When it comes to top-of-the-line preservation lines, be it for shipyards or steel rolling mills, customers around the world rely on the technical competence of Rösler. This is not surprising, because Rösler offers not only comprehensive knowledge and many years of experience but has also implemented numerous reference projects. Another positive aspect are the project teams consisting of experts from the respective Rösler sales branches and the specialists from the head office in Untermerzbach, Germany. This close global cooperation produces technical solutions with numerous benefits to the customers.
CMCS – successful entry
China Merchants Cruise Shipbuilding (CMCS) is one of the leading manufacturers of expedition ships, floating platforms and floating cranes. To date the company had outsourced the corrosion protection of the steel plates and beams required for the production of its products. With the expansion of its business activities into passenger and cruise ships the company had to abandon this outsourcing policy. The construction of a midsize passenger ship alone requires 25,000 metric tonnes of steel. For this reason, the company looked for a partner for the design and installation of a high-performance preservation line. After an extensive analysis of the market the Chinese ship builder chose Rösler as supplier for this crucial investment. Key factors for this decision were the implementation and technical, efficiency of several preservation lines at European shipyards. Rösler was the only supplier who could present such an impressive reference list.
The 180 meter long preservation solution was specially engineered to meet the requirements of CMCS. It includes a plate section, the so-called main line, and a steel beam section, from which the shot blasted beams are fed into the main line. This unique preservation line consists of two roller conveyor shot blast machines, equipped with perfectly adapted Gamma 400G and Rutten 400 HD turbines, a straightening system for the beams and up to 12,000 mm long plates, a fully automatic coating system including a paint supply unit and a thermal post-combustion system. All these line components are digitally connected and integrated into the production control system of the shipyard.
This intelligent control system allows the fully automatic processing of the steel components from the loading to the unloading zone at a speed of five meters per minute. The short pass-through times, a high process stability and consistent coating results provided CMCS with a significant competitive advantage. Of course, this was enhanced by the sturdy and wear- resistant design of the preservation line along with significantly lower personnel costs.
A new dimension
One of the largest manufacturers of steel and associated products with plants in the United States, Canada and Mexico convinced to purchase their new preservation line from Rösler. In this case it was the excellent experience with a preservation line installed a few years ago at another plant that prompted the major US company to choose a Rösler preservation line. The size of the steel plates with a width of 4,300 mm, a length of 18,000 mm and a thickness of up to 200 mm required a custom-engineered solution.
Handling of loads
The entire line, in which the steel plates are preheated, shot blasted, painted and dried, had to be designed for loads of seven metric tonnes per running metre instead of the usual three tonnes. The integrated roller conveyor blast machine has a usable width of 4,500 mm and is equipped with 10 Gamma 400G turbines, each with an installed power of 30 kW. Such a “fire” power ensures that consistent, homogeneous shot blasting results are achieved across the entire width of the plates at a speed of 4 m/minute. This guarantees a high productivity.