For the Farasan–Madayah Submarine Cable Project, deugro China, acting as the project’s control tower, together with the teams of deugro Saudi Arabia, deugro Chartering, and the engineers from dteq Transport Engineering Solutions (dteq), transported nearly 110 kilometers of 132 kV CTS submarine cables from China to the Port of Jazan, Saudi Arabia.
The subsea cables were collected at the Port of Changshu, China. To ensure their timely delivery to the Port of Jazan, a suitable deck carrier was required to safely accommodate and transport both the cables and the cable carousel, which had a combined weight of more than 5,380 metric tons and dimensions of 25 x 25 x 9.6 meters.
To secure a suitable vessel in time to meet the project’s demanding schedule, deugro China engaged deugro’s Chartering Department and worked closely with the team to identify the most suitable and efficient shipping solution. Despite a challenging market environment and limited vessel availability, the experts successfully identified and chartered a deck carrier offering the required technical capabilities and sufficient deck space.
The next step was the installation of the cable carousel. To ensure its installation on the deck carrier in full compliance with all technical requirements, and to facilitate the safe ocean transportation of the cables as well as efficient spooling operations during cable collection and delivery, deugro engaged dteq Transport Engineering Solutions’ local team in China. Throughout the installation phase, deugro China and a local dteq engineer provided continuous onsite supervision, coordinating all stakeholders, including the vessel owner, installation contractors, engineering specialists, and the cable supplier, to ensure smooth execution and adherence to the project schedule.
During a review of the original overall longitudinal strength calculations, dteq’s engineers identified that the highly concentrated weight of the submarine cable caused the proposed loading condition to fall outside the required acceptance criteria. In close coordination with the barge design institute, and based on technical guidance provided by dteq’s engineers, the allowable still-water bending moment and shear force values were re-evaluated and optimized to reflect the actual loading conditions. Using this revised calculation methodology, the overall longitudinal strength was subsequently verified as compliant with all transport safety requirements.
The concentrated cable load further imposed significant pressure on the local deck structure. By strategically placing small steel shims beneath the cable support areas, the load was effectively transferred to the primary load-bearing members—namely the deck longitudinal girders and transverse beams. This multi-point load dispersion approach ensured that local deck stresses remained within permissible limits.
“The use of steel shims for load distribution resulted in steel-to-steel contact surfaces with a friction coefficient approaching zero, substantially compromising horizontal slip resistance. Accordingly, the sea-fastening lashing calculations were revisited to ensure sufficient quantities and optimized arrangements of lashing materials. This provided adequate safety margins against both sliding and overturning under inertial forces induced by vessel motions,” said Ruth Yan, Transport Engineer at dteq Transport Engineering Solutions, China.
“The carousel’s circular geometry meant that it was originally restrained by A-type stoppers with point-contact interfaces, resulting in significant localized stress concentrations. To address this, auxiliary steel plates were installed at the contact zones to increase the effective bearing area. This modification effectively reduced peak contact stresses and mitigated the risk of local crushing, thereby ensuring the structural integrity of both the stoppers and the carousel,” Yan adds.
Following the successful 15-day carousel installation involving a 30-person-team, the deck carrier was repositioned to the supplier’s loading terminal, where the cables were spooled directly from the quayside onto the carousel in a round-the-clock operation personally supervised and coordinated by the local deugro and dteq teams. After 10 days, the subsea cables were safely stowed and secured for ocean transport, enabling the vessel to depart for Saudi Arabia on schedule.
Upon arrival at the Port of Jazan, the cables were delivered on schedule under the coordination of deugro Saudi Arabia’s experts, ensuring that the project’s cable-laying operations remained on track.
“We are proud to have contributed to the success of this operation by efficiently managing the hot work activities and conducting spooling operation surveys while upholding the highest standards of safety and operational excellence,” said Sethu Madhavan, Team Leader – Operations at deugro Saudi Arabia.
“The safe and timely delivery of this critical subsea cable project is another example of deugro’s ability to deliver complex cable logistics solutions. It further reinforces deugro’s position as a trusted logistics provider for the global cable industry and highlights the value of our integrated project solutions approach,” said Erwin Visser, Manager, Subsea Cable Logistics.
“The Farasan–Madayah Submarine Cable Project is a great example of how local client engagement combined with global expertise can create real value for complex infrastructure developments. From the early tender stage through engineering, vessel chartering, and final delivery to Jizan, our teams worked closely across multiple regions to ensure a seamless execution. We are particularly proud of the strong contribution from our China organization, which acted as the bridge between the client, manufacturing facilities, and global project teams. This achievement reflects our commitment to delivering reliable logistics solutions for the energy transition and supporting Saudi Arabia’s long-term infrastructure ambitions,” said Justin Zhu, Head of Sales and Business Development China, at deugro China.
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