Producing explosives: A delicate science
Producing explosives: A delicate science
Tour an explosives factory and learn about nitroglycerin.
Contunico © ZDF Studios GmbH, Mainz
Transcript
NARRATOR: Highly sensitive material here in this cave in Austria - each of its nine chambers holds up to 20 tons of explosives. Combined, it's the amount of explosives a rock quarry needs for an whole year, enough stock to supply customers all over Europe. To work here, you need nerves of steel.
Meet Dr. Gregor Englmayer. He is in charge of the factory that has its bunkers and labs housed in an isolated valley in Austria. Dr. Englmayer is a chemist who personally inspects the sensitive production facilities every morning, because safety is the top priority. Here every hand movement has to be exercised with great care. The pink mass known as blasting gelatine contains nitroglycerine. Even the smallest foreign particles could trigger uncontrolled explosions. This machine is constructed so that its metal elements and their sharp edges never come into contact with one another. Enough impact or friction could make the sticky mass explode. This explosive is used solely for non-military purposes. It is tailored for the construction of tunnels and roads and for explosive use in quarries and the mining industry.
DR. GREGOR ENGLMAYER: It’s certainly an adventure working with explosives. When you tell other people what you do for a living, they always say, 'Wow, that's dangerous.' Of course there are certain dangers involved in handling these kinds of substances. But we've had them under control for decades, if not centuries."
NARRATOR: Nitroglycerine – it all started with the invention of this highly explosive substance almost 150 years ago. But there is one major disadvantage to this blasting oil. It is so sensitive that it's virtually impossible to handle, making it a threat to anyone wanting to use it. Alfred Nobel was one of the pioneers in the field of nitroglycerine. He bonded it together with a carrier to make it less sensitive. Nobel invented dynamite, an explosive that changed the world.
Dr. Englmayer with his explosives experts - their latest job is to develop a tailor-made explosive for the construction of a tunnel. The explosive potential has to be measured precisely in advance according to the geology and rocks at the explosion site. The development of this explosive in the lab can now begin. The experts have chosen an emulsion explosive, one of the latest generations of explosives. It is insensitive to heat and shock. The chemists begin by creating the carrier material from a nitrate solution, wax and paraffin. There is no danger of explosion yet. Many years of experience are required to manufacture explosives. These chemists cannot leave anything to chance - composition, density, temperature and oxygen balance – every detail counts.
Then comes the decisive second step. Sodium nitrite is added to the mixture, and from this point on it's an explosive situation. Any oversight or mistake in the dosage can be dangerous. These professionals know the risks. The process is complete once bubbles of nitrogen gas form. The microscope shows that the number and thickness of the bubbles is correct and the explosive now has the desired force.
Testing is required before production can begin. Does this explosive, tailor-made in the lab, really have the specified explosive power? The lab technicians place the charge in the extremely heavy pendulum. A measuring tape is used to determine the pendulum's excursion and, thereby, explosive strength - a simple method. Only 10 grams of explosive develop a powerful force and push the steel pendulum by one meter, just as its creators predicted. Now production can begin. Tons of cartridges in the caliber calculated for the project now roll from the production line. Dr. Englmayer conducts a final inspection of the carrier material. The addition of nitrogen is the most dangerous phase, and is only conducted immediately before the mass is pressed into the tubes. Seconds later the cartridges are armed. You can only imagine the potential of the danger posed by these harmless looking, sausage-shaped cartridges.
Dr. Englmayer and his technicians are satisfied. They run through the blast pattern one last time on the computer before it's applied to the rock on-site. Heavy machinery is used to prepare bore holes for the explosive. The charges are wired to ensure the blast moves outwards from the inside with a minimum delay. Whether or not the concept developed on the computer and in the lab actually works as intended will only be clear after firing because no two blasts are alike. But one thing is certain. For Dr. Englmayer and his explosives team there are a great many more challenges.
Meet Dr. Gregor Englmayer. He is in charge of the factory that has its bunkers and labs housed in an isolated valley in Austria. Dr. Englmayer is a chemist who personally inspects the sensitive production facilities every morning, because safety is the top priority. Here every hand movement has to be exercised with great care. The pink mass known as blasting gelatine contains nitroglycerine. Even the smallest foreign particles could trigger uncontrolled explosions. This machine is constructed so that its metal elements and their sharp edges never come into contact with one another. Enough impact or friction could make the sticky mass explode. This explosive is used solely for non-military purposes. It is tailored for the construction of tunnels and roads and for explosive use in quarries and the mining industry.
DR. GREGOR ENGLMAYER: It’s certainly an adventure working with explosives. When you tell other people what you do for a living, they always say, 'Wow, that's dangerous.' Of course there are certain dangers involved in handling these kinds of substances. But we've had them under control for decades, if not centuries."
NARRATOR: Nitroglycerine – it all started with the invention of this highly explosive substance almost 150 years ago. But there is one major disadvantage to this blasting oil. It is so sensitive that it's virtually impossible to handle, making it a threat to anyone wanting to use it. Alfred Nobel was one of the pioneers in the field of nitroglycerine. He bonded it together with a carrier to make it less sensitive. Nobel invented dynamite, an explosive that changed the world.
Dr. Englmayer with his explosives experts - their latest job is to develop a tailor-made explosive for the construction of a tunnel. The explosive potential has to be measured precisely in advance according to the geology and rocks at the explosion site. The development of this explosive in the lab can now begin. The experts have chosen an emulsion explosive, one of the latest generations of explosives. It is insensitive to heat and shock. The chemists begin by creating the carrier material from a nitrate solution, wax and paraffin. There is no danger of explosion yet. Many years of experience are required to manufacture explosives. These chemists cannot leave anything to chance - composition, density, temperature and oxygen balance – every detail counts.
Then comes the decisive second step. Sodium nitrite is added to the mixture, and from this point on it's an explosive situation. Any oversight or mistake in the dosage can be dangerous. These professionals know the risks. The process is complete once bubbles of nitrogen gas form. The microscope shows that the number and thickness of the bubbles is correct and the explosive now has the desired force.
Testing is required before production can begin. Does this explosive, tailor-made in the lab, really have the specified explosive power? The lab technicians place the charge in the extremely heavy pendulum. A measuring tape is used to determine the pendulum's excursion and, thereby, explosive strength - a simple method. Only 10 grams of explosive develop a powerful force and push the steel pendulum by one meter, just as its creators predicted. Now production can begin. Tons of cartridges in the caliber calculated for the project now roll from the production line. Dr. Englmayer conducts a final inspection of the carrier material. The addition of nitrogen is the most dangerous phase, and is only conducted immediately before the mass is pressed into the tubes. Seconds later the cartridges are armed. You can only imagine the potential of the danger posed by these harmless looking, sausage-shaped cartridges.
Dr. Englmayer and his technicians are satisfied. They run through the blast pattern one last time on the computer before it's applied to the rock on-site. Heavy machinery is used to prepare bore holes for the explosive. The charges are wired to ensure the blast moves outwards from the inside with a minimum delay. Whether or not the concept developed on the computer and in the lab actually works as intended will only be clear after firing because no two blasts are alike. But one thing is certain. For Dr. Englmayer and his explosives team there are a great many more challenges.