coal annually around 1910.
- Permissible Explosives: The first list of permissible explosives, issued in May 1909, included 17 brands.
- Permissible Explosives (October 1909): The second list, issued in October 1909, included 31 permissible explosives.
- Black Powder Flame Duration: The flame of black powder is more than three times as long and has a duration three thousand to more than four thousand times that of one of the permissible explosives.
- Black Powder vs. Permissible Explosives: Permissible explosives are one and one-fourth to one and three-fourths times as strong as black powder.
- Coal Dust Moisture: Coal dust from mines in the Pittsburg district requires at least 12% of water to prevent ignition.
- 100-Mesh Coal Dust: Coal dust of 100-mesh fineness requires 30% water to prevent ignition.
- Ballistic Pendulum: The ballistic pendulum is used to measure the disruptive force of explosives, with a charge of ½ lb. of 40% nitro-glycerine dynamite serving as the standard.
- Trauzl Lead Block: The lead-block test, adopted by the Fifth International Congress of Applied Chemistry, is the standard for measuring the disruptive force of explosives.
- Explosive Calorimeter: The explosion calorimeter measures the amount of heat given off by the detonation of explosive charges of 100 grammes.
- Impact Machine: The impact machine, modeled after a German device, is used to gauge the sensitiveness of explosives to shock.
- Flame Test: The flame test apparatus measures the length and duration of flames given off by explosives.
- Rate of Detonation: The rate at which detonation travels through a given length of an explosive is measured using a device called the Mettegang recorder.
- Gas and Dust Gallery No. 1: This gallery is 100 ft. long with a minimum internal diameter of 6 1/3 ft.
- Gas and Dust Gallery No. 2: This gallery is 30 ft. long and has a diameter of 10 ft.
- Structural Materials Testing: Over 2,500 samples of structural materials were examined in a six-month period.
- Concrete Tests: Nearly 1,200 concrete or reinforced concrete beams, each 13 ft. long, were tested at the structural materials testing laboratory.
Terms:
- Permissible Explosives: Explosives that have passed rigorous tests by the U.S. Geological Survey and are deemed safe for use in mines with gas or dust hazards.
- Black Damp: A mixture of carbon dioxide and nitrogen, often found in mines, that can be fatal to humans.
- Fire Damp: Methane gas, a flammable gas found in coal mines, which can ignite and cause explosions.
- Ballistic Pendulum: A device used to measure the explosive force of a charge by the swing it imparts to a suspended mortar.
- Trauzl Lead Block: A test using a lead block to measure the expanding force of an explosive charge.
- Detonator: A device used to initiate the detonation of an explosive charge.
- Gas Producer: A device that converts solid fuels into combustible gas for use in engines.
- Briquetting: A process of compressing small coal particles into solid blocks for easier handling and combustion.
- Lignite: A type of brown coal with a relatively high moisture content.
- Peat: A partially decomposed plant matter found in bogs, which can be used as fuel.
Examples:
- Cherry, Illinois Mine Disaster: A 1909 mine fire, which killed 310 men, demonstrates the importance of mine safety and rescue operations.
- Marianna, Pennsylvania Mine Disaster: The Geological Survey rescue corps saved one man from a group of 150 bodies.
- Leiter Mine, Zeigler, Illinois: Two miners, trained by the Geological Survey, used oxygen helmets to rescue another miner.
- Sun River Project, Montana: Concrete structures on this Reclamation Service project experienced disintegration due to alkaline soil and water.
- Shoshone Project, Wyoming: Concrete structures on this Reclamation Service project also showed evidence of disintegration due to alkaline conditions.
- Carlsbad and Hondo Projects, New Mexico: Concrete structures on these projects exhibited disintegration due to alkaline soils and waters.
- Isthmian Canal Commission: The Commission, responsible for building the Panama Canal, is a major user of explosives, with samples tested by the Geological Survey.
- Quartermaster’s Department: The department utilizes explosives for construction and testing, with the Geological Survey providing research and analysis.
- North Carolina Peat: Peat with 30% ash and 15% water was successfully used in a gas producer, demonstrating the potential of low-grade fuels.
- Florida and Michigan Peat: These peats also proved effective when utilized in gas producers, confirming the feasibility of using peat as an alternative fuel source.
Conclusion:
This comprehensive study by the U.S. Geological Survey in 1910 revealed the urgency of addressing mine safety, improving fuel efficiency, and developing safer and more effective construction materials. The paper highlights the significance of research and testing in advancing these areas, emphasizing the role of the government in promoting safety and conservation of natural resources. The findings from these investigations, particularly regarding the use of permissible explosives, coal dust control, and the potential of low-grade fuels, have lasting implications for the mining, construction, and energy industries.