Crane Accidents Analysis and Preventive Measures

In the mechanical world, cranes are frequently to be seen in construction areas, in mining, logging, steel factory, plastic plant, warehouse and other applications for material handling. There is no exaggerate that industry cranes are the workhorse which have increased productivity and economic growth in their own ways. However, behind the splendid contribution made by various cranes, there are sacrifices caused by crane accidents. In order to avoid crane accidents from happening, the probable causes are analyzed and preventive measures are recommended for your reference. Crane Accidents Causes An industry crane can be a dangerous piece of equipment. Each and every year there are injuries and death occurred due to the crane accidents. According to the statistics of U.S Bureau of Labor Statistics, from 1992 to 2006, there were 632 death caused by crane accident in the construction area alone. Causes of Crane-Related Deaths in Construction, 1992- 2006 *64 stuck by falling crane booms/jibs included. ** 21 falls from cranes, 9 falls from crane baskets, 8 from crane loads included. *** 9 highway incidents are included in other causes. Source: U.S. Bureau of Labor Statistics Census of Fatal Occupational Injuries Research File From the above statics, the deaths mainly are caused by overhead crane power line electrocutions, struck by crane loads, crane collapses, struck by crane booms/jibs, and falls, etc. Electrocutions –from overhead power lines Among these causes, the electrocutions from overhead power lines takes away 157 people, which mainly caused by foot touching/ guiding loads cables, operating crane, foot touching crane, with the percentage of 52%, 25%, 13%, and 10 % for other reasons. *64 stuck by falling crane booms/jibs included. ** 21 falls from cranes, 9 falls from crane baskets, 8 from crane loads included. *** 9 highway incidents are included in other causes. Source: U.S. Bureau of Labor Statistics Census of Fatal Occupational Injuries Research File Struck by crane loads There were132 people who were died of being struck by crane load, which mainly happened during loading or un-loading, or caused by other crane related work, or happened during flagging, directing or guiding, or happened during crane operating, with the percentage of 32%, 15%, 14%, 7%. Even there were 32% of accidents happened to workers which were not involved with cranes. Crane collapse From 1992 to 2006, there were 81 crane collapses, causing the deaths of 89 people. Among the 89 crane collapses, the main causes were unknown which takes 51% of the crane collapse cases, and the other left are caused by unstable surface such as uneven surface or slippy surface such as icy surface, or caused by broken crane cables or rigging or stabilizers, or caused by crane load or boom shift, with the percentage of 15%, 14%, 12%，and 9% respectively. Struck by falling boom/jib According to the statics, 64 people were killed by falling crane booms or jibs. The deaths of 64 peoples were caused by the striking of the dismantling boom, the broken boom or boom cable, lengthening boom, and others, with the percentage of 56%, 22%, 9%, and 22% respectively. Cranes Involved in Fatalities Mobile cranes Mobile cranes took 71% of the crane accidents, which was mainly involved with the overhead power supply line accidents, crane collapses, and boom or jib cranes, taking the percentage of 84%, 63%, and 60 % respectively. Tower cranes Tower cranes took 5% of crane related accidents, which were mainly caused by crane load accidents, and by jib striking. Floating cranes and unspecified crane There was 24% of crane accidents caused by floating cranes or unspecified cranes according to the statics. There are 13 floating crane accidents, 12 overhead crane accidents and 49 unspecified crane accidents involved. Occupations of the death or injuries According to statics, the construction laborers, heavy equipment operators including the crane operators, operating engineers, hoist operators, winch operators and other construction equipment operators, supervisors, mangers, iron workers, mechanics, and others such as welders, cutters, electrical workers, mechanics, sheet metal workers, trucker driver, etc., are exposed to the danger of crane accidents in the construction application. The specific diagram is presented for you reference. Causes of Crane-Related Deaths in Construction, 1992- 2006 *62 crane and tower operators, 21 operating engineers and other construction equipment operators, and 7 hoist and winch operators. ** 24 welders, and cutters, 22 electrical workers, 21 mechanics, 17 sheet metal workers, 14 truck drivers, and 73 others. General Cranes Hazards According to study and statics, there are inherent hazards that may occur during the application environment. A crane is dangerous. Most of the crane accidents are attributed to several basic hazards. The general crane hazards can be classified in the following forms:

1. Dormant hazards refers to the undetected hazards, caused by crane design or crane use.

2. Armed hazards is the armed dormant hazards which become ready to cause harm during certain conditions.

3. Active hazards is the armed hazards triggered by certain conditions which cause harms and damages and preventive measures are too late to escape.

General Crane Hazard Preventive Measures There are rare chance to change the design of a crane at the working site to make it safer, however, crane hazards are controllable if the crane operator and user take preventive measures: 1. Minimize or eliminate the hazards. During the crane designing projects, the hazards produced by particular work circumstances should be minimized or eliminated. 2. Guard hazard. Hazard that can not be totally eliminated should be minimized or reduced through appropriate measures to protect and monitor to prevent the hazards from being activated or triggered. Preventive measures are recommended as follow:

• A. Screens or covers should be installed over moving parts.

• B. To prevent electrocution, the energy power lines of cranes should be covered by local electric utility install line guards or covers. Also, the insulated link on the hoist line should be installed to prevent the passage of electric current from the hook through the load to the person guiding the load on the ground.

• C. The dangerous zone produced by the rotating crane cab should be banned from entry by guardrails or barriers.

• D. A crush-resistant can and restraint system should be installed to protect the crane operator in case of the occurring of upset.

3. Warnings. Warning devices should be installed to detect hazards and emit warning signal when the hazards can not be controlled by the above mentioned measures. 4. Special procedures and training. Special operating procedures, training and audits must be employed to guarantee that a viable, continuing regimen will effect avoidance of the hazard. 5. Personal protective equipment. Crane user, operators, and other related workers should wear proper protective equipment, such as, gloves, hard hats, safety shoes, aprons, goggles, safety glasses, life jackets, lifeline, taglines to guide the load, etc.