Gas Transmission Pipelines

Nord Stream Pipelines – Diverless Repair Clamp Project

Project Overview

The Nord Stream Project consists of twin 48” pipelines passing through the Gulf of Finland and the Baltic Sea from Portovaya Bay, North of St. Petersburg (Russia) to Griefswald in Germany, each approximately 1200km in length.

Nord Stream contracted CONSUB to provide engineering consultancy services to assist with the development and implementation of a repair strategy for the offshore section of the pipelines.

Scope of Services

CONSUB provided full engineering and package management of the supply contract including:

  • Preparation of tender documents including scope of work and the tender evaluation procedure.
  • Review and approval of the detailed design analysis and drawings performed by the supplier.
  • Review and approval of all manufacturing, assembly and testing documents.
  • Inspection oversight at select subsupplier facilities (e.g. Sheffield Forgemasters).
  • Attendance as Client representative at factory acceptance testing activities in Houston, USA.

Houston FAT – Clamp under full hydrotest at 3725psi – for the 48” pipe that equates to about 2740 tonnes of force on each end of the clamp

The Nord Stream clamps represent an industry step change in subsea repair clamps with respect to their size. The clamps weight approximately 100 tonnes in air and have dimensions of 10m (l) x 2.5m (w) x 3m (h). This is approximately 4 times the size/weight of any subsea repair clamp in the industry to date. The first clamp was delivered in 2016.