FALLING LOADS from mobile cranes was the most common cause of death and injury in the Californian crane industry between 1997 and 1999, an analysis of crane accidents has shown.
The study was conducted by the crane unit of California’s division of Occupational Safety & Health (Cal/OSHA).
The major cause of mobile crane accidents was instability, which generally resulted in either the load falling off the hook or slings, or the crane tipping over.
Lack of communication was another major cause, particularly with mobile cranes as the load is not always visible from the operating position.
On the subject of training, the report’s authors noted: “Although ‘lack of training’ did not rank very high as a primary cause, it would have been ranked within the top three if a secondary cause was listed.
The report, called simply Crane accidents 1997-1999, shows that there were 158 reported accidents involving a crane in California between 1 January 1997 to 31 December 1999. Of these, 115 (73%) involved mobile cranes, 26 (16%) bridge cranes, five involved gantry cranes, four were tower cranes and one was a ship crane. In seven cases there was not enough information to determine the type of crane involved.
The one crane operator killed during the period was a mobile crane operator. Of the 23 non-fatal injuries to operators, 14 were bridge crane operators, eight were mobile crane operators and one operated a bridge crane.
Accidents were far more likely to involve other workers; 91 non-operators were injured during the period, 12 of them fatally. These workers included mechanics, oilers, riggers and ironworkers. Of these 91 accidents, 72 involved mobile cranes. Eight of the 12 non-operator fatalities were people working in the vicinity of mobile cranes.
Of the 13 fatal crane accidents, four resulted from falling loads, and three from electrocution.
Out of the total 158 accidents, 43 were caused by falling load and 35 by the crane tipping over. The 35 tip-overs resulted in just one death (trapping a worker underneath). The 14 incidents of contact with power lines resulted in three deaths, two of which involved mobile cranes and one a bridge crane.
Of the 158 crane accidents, 78 occurred in construction work and 80 in non-construction work.