The crane, which was delivered by Linden Comansa’s Bulgarian dealer Bulgarcom, will be used by the Aurubis Group at its plant near Pirdop.

Aurubis is one of the leading global copper manufacturers but also produces sulphuric acid as a bi-product.

The company is constructing outgoing gas cleaning facilities at the plant, as part of a €44.2m project launched in 2011 to improve productivity and environmental performance.

To assist construction of the towers, which comprise a fibre-glass pipe with a supporting steel structure, Bulgarcom erected the 18t 21LC290 crane in April with an initial freestanding height of 63.1m and a jib length of 40m.

As the towers gained height, the crane was tied to the steel structure with a bracing at 49m. Bulgarcom then used a Linden Comansa J2-10 cage to climb the crane to a height of 101.6m.

In July another tie-frame was added at 88m and the crane climbed again, to a final height under hook of 134.6m. In October the crane was disassembled and erected elsewhere at the plant to build the second, 120m-high chimney.