Tensar Access Road Solution

Tensar Access Road Solution has saved £120,000 for Manx Electricity

During the installation of a new gas pipeline across the Isle of Man, Manx Electricity Authority (MEA) needed to establish access roads for contractor's plant over uneven terrain characterised by poor ground conditions.

The solution involved a layer of Tensar geogrid over the existing ground topped with locally available slate aggregate to create a robust working platform.

This brought about cost savings of around £120,000, compared with the option of using Type 1 sub-base, as well as considerable benefits for the environment and the local farming community.

The new pipeline stretches from its point of entry at Glen Mooar on the west coast to its termination location at Douglas on the east coast.

The development involves a 20-metre wide construction corridor with a 4-metre wide access road for the contractor's machinery.

The solution adopted on the project used 300mm of slate aggregate with a single layer of Tensar SS30 geogrid installed at the interface between the aggregate and the existing formation.

The resources of top quality Type 1 aggregate on The Isle of Man are limited.

MEA had a surplus of poorer quality local slate available at Glen Mooar, without which they would have faced elevated haulage and disposal costs.

In the absence of the Tensar geogrid, it would have been necessary to use the more expensive Type 1 aggregate or considerably increase the thickness of the poorer quality local slate.

Cont'd - 2 - The Tensar solution covered approximately 10km of the total 22km length of the pipeline's construction corridor.

It is estimated that savings of around £12 per metre length of road were obtained giving a total saving of around £120,000.

An additional benefit was the damage limitation to the surrounding countryside as there had been concern relating to the protection of a local orchid population.

On completion of the project, the geogrid solution has allowed the recovery of the fauna in the area.

Furthermore, many of the access roads have since been topsoiled and retained for agricultural use by the landowners, promoting good local relations within the community.

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