Custom-designed gantry cranes will work individually or synchronically to transfer and store materials and precast concrete panels used to construct this motorway rote.
Zaydoon Tabrah, export sales engineer, CMAK, said that site and load conditions required a design for a main 70 ton capacity hoist and still be on a single girder crane. In addition, a second supporting hoist with a 10 ton lifting capacity works on an attached girder and continues on a 6 metre cantilever.
Each crane has a span of 15m and can be controlled either from the operator’s cabins, which travel with the cranes, or by radio control which duplicate the cabin controls.
After receiving the client requirements, the engineering team started the design according to the critical conditions of the load, which needed each crane to have two lifting points with equal 35 ton load on each point.
“The design challenge was to fit two main hoisting groups each one with a 35 ton capacity on one girder and synchronise their movement to lift a specially-designed hook block while maintaining the highest level of balance during the process,” said Tabrah.
“Thorough consideration was given to continuous operation conditions in view of DIN 15018 grading in the hoisting gear and load group. At nominal load, sag is less than 1/1000 of the span. Gantry cranes are of welded box-girder construction.”
The controls are designed to increased operational throughput. The inverter speed control systems reduce mechanical stress in components, reduce component wear and minimise load swing and maintenance costs.
“We had the flexibility to adapt to site conditions such as using outdoor applications, rain covers and load balancing additions. The order included the cranes runways, electric feeding systems, and operator cabins.” said Tabrah.
CMAK also included its latest product NXS Series hoist, as a supporting single girder 10 ton hoist, used for low and medium lifting operations during this process.
NXS Series hoists, are now capable of meeting / exceeding all current ranges of CMAK previous designed hoists. Its development started years ago, to make hoists for the next generation speed variation, increased durability, lowered vibration, cost saving, increase height of lift and more.
Tabrah added absolute precision was necessary for safe and successful transportation, supporting steel structures, where added to prevent any damages that may occur to the loads during shipping. Another main challenge was working at the site at the same time during the ongoing construction.
We have always worked to improve efficiency and stay ahead of industry trends, in response to this, CMAK HoistSens+ is now a built-in feature in the new designed hoists as per the customer needs. HoistSense+ is an advanced electronic system that constantly keeps track of usage, load and critical incidents; while using this information to the advantage of the user to further increase the efficiency and decrease the downtime of the crane.
Nowadays, after rigorous very heavy testing together with extreme endurance tests (cumulative hundreds of thousands of hours), now heavy lifting NXS Series hoists are available to use. The new adaptable design concept provides efficient and economical solutions for high lifting heights. Compared to old designs, the NXS hoist enables the maximum number of reeving for easily reached lifting heights up to 240m.
