Tangara trains have a number of safety and vigilance devices installed, such as a
deadman's brake, to address problems when the driver becomes incapacitated. If the driver releases pressure from this brake, the train will safely come to a halt. The train in question was a four-car
Outer Suburban Tangara set, numbered G7 and fitted with a
Mitsubishi Electric alternating current traction system for evaluation purposes. The driver was in the leading driving carriage and the guard was in the rear driving carriage, in between which were two non-driving motor cars. On this service, the guard, who could have applied the emergency brake, and the deadman's brake were the main safety mechanisms in place. The train was later found to be travelling in excess of as it approached the curve where the accident occurred. Neither the deadman's brake nor the guard had intervened in this situation, and this excessive speed was found to be the direct cause of the accident. Deficient training of train staff was also found to be a contributing factor in the accident. Train G7 did not re-enter service. It was scrapped in 2005 due to the damage sustained in the accident as all four cars were damaged beyond repair. These were the official findings of the
NSW Ministry of Transport investigation of the accident. A report of the accident, managed by Commissioner
Peter McInerney, was released in January 2004. and had developed a reputation amongst the mechanical operations branch, saying the problems were "normal" for the set in question. During the six months leading up to the accident, three reports of technical problems were made. The inquiry found a number of flaws in the deadman's handle (which was not implicated in the accident) and related to the deadman's pedal: • The dead weight of the unconscious and overweight driver after he suffered a heart attack appeared to be enough to defeat the deadman's pedal, of which 44% of Sydney train drivers' legs were of sufficient mass. • The design of the deadman's pedal did not appear to be able to operate as intended with drivers above a certain weight. • Marks near the deadman's pedal indicated some drivers were wedging a conveniently-sized red signalling flag to defeat the deadman's pedal to prevent their legs from
cramping in the poorly-configured footwell and to give themselves freedom of movement in the cabin. Some of the technical problems reported for Tangaras generally, included brake failure and reported power surge problems. After the accident, they were often blamed by some for being the cause of the accident. Many of the survivors of the accident mentioned a large acceleration before the accident occurred. Furthermore, there was an understanding that the emergency brake should be seldom used because the train would accelerate between before the brake came into effect. It was noted that the G7 trainset was the only train in the Tangara fleet to use 3-phase induction motors, and that these are not able to "run-away". Furthermore, the majority of braking and traction system components were thoroughly examined and tested by experts from Australia and overseas, and found to be working normally. Those damaged in the crash were examined and were also found not to have had pre-existing damage able to cause such an accident. Official findings into the accident also blamed an "underdeveloped
safety culture". There has been criticism of the way CityRail managed safety issues, resulting in what the
NSW Ministry of Transport termed "a reactive approach to risk management". At the inquiry, Paul Webb,
Queen's Counsel, representing the guard on the train, said the guard was in a
microsleep at the time of the question, for as much as 30 seconds, which would have removed the opportunity for the guard to halt the train. Webb had also proposed there had been attitudes that the driver was completely in charge of the train, and speeding was not an acceptable reason for the guard to slow or halt the train, which would have been a contributing factor in the accident. Prior to this derailment, neither training nor procedures mandated the guard to exercise control over the speed of the train by using the emergency brake pipe cock ("the tail"). Apart from the driver being considered to be the sole operator of the train, the emergency brake pipe cock does not provide the same degree of control over the automatic brake as a proper brake valve. The consensus among train crews was that a sudden emergency application from the rear could cause a breakaway (which is in fact not possible, as the cock does not apply the brakes solely to the rear car but rather uniformly along the full length of the train), and there was some evidence from previous accidents to validate such an opinion, however these were not involving the modern multiple-unit train design of which the Tangara is an example. Since this derailment, CityRail training and operational procedures now emphasise the guard's responsibility to monitor the train's speed, and if necessary,
open the emergency brake pipe tap to stop the train. ==Changes implemented==