Louis Dreyfus TravOcean has been awarded the contract from Seaway 7 for the provision of Offshore Burial Trials of its new TM05 diverless trencher fitted both with cutting wheel and digging chain onboard one dedicated Trenching Support Vessel (TSV) within the frame of the Hornsea 2 Offshore Wind Farm (HOW02) Array Cable Installation and protection project.
The aim and focus of the offshore trials was to prove and demonstrate that the mobilised cable burial spread TM05 (Diverless Crawler fitted with a cutting wheel and/or digging chain) was functional and tested.
Trenching Trials have been done in August 2020 on the HOW02 site.
The burial trials have been conducted with and without cable in 4 areas of various soil conditions which are representative of site conditions and using the 2 different tools (cutting wheel & trenching chain).
Three (3) areas were foreseen for TM05 trench trials in accordance with anticipated ground conditions, an ALARP corridor was provided by the Client and the location were a sufficient distance away from the planned cable route. One fourth area has been added during offshore operations.
A single inter array cable sample 192m long has been supplied for the trial and has been laid then recovered for trenching trials with cable.
• Trials without cable
Burial trials without cable have been done in four (4) locations.
Both cutting wheel and digging chain have been tested and it was expected that each trial run had to be at least 100m in length.
• Trials with cable
Burial trials with cable have been done using the digging chain only in one (1) location.
The 192m section of inter array cable has been laid from the support vessel using hold-back anchors to maintain sufficient bottom tension along the cable sample.
Trial cable has been recovered on board support vessel after completion of the burial trials with cable.
See also our YouTube channel: video about TM05 diverless trencher. Click here.