Nautilus has laid, during a period of three months, a new section (length of approx. 10.5 km) of 132 kV HVAC underwater power line connecting the island of Sacca Serenella (Murano) to Cavallino Treporti within the Lagoon of Venice.
M/s Terna Rete Italia - Terna Group
M/s Prysmian Powerlink
Venice Lagoon, Italy.
Project scope brief
- Underwater installation, in trench, of a triad of 150 kV HVAC power cables, to a depth of burial varying between 2.00 and 3.00 m from the lagoon bottom
- Track length: 10.50 km, for an overall length of cables installed of 42 km.
The works consisted in the simultaneous laying of three single-core 150 kV HVAC power cables and one fiber-optic telecommunication cable, tied to form a bundle.
The laying activities were performed without causing any shutdown of the existing utilities as well as without interrupting the navigation within the waterways encountered along the route, and by constructing a single cables joint.
The submarine cables installation was executed within areas characterized by very shallow water and considerable environmental value.
Summary of activities carried out
- Onshore landing of cables at the starting / end points by means of a controlled pulling winch. The concerned activities consisted in the pulling of the head of each single cable through a dedicated HDPE conduit installed by HDD (Horizontal Directional Drilling) method.
- Underwater controlled laying of bundle of cables by means of the subsea wheel trencher MAC1.
- Construction of all complementary works such as infrastructures for crossing of existing utilities, marker posts, etc.
Single Core 150 kV HVAC Power Cables
- Outside Diameter: 116 mm
- Minimum Bending Radius: 2.5 m
- Weight in air: 31 kg/m
- Type of cables: XLPE 150 kV Cu 1x1000 mm2
Marine Fiber Optic Cable (48 fibers)
- Outside Diameter: 35 mm
- Weight in air: 3 kg/m
- Type of fiber: ITU T G 652D