WINDCRANE Monitoring for Sword Construction at the Devonshire Dock Hall, UK

The actual unit is very robust. It works very well with accurate data. It has helped improve our lifting and gets the jobs done safely that we were not able to complete without it. A good piece of kit.

Tony Donnelly, Appointed Person at SWORD CONSTRUCTION UK LIMITED

The importance of measuring wind conditions at the exact location of your cranes.

Sword Construction required an accurate and reliable wind monitoring solution for the Devonshire Dock Hall expansion, where they used two Wolffkran luffing cranes. The facility is owned by BAE Systems, and the expansion will be used to assemble Royal Navy submarines.

The project site represented a unique challenge, since the existing assembly hall was funnelling the wind, causing variable and unpredictable conditions for any cranes in operation.

• There can be major differences in wind conditions, even across short distances in the same site, and wind speed also tends to increase with height.

• Even if two identical cranes are close to each other, wind loads can vary depending on their slew direction and jib luff angle.

• The placement of your anemometer is also very important. If the wind is blocked by a structure or by the crane itself, you will not get an accurate measurement.

For example, you cannot rely on a ground-level measurement to determine wind conditions for a crane that is located 200 m away, with a boom 50 m above the ground. Construction sites in urban locations tend to have more wind speed variations across short distances, due to the effect of surrounding buildings and other structures. Open sites tend to have steadier winds, but this normally changes as new structures are built.

As we have discussed in previous articles, keeping track of wind turbulence is also very important. Your construction site could have two locations with the same average wind speed, but very different turbulence conditions. Even at low average wind speeds, turbulence can cause your crane to become unstable if left unchecked.

WINDCRANE data chart above showing the max/gust and average wind speeds for Sword tower crane WINDCRANE systems, during storm Arwen:

WINDCRANE’s Solution for the Devonshire Dock Hall Expansion

The cranes used by Sword Construction were located at the western end of the assembly hall, very close to one of its walls. The large building was funnelling the prevailing wind, causing variable speeds and unpredictable conditions across the entire construction site. To operate safely, Sword Construction required live wind data for each of the cranes. They also required a portable anemometer, to monitor wind speeds in any point of the structure and scaffolding.

• The two luffing cranes were already equipped with WINDCRANE monitoring systems.

• These were upgraded to provide live wind measurements through our mobile app, in addition to historical data and reports that can be accessed online.

• WINDCRANE also provided a rugged, compact and portable wind monitoring station.

• This unit has the same capabilities as the monitoring systems installed on the cranes, and can easily be placed wherever wind monitoring is required during critical lifts or to gauge the differences in wind conditions across the site.

The following chart compares the wind speed data logged by the three WINDCRANE systems between December 7 and 13.

• Measurements for the two crane-mounted systems are displayed in blue and red, while the portable system is displayed in magenta.

• As you can see, wind conditions for the two cranes were similar but not identical, and both had notable differences with the monitoring results from the portable system which was positioned nearby but closer to ground level.

In this case, the wind speeds experienced by the cranes are much higher than those recorded by the portable anemometer. Without a dedicated monitoring system for each crane, their wind conditions would have been underestimated drastically.

With crane-mounted monitoring systems, project managers can decide whether to proceed with a lift or not based on live data.