Extreme escort tugs: the Costa Azul experience

As a marine operator with decades of experience, Capt Mockabee stressed the significance of these dynamics from a seafarer’s point of view. “I’ve been on board for nearly every job,” he said. “The ability of the Markey winch to maintain steady line tension under active sea state is exceptional. There’s no spike. There’s no slack. It’s seamless.”

Each towage operation is recorded and analysed in detail. Tension monitoring systems log the full load profile of each towing line, and onboard cameras are used to trace any spike back to its source. “If we see an anomaly, we go to our BlueBox data system, cross-reference with footage and telemetry, and determine whether it was crew-related, environmental, or mechanical,” Capt Mockabee noted.

While equipment capability is foundational, the human element remains critical to SMBC’s operating philosophy. “Even the best machinery is only as good as the crew that operates it,” he said. SMBC mandates LNG terminal familiarisation, simulator time, FiFi system training, English language proficiency, and ISM auditing for all personnel. Additional modules include firefighting, first aid, survival techniques, and oil spill response. Importantly, training is not confined to classrooms: instructors accompany crews onboard during operations, and pilots routinely participate in joint simulations with tug masters. “In many ports, pilots and tug captains barely speak. We train together so that everyone understands each other’s capabilities and equipment response times.”

This integrated approach extends to maintenance. Preventive programmes, including the Moran-developed FleetCheck system, are central to SMBC’s strategy. “In 15 years, we’ve never had a winch failure during operations. That is not luck. That is maintenance discipline,” said Capt Mockabee. Redundancy is also engineered into the winch systems, which can be operated using auxiliary 24V power and compressed air in the event of generator failure. Remote access from Markey further enhances diagnostic capability.

The Cortland towing line used at Costa Azul is a 10-inch (25.4 cm) circumference synthetic line with a 470-tonne breaking load and only 2% elasticity. The final 20 metres are fitted with a stretcher to absorb shock loads. “It is a system built for resilience,” he said.

Asked about the decision to adopt ASD tugs rather than ATD tractors, Capt Mockabee said the project team relied on early expert input and simulation outcomes. “We began this process in 2006, and at that time, the advice from Capt Greg Brooks and the results from our simulations clearly supported the ASD approach. That decision has been fully validated in practice.”

Despite the winch’s 57-tonne weight, stability has not been compromised. Each tug is fitted with 40 tonnes of ballast in twin aft tanks to ensure even trim. “The winch is massive, yes — but the tugs respond quickly, smoothly, and maintain trim through all manoeuvres,” he explained. “Our seakeeping analysis confirmed significant improvements in motion behaviour compared to standard hull forms.”

Yet perhaps the most revealing insight came not from a technical specification, but from a real incident. During one particularly foggy manoeuvre, the LNG carrier experienced a blackout mid-berthing. “We had no propulsion on the LNG vessel and relied entirely on four tugs to maintain control,” Capt Mockabee recalled. “It was a textbook operation under non-textbook conditions. That’s what the training is for.”

The philosophy underpinning SMBC’s approach is rooted in day-to-day presence and accountability. “I’m not an office captain,” he said. “I still go aboard. I handle the winch. I talk to our crews, our pilots, and our clients. That’s how we detect issues early and refine performance continuously.”

This operational vigilance is increasingly relevant as North America’s LNG export footprint expands. Terminals from Port Arthur to Canada’s Pacific coast are being developed, many in locations where environmental conditions remain misunderstood or underestimated. The Costa Azul experience offers a counterpoint to the view that standard solutions can be applied.

“There is no one-size-fits-all,” said Capt Mockabee. “You need the right boat, the right winch, and — most importantly — the right people.”