Asso.subsea orders ‘world’s most powerful’ trenching support vessel from China

September 23, 2025, by Nadja Skopljak

Greece’s Asso.subsea has signed a shipbuilding contract with China Merchants Heavy Industry (CMHI) for the construction of its next-generation trenching support vessel (TSV), described as the world’s most powerful TSV ever built.

The shipbuilding contract was signed at Asso.subsea’s headquarters in Elefsina, Greece, and will see the TSV Avra built at CMHI’s Shenzhen Shipyard, with delivery estimated at the end of 2027.

The vessel will have 24 MW hybrid power and over 180 tons bollard pull, a 4,000-ton under-deck cable carousel capability and twin working decks and will be able to support a wide range of projects including dynamic cable spreads, floating wind installations, inter-array and export cable operations.

It will be methanol and biofuel-ready, equipped with a large battery hybrid system and cold-ironing capability, and will feature a 150-ton offshore/subsea crane and dual heavy-duty A-frames.

According to Asso.subsea, Avra will be able to operate with heavy trenching, ploughing and boulder clearance tools simultaneously and is positioned as a multi-role powerhouse, supporting the entire lifecycle of subsea energy projects.

“The contract signing for the construction of the Avra is a strategic milestone for our company,” said Ioannis Togias, Executive Director of Marine Technology at Asso.subsea. “This partnership with CMHI marks the beginning of building the most powerful vessel of her kind. The Avra is designed to provide our clients with an unassailable advantage in efficiency and project execution. This investment underscores our commitment to driving the offshore industry forward.”

This is the Greek company’s second new vessel announcement this year, following the shipbuilding contract for the construction of the DP-2 cable-laying vessel (CLV) Althea in January, also set to be built at CMHI.