Marine System Solutions

ZTT provides comprehensive marine system solutions tailored for power transmission, communication networks, offshore oil & gas platforms, and offshore wind energy. With industry-leading technologies, robust engineering capabilities, and a strong track record in global deployments, we connect continents, energize industries, and enable a more sustainable and connected world beneath the waves.

Industry Overview

Power Transmission Solutions

Subsea power transmission enables long-distance electricity exchange via sub-sea interconnectors for cross-border, inter-continental and inter-island grid links. It facilitates cross-region power trading, balances supply-demand gaps and strengthens energy security for geographically separated power networks. Growing pursuit of grid resilience and energy-resource optimisation continues to drive investment in high-capacity undersea interconnection infrastructure.

Industry Challenges

Harsh Marine Environments

Resisting extreme water pressure and chemical corrosion over a 30-year lifespan.

Installation Complexity

Precision laying in varied seabed terrains to avoid mechanical damage.

Transmission Loss

Minimizing energy dissipation during long-distance underwater delivery.

Our Solution

ZTT provides complete subsea power transmission solutions for cross‑border, inter‑continental and inter‑island grid links. We offer a comprehensive portfolio including AC 10kV–500kV and DC ±160kV–±525kV submarine cables, integrated with factory‑molded joints for superior insulation. Our full‑fledged EPIC competence and offshore installation capacity enable turnkey execution of undersea interconnector projects under diverse marine conditions.

MV AC Submarine Cables

Optimized for short- to medium-distance power transmission, ideal for offshore wind inter-array systems, island connections, and nearshore power supply, offering flexibility, reliability, and cost efficiency.

HV AC Submarine Cables

Engineered for high-capacity, medium-distance transmission, supporting offshore wind export cables and cross-sea interconnections with strong performance and long-term reliability.

HV DC Submarine Cables

Designed for long-distance, large-capacity power transmission, enabling low-loss energy delivery and stable integration of large-scale renewable energy and cross-border interconnectors.

Marine Engineering

Deepsea Self-propelled Cable Laying Vessel

Value Contained

High Reliability

Rigorous testing protocols ensure zero-failure performance under extreme underwater conditions.

Energy Efficiency

Low-loss conductor designs maximize power delivery efficiency.

Turnkey Service

From design and manufacturing to specialized vessel installation and maintenance.

Successful Cases

Vietnam - Con Dao Island Project

End User: EVN

Contract Period: Dec. 2024 – Jun. 2025

Cable Type: 110 kV, 3*630mm2

Length: 80.427 km

Philippines - NGCP EPCI Project

End User: NGCP

Contract Period: Dec.2020 – Oct.2022

Cable Type: 230 kV, 1*1600mm2

Length: 57.62 km

Croatia - MV Submarine Cable Project

End User: HEP

Contract Period: Jun. 2024 – Dec. 2024

Cable Type: 36 kV, 3*120mm2

Length: 65.78 km

Denmark - HVAC Submarine Cable Projects

End User: Energinet

Contract Period: Aug. 2023 – Nov. 2025

Cable Type: 145 & 170 kV

Length: 80 km

Denmark – Purchase of 150 kV AC Submarine Cable-HAT-RYT

End User: Energinet Eltransmission A/S

Contract Period: Oct. 2023 – Jun. 2025

Cable Type: HVAC 91/167(170) kV, 3*1800mm²

Cable Length: 5.5 km

Saudi Arabia – Shushah Island Subsea Cable EPCI Proejct

End User: NEOM

Contract Period: Jan. 2024 – Ongoing

Cable Type: 33 kV, 3*400mm², 2*96G652

Transmission Capacity: 25.5 MW

Total Cable Length: 58 km

Australia – SA Power Networks / Fugro Kangaroo Island 33 kV Submarine Composite Cable Project

End User: SA Power Networks

Contract Period: Jul. 2017 – Aug. 2018

Cable Type: 33 kV, 3*150mm²

Transmission Capacity: 15 MW

Total Cable Length: 16.1 km

Denmark - HVAC Submarine Cable Projects

End User: Energinet

Contract Period: Aug. 2023 – Nov. 2025

Cable Type: 145 & 170 kV

Length: 80 km

Successful Cases

Vietnam - Con Dao Island Project

End User: EVN

Contract Period: Dec. 2024 – Jun. 2025

Cable Type: 110 kV, 3*630mm2

Length: 80.427 km

Philippines - NGCP EPCI Project

End User: NGCP

Contract Period: Dec.2020 – Oct.2022

Cable Type: 230 kV, 1*1600mm2

Length: 57.62 km

Croatia - MV Submarine Cable Project

End User: HEP

Contract Period: Jun. 2024 – Dec. 2024

Cable Type: 36 kV, 3*120mm2

Length: 65.78 km

Denmark – Purchase of 150 kV AC Submarine Cable-HAT-RYT

End User: Energinet Eltransmission A/S
Contract Period: Oct. 2023 - Jun. 2025
Cable Type: HVAC 91/167(170) kV, 3*1800mm² 
Cable Length: 5.5 km

Saudi Arabia – Shushah Island Subsea Cable EPCI Proejct

End User: Energinet Eltransmission A/S

Contract Period: Oct. 2023 – Jun. 2025

Cable Type: HVAC 91/167(170) kV, 3*1800mm²

Cable Length: 5.5 km

Saudi Arabia – Neom Sindalah Project KSA for Supply of 33 kV Submarine Cable

End User: NEOM

Contract Period: Jan. 2024 – Ongoing

Cable Type: 33 kV, 3*400mm², 2*96G652

Transmission Capacity: 25.5 MW

Total Cable Length: 58 km

Australia – SA Power Networks / Fugro Kangaroo Island 33 kV Submarine Composite Cable Project

End User: SA Power Networks

Contract Period: Jul. 2017 – Aug. 2018

Cable Type: 33 kV, 3*150mm²

Transmission Capacity: 15 MW

Total Cable Length: 16.1 km

Denmark - HVAC Submarine Cable Projects

End User: Energinet

Contract Period: Aug. 2023 – Nov. 2025

Cable Type: 145 & 170 kV

Length: 80 km

Marine System Solutions

Industry Overview

Power Transmission Solutions

Industry Challenges

Lan Hai Ling Hang

Offshore Engineering Accessory

Offshore Engineering Accessory

AC Submarine Power Cables

DC Submarine Power Cables

Our Solution

MV AC Submarine Cables

HV AC Submarine Cables

HV DC Submarine Cables

Marine Engineering

Value Contained

High Reliability

Energy Efficiency

Turnkey Service

Successful Cases

Vietnam - Con Dao Island Project

Philippines - NGCP EPCI Project

Croatia - MV Submarine Cable Project

Denmark - HVAC Submarine Cable Projects

Denmark – Purchase of 150 kV AC Submarine Cable-HAT-RYT

Saudi Arabia – Shushah Island Subsea Cable EPCI Proejct

Australia – SA Power Networks / Fugro Kangaroo Island 33 kV Submarine Composite Cable Project

Denmark - HVAC Submarine Cable Projects

Successful Cases

Vietnam - Con Dao Island Project

Philippines - NGCP EPCI Project

Croatia - MV Submarine Cable Project

Denmark – Purchase of 150 kV AC Submarine Cable-HAT-RYT

Saudi Arabia – Shushah Island Subsea Cable EPCI Proejct

Saudi Arabia – Neom Sindalah Project KSA for Supply of 33 kV Submarine Cable

Australia – SA Power Networks / Fugro Kangaroo Island 33 kV Submarine Composite Cable Project

Denmark - HVAC Submarine Cable Projects