Tim Skelton learns more about SuBastian, the latest ROV being developed by the Schmidt Ocean Institute
ROVs come in all shapes and sizes. Hundreds of companies supply thousands of vehicle variants to users across the world, outfitted with all sorts of standard and bespoke equipment depending on the mission at hand. Yet when you have the technical capability and drive for innovation of the Schmidt Ocean Institute, nothing beats doing it yourself.
Schmidt’s 272-foot (83-metre) ocean-going research vessel Falkor has successfully operated a Saab Seaeye Falcon ROV equipped with high-definition cameras for some time. Yet this “off-the-shelf” model is only suitable for use in relatively shallow water depths of up to 300 metres. Based on its experience with the Falcon, the Palo Alto, California-based Institute has now gone on to create its own ROV – the first submersible vehicle it has designed and built completely from scratch. Moreover, it also raises the Falcon’s operational depth range by an entire order of magnitude.
The deep-rated ROV “SuBastian” was built by the Institute’s engineering team with the express intention of making it able to withstand high pressures and to remain fully functional down to depths of up to 4,500 metres. Such a range would make it easily capable of reaching the seabed at the world’s deepest offshore oil and gas development, currently Shell’s 50,000 bpd Stones project in the Gulf of Mexico, which lies in 2,900 metres of water.
Ready for the seafloor
SuBastian is intended to be used for high-resolution seafloor mapping, the production of large-area photographic mosaics, video and image gathering, and for the collection of samples of subsea rocks and other materials. The ROV’s state-of-the-art equipment includes a reconfigurable payload skid for sample collection, a 4K camera capable of streaming real-time video to the surface, as well as a range of scientific sensors for data collection. Additional power and data interfaces also add flexibility by enabling a range of other deep-sea instruments to be added as and when needed.
The vehicle is connected to the ship via an umbilical cable tether that provides it with power from the surface and transfers data collected in the opposite direction. This tether gives the ROV the freedom potentially to remain submerged for several days, whilst still transmitting pictures and other data to a surface-based control room.
SuBastian is controlled, positioned and navigated using an integrated system which can track and guide equipment and provide accurate, fast-update data down to depths in excess of 5,000 metres. The system was supplied by and developed in co-operation with the Houston-based marine engineers Sonardyne, and incorporates Sonardyne’s SPRINT Subsea Inertial Navigation System (INS).
Other key parts of the system include a 600 kHz Doppler Velocity Log, and a Wideband Mini Transponder – a high-power sixth-generation (6G) ultra-short baseline (USBL) acoustic positioning transponder. Schmidt says all these new systems are fully compatible with Falkor’s existing ship-based hardware.
One unique feature of SPRINT is that it is able to operate simultaneously in dual INS and gyrocompass modes. This effectively means that both the pilots controlling the vehicle and the science teams collecting information from it can make use of SuBastian’s data output at the same time. The system’s compact and lightweight titanium housing also saves on both space and weight.
Tests and trials
Having undergone and completed its Factory Acceptance Tests in April this year, SuBastian underwent its Sea Acceptance Tests in August with a series of dives at the Santa Rosa Reef, off the coast of Guam in the western Pacific. The aim on the latter occasion was primarily to test and demonstrate the functionality of the ROV’s manipulator arm. Like its shallow-water predecessor Falcon, SuBastian was also deployed from the deck of the Falkor. The 25-day trials involved a rigorous workout in open-ocean conditions that comprised a total of 22 dives and more than 100 hours under water.
Now that the vehicle’s reliability tests have been completed successfully, the team is confident that SuBastian is nearly ready for full operations. “We plan to hold a week-long science verification cruise in November. The first scientific expedition will then take place in late November and December,” Schmidt’s Carlie Wiener told InnovOil. Until then, the team remains busy working on making small adjustments and improvements so that SuBastian will be ready for its first full-scale mission at the end of the year.
The objective of November’s verification cruise will be to perform tests in real-world conditions to demonstrate and confirm SuBastian’s capability as a deep-sea vehicle. While it remains out at sea, a rigorous new series of tests and exercises will ensure it can meet the demands expected of it by any future potential users. All the vehicle’s basic functions will come under scrutiny, including the smooth running of all winching operations, acoustic mapping facilities, lighting and video functionality at the seabed, and sampling collection capability.
All high-resolution video footage collected during the tests will be made openly available to any interested parties.
Schmidt says that once the SuBastian ROV has been fully developed, its next planned step will be to design and produce an even more advanced Hybrid Remotely Operated Vehicle (HROV). This will be developed sequentially and will build on the work already carried out in creating the SuBastian ROV. In so doing it will be able to work at gradually increasing water depths and with enhanced capabilities that will support its operation in all ocean conditions.
As Schmidt is a private non-profit operating foundation, Wiener admits that the company has no current plans to work directly with the oil and gas sector. Nevertheless, the lessons the institute learns and the experience it gains from testing and developing ROV technology could prove invaluable to those who do work in the field. The potential applications that could benefit include remote-sensing and seafloor mapping for exploration purposes.
Moreover, similar vehicles could be used for maintenance operations and monitoring work on subsea installations, even helping to protect the marine environment by minimising the risk of oil spills.