Project
Dredging of a trench for sewage water pipeline through the entrance channel to the Maracaibo Lake. Trench dimensions: length 1000m, bottom width 15m, 3-5m average depths.
Location : Maracaibo - Venezuela
Client : Instituto de Conservacion de Lago de Maraciabo
Contractor : Dredging International
Period : march 2000 – march 2000
Value : USD/Euro 0,47 mio |
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Scope of work
Dredging
Trenching
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Description of the works
Dredging International’s 2,575 cu m capacity trailing suction hopper dredger Orwell arrived on Lago de Maracaibo, Venezuela in March. The vessel’s trenching contract here continues an unbroken tour of duty around the Caribbean Sea that began in Costa Rica in February 1999 and has also taken in assignments at Guadeloupe, Trinidad and Guatemala.
Despite its name, Lago (“Lake”) de Maracaibo is a large, narrow-necked bay extending southwards from the Golfo de Venezuela, which itself opens onto the Caribbean. The Orwell's task is to dredge a 3.5 km long trench across the entrance channel to the lake, for the Instituto de Conservacion del Lago de Maracaibo.
The trench, to be laid at a depth of -17.5 m, will carry a sewage pipeline across the navigation channel from the city of Maracaibo on the west bank to the Pequiven (Petroquimicas de Venezuela) refinery of El Tablazo on the east bank. Main contractor on the pipeline project is the state-owned Instituto Nacional de Canalizaciones, which awarded the dredging sub-contract to Dredging International.
The Orwell had sailed to Venezuela in early March from Puerto Guatemala, immediately following completion of a maintenance dredging contract at Puerto Barrios. On the Golfo de Honduras, Puerto Barrios is the main port of Guatemala’s short Caribbean seaboard.
DI’s client was Cobigua (Compañia Bananera Guatemaltica). The Orwell’s task was to remove around 360,000 cu m of material from Cobigua’s quay, used for banana exports, and a stretch between the quay and its access channel. The quay extends into the water and dredging was required on both north and south sides.
The Orwell was able to dredge as close as 2 m from the quay walls. Material closer to the walls slipped into the trailer’s reach as it worked alongside, so could be taken up at that distance. The quay was returned to the required depth of – 9.5 m within the one-month schedule.
DI had deployed the Orwell at two ports in Trinidad from August until just before Christmas last year. The contract, for capital and maintenance dredging at Point Lisas and La Brea, was for the state gas company.
At Point Lisas, the Orwell first deepened the access channels, main turning basin and cargo berths for the gas company’s quays, allowing larger vessels to use the terminal. The trailer removed approximately 170,000 cu m of material, to achieve new depths varying from –7.8 m at quayside to –12.8 in access channels. The Orwell then performed the maintenance phase of the contract, removing a further 180,000 cu m. Around 30,000 cu m was then removed from the port of La Brea in a further maintenance phase.
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Activities