Spanish global infrastructure company FCC on Tuesday announced is preparing to ship the first five caissons from Algeciras Port (Cádiz), which will mark the beginning of construction work on Açu Port–around 315 kilometres north of Río de Janeiro (Brazil). The rectangular caissons have a volume of 3,722 cubic metres of concrete and weigh 9,871 tonnes. Construction of the caissons in Algeciras Port has generated more than 700 direct and indirect jobs.
FCC’s construction subsidiary is building 9 of the 49 reinforced concrete caissons, which will form the foundation of Açu Port. The company chose Algeciras (Spain’s most important port) as the site to build the first components because of its draught since the Açu facilities are not yet prepared to moor the caisson production vessels.
The caissons are 45 metres long, 24 wide and 18 high. Caisson-loading requires high-precision manoeuvring given their size and the limited space between them (approximately 4 metres). They can only be moved with tugboats, with the result that any unfavourable sea and wind conditions could complicate the placement of caissons on deck.
The five caissons will be loaded onto a Black Marlin semi-submersible vessel measuring 217.50 metres long (the equivalent of two football pitches) with a beam of 42 metres. They will then be transferred from the dock to the vessel using two tugboats and two support boats.
The Black Marlin will partially submerge to a depth of around 12 metres during the loading process and, once complete, it will rise back up to surface level. The caissons will then be secured to the deck using steel plates in order to impede movement during the journey.
The vessel will take 15 days to cover the 4,300 nautical miles (7,960 kilometres) between Algeciras and Río de Janeiro (Brazil). After passing through customs in Río, the caissons will be towed to São João da Barra and submerged in Açu Port to form the temporary breakwater, behind which the Mar del Aneto and Mar del Enol caisson production vessels will be moored.
The 4 remaining caissons (of 9 in total) will be completed by mid-May and transported at the end of that month in a second journey, along with the Mar del Aneto caisson production vessels.
Açu Port, the soon to be third-largest in the world
FCC heads the consortium that will complete this complex civil engineering project. The project includes the construction of a 2,438 linear metre dock to be executed by manufacturing 49 reinforced concrete caissons and a 600-metre dike. The contract also includes dredging more than 4.1 million cubic metres to attain an average depth of 31 metres, the dike superstructure works, and the provision of nautical equipment and buoys.
The port is located inside the Açu Superport industrial complex, which spans 90 square kilometres (2.5 times the size of Manhattan), and will comprise 2 terminals with 17 kilometres of pier and 40 berths, capable of receiving ships of up to 400,000 tonnes. As a result of this project, Açu will be the third-largest port in the world and the largest in the Americas, with an annual capacity of 350 million tonnes.