Taiwan's navy takes its new ARD-7 floating repair dock to sea for the first time

Taiwan's navy has taken its new floating repair dock, ARD-7, out to sea for the first time, a step towards replacing the dock that sank inside Zuoying naval harbour in May 2025. The first sea trial took place on 3 November, with four tugboats from builder CSBC Corporation, Taiwan, towing the dock out of Kaohsiung, United Daily News reported. Under the contract the dock is due to be handed to the navy by 30 November.

A tug named CSBC No. 11 served as the lead towing vessel, with one tug on each side of the dock and another at the stern to keep the test safe. United Daily News noted that the escort was far smaller than the large flotilla of support boats that followed the submarine Hai Kun during its own sea trials.

What is being tested

The trial focused on the systems that let the dock sink and rise: ballasting and deballasting, submerging, valve control and power management. According to United Daily News, the dock uses locally developed automatic ballast, valve control and power management systems that can be monitored remotely, which is meant to make operations safer and more efficient. CSBC described the same features when the dock was launched, saying operators can watch equipment from an integrated monitoring system.

ARD-7 is 126 metres long with a maximum moulded beam of 36 metres. It can submerge to a draught of 12 metres and can lift warships of up to 3,800 tonnes for repairs. CSBC said at the launch that the dock can handle vessels below that weight without special restrictions. The contract is worth about NT$860 million, according to the shipbuilder and Taiwan News.

A replacement for a sunken dock

The navy needs the new dock because its predecessor, ARD-6, is gone. On 29 May 2025, compartments on the roughly 70-year-old dock began taking on water for reasons that were not clear while it was carrying out a ballast test inside Zuoying naval harbour in Kaohsiung. The navy's maintenance command said at the time that crews tried emergency pumping, but the flooding could not be controlled and the dock settled on the harbour bottom. Nobody on board was hurt.

The navy later decided the old dock was not worth salvaging. It plans to finish dismantling ARD-6 where it lies by the end of this year, and ARD-7 will take over its role once it is delivered, restoring the navy's floating dock repair capacity, United Daily News reported.

From contract to sea

CSBC signed the construction contract on 18 August 2023, started work on 4 May 2024 and laid the keel on 9 January 2025, the shipbuilder said at the launch. The dock met the conditions for launching on 3 February 2026 and was floated out at CSBC's Kaohsiung yard on 10 April in a ceremony led by company chairman Chen Cheng-hung and navy commander Admiral Chiang Cheng-kuo. Since then it has gone through mooring and harbour tests and yard trials before this first trip to sea.

Why it matters

Floating docks rarely draw attention, but they decide how quickly damaged or worn ships can be lifted out of the water and returned to service. Losing ARD-6 left the navy with less of that capacity at Zuoying, and CSBC has called the new dock an important part of the navy's overall logistics. Whether ARD-7 is handed over on schedule at the end of November will show how soon that gap closes.