1事故概况2011年6月,舟山某造船厂,一台门座起重机在检查幅度限位器是否有效时,空载将起重臂往上扳起到接近最高位置,发现幅度限位器失效后,又慢慢往下放至75°左右时,突然发生起重臂断裂事故(图1)。幸未造成人员伤亡,但起重臂及部分其它构件报废,连成直接经济损失300多万元。事故门座起重机的情况如下: 1 Accident Overview In June 2011, a shipyard in Zhoushan, a gantry crane in the check amplitude limiter is valid, no-load jib up to close to the highest position and found amplitude limiter failure , And slowly down to about 75 °, a sudden boom rupture (Figure 1). Fortunately, no casualties were caused, but the jib and some other components were scrapped and even the direct economic losses amounted to over 3 million. Accident gantry cranes are as follows: