Concord Cranes flexes its heavy-lift capability on Mthatha River bridge
 | Concord Cranes flexes its heavy-lift capability on Mthatha River bridge | 38.5 KB | Download |
 Preview | An in situ concrete slab covered the beams in order to cater for two lanes crossing the river. | 209.33 KB | Download |
 Preview | Concord Cranes flexes its heavy-lift capability on Mthatha River bridge. | 5.33 MB | Download |
 Preview | The height from the platform to the top of the deck was between 9 m to 10 m. | 3.86 MB | Download |
 Preview | The project for main client Haw & Inglis involved construction of a 90-m-long bridge. | 5.61 MB | Download |
 Preview | The superstructure comprised 18 precast beams, each 29.9 m long and weighing about 60 t. | 4.79 MB | Download |
The project for main client Haw & Inglis involved construction of a 90-m-long bridge comprising three 32-m-long spans, with an average height from ground level of 8 m. The substructure comprised two abutments and two piers. All foundations were founded on 1 050 mm piles augered and socketed into bedrock with an average depth of 7 m.
The superstructure comprised 18 precast beams, each 29.9 m long and weighing about 60 t. These beams were constructed on a site adjacent to the bridge, from where they were transported and placed in position. An in situ concrete slab covered the beams in order to cater for two lanes crossing the river. The superstructure was completed by F-shape Type A parapets.
The bridge deck and parapets have largely been completed, with concrete work 100% complete by the first week of September. Premix, joint installation, and road marking are on track for completion by end September, Haw & Inglis Contracts Manager Johan Ehlers explains.
The civil engineering company contacted Concord Cranes regarding the transportation and placing of the precast beams to a radius of about 20 m. The height from the platform to the top of the deck was between 9 m to 10 m.
The 750 t crane required for this project was sourced from group company Concord Castle, Concord Cranes CEO Herman van Staden points out. The original quote was based on a 550 t crane, the largest available in our fleet at the time, which would have necessitated construction of large platforms in order to extend the reach of the 550 t crane. These platforms required stabilisation on the 3-m-deep silt riverbed.
Concord Castle therefore proposed that its new 750 t crane be deployed on the project, which was still in Germany at the time. However, its delivery to South Africa was well in advance of the date when it would be needed. “This is a seriously impressive piece of machinery that is able to work with great accuracy,” Ehlers comments.
The contract with Concord Castle was based on the site establishment of all required cranes, equipment, and trucks to complete the transportation and placement of the precast beams. Equipment supplied included all lifting slings, guide ropes, shackles, and chains needed to carry out the work safely.
In addition, Concord Castle provided trained riggers and staff. “Our teams assisted with the manual labour, and supervised the exact positioning of the precast beams,” Ehlers confirms. Concord Castle submitted the required lifting and rigging studies, method statements, and occupational health and safety file to the satisfaction of the main contractor and engineer. Lastly, it oversaw the mechanical, maintenance, and back-up support for all of the machinery.
While the 750 t crane travelled on its own to site, about 13 additional horse-and-trailer trucks were needed to transport some of its components and counterweights, which had to be erected on-site. The 750 t crane was operational in two days, along with a 90 t and 110 t mobile crane.
A qualified rigger supervised the lifting process at the precast yard, where the 60 t beams were lifted in tandem by the 90 t and 110 t cranes onto an extendable trailer. Two 32-mm-diameter steel lifting hooks were cast into each end of a beam. The cranes were positioned at each end with the trailer parked next to the beam.
Once the beam was placed onto the truck, it was tied down with chains. The 40-m-long truck then drove to the bridge, which was about 300 m away from the precast yard. The main rigger then assumed charge of the operation, and supervised the lifting and placement of each beam onto the bridge.
The truck stopped at a predetermined position, from where special slings were connected to the lifting hooks on each beam. Guide ropes were also tied to each end of the beam. Each rope was handled by a team of about five workers, and a leader employed by Concord Castle. Guide ropes were used to stabilise and steer the elements when these were up in the air. This was critical, as any wind or other external forces could cause the elements to rotate or swing out of control.
The rigger communicated with the 750 t crane operator by means of a two-way radio, and supervised the guide-rope teams in securely lifting and placing the beams into position. Separate teams were positioned on top of the bridge to receive the beams and steer them onto the bridge bearings.
Before the crane released the load completely, the beams were secured to the bridge by the main contractor in order to prevent them from falling over. Once secured, the load was released and the slings untied. During the placement process, the extendable trailer travelled back to the precast yard, and the process was repeated for the next beam.
“The service and supervision provided by Concord Castle was professional and safety-conscious,” Ehlers notes. “At no time were any risks taken. We had a sense of them being in full control all of the time. It was a technically difficult operation well executed within the planned time.” Van Staden concludes that the close collaboration between Haw & Inglis and Concord Castle, as well as the exchange of ideas and knowledge, was key in making this a successful operation.
Ends
Notes to the Editor
To download hi-res images for this release, please visit http://media.ngage.co.za and click the Concord Cranes link to view the company’s press office.
About Concord Cranes
Concord Cranes is part of Industrial Services Holdings (InServe). Concord AngloV3, Concord Castle, and Concord Elcon make up our lifting services available in South Africa. Likewise, their head offices are located in Midrand, Port Elizabeth and Durban respectively. Concord Namibia is located in Okahandja, and covers the Northern and Central territories of Namibia. We are a preferred provider of professional, compliant lifting services that are customised to fit our clients’ needs. Our fit-for-purpose lifting services are aligned with our clients’ objectives which, when combined with exceptional technical support, safeguards the integrity of all projects.
Concord Cranes Contact
Herman van Staden
CEO
Phone: (011) 805-8071
Cell: 083 269 9497
Email: herman [at] concordcranes [dot] com
Web: www.concordcranes.com
Media Contact
Jonathan Ducie
NGAGE Public Relations
Phone: (011) 867 7763
Fax: 086 512 3352
Cell: 084 709 0167
Email: jonathan [at] ngage [dot] co [dot] za
Web: www.ngage.co.za
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