Deepwater Pipeline Plough Trials Successful

The main trenching plough was designed to bury pipelines up to 1550mm diameter up to 2.5m below the seabed, sustain a bollard pull of over 350T and maintain speeds of up to 3000m/hr, where seabed conditions permit. The backfill plough, an all-new EB-designed concept, sees all four of the main skids sit outside the trench enabling the plough to run on undisturbed soil, thus increasing stability and reducing risk of damage to the laid pipe.

Over the course of six weeks an EB team worked with SUKL personnel and led the electrical installation and commissioning of equipment onboard the Far Samson in preparation for the sea trails which were design to rigorously test all key aspects of both ploughs' performance. The trials programme included a trenching plan that would test the ploughs' ability to transition in and out of work, demonstrate multi-pass capability, and allow operators to gain an understanding of the general performance of the ploughs in terms of speed, tow force, trench profiles, steering ability and overall control.

The trenching plough was tested up to rated bollard pull and stable trenches up to 2.7m deep were created. Trenching speeds in excess of those expected or required were achieved and many of the new design features were proved to be a major advance on previous pipeline plough systems. For example, water jetting to aid with share closing and a novel system to prevent soil ingress into the skids.

The backfill plough was easy to steer and very stable, even at relatively high offset steering angles and provided effective backfilling of the 2.7m trench.