Regular IC contributor Terry McGettigan presents his total figures for tower crane accidents worldwide for the whole of 2010
Accidents or, to use a more accurate description, incidents, continue to destroy, life, property and reputations at an unacceptable rate.
Worldwide in 2010 there were at least 154 major incidents involving tower cranes. They resulted in more than 113 deaths and countless injuries. It should be noted that these figures are compiled from reported incidents, whereas it is safe to say that the actual number is much higher.
On a positive note, there was a slight decline in the year-total numbers compared to 2009, when there were 188 accidents and 78 deaths. The reduction, however, can be attributed to a decline in construction activity in much of the world.
Unfortunately, the number of deaths, in terms of the deaths to accidents ratio, was up sharply. Climbing tower cranes to raise their height was involved in incidents that contributed to 46 deaths alone.
In analysing these events, care was taken to avoid misrepresenting a tower crane as a mobile crane or other type of equipment. When in doubt, photo identification was used to corroborate authenticity. These are not minor incidents by any means. The vast majority include major structural and-or mechanical failures that led to partial or total collapse, resulting in deaths and or injuries.
1) In-operation: 59 incidents causing 31 deaths. Causes include operator error, poor or lack of maintenance and or inspections, improper commissioning, faulty equipment systems, foundation failures, improper set-up, and wilful tampering with safety devices.
Due to limited availability of detail, it is believed that many in this category could be associated with C/A/D (see below).
2) Climbing - Assembly - Disassembly (CAD): 48 incidents causing 63 deaths.
Climbing - 18 accidents causing 46 deaths
Assembly - 15 accidents causing 13 deaths
Disassembly - 15 accidents causing 4 deaths.
The same crews perform all three of these operations so it was considered reasonable to combine them into one group. As for assembly and disassembly, many of these incidents are due to the assist crane or erection crane overturning.
3) Wind: 25 incidents causing five deaths:
The high incident rate, for the second year in a row, warrants bringing this to light. It is believed that most of these are caused by operator error, i.e. not weather-vaned. Other causes include improper set up and-or malfunction, and inadequate foundations. Noticeably, most of the toppled tower cranes are ballast or bogie-based.
4) Unknown: 12 incidents, causing 14 deaths:
Insufficient details are available on the cause of these incidents.
The bottom line is that tower cranes are far safer and more efficient than any other hoisting method out there, as long as the equipment is of good quality, commissioned to standards, and operated, maintained and inspected with the highest degree of competency.