The first of two rock installation vessels for Jan De Nul, built at AVIC Weihai, was delivered on 29 June 2017. To this vessel, Ulstein Power & Control has delivered the power package, automation system, DP system, thruster control and commissioning. Ulstein Electrical Technology has performed the pre-commissioning.

First rock installation vessel from AVIC
Caption: Jan De Nul Group's rock installation vessel, 'Adhemar De Saint Venant' - Photo: AVIC Weihai

The multipurpose vessel, Adhémar de Saint-Venant, is a DP2 Trenching and Offshore Support Vessel and Subsea Rock Installation Vessel. In the Subsea Rock Installation mode, the vessel can install about 5,100 tonnes of rock in a single load by means of the excavator, conveyor belt and the fall pipe for accurate rock installation at up to 600 m water depth, according to Jan de Nul Group. Alternatively, the rock can be handled through an inclined fall pipe, for secure installation against offshore structures such as jacket platforms, gravity bases or monopile foundations.

The Power package consists of generators, switchboards, motor control centre, thruster frequency converters and motors. The control system is branded ULSTEIN IAS and has been developed by Ulstein.

Ulstein Power & Control has solid expertise in the offshore segment, and with this contract the company entered into a new segment.

Caption: Adhemar De Saint Venant is a multipurpose vessel for trenching and offshore support as well as for subsea rock installation

System integration

During the assembly of the package, focus has been on achieving the best possible system integration between different products and systems.

“The solutions and products in a system delivery must be safe, green and cost-effective,” comments managing director Gunnar H. Hide in Ulstein Power & Control.

“With the joint effort from our Headquarter in Norway and our office in China, we managed to win the contract based on price, delivery time, functionality and system quality."

Caption: Switchboards on board the AVIC Weihai-built vessel

Ulstein Electrical Technology Co. Ltd (UET), performed the pre-commissioning. The scope of work included the supply of necessary cable glands and cable penetrations, a check of all cables, marking of the cables inside the cabinets, and the necessary ground connection according to cable plan, rules and regulations. Additionally, the connection of wires on Ulstein equipment as well as equipment from other providers, organisation of cables inside I/O cabinets and other control cabinets, the check and confirmation of systems ready for commissioning, and preparing pre-commissioning and commissioning plans.

The company has been firmly positioned in Ningbo, China, for several years. "Our teams of trained electrical personnel carry out pre-commissioning at several yards in China, the latest projects have been for PSV vessels at yards such as Wuchang, SWS and ROC,” says deputy managing director Stig Hjelvik.

Jan De Nul Group, headquartered in Luxembourg, is an expert in dredging and marine construction activities, and in specialised services for the offshore industry of oil, gas and renewable energy.

Caption: The Ulstein Electrical Technology team in front of Adhemar De Saint-Venant

AVIC Weihai Shipyard Co. Ltd. is based in the Shandong province of China. The yard, established in 1951, started the production of vessels for the international market in 1998. AVIC International has been main shareholder since 2011.

Ulstein Group is a group of maritime companies, specialising in ship design and maritime solutions, shipbuilding, power and control and shipping.

Source: Ulstein