RAIB has released its report into a Derailment of a tram at Bulwell, Nottingham, on 12 June 2023.
At around 17:06 hrs on 12 June 2023, a southbound tram, travelling at around 41 km/h (25 mph), approached a set of facing points in an unsafe condition at the north end of Bulwell tram stop in Nottingham. As it travelled over the points, the first and second bogies of the tram were routed in different directions and the tram subsequently derailed.
During the derailment, the tram struck a pole that supported overhead line equipment causing a pane of glass to dislodge and strike a passenger, resulting in minor injuries. The driver of the tram also suffered a minor injury. Significant damage was caused to the tram and infrastructure, with the line reopening on 23 June following extensive repairs.
The set of spring-loaded points were in an unsafe position because they had not reset correctly after the passage of the previous two northbound trams. This can sometimes happen in normal working conditions, but the risk of this happening at the time of the accident had possibly been increased due to the environmental conditions causing the slide plates to be dry or contaminated.
A visual indicator located alongside the points, which was showing that the points were not in the correct position, was not observed by the tram’s driver. The driver believed that they would be informed if there were any issues with a set of points but had not been so on this occasion. The driver had probably become conditioned to there being no issues at this location and was also possibly distracted.
RAIB’s investigation found that Nottingham Trams Limited did not have an effective policy in place to inform drivers of points failures and had not specifically assessed the risk of a driver incorrectly passing a lineside indicator. RAIB also observed that the process Nottingham Trams Limited used when introducing a new system to the tram fleet had not considered the effect the change may have on its tram drivers.
Recommendations
RAIB has made three recommendations, all addressed to Nottingham Trams Limited. The first recommends a review of control room policy and procedures to ensure that clear and practical guidance is available to manage the response to engineering faults. The second recommendation relates to the improvement of risk assessments in light of this accident. The third recommendation concerns the consideration of human factors when assessing the effects of a proposed engineering change.
RAIB has also identified a learning point to remind tram drivers to not make assumptions about the status of signals or indicators based on their previous experience.
Image credit: RAIB
