Some examples of mechanical accidents and their reasons

Abstract

Five accidents on mechanical structures which the author investigated and their sources were described. (1) Two workers were killed by soil collapse due to a rupture of bolted joints in sheet pile structures. (2) Drive recklessly of tractor due to brake trouble. (3) Leakage accident of LPG internal fluid from bolted pipe flange connection due to earthquake. (4) Gas explosion from buried pipe line. (5) An accident where two workers were killed by a rupture of chains in operation. As conclusions, the author pointed out that engineers hand to pay a lot of attentions to the design and the instruction for structures. Especially, it is pointed out that a technology for bolted joints is important in practice.