Home / Company activities / Underwater high-voltage cable lines /

Underwater high-voltage cable lines

The CES Group has vast material, technical and human resources for turnkey construction of long distance underwater high-voltage cable lines.The CES Group employs its own fleet of special purpose sea and river equipment to lay underwater high-voltage cable lines. Our professionals have been trained at equipment and material manufacturing plants in Europe.

The CES Group is the key contractor of OJSC FGC of UES for the construction of underwater high-voltage cable lines. In 2009, the CES Group carried out the unique project on external power supply for the island of Valaam, which involved laying of a double-circuit underwater cable line across the bed of Lake Ladoga. The cable was laid without any coupling sleeves.

Today, the CES Group applies its knowledge and experience in successful underwater laying of high-voltage cable lines in other large scale projects:

  • Construction of a 330 kV underwater cable line as part of the project «Construction of the Vasileostrovskaya 330 kV substation with a 330 kV cable line Vasileostrovskaya – Severnaya, a 330 kV cable line Vasileostrovskaya – Ilyich Abrasive Company in Saint Petersburg for the purposes of the Bulk Power Systems of the North-West, a branch of OJSC FGC of UES;
  • «External electric power supply for the island of Kizhi», which involved laying of a 10 kV underwater cable line across the bed of Onega Lake for the purposes of Karelenergo, a branch of OJSC IDGC of the North-West.

Underwater cable trenching

In order to avoid any damage that anchors of the vessels may cause to an underwater cable, a cable should be trenched (cable laying into a narrow underwater trench). The cable laying ship is equipped with a trencher (underwater self-propelled trencher) for trenching operations. In its turn, the trencher is fitted with a mechanical chain cutter, which makes trenches in the soil. The trencher lays down a cable by dragging it along the chain cutter via the rolling system. After the cable is laid, the trench is filled up.

Trencher specifications:

  • Direct burial cable diameter: up to 300 mm;
  • Types of developed soils (silt, sand, soft and firm clay, boulder rock, collapsing rock);
  • Cable trenching (trench depth): up to 3.3 meters;
  • Overall dimensions: 6.5 meters long, 5.5 meters wide, 3.3 meters high;
  • Weight: 42 tons ashore, 37 tons underwater;
  • Tractive power: up to 8 tons (based on the seafloor conditions);
  • Soil bearing pressure: 20 kPa;
  • Cable laying speed: from 60 to 400 meters per hour (based on the type of a developed soil).

Underwater cable trenching approach is chosen at the project stage after soil surveying.

State-of-the-art cable trenching approaches:

  • Hydraulic plow — trenches are made by washing out the soil by high pressure water head. The plow, operating in silts and sands, may be self-propelled and nonpropelled.
  • Disk underwater plow — it operates in heavy-textured soils, including solid rocks.

© 2018 CES. All rights reserved.

Site created by Web Bureau

18A,Khrustalnaya Street,
Saint-Petersburg, 192019

Tel.: +7 812 309-36-38;
Fax: +7 812 319-36-38
E-mail: info@c-es.org

6/5, Barklay Street
Moscow, 121087

Tel.: +7 495 989-61-49

E-mail: info@c-es.org

72 Svetlanskaya Street,
Vladivostok, 690091

E-mail: info_vld@c-es.org