Construction of the second submarine cable in the Väike strait has started

The second 110-kilovolt cable line to be built in the Väike Strait on commission from Elering will connect the overhead power line that ends on the west coast of the island of Muhu with the Orissaare substation in Saaremaa.

The new submarine cable will have a total length of 6.9 kilometres, of which 5.2 kilometres will be offshore. The submarine cable has a diameter of 210 millimetres and weighs 75 kilograms per metre. The cable has a total weight of 390 tonnes and a capacity of 520 amperes. The submarine cable will be manufactured at the Prysmian Group’s Pikkala factory in Finland.

In the first phase of the project, the pipeline will be excavated and the underground cable will be laid onshore. In the second phase, excavation work will be carried out in the Väike Strait storage area and the cable will be laid in the sea. The final phase of the project will involve the dismantling of an 110 kV high-voltage overhead line on the Väinatamm.

The cable will be laid in the sea from a special vessel as a single long cable, i.e. without extension sleeves. A fibre-optic communication cable will also be laid in the sea together with the new electrical cable. During installation, the cable will be buried in the seabed to reduce the risk of damage from anchors, ice and other external agents. The submarine and underground cables will be connected by means of a special continuation sleeve made by trained sleeve fitters.

The first modern 110-kilovolt submarine electric cable was laid by Elering in 2015 between the mainland and the island of Muhu in the Suur Strait. At the end of 2019, the first 110-kilovolt submarine cable was laid in the Väike Strait. A year later, a 110-kilovolt submarine cable was completed in the Suur Strait, replacing two obsolete 35-kilovolt submarine cables.

The construction of a second submarine cable through the Väike Strait will significantly improve the islands’ security of electricity supply and the possibility of connecting new renewable energy generation capacity. In addition, the Väinatamm area will become safer for birds.

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