New Comansa device for cooling tower giants

BGR Energy Systems has used two Comansa Jie tower cranes to help build the world's tallest cooling towers, in India. The job required parent company Linden Comansa to design a new device to dismantle them.

The 18 tonne capacity 21CJ290 flat top tower cranes were jacked-up with a hydraulic cage in different phases to their 217 metre maximum working height. Both have jib length of 74 m, the maximum of this model, which allows them to reach the tower's base diameter, of 142 m.

At 202 m, the pair of cooling towers, part of India's Kalisindh Thermal Energy plant, are believed to be world's highest, ahead of Niederaussem in Germany.

BGR Energy Systems, an energy plant engineering and construction specialist, is in charge of the project with an initial budget of almost €725 million (US$820 million). The plant is expected to generate up to 1,200 MW (2 x 600) when it is in operation.

The 21CJ290s are attached to the walls of the cooling towers using rope anchorages. The construction of the first cooling tower ended in June 2012. To dismantle the crane at such height, and without access for a mobile crane, a new dismantling device, designed by Linden Comansa, was used.

The device allows the jib sections to be dismantled and hoisted down inside the cooling tower. To dismantle the first jib sections, the jib length of the 21CJ290 was decreased to 35m, shorter than the minimum diameter of the tower. This allowed enough space for 21CJ290 to jack down the tower using the hydraulic cage.

Comansa Jie, Linden Comansa's subsidiary in China, said the 21CJ290 was proving popular in India and there were now seven units working on cooling towers in energy plants in the country.

Apart from the pair at Kalisindh, there are a further two belonging to BGR Energy Systems at its Marwa plant project, working on 2 x 500 MW towers. Indian engineering giant Larsen & Toubro is using two units at the Rajpura plant with 2 x 700 MW towers and a further one is being used in the construction of the Talwandi Sabo plant, with 3 x 600 MW cooling towers.