Persberg Explosives Factory

Founding and Early History

• Founded by Sebastin Aktiebolag, Stockholm in 1874.

• In 1875, the factory was taken over by miners from Filipstads Bergslag.

• Engineer and manager: Johan Algot Törneman.

• The factory was likely established because Nitroglycerin Aktiebolaget’s patent on the production of blasting oil expired in 1874.

• Törneman also invented a detonator tube and transferred the patent to the factory.

Location: The factory was placed by Gubbdammen due to its proximity to process water from Yngshytteälv, its secluded location, and the nearby railway.

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Legislation and Transport of Nitroglycerin

• 1868: Trade and transport of nitroglycerin was prohibited.

• 1870: Nora-Gyttorp Krutbruk received permission to transport 12.6 tons of liquid nitroglycerin annually to several mines, on the condition that the nitroglycerin was mixed with at least 2% gasoline or nitrobenzene.

• This permission was extended until 1899.

• 1875: Persberg Explosives Factory received permission to transport nitroglycerin to certain mines in Färnebo Härad.

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Resistance to Dynamite

• Mine owners in the Värmland region were reluctant to replace blasting oil with dynamite.

• In 1871, negotiations were held with Nitroglycerinbolaget to manufacture nitroglycerin from dynamite, likely to circumvent transport regulations.

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1918–1920: Cooperation and Expansion

• In 1918, Svenska Sprängämnesföreningen planned to take over the factory.

• Bofors Nobel Krut considered this a threat and initiated negotiations.

• In 1920, an agreement was reached for close technical and economic cooperation.

• Factory capacity was expanded, and Bofors delivered powdered explosives (”Stjärnnobelit”).

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Dynamite and Production

• Persberg dynamite of extra dynamite type contained nitrocellulose, wood flour, ammonium nitrate, nitrobenzene, and ~53% nitroglycerin.

• For a period, pre-charged wet clay cartridges were also produced – same size and packaging as dynamite sticks. These were popular among miners because they saved time.

• Production in the 1920s was low:

  • Annual production: 40 tons

  • 1924–1926: Production completely stopped

• In 1929, Nitroglycerin Aktiebolaget took over deliveries, intending to gradually close the factory.

• To maintain production rights, 10 kg of dynamite per year was still produced using raw materials from Gyttorp.

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Early Experiments with Nitroglycerin

• Autumn 1865: Experiments at Persberg mines, documented by Herr Sundberg, Jernkontorets Stat.

• Nitroglycerin showed greater effect than gunpowder, reducing mining costs and was appreciated by workers despite the dangers.

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Transport of Nitroglycerin

• Nora-Gyttorp Krutbruk constructed two types of wagons:

  • Large oil wagon: 2 horses, 340 kg capacity

  • Small oil wagon: 1 horse, 210 kg capacity

• Wagons had soft springs and a brake claw to hold the wagon on slopes while horses rested or on icy roads.

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Invention of Nitroglycerin and Alfred Nobel’s Early Experiments

• 1847: Professor Sobrero, Turin invented nitroglycerin.

• Early 1850s: Alfred Nobel’s father, Imanuel, attempted to use nitroglycerin as explosive – unsuccessful.

• 1862: Alfred Nobel developed a method for controlled detonation using a powder fuse (early “blasting cap”).

• 1863: First successful detonation with blasting oil.

• 1867: Nobel patented Gurdynamite, a safe and moldable nitroglycerin mixture with diatomaceous earth.

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Sources

• Josefin Sabo: Reglerad sprängkraft – Dynamiten, staten och den svenska civila sprängmedelsindustrin 1858–1950.