Thursday, July 29, 2021

Safety Message: Short Warning Times (overspeed or procedural breaches)

Level crossings are designed to provide the appropriate warning of an approaching train to motorists, cyclists and pedestrians. This “warning time” is defined as the time between the level crossing activating and when the train first enters the level crossing. A short warning time (SWT) is when the time between crossing activation and the first train entering the level crossing is less than the minimum designed warning time. SWTs result in motorists and pedestrians having less time to:

• Stop before the crossing or;
• Exit the crossing before the train arrives at the crossing.

These incidents can result in collisions and derailments that can ultimately cause serious injuries and even fatalities. One of several factors that can cause a SWT incident are train overspeed or procedural breaches. ONRSR’s investigations have shown there are several mitigations that can minimise the risks. While not exhaustive, given the range of operational environments within the Australian rail industry, the following causes/contributing factors and controls should be noted.

CAUSES AND CONTRIBUTING FACTORS

Organisational factors e.g.

• management of driver training and safety culture.
• inadequate interface and communication agreements with third party rolling stock operators e.g. a freight operator running services on a rail line managed by a different infrastructure owner.
• drivers provided with incorrect information resulting in actions which do not comply with the required procedures.

Technological or equipment factors e.g.

• speedometer calibration issues.
• crossing predictor signs installed at the wrong location.
• train speed on approach and over the level crossing.

Individual factors e.g.

1. Driver:

• insufficient route knowledge or training

• unable to control the speed of the train within the approach of a level crossing, fatigue, distractions, miscommunication, workload, error due to driver expectancy and habituation, intentional actions by the driver.

2. Rail Safety Worker:

• incorrectly isolates components of the signalling interlocking or level crossing equipment required for track works to be completed.
• incorrectly reinstates components of the signalling interlocking or level crossing equipment for rail services to operate.

Environmental factors eg:

• poor visibility of level crossing warning signs, speed boards, weather conditions.
• track gradients.

CONTROLS

While not an exhaustive list, ONRSR is aware of the following controls that are available and have been used in railways both in Australia and overseas. Rail Transport Operators (RTO) should note that there are safety and operational benefits and possible detriments associated with each control.

Operators must consider a range of factors, including the likelihood of the hazard and the degree of harm to determine what controls are reasonably practicable to implement – see the ONRSR Guideline – Meaning of duty to ensure safety so far as is reasonably practicable SFAIRP for more information.

Elimination

The following controls are likely to eliminate the risk but this may not be reasonably practicable - see the ONRSR Guideline – Meaning of duty to ensure safety so far as is reasonably practicable SFAIRP for more information):

• Grade separating of the road and level crossing
• Closing or diverting the road, closing or diverting the rail line.

Engineering:

Rolling Stock systems

• Speed limiting onboard systems to enforce the maximum speed on the approach to a level crossing by cutting traction power or;
• Train Protection Systems which apply a penalty brake to the train should the speed be exceeded (connected with the signalling controls – see below).

Signalling controls

• Utilisation of fixed-block systems, cab signalling systems or moving-block signalling systems which interface with enforcement systems (i.e. mechanical systems such as train stops; inductive loop / radiofrequency systems such as TPWS or AWS; and computerised / wireless systems such as ATP).

Administrative:

Some of the administrative and organisational controls that railways can employ to mitigate the risks associated with SWT at level crossings include the following:

Monitoring

• Real time remote level crossing monitoring systems: these systems include system/asset condition monitoring allowing for immediate notification of a short warning time and prompt responses to be implemented. This helps ensure network safety and quick rectification.
• Regular review of level crossing events and system condition monitor logs. This should be undertaken by appropriately competent and experienced workers. Adopting this process helps identify emerging risks which may affect the integrity of a level crossing.
• Human factors review of routes and procedures pertaining to level crossing activation which considers sightlines, signage, train handling conditions, adhesion conditions.

Signs and notices

• Notice boards and signs such as notice boards, speed boards and level crossing approach signs: can be a cost-effective solution when coupled with driver training and route experience.
• Circulars and notices: safety circulars can be used to distribute information to a large audience in a short period of time and provide information regarding the causes of short warning times events and outline the correct procedures to follow to prevent reoccurrences.

Training and auditing

• Train driver education and training: including route knowledge; mentorship and regular assessment using practical simulator event-based activities and scenario experiences
• Structured, practical, competency-based training of signalling technicians including:
  • applicable, regular and timely refresher training and mentorship
  • regular on the job task-based audit/assessment of signalling technicians
  • ongoing documented practical formal and informal skill and competency training, mentorship and assessment.
• Train driver auditing: can provide positive mentorship while enhancing skills in how to appropriately control a train in specific situations such as speed regulation when approaching a level crossing.

Restrictions

• Restrictions on road vehicles: this can reduce the risk of a collision by removing heavy and long vehicles (e.g. heavy loads, B- Doubles) from accessing specific level crossings.
• Speed restrictions: restricting the line speed may increase the chance of train stopping short of a level crossing if any irregularities are detected with the protection equipment.

Documentation and standards

• Specific and detailed standards, procedures and work instructions covering the following:
  • isolation/disconnection
  • certification/testing
  • reconnection/commissioning of level crossing equipment; including:
    • independent review, authorisation and approvals
    • documented in field cross checks of disconnection, reconnections and certifications.
• Interface agreements: where third-party operators such as freight and tourist operators access the rail infrastructure managed by the rail infrastructure managers, interface agreements can clearly define and outline how risks and communications can be managed between operators concerning SWTs.