Posted By Andy Brazier The link below takes you to the HSE's page on fatigue. The calculator allows you to enter a shift pattern and get a fatigue profile. As with all these things the absolute results are not always as useful as comparisons (in this between current and proposed new pattern). http://www.hse.gov.uk/research/rrhtm/rr446.htm I'd doubt that a change from 11 to 12 hours will make much difference. According to HSG48 from HSE, error rates start to increase after 12 hours at work, but there is little indication of a time at work correlation if the shift is less than 12 hours. From what I can understand it is quality of breaks between shifts that has a larger impact than the hours worked per shift. It is easy to only consider fatigue, but there are other issues to consider. I have assisted a number of companies moving from 8 to 12 hour shifts. In this case the reduction in the number of shift handovers, and the fact that maintenance work is often finished in a 12 hour shift, but would have carried over the 8 hour shift handover create improvements that have been judged to outweigh any potential increase in fatigue. The only job I have heard to limit time working to a relatively small number is air traffic control. I don't know the details, but understand they have to have long breaks every couple of hours. It has been suggested that control room operators and oil and gas plants should be limited to 4 hour stretches, but I don't think that is advisable because you end up with 6 handovers in a day.

Posted By John Murgatroyd Isn't there something in the working time directive about night workers and time worked ?