Page:ATSB RO-2018-004 - Collision of passenger train A42 with buffer stop.pdf/29

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ATSB – RO-2018-004

Figure 11: Driver safety systems

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This figure shows the location of the driver safety systems on A42. The insert shows the power / brake handle and the twist grip which acts as part of the operator enable system.
Source: ATSB

The operator enable system on Waratah trains consists of both an OEP and an OEH. The presence of both handle and pedal allows drivers to alternate between arm and leg muscle groups and give drivers the option to stand while driving.

The OEP is also used as the driver’s footrest. The height of the pedal and surround can be raised or lowered by the driver. The angle of the surround is approximately 28° from horizontal which slopes towards the driver. The pedal has a normal operating position range of approximately 26° to 30° from horizontal.

In order to enable traction and release the brakes, either the OEP must be depressed or the OEH power / brake handle twist grip turned approximately 20° clockwise. The power / brake handle needs to be in the forward or reverse position for this to operate. To operate the OEH a force of 8 N (± 10 N) is required. The force specification is such that the force required to be applied shall not cause injury or discomfort taking into account the shift length the drivers are required to operate.

There are three main stages to the OEP (Figure 12):

Released range: here the pedal is in the fully released position where no force is applied.
Normal operating range: the driver depresses the pedal into this range which activates the system and suppresses the automatic brake application. The force required to depress the pedal from the released range to the normal operating range is 50 N (±10 N). In order to hold the pedal in-line with the surround a force of less than 80 N is required. (This equates to a mass of approximately 8 kg).
Vigilance acknowledgement range: when the driver further depresses the pedal it links to the vigilance control system, vigilance is acknowledged and the automatic brake application suppression is maintained. The force required to depress the pedal from the normal to vigilance acknowledge range is 120 N (± 10 N). If the pedal is held in this range for more than three seconds, a second stage vigilance activation will occur and give an

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