Friday, June 6, 2008

February 3rd 2004

Dublin Ireland lost the jib of a Wolffkran in a windstorm over night. No injuries were reported but a apartment had to be evacuated and a rail line halted. Early reports focused on weather vaning the crane.

When a tower crane is out of service the slewing (swing) brakes are opened so that the longer jib of the crane can point in the direction the wind is blowing and change directions with the wind. This keeps the crane profile as small as possible and since cranes are counterweighted then lean back, and weathervaning allows the crane to lean into the wind just like when we try to walk into the wind.

1 comment:

brian gallagher said...

weather had a significant factor with this incident but so too had some erection issues of the crane as a detailed report later found out.A jib pin had been inserted the wrong way i.e. upsidedown.together with the wind it worked its way out over time and hence the jib collapsed.The report also found that the operator had engauged the free slew and not left the slew brake on as what had been reportly said at the time of the incident.This was a very lucky incident to happen so late in the evening and that it had no injuries as the crane had been operating for quite some time upto and on the morning of the day in question.