Crane Accidents 1997 - 1999

A Report of the Crane Unit of the Division of Occupational Safety and Health

Prepared by Philip Yow
Associate Cal/OSHA Engineer

23 May 2000

Ray Rooth,
Principal Safety Engineer, Research and Standards Safety Unit


Ken Fry,
Senior Cal/OSHA Engineer, Crane Certifier Accreditation Unit

Division of Occupational Safety and Health
California Department of Industrial Relations

I. Data Sources

A. Data for the Crane Report was gathered from Federal OSHA's Office of Management Data Services (OMDS) Website. Searches were made on the OMDS website by:

  • Various keywords, e.g. "crane," "mobile crane," "hydraulic crane," "load"
  • 2, 3, and 4 Digit Standard Industrial Classification (SIC) Codes, e.g., 15xx, 16xx, 17xx
  • Establishments – "Crane XXX"

B. Data was also gathered from Micro-to-Host Reports from the Integrated Management Information System (IMIS). The following requests were made:

  • All Accidents Reports (Form 36) from 1/1/97-12/31/99
  • All Inspections with Optional Information "S-10 Cranes"
  • All Citations involving 8 CCR 4999 and 8 CCR 2946

II. Total Number of Crane Accidents

From 1 January 1997 through 31 December 1999, the Division of Occupational Safety and Health learned of, or had reported to it, a total of 158 accidents involving a crane.

Over the three-year period from 1997 through 1999, at least one crane accident has occurred in each month of the three year period.

III. Types of Cranes Involved in Accidents

The types of cranes involved in the 158 accidents are as follows (N=158):

Crane Type Count Percentage
Mobile Cranes 115 73%
Bridge Cranes 26 16%
Gantry Cranes 5 3%
Tower Cranes 4 3%
Ship Cranes 1 1%
Not Determined 7 4%

IV. Crane Operator and Non-Crane Operator Injuries

A. Total Injuries, Serious and Fatal, By Type of Worker

  1. Crane Operator -- One Fatal Injury and 23 Non-Fatal Injuries
  2. While fourteen of the operators injured were bridge crane operators, the one fatality was a mobile crane operator.

  3. Non-Crane Operators -- 12 Fatal Injuries and 79 Non-Fatal Injuries
    1. Ninety-one non-crane operators were injured in crane accidents. Of the 91 crane accident-related injuries, 72 of these accidents involved mobile cranes. These non-crane operators include occupations such as mechanics, oilers, ironworkers, riggers, and stevedores.
    2. In this category, 12 involved fatal injuries 8 of which involved non-crane operators who were engaged in work in the vicinity of mobile cranes.
  4. Of the total of 13 fatalities for crane operators and non-crane operators, four (4) were the result of falling loads. All of the falling load fatalities involved a mobile crane. There were 3 fatalities from the 14 electrical contact accidents. Two of the electrical contact fatalities involved mobile cranes.
  5. Although there were 35 mobile crane "tip-over" accidents, there was only one fatality in all tip-over accidents when a worker was killed when a crane tipped over onto him.

V. Private vs. Public Sector Crane Accidents

Of the 158 crane accidents, 150 accidents involved private sector entities and 8 involved public sector entities. Of the 8 public sector cases, 7 resulted in serious injuries. All 8 of the public sector cases involved a mobile crane.

VI. Construction vs. Non-construction Crane Accidents

Of the 158 crane accidents, 80 accidents occurred in non-construction work and 78 in construction related work.

VII. Accident Causation

A. Most Frequent Causes: All Crane Types (N-158) and Mobile Cranes (N-115)

All Crane Types Mobile Cranes
1.  Instability 67 49
a.  Unsecured Load 34 6
b.  Load Capacity Exceeded 0 29
c.  Ground not level/too soft 0 4
2.  Lack of Communication 32 24
3.  Electrical Contact 13 10
4.  Misc. in 14 Categories 46 32

B. Instability, Lack of Communication and Other Causal Factors

  1. Instability

    Instability accidents for mobile cranes generally resulted in either the crane tipping over, or the load falling off the hook or slings. Instability accidents were further broken down into separate categories.

  2. Lack of Communication

    Lack of communication was another major cause of accidents because the point of operation is usually some distance from the crane's operator station or not in full and direct view of the operator in operations involving mobile cranes. Seventy-five percent of accidents caused by both "lack of communication" and "electrical contact" involved mobile cranes.

  3. Lack of Training

    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 were listed.