On the 9 November 2016, a tram on the Croydon tramway network overturned at Sandilands. The tram had been travelling at 73 km/h when it entererd a curve that had a maximum speed limit of 20 km/h. The speed caused the tram to overturn as it passed through the curve, and resulted in passengers being thrown around inside the tram, with some being ejected through broken windows. Of the 69 passengers involved in the accident, seven died and 61 were injured; 19 seriously.
The Rail Accident Investigation Branch's report has been released today and makes some far-reaching recommendations for the way tram operations in the UK are regulated and managed. Sadly, many of the recommendations are made about things that are already known about (and managed) in the rail sector, but which were not applied to tramway operations - tramways are often regarded as being more akin to road operations than rail operations. The accident at Sandilands makes it clear that rail sector engineering standards and management systems (for example fatigue management) are highly relevant to tram operations.
The investigation report concludes that it is probable that the tram driver temporarily lost awareness on a section of route on which his workload was low. A possible explanation for this loss of awareness was that the driver had a microsleep, and that this was linked to fatigue. Exacerbating this was that there were few landmarks so that the driver was unable to quickly reorient himself.
The report makes 15 recommendations to improve tramway safety. Some apply to the operator of the Croydon tram network (First Group), but many apply across all UK tram operations:
We've just posted some examples of 'bad' human factors that we've come across - things that have (or are likely to) shape the actions of people in an undesirable way. Take a look at these examples, and if you have any that you'd like to share please contact us!
When a driver left his tram to investigate a problem with the power supply, an unfortunate error led to considerable damage. The driver had left the tram in 'on' mode, so when the power problem disappeared the now driverless tram set off on its own. To see the full story, read the story on the Rush Lane and the Times of India's websites.
Eliminating the potential for errors like this is normally common practice, but much of Calcutta's tram system is now very old. Nevertheless, this accident should raise concerns about many human factors issues including task design, training and competence and procedural controls as well as risk management.