Asso.subsea, a subsidiary of Greece-headquartered Asso Group, has unveiled a new trench- jetting ROV, boasting 1.56MW of jetting power and specially designed to operate with cohesionless soil.
The AssoJet III Mk2 measures 7.1m x 5.2m, has a height of 3.9m and can descend to 1,500m. The ROV can create trenches up to 3.2m-deep from seabed level, with a maximum soil shear strength of between 120150kPa. With the capability to operate in Sea State 6 conditions, Asso.subsea suggests that the ROV could take on additional subsea roles, such as surveys and repair support.
The 35tonne ROV makes use of six electric motors, rated 260kW per unit. Two of the motors drive a pair of high-pressure water pumps, each rated 700m3/hour at 20bar; two drive twin low-pressure water pumps, each rated 2,400m3/hour at 6bar; and two drive the hydraulic pumps for the thrusters and the auxiliary hydraulic circuits.
The vehicle utilises six 480mm horizontal thrusters and four 480mm vertical thrusters to manoeuvre. Its typical payload will include up to eight low-light cameras, up to 12 LED high-intensity lights and up to four imaging/profiling sonars. Other options include a bathymetric sensor, a cable tracker and/or a cable cutter. “[The vehicle] can deploy an independent eductor system for cleaning operations in addition to backfilling swords,” Asso.subsea says. “Moreover, it can operate with skids or tracks, allowing for low ground pressure and high manoeuvrability.
