Surveying at speed
MMT Sweden AB and Reach Subsea ASA have jointly invested in developing a new special underwater tool for seabed mapping and pipeline inspection with the Norwegian ROV manufacturer Kystdesign AS.
This new remotely operated vehicle (ROV), called Surveyor Interceptor, has, according to its builders, the innovative shape, powerful propulsion and advanced instrumentation to perform work 4-8 times faster than existing Work Class ROVs. The umbilical and handling system yields up to 6 times better endurance than Autonomus Underwater Vehicles (AUV), they claim.
“I am very pleased with the team and the effort resulting in this fantastic machine. Looking forward to present this extreme surveyor to the market” said Jostein Alendal CEO Reach Subsea ASA.
Great emphasis is put to high resolution and accuracy. To achieve this the ROV is equipped with an onboard inverted USBL from Sonardyne doubled by normal Kongsberg Hipap transponders. This will increase accuracy and ensure redundancy. Also the positioning is supported by 2 INS systems and a DVL. The test of station holding, line running and tracking are said to have given outstanding results.
The ROV propulsion has allowed MMT to reach speeds well over 6 knots with auxiliary power intact. The driveline will be adjusted after finishing the trials to ensure stability and power management up to 8 knots. MMT believe this is a world record for a ROV.
The Multibeam system delivers 40 Hz ping up to 20 m above seafloor. This together with the 800 beams ensures dense point coverage, even at high speed. To improve top of pipe accuracy and ovality measurements a 25 Hz triangulating laser system from Cathx Ocean covers the central 5 m of the survey corridor delivering mm accuracy measurements.
By Jake Frith
Specification:
Dimensions 5 m long, 2.3 m wide and 1.3 m high.
Payload 700 kg
Weight in air 4700 kg
Propulsion Hydraulic 225 Hp
Bollard Pull ~2 tons
Umbilical Armoured 25 mm
