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Tug Technology & Business

Tug Technology & Business

Capsize drives improvements in towage best practice

Mon 10 Jul 2017 by Martyn Wingrove

Capsize drives improvements in towage best practice
Asterix mooring launch was assisting small chemical tanker, Donizetti in Southampton when it capsized

When the mooring vessel Asterix capsized in Southampton, UK, it raised awareness of the need for towage best practice guidance

A lack of training and experience were singled out when the UK’s Marine Accident Investigation Branch (MAIB) reported its findings into the girting and capsize of the 13m mooring launch Asterix in May last year.

Fortunately, the two crew on board were not injured, although one was trapped for an hour, but it prompted the UK’s National Workboat Association (NWA) to update its Towage Good Practice Guide and a draft version was published at the end of 2016 for industry feedback. It expects to publish a final version in September this year.

As well as the Asterix harbour accident, it draws on discussions the NWA held with the UK towage industry and feedback from P&I clubs and safety inspectors for the guide. NWA also worked with the MAIB to improve its best practice guide with new annexes, including advice on rope and towing line best practice to prevent tugs capsizing.

One of the safety issues highlighted by the MAIB was that the coxswain’s training “did not equip him for the task, and specifically did not equip him to use the gog rope/bridle effectively”. NWA secretary Mark Ranson, who is a former head of safety at tug group Svitzer, explained to Tug Technology & Business that “misuse, or lack of, gog ropes is one of the main causes of major incidents and will be covered in the towage guide to reduce the risks and raise the standards of towage.”

He outlined some of the guidance on preventing vessels from girting. Using gog ropes “has the effect of moving the towing point further aft towards the propellers while still using a winch near mid-ship. This reduces the risk of the tug being turned sideways on to the tow, being girted and capsizing.”

"A number of incidents have been attributed to lack, misuse or failure of the gog rope and its emergency release"

Rob Cranstone and Nick Hance from the MAIB reiterated the safety concerns and guidance in a presentation to the towage industry in Southampton in June this year. They said: “A number of incidents have been attributed to lack, misuse or failure of the gog rope and its emergency release, leading to or exacerbating girting scenarios.” They recommended: “More rigorous preparation, with contingency plans in case of bad weather or emergency situations, along with a clearer allocation of responsibilities to the coxswain and vessel pilot.”

There will be further development of NWA’s Towage Good Practice Guide after its publication in September to address the industry skills gap and reduce the risk of other causes of major incidents. For example there will be more coverage of towage stability, emergency towline release equipment and communications between tug masters, ship captains and pilots.

This emphasis on communications reflects other concerns highlighted by MAIB among the contributing factors to the Asterix incident. Mr Ranson explained: “The captain and pilot [on the tanker Asterix was working] did not communicate to the tug master their intended manoeuvre in advance to allow him to better position his tug.”

It is important that the towage team communicate before and during the manoeuvring operations. “Ships have their own power, captain and pilot to assist, so it is essential that they have some understanding how the tug master will be assisting the vessel,” Mr Ranson explained.

There need to be ship assistance plans and prior knowledge of what the pilot intends to do with the ship being manoeuvred “so captains do not use the ship’s engines and catch the tug master unaware. The tug may not be capable of reacting in time, so maintaining communications is essential before and during the job,” Mr Ranson explained.

There will also be an annex on emergency release equipment design and testing, since the published standards do not take into consideration varying weight, fatigue and training requirements, said Mr Ranson.

“Some classification societies have standards of towage hooks and testing, but this [testing] needs to be done with full weight as it may require considerable force on the hook to trigger a release. There are cases where the operator could not physically operate the emergency release because there was too much weight on the hook,” he explained.

"There are cases where the operator could not physically operate the emergency release because there was too much weight on the hook"

The NWA is working with the UK’s Maritime and Coastguard Agency on writing an annex to its towage guide to include explanations of how tug crews should test emergency release devices. It will also cover methods of triggering emergency release, whether this is physically on deck or from a remote control in the wheelhouse

It is hoped that the publication of NWA’s Towage Good Practice Guide will improve the safety of towage not only in the UK but also worldwide. It is thought to be the first to provide practical advice on the use of gog ropes and emergency release systems and will subsequently be revised next year on the basis of operational feedback.


Asterix accident and investigation

Solent Towing’s mooring launch Asterix capsized on 30 March 2015 while assisting the manoeuvring of the small chemical tanker, Donizetti, owned by Bera Beteiligungsgesellschaft, at the Fawley oil refinery in Southampton.

The two crew from the launch were rescued and the vessel was declared a constructive total loss after its recovery. In a report into the incident, the Marine Accident Investigation Branch (MAIB) highlighted that the coxswain was not trained in the use of gog rope and bridle equipment and the launch crew were not sufficiently experienced in the use of the emergency release mechanism and could not activate it effectively.

MAIB’s report included recommendations for Solent Towing’s parent company, Østensjø Rederi.

• Read MAIB’s report into the accident via

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