5th September 2022

Open hatches lead to tug sinking

Initial Report

A towing vessel was in transit when its stern compartments began to flood. The three crew members aboard attempted to pump out the water but were unsuccessful and subsequently abandoned the vessel. They were rescued, and the towing vessel later sank close inshore. No injuries were reported. The ship was later recovered but was considered a constructive total loss. Pollution in the form of an oil sheen was sighted when the tug sank.

The investigation determined that the probable cause of the sinking of the towing vessel was unsecured or open aft deck hatches, which resulted in the flooding of the vessel’s aft compartments from water on deck, leading to progressive flooding of other compartments through openings in watertight bulkheads. Contributing to the flooding of the vessel was the owner’s lack of a practical hull inspection and maintenance program.​

The investigating authority noted that in the last five years, it had investigated five casualties involving towing vessels whose weather decks and openings were in poor condition—leading to flooding and subsequent sinking.

To protect vessels and the environment, it is good marine practice for owners to conduct regular oversight, inspection, and maintenance of hulls, including between drydock periods, regardless of inspection requirements.

Effective maintenance and hull inspection programs should proactively address potential steel wastage, identify hull and watertight integrity deficiencies, and ensure that corrosion issues are repaired promptly.​

CHIRP Comment

There have been a number of incidents of tugs foundering, and in several cases the common cause was the leaving open of weatherdeck doors . Although this may make it easier to access internal compartments it compromises the tug’s watertight integrity and is an incorrect and unsafe local practice. Watertight doors must be closed during towing operations, especially during heavy weather.

This report again reinforces the need to understand the stability characteristics of the tug doing the towing.

Key Issues relating to this report

Local Practices- Tug owners and operators must ensure weather deck doors are closed when towing. Training is crucial and should be from a recognised authority to ensure consistency. Even if the good practice has been passed down in your company, refresher courses should be part of the company’s safety culture to ensure that best practice is followed.


Capability- Tug companies should assess their staff for their skills and emergency preparedness as part of their employment criteria. The ISM code demands that all identified risks are assessed – when was the last time you reviewed your risk assessment (RA) for towing operations?


Culture- What is the training culture in your company? Is knowledge passed on informally between employees or is it provided through recognised training courses given by expert training providers?

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