Operated by Helix Energy Solution Group Inc.’s subsea UK robotics subsidiary Canyon Offshore Limited, the T1200 burial and trenching unit is building a successful track record in the North Sea after launching into service in 2012.
Delivered by Forum Energy Technologies’ Perry Slingsby Systems ROV manufacturer, the 1200hp water-jet trencher is well suited for both windfarm power cable and large diameter pipeline burial in water depths up to 3,000m (10,000ft) anywhere in the world. The ROV’s hydrodynamically shape provides improved stability in high currents and features lateral and vertical thrusters that allow it to fly directly to the site.
Once at the starting location, the hydraulically driven system uses high pressure jet swords to cut into the seabed and then low pressure jet swords discharge the soil to allow the cable or pipeline to sink into place under the liquidized soil. The T1200 conducts the entire operation without actually touching the burial product.
Pipe tracking equipment detects the presence of the cables or pipeline and automatically guides the T1200’s steering mechanisms over the product. For each deployment the 30t (1.5t in water) T1200 is specially configured based on the soil conditions in the project field. The T1200’s caterpillar tracks can also be replaced with skids when trenching in soft mud.
The trencher’s high pressure jets are capable of cutting through soils and hard clays with up to strength of 150kPa. With its tracks on the T1200 has the ability to trench at speeds of 350-1000m per hour and when not trenching it can move at nearly 2,500m per hour.
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Press release, March 14, 2013; Image: Helix