Worker Fatigue


As the rest of the world prepares for BBQ’s and hitting the beach, the silviculture industry is just hitting its stride.  Many companies have avoided snow or weather delays and had a good start to the season, allowing for full days of uninterrupted work and contracts finishing on time.  It’s the ideal scenario for keeping clients and planters happy – and supervisors busy.  Now is a good time to consider how to keep the momentum going and avoid some common issues with fatigue.

Fatigue refers to the state of feeling very tired, weary or sleepy resulting from insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety.  Fatigue can be either acute or chronic.

Acute fatigue usually happens suddenly and is short-term.  This is the type of weariness felt after spending all night awake fixing the water pump in camp or chasing bears out of the mess tent.  Acute fatigue can be managed by sleep and/or relaxation.

Accumulated fatigue is the constant state of tiredness not relieved by rest.  A sleep deficit starts to build with each successive sleep-deprived night (generally defined as being awake for longer than 16-17 hours) and may take two or three conventional sleep cycles to correct.[1]

The demands of short, intensive seasons mean supervisors and workers are constantly facing fatigue issues.  In addition to countless other examples, fatigue can impact production by increasing the risk of injury out on the block, and safety by impairing your drivers behind the wheel. 

Studies on athletic performance have shown that fatigue reduces balance, accuracy, reaction times, technique and decision making.[2] Fatigued workers may trip or fall more and poor technique can contribute to tendonitis, shoulder or back injuries.  Boring or repetitive tasks can intensify feelings of fatigue, compounding the problem further.

At the end of the day when fatigued workers become fatigued drivers the implications are potentially more severe.

Most people need 7.5-8.5 hours of sleep each 24-hour day. Sleep loss built up slowly over several nights can be as harmful as sleep loss in one night. Both produce a decline in performance such as slower reaction times, failure to respond to changes, and the inability to concentrate and make reasonable judgments.

Research that tested a fatigued state from continuous hours of wakefulness against blood alcohol levels concluded that[3]

  • 17 hours awake is equivalent to a blood alcohol content of .05
  • 21 hours awake is equivalent to a blood alcohol content of .08 (the legal limit in Canada)
  • 24-25 hours awake is equivalent to a blood alcohol content of .10

You’d likely notice if a foreman climbed behind the wheel with a six-pack in their hands but it is much more difficult to notice the impairment caused by a late night running tree’s to a block or an early morning doing numbers.

Fatigue is a fact of life for silviculture companies but good planning, awareness and management can minimize the impact to worker health and production.  

Fatigue Management Strategies in Silviculture Operations

Recognize when the conditions create additional hazards for fatigue impairment

  • Long drives, extra days in a shift or longer days;
  • Unexpected events that extend the work day and limit rest (flat tire, getting stuck)
  • Working fire hours
  • Large volume days
  • Personal factors (interpersonal conflict, stress, family concerns)

Adapt the work plan to deal with changing conditions

  • Schedule shorter days or find closer blocks to ensure adequate rest can be achieved
  • Allocate additional crews to blocks with long drives to minimize the fatigue on a single crew

Actively support self-care

  • Promote adequate rest –including on days off and after work
  • Encourage workers to tend to minor injuries quickly and practice preventative care
  • Provide information on the importance of diet and hydration (Dr. Delia Roberts Fit to Plant)
  • Discuss pacing strategies for energy conservation (moderate sustained vs short duration, highly intensive effort)
  • Pay particular attention to the lifestyle habits of your drivers – are they limiting alcohol consumption,  getting enough sleep and recharging themselves for the additional demands of driving?

Additional resources:

ENFORM Fatigue Management

Health & Safety Executive – Sleep & Fatigue Bulletin

Share your ideas at the BC Forest Safety Council Forum

Laura worked in the silviculture industry for 11 years. She now brings her field experience to helping companies create practical solutions to their safety issues and wishes she could have taken her own advice when she was putting in trees. She can be reached at [email protected].


[2]Simoneau, Begun and Teasdale (2006) “The effects of moderate fatigue on dynamic balance control and attentional demands”

[3] Dawson, D., and Reid K. (1997). "Fatigue, alcohol and performance impairment." Nature 388, 235.

Focus on Safety