Van Oord Offshore placed the order in mid-September 2006 with sub-sea specialist Seatools of Numansdorp for the development, assembly and testing of the ROV5, including an air-conditioned container with control system. The ‘5’ refers to the fact that it is the fifth stone-dump ROV in use by Van Oord worldwide.
The ROV5 is an underwater robot developed and built according to Van Oord’s specifications. Remotely controlled, the ROV5 is designed to operate to a depth of 250 msw. At maximum depth, it can continue the stone-dumping cycle to cover the fall pipes, level the seabed and place protective structures, with extreme precision. The advanced device particularly stands out for its simplicity of design. “One requirement of the customer was to make the ROV as compact as possible and easily manageable. The result produced by our mechanical, electrical and software engineering team was a maintenance-friendly ROV only two metres high, 1.66 metres wide and 2.55 metres long. This makes it the smallest ROV ever supplied to Van Oord,” according to Jos Hagen, project manager at Seatools.
The remotely controlled ROV5 consists of a 2.30-metre length of removable tube in the centre, with a diameter of 766 mm. The positioning of the device is done by means of four thrusters, equipped with hydraulic motors, which are driven by a 75kW power pack with hydraulic pumps. In addition to the special control system developed by Seatools, the ROV5 is also fitted with an E-pod, protecting the electronic equipment against ingress of seawater. The control panel is placed on the bridge of one of Van Oord’s flexible fall-pipe vessels. From there, the ROV5 can be operated and the data received interpreted. Including the pipe, the ROV5 weights a mere 3150 kilograms.
Project manager Igor Jeuken of Van Oord enjoyed working with Seatools. “Seatools did a good job of anticipating our preliminary design. Their feedback showed that engineering-wise we were on the same wavelength. Being able to engineer, assemble and run extensive factory tests on an ROV within a four-month period is a remarkable achievement.”
On 19 January last, the ROV5 and control container were delivered ex works, ready for transport to Singapore. There, the sea trials were carried out successfully in mid-March. During the tests, the ROV’s underwater performance was tested under various conditions, along with the response speed to the ROV’s controls.
Van Oord plans to employ the ROV5 for the first time in the second quarter of this year on the flexible fall-pipe vessel, Jan Steen, for a stone-dumping project off the coast of Indonesia.