Heavy lift ring crane - video

[Papa Smurf]

A question was asked about what should be the approach with securing tower cranes against damage from an incoming storm.

There are not a lot of options available. The video showing the erection of the Liebherr crane lasts less than 3 minutes - this represents an actual elapsed time of (I guess) 5 days or more. The erection or lowering of the main boom can take a day. Therefore dropping the boom is seldom a viable option. Also, free space is needed to lay the boom on the ground - both for erection and dismantling, and that free space is very quickly taken up by other activities on a construction site. The most common precautions have been mentioned - allow the mast to weathercock freely. Pray. There are very few athiests around when Mother Nature shows what She is capable of.

All heavy lifting is subject to pre-determined maximum wind speeds - you just have to trust that weather predictions are correct and that the wind doesn't freshen significantly. On a construction project I was involved with, we monitored weather at various remote sites up to 500 km away.

As a general statement, I gained tremendous respect for the amount of detailed planning and meticulous preparation that went into high and heavy lifting. I worked on the project for 7 years and in that time we "killed" 8 cranes, ranging from small rubber-tyred mobiles to a 400-ton lattice-boom tracked crane, and in most of those the sequence of failures started with a deviation from the original detailed plan. With that record of equipment damage we were extremely lucky to only injure 3 people. In the case of the 400-tonner there was the potential for multiple fatalities if it hadn't happened immediately after a meal break before the workforce returned.