The Waterfall rail accident was a train accident that occurred on 31 January 2003 near Waterfall on the Illawara railway line. The train failing to negiotiate a curve at high speed, killing seven people aboard, including the train driver. The cause was found to be an incapacitated driver that the train's safety systems failed to detect.
Incident[]
On the day of the disaster, a Tangara set G7 was operating the 6:24am South Coast Line service from Sydney Central to Port Kembla via Wollongong (run C311). The run through suburban Sydney was uneventful, apart from the fact that CCTV showed the train stopped past the stopping mark (albeit still entirely on the platform as the train was 4 cars long) at many stations. At worst, the train stopped 22m (or one car length) past the stopping mark at Heathcote.
At some point after departing Waterfall, the driver very likely suffered a sudden heart attack and lost control of the train. At the same time, according to his solicitor, the train guard may have been in a microsleep for up to 30 seconds. As such, the train's power was not reduced after accelerating out of the station and so the train soon exceeding the speed limit of 75km/h. The speed limit soon dropped to 60km/h in advance of a left hand curve in a cutting. The train took this curve at approximately 117km/h and derailed, overturned and collided with the rocky walls of the cutting. Two of the carriages landed on their sides and another two were severely damaged in the accident.
In addition to the seven fatalities, many more passengers were injured. The initial emergency reponse was severely hampered by many factors. Mobile signal was limited at the accident site due to its remoteness, so it took several minutes for the accident to be reported to both control and emergency services. Emergency services were also given varying and incorrect information about the accident location, and they also did not know where the rail corridor access gates were, nor did they have the keys to open them. In the end, station staff at Waterfall helped emergency services to access the site.
Once emergency services reached the site, they also had some difficulty accessing the passengers inside. Tangaras have triple layered windows, making it harder for access via the windows, however some passengers eventually were able to break them. Rescuers attempted to use the external emergency door release (EDR) buttons, however these did not work due to low air pressure in the door system. Passengers could not release the doors either as SRA policy at the time specified internal EDR was not to be fitted.
Investigation[]
Speed was the primary cause of the accident. The train took a curve with a 60km/h limit at ~117km/h. It was found the margin of safety was such that the train would overturn on the curve at speeds of over 110km/h.
The primary defence against a driver incapacitation at the time was the deadman's device, which required the driver to twist the master controller and hold it in position and/or hold a foot pedal in a certain position, otherwise emergency braking would be applied. However, it was found that the system was not activated, either due to the dead weight of the driver, or the driver wedging their feet under the foot heater. The investigation also found that drivers often knew of or used various ways of circumventing the system using flags, timber poles or other items.
The guard could also have stopped the train, but did not. Fatigue modelling shows the guard's previous shifts had resulted in a fatigue level of 200+% of a normal working week, which his soliticitors argue likely induced a microsleep, although the guard denies this. Nevertheless, the investigation found many staff believed the driver was solely responsible for driving the train and that speeding was not a reason for them to use the emergency brake pipe cock in their cab to slow or stop the train. Many also believed that operating the cock would not be as effective, or that it would be dangerous.
The driver was also likely fatigued as they had come back from annual leave the previous day, straight into an overnight shift. While fatigue modelling cannot account for the driver's sleep schedule while not working, he had been over 2 hours late for his shift the previous day. It was found that, as his shift started with taking a taxi from Wollongong to Port Kembla, the driver used a procedure known as 'joiner rights' to start his shift at Port Kembla, meaning that his supervisor/manager could not observe that he appeared fit to work.
In addition, the investigation found that speed limits were often exceeded at this location (by at least 37% of trains in the past week), for many reasons. Rules had changed in November 2001, such that a train could only accelerate only after the entire train had passed a speed board (sign), instead of when the front of the train passed the board. Sign locations had not been changed, leading crews to believe it was safe to exceed the limit a little as they did before and that they would not be able to keep to timetables without speeding.
Some drivers had reported Tangaras would 'surge' or have braking issues, however it was found the train involved in the incident had no mechanical failures. The reports of issues were generally found to be related to normal drops in deceleration rate while braking caused by the regenerative brake 'dropping out' or the wheel slide protection system.
Aftermath[]
All trains in NSW have since been retrofitted with a driver vigilance device to supplement the shortcomings of the deadman's device identified. This device requires the driver to press a button if the train's controls have not been moved in a certain time. Otherwise, both visual and aural alerts are triggered and the emergency brake is eventually applied.
All trains have also been fitted with data loggers to continuously record various parameters such as the train's speed and the position of the master controller (throttle). This would have helped immensely in the investigation, as the speed of the train at the time could only be estimated based on the time it occupied the signalling block it was on at the time. Such a system had been fitted to G7, but was in the early stage of fleet roll-out, and hence had not been commissioned and switched on at the time of the accident.
Internal EDR has since been fitted on all new trains and is slowly being retrofitted to older trains. All new trains now are specified with electric door motors, so lack of air pressure should no longer cause EDR to fail.
Automatic train protection (ATP) would likely have prevented this accident as it automatically stops the train if the speed limit is exceeded. After many years, ATP is slowly being installed and tested on the network, however progress is currently slow.
The 2004 changes to medical assessments of rail workers were developed in response to the incident. Overseen by the National Transport Commission, cardiac assessments are mandatory for certification and re-certification with a proscribed mandatory checklist as part of the national standard in the interest of ensuring public safety, the intended purpose of the health assessments whereas previously the health assessments did not have an occupational risk but a clinical focus.