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Armour-piercing discarding sabot (APDS) was initially the main design of the kinetic energy (KE) penetrator. The logical progression was to make the shot longer and thinner to increase its sectional density, thus concentrating the kinetic energy in a smaller area. However, a long, thin rod is aerodynamically unstable; it tends to tumble in ...
At that time, cannons were cast at the foundry with an extra section of metal forward of what would become the muzzle, and this section was removed and discarded later in the manufacturing process. [ 12 ] [ g ] Rumford took an unfinished cannon and modified this section to allow it to be enclosed by a watertight box while a blunted boring tool ...
Fire making, fire lighting or fire craft is the process of artificially starting a fire. It requires completing the fire triangle , usually by heating tinder above its autoignition temperature . Fire is an essential tool for human survival and the use of fire was important in early human cultural history since the Lower Paleolithic .
Friction between relatively moving parts; Fragments from bursting vessels; Fresh metal exposure: Heat of oxidation released when unoxidized metal is exposed to an oxidizing atmosphere. Usually associated with fracture, impact or friction. Galling and friction: Heat generated by rubbing components together. Lightning and other electric arc discharge
Forge welding (FOW), also called fire welding, is a solid-state welding process [1] that joins two pieces of metal by heating them to a high temperature and then hammering them together. [2] It may also consist of heating and forcing the metals together with presses or other means, creating enough pressure to cause plastic deformation at the ...
A fire plough (or fire plow) is a firelighting tool. In its simplest form, it is two sticks rubbed together. [1] Rubbing produces friction and heat, and eventually an ember. [2] More advanced are "stick-and-groove" forms, which typically uses a V-shaped base piece of wood, and a "friction stick" as the activator. [2] [3]
From the Iron Age forward, until the invention of the friction match in the early 1800s by John Walker, the use of flint and steel was a common method of fire lighting. Percussion fire-starting was prevalent in Europe during ancient times, the Middle Ages and the Viking Age. [3] [6]
The heat eventually turns the wood at the point of contact into charcoal, which is ground to a powder by the friction, that collects into the "V" notch. Continuing operation eventually ignites the charcoal dust producing a tiny ember, which can be used to start a fire in a "tinder bundle" (a nest of stringy, fluffy, and combustible material). [4]