Why 1840s Roebling's Hand-Twisted Wire Rope Held 150+ Years While Modern Machine-Made Cables Snap скачать в хорошем качестве

Why 1840s Roebling's Hand-Twisted Wire Rope Held 150+ Years While Modern Machine-Made Cables Snap

Why 1840s Roebling's Hand-Twisted Wire Rope Held 150+ Years While Modern Machine-Made Cables Snap John Roebling's 1842 patent was for "spiral laying of the wires around a common axis without twisting the individual wires" while having them "each under a uniform and forcible tension" Roebling developed seven-strand wire rope manually along a wire rope walk on his land in Saxonburg, after seeing two workers killed by breaking hemp rope. The old method: Each wire tested individually, twisted by hand with uniform tension, built by a man who witnessed death from rope failure. Modern method: Machine-made cables to minimum specifications, no one takes personal responsibility. Bridges built with Roebling's cables in the 1850s-1880s are still standing and carrying traffic today.