Brazilian construction company Norberto Odebrecht is using Linden Comansa tower cranes to help with the renovation and expansion of the Cambambe hydroelectric power station near Angola, Africa.
The power station is on the Kwanza River, about 180 kilometres southeast of Luanda, the capital of Angola. It supplies power to approximately 8 million people in Luanda, Ndalatando, Cacuaco, Malanje, Gabela, Porto Amboim and Sumbe.
The project is being carried out to increase the stations power supply from 180 MW per year to 960 MW. Once complete it will become the largest power production plant in the Kwanza basin. It currently has ISO 9001, 14001 and 18001 seals and is the first hydroelectric project in Africa to obtain this certification.
Norberto Odebrecht has been contracted to raise the dam’s height by 20 metres, increasing the capacity of the reservoir from 2 to 5.5 square kilometres. The increase will mean the four existing generators will be able to produce 65 megawatts each instead of 45.
To raise the height of the dam, more than 65,000 cubic metres of concrete will be used. To help with the construction, three Linden Comansa tower cranes are currently on site, including two 21LC750 with maximum load capacity of 48 tonnes and a 21LC400 with maximum capacity of 18 tonnes. The 21LC400 has been leased by Ibergru, the Linden Comansa distributer in Angola.
The first 21LC750 was located on the left bank of the Kwanza River with a freestanding height of 78.8 m and an 80 m jib. It was set up with 2.5 metre-wide mast sections which were fixed on a concrete foundation. The second 21LC750 was erected with a freestanding height of 87.2 m on the right side of the river bank. It was erected with 12 2.5 metre-wide mast sections and three 5-metre-wide mast sections at its base. It was fixed on a concrete foundation, which was also anchored on the riverside.
The 21LC750 on the left bank was on site for 18 months, lifting concrete and materials, before being replaced by a 21LC400. The 21LC400 was also rented from Ibergru. The tower crane was erected with a freestanding height of 80 m and a 70 m jib. It
“This crane was assembled on the same fixing angles of the previous 21LC750, so it was necessary to have two transition sections in order to allow the progression from the 4 metre-wide fixing angles to the 2.5-metre-wide D33 mast section,” a company spokesperson added.
Once removed from the bank, the 21LC750 was put to work on the construction of the power house. Tasks for the tower crane include moving precast segments weighing up to 19 tonnes each. It is also being used to lift and place turbines and generator sets.
A team from Linden Comansa completed the assembly and jacking-up of the first 21LC750, while the remaining assemblies, jacking-ups and technical service was carried out by Ibergru.
The power station is due for completion in December 2015.