Construction techniques

The pipelines will be laid below ground generally by open cut and laying the pipe in a mechanically dug trench. Major road and river crossings may require the pipe to be laid by tunnelling or drilling.

The majority of the main transmission pipeline will be laid across open country and the arterial legs feeding the towns will be laid in the roadways where possible.

For the pipelines that will be laid across open country, the working area will be fenced off in a strip about 30m wide along the length of the pipeline and pre-construction drainage installed. The top soil will be carefully removed and stored within the working width. The steel pipes will then be laid out and welded together onside with breaks in the pipes for road and river crossings.

As each section is welded and coated, the trench is dug and the pipe is placed carefully into it. The trench will be left open for the minimum amount of time for safey reasons and to prevent the likelihood of it being affected by adverse weather.

The trench will then be filled back in, post-construction drainage will be installed and the land will be reinstated in the original layers that were removed.