Rotating of a column by Bok Seng
This oversized column was transported from Italy to Singapore by boat. Because of the dimensions was the column rotated 90 degrees, after arrival at the port near the construction site in Singapore was it required to bring the column back into the right position. That sound like a good job for the professionals of Bok Seng!
The column with transport saddles weights in total 232.5 tonnes, is 38.5 meters long, 9.1 meters wide and is 6.8 meters tall. The column is here loaded on a double 24-axle SPMT.
In total four mobile cranes will be used to rotate the column, the SPMT is now driven between the cranes.
An overview of all the cranes that will be used; starting with this sharp Liebherr LTM 1350-6.1. The outrigger base of the crane measures 8.932 x 8.53 meters.
Here is the crane fitted with 95 tonnes of counterweight.
The second crane is this Liebherr LTM 1200-5.1.
The outrigger base of this crane measures 8.9 x 8.3 meters. The crane is fitted with the full counterweight of 72 tonnes.
The third crane is the large Liebherr LTM 1750-9.1, fitted with 144 tonnes of counterweight. The outrigger base measures 12 x 12 meters.
The fourth crane is this Liebherr LTM 1500-8.1. The outrigger base measures 10 x 9.6 meters, the crane is fitted with 135 tonnes of couterweight.
The booms are extended and the load is attached to the cranes. The LTM 1350-6.1 has the boom extended to a length of 25 meters, the LTM 1200-5.1 has the boom extended to a length of 26.7 meters, the LTM 1500-8.1 has the boom extended to a length of 26.5 meters and the LTM 1750-9.1 has the boom extended to a length of 27.2 meters.
After all cranes are attached to the load is the lashing with the saddles removed.
The LTM 1200-5.1 and LTM 1350-6.1 will pick up the load later on a radius of 6 resp. 6.5 meters, the LTM 1500-8.1 and LTM 1750-9.1 will lift the load at a 9.5 meter radius.
The column is now hanging in the cranes! Each of the cranes is now lifting about 63 tonnes.
The column must be lifted at appropiate height so that the SPMT can be driven away. It is required to add axtra support plates below the saffles to create additional height for the column later in its new position.
The rotating of the column will start now. While the two "smaller" cranes are winching down, are the "large" cranes only booming down to a radius of approx. 11 meters.
Slowly is the column rotated here, proper communication and coordination between the crane operators and lifting supervisors is very important now.
It took about 10 minutes to rotate the column. The load is now fully transferred to the LTM 1750-9.1 and LTM 1500-8.1. The LTM 1350-6.1 and LTM 1200-5.1 are now finished and the rigging can be removed now.
The column is now hanging in the two large cranes, each of the cranes is now lifting about 126 tonnes. In the meantime are the saddles re-configured to that the column can be loaded on the SPMT again later. Unfortunately the loading couldn't be seen. A very sharp job performed by Bok Seng!