Clear procedures, simplified safety management systems and better heaving-line usage will reduce risks during tanker escorting and terminal operations
Tug operators should reduce the complexity of onboard safety management systems (SMS) and have clear procedures in place to prevent accidents. This was one of the clear messages that came from the British Tugowners Association (BTA)’s annual safety seminar, held at the UK Chamber of Shipping in London on 8 November. During the seminar, BTA chairman Nick Dorman said safety had improved, but there is no room for complacency as not all stakeholders are following procedures.
“Safety towage practices need to be understood at every level, by pilots, terminal operators, owners, managers, regulators and ship operators,” he said. “There have been examples of seafarers being injured.”
Some of these injuries have occurred during terminal operations and escort duties, with the main explanations being human error and equipment failure or misuse. “There needs to be a balance between safety and commercial requirements, with all stakeholders understanding the challenges,” said Mr Dorman.
He highlighted the need for more practical SMS and clear guidance for tug crews on safe operations. “The way ahead is to have simple SMS, risk assessments and procedures that are not too detailed and are practical,” Mr Dorman explained.
Multratug 32 has a rotating winch and two Voith in-line propellers for dynamic towage
Another way forward it through the adoption of better towage technology, that minimises the risk of a tug capsizing. To this end, Multraship Towage & Salvage has started operating two of Novatug’s revolutionary Carrousel RAVE tugs, that incorporate a safer towage system. Multratug 32 and Multratug 33 came into service in Q1 and Q2 in 2018, enhancing safety and efficiency of ship escort operations. They each have a carrousel towing system that revolves around the wheelhouse, minimising the risk of tugs becoming unstable.
“Capsizing should be impossible when towing with the carrousel system,” said Novatug managing director Julian Oggel. “This allows for the safe execution of manoeuvres that would be a higher risk with traditional tugs.” These tugs have Voith Turbo inline propulsion for manoeuvrability and for dynamic towage to escort oncoming tankers into terminals, instead of static towage.
Multratug 32 and Multratug 33 have an overall length of about 32 m and 77 tonnes of bollard pull. They were designed by Robert Allan and classed by Bureau Veritas. They each have two Voith 32RV5 EC/250 propellers with precise thrust control, quick response and insensitivity to variations in inflow direction. They enable the towline force to be continuously controlled safely from the wheelhouse. Novatug’s vessels are driven by two ABC 12VDZC engines that each deliver 2,650 kW at 1,000 rpm.
Machinefabriek Luyt delivered the carrousel unit, which consists of a base structure surrounded by a ring that can rotate freely 360˚ in the horizontal plane around the tug’s deckhouse. This carries a towing winch that can tilt vertically 45˚ so that the winch can always be aligned with the towing line, providing optimal control.
During the BTA seminar, Shipowners P&I Club loss prevention manager Carri Woodburn said inadequate procedures and guidelines were a contributing factor in multiple tug-related incidents. She gave an example of a tug accident that occurred partially because seafarers had not read the SMS or updated onboard charts. This tug hit a charted obstruction and caused US$1.75M of damage.
“The tug’s SMS had so many checklists that it was not viewed by the crew and charts had not been updated for two years,” Ms Woodburn explained. There had been no risk assessment, no towage plans or operations procedures.
She said the lessons learnt from this accident should be “to ensure the SMS and checklists are viewed by crew and are easy to read and charts are updated.” Other lessons taken from this and other accidents include ensuring that toolbox talks and risk assessments are conducted and that crew receive regular skill assessments and retraining if necessary.
Lessons can also be learnt from maritime accidents involving tankers during tug escort, the latest of which occurred on 8 November near the Sture oil terminal in Norway. Østensjø Rederi-operated tugboat Tenax was escorting tanker Sola TS when the Tsakos Energy Navigation Aframax struck a Norwegian naval frigate.
There are reports that the frigate had its AIS locator beacon turned off, but there are questions as to why the 2017-built, 112,700-dwt tanker nor the escort tug failed to prevent the accident off the island of Øygarden.
At the BTA seminar, UK Maritime Pilots’ Association secretary general Don Cockrill discussed the risks of crew fatigue and the ease with which crew awareness can be degraded. He urged tug owners and pilots to use checklists to reduce risks.
His organisation has worked with BTA and UK Chamber of Shipping to produce Pilots’ Pocket Guide & Checklist to improve towage and ship escort safety. This includes best practices, an information exchange checklist, points on good seamanship, operations during restricted visibility, and guidance on the use of messenger, heaving and towing lines.
“There needs to be a balance between safety and commercial requirements, with all stakeholders understanding the challenges”
The guide also features a section on escort towage of tankers, in which it recommends that when an escort tug is tethered and following a tanker, speed is maintained between 10-12 knots for indirect towing, in case the tanker needs assistance with steering. When the speed of the tanker falls to 4-5 knots, it is more efficient for the escort tug to change to the direct towing mode.
Heaving line dangers
Pilots’ Pocket Guide & Checklist also highlights the increasing use of dangerously weighted heaving lines. Heaving lines are used by the assisted ship to bring the messenger and towing lines on board. They should be made of 8-10 mm diameter rope so they are not too heavy to handle.
A tug takes the heaving line and attaches a 30-m messenger line, which in-turn is connected to the towline. The tug remains on the lees side under the bow of a tanker, ready to receive the heaving line. However, if these heaving lines are too heavy it increases the time that tugs need to remain close to the ship, prolonging the most dangerous part of the assist.
Delegates at the BTA seminar said tug operators and pilots should report ships that are using dangerously weighted heaving lines, as this increases risks and causes serious incidents. Around a third of all serious incidents on tugs, reported to the BTA, are related to dangerously weighted heaving lines.
If bad heaving line practice is reported, this could trigger a port state control inspection, which depending on the port authority, could lead to a deficiency notice or ship detention, or even prosecution of the offending master or shipowner.
At the BTA seminar, the UK Government’s Marine Accident Investigation Branch (MAIB) chief inspector Andrew Moll set challenges for the towage sector to improve safety throughout 2019. This included insisting that tug operators understand the towage project requirements prior to them commencing and for improvements to be made in communications between ship, tug masters and pilots. “There have been problems in master-pilot exchanges and communications,” he said.
Mr Moll said tug masters should have a clear understanding of what might be required if and when projects change and there should be contingency plans in place, especially when escorting tankers. “They should insist that pilots fully explain plans to ship and tug masters,” he said.
Mr Moll also challenged the towage sector to ensure that crewing levels on tugs remain at practical levels for the work they are expected to conduct.
Types of escort towage
Passive escort – tug follows a ship closely but is not connected.
Active escort – tug is connected centre lead aft to assist steering of a ship.
Indirect towage – tug assists a ship around a channel. It uses propulsion to steer the tug away from the general direction of heading to create drag and includes towline force.
Powered indirect – similar to indirect, but the tug actively drives forward and turns away from the direction of heading, generating high towline forces and doubling tug bollard pull.
Transverse arrest – tug is connected centre lead aft, but used to slow and stop ship – can be brought around into direct pull once speeds drop to less than 7 knots.
Source: Pilots’ Pocket Guide and Checklist