THE PROJECT
The 2km 600mm gas pipeline will feed the new Isle of Grain power station. The challenging route crosses heavily contaminated ex-refinery land and crosses under a major cryogenic LNG line. Challenging geology and the usual environmental concerns added to the difficulty of this project. A combination of open-cut techniques and Horizontal Directional Drilling were used to complete the project, which also included the construction of an AGI pigging facility.

HDD
Horizontal Directional Drilling, using the 250 tonne maxi-rig, enabled Stockton to create a secure route without disturbing the sensitive cryogenic line. A pre-welded and tested pipeline string was then pulled through the prepared hole, completing the crossing with no risk of subsidence or post construction settlement.

ENVIRONMENT
A brownfield ex-refinery site meant that particular attention had to be paid to potential contamination and difficult geology and ground conditions over the whole pipeline route. In addition Stockton had to deploy an advanced environmental management system, independently audited due to the challenging environmental conditions.

Located in an environmentally sensitive site with vole and great crested newt habitats meant that strict constraints were placed on Stockton by both the NGPHL and Medway Council environmental plans. Stockton conducted an in-depth assessment and a Stockton environmental advisor was present on-site throughout the project, supported by a specialist ecologist.

PROJECT MANAGEMENT
Stockton managed all aspects of the project, liaising closely with designers Mouchel Limited and the client, with particular focus on environmental and health and safety management, from site mobilisation and personnel induction to regular tool box talks – all customised to tackle the particular challenges of the Grain site.