ASV Global has announced that one of its C-Worker 7 class of autonomous surface vessels was successfully deployed for Subsea 7, which is a subsea engineering, construction and services company. The C-Worker 7 was used to support a pipelay operation off the coast of Egypt.

The C-Worker 7, which was equipped with a survey suite made up of a multibeam echosounder and side scan sonar, conducted touchdown monitoring in support of the Seven Antares pipelay vessel.

“The C-Worker 7 has proven to be a very capable vessel providing an excellent stable survey platform controlled by the Pipelay Vessel,” says a spokesperson from Subsea 7.

Richard Daltry, Technical Director at ASV Global, adds, “we are delighted to be supporting Subsea 7 in their quest to increase operational efficiency through the use of autonomous surface vessel technology. This operation marks a huge step in realizing the potential of this technology and goes a long way to prove its operational readiness, particularly in a demanding offshore environment.”

Operating for a total of 37 days, the C-Worker 7 replaced the need for another survey vessel, which ultimately lowered costs.

Thanks to its “superior endurance and improved availability compared to an equivalent manned vessel,” the C-Worker 7 also provided greater operational flexibility.  

Using the C-Worker 7 also resolved the technical challenge of surveying in very shallow waters, while also removing the risk to personnel working at sea in small craft.

The specified survey suite was housed in a custom payload frame. The modular frame slotted into the C-Worker 7’s moonpool to mount and deploy the sensors. Comprehensive testing confirmed that repeated sensor deployment was achieved “within millimeter accuracy,” which ensured that no further survey sensor calibrations were required.

Before the vessel was mobilized from ASV’s UK facility, vessel trials and testing took place in the Solent, UK.

The C-Worker 7 was controlled and monitored during the operation using the ASView control system from a control station set up onboard the Seven Antares pipelay vessel. The C-Worker 7 was piloted by Subsea 7 Survey personnel, who also operated the survey sensors to ensure data accuracy and quality.