Crane lifting machinery is intermittent work cycle , from lifting hooks or other devices extract by lifting up or moving heavy machinery and equipment plus . Features integrated lifting machinery work , from the perspective of security technology , you can usually know the general lifting huge mechanical structure , institutional complexity , to complete the lifting movement , horizontal movement . In the 15 ton Electric Chain Hoist operation process, often several different directions at the same time the movement operation, greater technical difficulty. The lifting of the heavy lifting machinery diverse load varies. Some heavy weighing hundreds of tons and even thousands of tons , and some objects up to tens of meters , but also very irregular shape , with scattered grains , hot melt state, inflammable and explosive dangerous goods, etc. , lifting process is complex and dangerous. Some lifting machinery requires direct staff to do the lifting movement of the carriage on the rails , platforms or rope , which directly affects the reliability of personal safety . Lifting machinery exposed parts are more active , and often in direct contact with the lifting workers , many potential risk factors for sporadic . Lifting machinery operations often need people with common proceed. An operation requiring command, strapping , drivers and other workers with skilled , motor coordination , care of each other . Workers should be able to deal with emergency situations on site . Close coordination between multiple operators , usually there is a big difficulty. Mechanical lifting work characteristics , determine its relationship with a lot of production safety . If the lifting machinery design , manufacture, installation and maintenance aspects of slight negligence may cause injury or equipment accidents . On the one hand causing casualties , on the other hand can also cause great economic losses .