MIC Corporation, Japan’s largest lifting contractor, completed the installation of a 700t bridge section in just seven and a half hours, using two Demag CC 8800s lifting in tandem.
MIC took delivery of the two big Demags, rated at 1,250t capacity, in September 2003 and the cranes were transported straight to Nagoya in the south of Japan, where they were needed for their first job.
Nagoya is growing rapidly and a highway expansion programme is under construction. Part of the project involved lifting in a new bridge to link the old and new highway lanes. Work was planned to begin at 10pm on 10 November 2003 and had to be finished in time for the existing highway to be re-opened to traffic by 5.30am the following morning. Delay of any kind was not an option.
The two challenges for MIC were soft, muddy ground and lack of space for setting up and operating the cranes. The site was covered with steel plates to reduce ground bearing pressure and the rigging crew managed to set up despite having little space.
The first crane, CC 8800 serial number 7, was rigged with 66m of main boom (SSL) and 440t of counterweight on the carrier. The second, serial number 8, had 66m of main boom and 540t of counterweight on the carrier.
The concrete bridge was connected and slung to the crane hooks and then lifted 15m in the air. The cranes, holding 700t between them, travelled 10m to place the load in its final position, and then lowered the bridge into place and returned to their start point.
By 5.30am the existing highway was back open to traffic once again, just as planned.
A photograph of a test lift by the cranes on site is featured in the January issue of Cranes Today, which is now out.
