Permissive Signalling System
Date issue released
Issue number
Issue Status
Closed – Adequately addressed
Transport Function
Rail: Other
Issue Owner
Metro Trains Melbourne
Mode of Transport
Rail
Safety Issue Description

The rules pertaining to passing a permissive signal at stop, place sole reliance on the train driver to provide separation between trains by line-of-sight observation. In the absence of any additional risk mitigation measures, this administrative control provides the least effective defence against human error or violations.

Issue Status Justification

The ATSB accepts MTM's proposed safety actions on this safety recommendation. 

Safety recommendation
Action number
RO-2014-016-SR-38
Organisation
Metro Trains Melbourne
Action date
Action Status
Closed - Action Taken
Action description

The ATSB recommends that Metro Trains Melbourne consider additional risk mitigation measures to maintain train separation where the safeworking system allows permissive working.

Organisation Response

Date Received
Organisation
Metro Trains Melbourne
Response Status
Released
Response Text

MTM Response to Recommendation RO-2014-016-SR-038
1. MTM agrees with this action.
2. MTM refers to and repeats the proactive safety actions already taken by MTM since the incident, as acknowledged in the Report.

3. In addition:
a) MTM has been pursuing a rulebook re-write and has obtained agreement from PTV and all large infrastructure managers who use the same/similar rulebook. The rulebook re-write will have specific focus on reviewing degraded mode operations. This will include consideration of the application of Rule 1 – Section 3.
b) MTM is continuing to apply the Train Protection Warning System (TPWS) in areas of the network utilised by V/Line and removal of dark territory on a riskbased approach progressively as projects are being delivered. A proposal to apply the TPWS to additional signals identified as a risk across the network (i.e. signals not already covered by projects) has been submitted to PTV for funding and approval. Regarding Train Protection Warning System (TPWS) whilst it is acknowledged that the application of TPWS will not enforce compliance with Rule 1 – Section 3, the facility does provide an ‘electronic’ train stop facility for the V/line TPWS fitted fleet.
c) In the interim, risk relating to Dark Territory continues to be managed in accordance with MTM's Enterprise Risk Management procedure. In addition to managing risks associated with Dark Territories, MTM is working with PTV to determine funding requirements and priority. The removal of dark territory, in conjunction with a re-write of the rulebook (as per above), will further support the management of degraded mode scenarios, including management of automatic signal failures which have a direct relationship to Rule 1 Section 3.

Organisation Response

Date Received
Organisation
MTM
Response Status
Closed
Response Text

MTM advised in relation to the deployment of TPWS:

  • a comprehensive master list of TPWS eligible signals had been developed.
  • a priority signal list (approximately 73) based on the number of scheduled V/Line services, signal protective function, historical SPAD data had been determined and funding agreed with DoT.
  • design and field works had commenced and were anticipated to be completed in 2022 (currently had completed $11m worth of work).

MTM advised in relation to the removal of dark territories:

  • a project had been developed and funded under the MR4 franchise contract with DoT to eliminate dark territories not already convered by major project activity.
  • project initiation commenced in 2018 with main field works scheduled from 2020 through to completed in 2025.
  • majority of benefit in relation to visibility of previous dark territory areas will not be realised until the final phase of the works. 
  • that there is a significant reliance on 3rd party vendors to deliver this multi-year program. 

This does pose a risk to the program as these vendors have s significant workload within the rail industry. This risk is under active management. 

ATSB Response

The ATSB accepts MTM's proposed safety actions on this safety recommendation. 

ATSB Response

The ATSB accepts MTM's proposed safety actions on this safety recommendation. 

Proactive action
Organisation
Metro Trains Melbourne
Action date
Action Status
Released
Action description

MTM issued a Weekly Operational Notice on 28 July 2015 stating that the existing details contained in Section 3, Rule 1 of the Book of Operating Rules and Procedures 1994 are to be deleted and the attached details in Annex 6 incorporating an automated voicemail facility is inserted. The voicemail facility includes a recorded recitation of the Rule. Annex 6 requires train drivers to call a telephone number and record a message advising that they are at an automatic signal at Stop and will be proceeding past the signal in accordance with the requirements of Section 3 Rule 1 of the Book of Operating Rules and Procedures 1994.

ATSB Response

The ATSB accepts that the voicemail facility acts as a means of alerting train drivers to the operational rules governing permissive working. However, the ATSB is not satisfied that this process sufficiently mitigates the risk of a similar accident. Accordingly, the ATSB issues the following Safety Recommendation: