THERMITE
Posted: 22 Apr 2012, 10:03
THERMITE
I went for a furtle on the web and here’s what I found, most of it on Wykepedia.
Thermite was discovered in 1893 & patented in 1895 by German chemist Dr. Hans Goldschmidt. Consequently, the reaction is sometimes called the "Goldschmidt reaction" or "Goldschmidt process". Dr. Goldschmidt was originally interested in producing very pure metals by avoiding the use of carbon in smelting, but he soon realised the value in welding. The first commercial application was the welding of tram tracks in Essen, in 1899. Degussa, a corporate descendant of Goldschmidt's firm, is still today one of the world's largest producers of welding Thermite.
Thermite grenades are used as incendiary devices to quickly destroy enemy equipment. Additionally, thermite grenades are used by friendly forces to destroy their own items and equipment when there is imminent danger of them being captured. Because of the difficulty in igniting standard iron-thermite, plus the fact that it burns with practically no flame and has a small radius of action, standard thermite is rarely used on its own as an incendiary composition. It is more usually employed with other ingredients added to enhance its incendiary effects. Thermate TH3is a mixture of thermite and pyrotechnic additives which have been found to be superior to standard thermite for incendiary purposes. Its composition by weight is generally 68.7% thermite, 29.0% barium nitrate, 2.0% sulphur and 0.3% binder. Addition of barium nitrate to thermite increases its thermal effect, creates flame in burning and significantly reduces the ignition temperature. Although the primary purpose of Thermate-TH3 is as an incendiary, it will also weld metal surfaces together.
A classic military use for thermite is disabling artillery pieces and it has been used for this purpose since the Second world War. Thermite can permanently disable artillery pieces without the use of explosive charges and therefore can be used with a reasonable amount of stealth. There are several ways to do this. By far the most destructive method is to weld the weapon shut by inserting one or more armed thermite grenades into the breech and then quickly closing it. This makes the weapon impossible to load. An alternative method is to insert an armed thermite grenade down the muzzle of the artillery piece, fouling the barrel. This makes the piece very dangerous to fire. Yet another method is to use thermite to weld the traversing and elevation mechanism of the weapon, making it impossible to aim properly. Thermite was also used in German incendiary bombs during the blitz.
Incendiary bombs, also known as firebombs, were used as an effective bombing weapon in WWII. The large bomb casing was filled with small sticks of incendiaries (bomblets), and designed to open at altitude, scattering the bomblets in order to cover a wide area. An explosive charge would then ignite the incendiary material, often starting a raging fire. The fire would burn at extreme temperatures that could destroy most buildings made of wood or other combustible materials (buildings constructed of stone tend to resist incendiary destruction unless they are first blown open by high explosives). Originally, incendiaries were developed in order to destroy the many small, decentralized war industries located (often intentionally) throughout vast tracts of city acreage in an effort to escape destruction by conventionally-aimed high-explosive bombs. Nevertheless, the civilian destruction caused by such weapons quickly earned them a reputation as terror weapons (ex. German Terrorflieger) with the targeted populations, and more than a few shot-down aircrews were summarily executed by angry civilians upon capture. The Bombing of Dresden, and to a lesser degree the 1943 bombing of Hamburg, and the firebombing of Tokyo remains a source of controversy to this day (though in the case of the latter, the effect on Tokyo's intentionally decentralized subcontractor war industry manufacturers was devastating).
Modern incendiary bombs usually contain thermite, made from aluminium and ferric oxide. The most effective formula is 25% aluminium and 75% iron oxide. It takes very high temperatures to ignite, but when alight, it can burn through solid steel. In WWII, such devices were employed in incendiary grenades to burn through heavy armour plate, or as a quick welding mechanism to destroy artillery and other complex machined weapons.
[I found a good description of rail welding on this site; http://www.northeast.railfan.net/high_iron.html#cwr
Well worth a look if you are interested.
I went for a furtle on the web and here’s what I found, most of it on Wykepedia.
Thermite was discovered in 1893 & patented in 1895 by German chemist Dr. Hans Goldschmidt. Consequently, the reaction is sometimes called the "Goldschmidt reaction" or "Goldschmidt process". Dr. Goldschmidt was originally interested in producing very pure metals by avoiding the use of carbon in smelting, but he soon realised the value in welding. The first commercial application was the welding of tram tracks in Essen, in 1899. Degussa, a corporate descendant of Goldschmidt's firm, is still today one of the world's largest producers of welding Thermite.
Thermite grenades are used as incendiary devices to quickly destroy enemy equipment. Additionally, thermite grenades are used by friendly forces to destroy their own items and equipment when there is imminent danger of them being captured. Because of the difficulty in igniting standard iron-thermite, plus the fact that it burns with practically no flame and has a small radius of action, standard thermite is rarely used on its own as an incendiary composition. It is more usually employed with other ingredients added to enhance its incendiary effects. Thermate TH3is a mixture of thermite and pyrotechnic additives which have been found to be superior to standard thermite for incendiary purposes. Its composition by weight is generally 68.7% thermite, 29.0% barium nitrate, 2.0% sulphur and 0.3% binder. Addition of barium nitrate to thermite increases its thermal effect, creates flame in burning and significantly reduces the ignition temperature. Although the primary purpose of Thermate-TH3 is as an incendiary, it will also weld metal surfaces together.
A classic military use for thermite is disabling artillery pieces and it has been used for this purpose since the Second world War. Thermite can permanently disable artillery pieces without the use of explosive charges and therefore can be used with a reasonable amount of stealth. There are several ways to do this. By far the most destructive method is to weld the weapon shut by inserting one or more armed thermite grenades into the breech and then quickly closing it. This makes the weapon impossible to load. An alternative method is to insert an armed thermite grenade down the muzzle of the artillery piece, fouling the barrel. This makes the piece very dangerous to fire. Yet another method is to use thermite to weld the traversing and elevation mechanism of the weapon, making it impossible to aim properly. Thermite was also used in German incendiary bombs during the blitz.
Incendiary bombs, also known as firebombs, were used as an effective bombing weapon in WWII. The large bomb casing was filled with small sticks of incendiaries (bomblets), and designed to open at altitude, scattering the bomblets in order to cover a wide area. An explosive charge would then ignite the incendiary material, often starting a raging fire. The fire would burn at extreme temperatures that could destroy most buildings made of wood or other combustible materials (buildings constructed of stone tend to resist incendiary destruction unless they are first blown open by high explosives). Originally, incendiaries were developed in order to destroy the many small, decentralized war industries located (often intentionally) throughout vast tracts of city acreage in an effort to escape destruction by conventionally-aimed high-explosive bombs. Nevertheless, the civilian destruction caused by such weapons quickly earned them a reputation as terror weapons (ex. German Terrorflieger) with the targeted populations, and more than a few shot-down aircrews were summarily executed by angry civilians upon capture. The Bombing of Dresden, and to a lesser degree the 1943 bombing of Hamburg, and the firebombing of Tokyo remains a source of controversy to this day (though in the case of the latter, the effect on Tokyo's intentionally decentralized subcontractor war industry manufacturers was devastating).
Modern incendiary bombs usually contain thermite, made from aluminium and ferric oxide. The most effective formula is 25% aluminium and 75% iron oxide. It takes very high temperatures to ignite, but when alight, it can burn through solid steel. In WWII, such devices were employed in incendiary grenades to burn through heavy armour plate, or as a quick welding mechanism to destroy artillery and other complex machined weapons.
[I found a good description of rail welding on this site; http://www.northeast.railfan.net/high_iron.html#cwr
Well worth a look if you are interested.