Fatigue: Causes, Consequences, and Informed Solutions

What do we need from the IMO?

What have we learned about the root causes of fatigue?

Captain Ann Pletschke CMMar FNI, who manages the STEER Project, said that in 14 years at sea, she has rarely seen a ship correctly record hours of work and rest. She shared several reports from seafarers, with multiple saying that rest hour records are often not completed by seafarers themselves or are altered by senior officers after they are submitted. 

Common work schedules and practices also contribute to fatigue. Pletschke mentioned the 6-on/6-off system, which she said necessitates non-compliance with standards for adequate work and rest. Captain Chris O’Flaherty AFNI, who represents the Nautical Institute at the IMO, confirmed this finding. Evidence presented to the IMO to prove the success of 6-on/6-off schedules actually proved their non-compliance with rest requirements, he said. 

In this evidence, not one ship recorded a single instance of insufficient rest hours, and almost none recorded a watch handover. This means that either handovers were not being conducted or were not recorded, O’Flaherty said. Essentially, records leave handovers as taking place during hours of rest, creating non-recorded work hours that cut into an already intense schedule. Fatigue causes between 20-30% of all maritime casualties, according to evidence submitted to the IMO. 

The UK P&I Club’s Head of Ship Inspections, Petar Modev, listed other common factors in fatigue. These included 6-on/6-off; consecutive port calls; unfamiliarity with new schedules, crew, and equipment; sleep disruptions from alarms and handovers; and shore-generated workload, such as audits and urgent business-related requests. 

The STEER Project findings also showed that technology increasingly contributes to fatigue, with crew members reporting screen fatigue and pressure to constantly respond to emails at all hours. Another seafarer commented on the difficulty of resisting social media use during rest hours. 

What did Horizon and MARTHA find about the consequences of fatigue?

Dr Claire Pekcan, a maritime applied psychologist who worked on the MARTHA study, discussed the two studies and how they can inform successful solutions to the fatigue issue. 

Pekcan said the 2012 Horizon project showed that “compliant ships could still place dangerously fatigued seafarers on safety-critical tasks.” The study detected microsleeps (ongoing drowsiness during work) in 40-45% of watch groups. It showed that the 6-on/6-off pattern was more tiring, as split sleep led to slower reaction times, especially at the end of the night watch. 

Pekcan described Horizon’s results as the best case rather than the worst, given that it was conducted through simulations. The 2017 MARTHA study looked at fatigue at sea, finding that after six months, seafarers suffered from high levels of sleepiness and reduced motivation. 

Peckan said that hours of rest alone are an insufficient metric for fatigue: "Rest is a time allocation; sleep is a biological outcome," she said. Fatigue is caused by a lack of both, as well as workload type and disruptions to circadian rhythm (port work and night watches contributed the most to fatigue).

What should the IMO do?

Pekcan said the IMO should treat fatigue as a “dynamic, risk-based control system” rather than a recording of rest hours. She suggested requiring a fatigue risk management system (FRMS) within the ISM Code, backing it with science-based scheduling and enforceable stop-work authority that would empower Masters to hold off on departure until the required amount of crew is available. Such a system should reduce the record-keeping burden, not add to it, she said. 

O’Flaherty discussed current IMO efforts to address fatigue, sharing updates from the IMO’s Correspondence Group. Possible outcomes include new MSC guidance on recording hours of work and rest, with attention to the impossibility of maintaining 6-on/6-off once handovers are included.

The Nautical Institute remains committed to understanding the causes of fatigue, advocating for solutions at the IMO and other fora, and informing our members of developments. 

Author: Claire Conner