Thursday, April 20, 2023

Safety message: Managing your bridge assets

ONRSR is highlighting some of the key good practices and requirements for effective management of railway bridges.

Safety message bridge assets

ONRSR conducts regulatory activities, including audits, inspections, and site visits, across multiple operators and sectors. In doing so, ONRSR observes both good and bad safety practices.

Rail bridges are key pieces of infrastructure that many Rail Transport Operators (RTOs) are required to manage and maintain safely, so far as is reasonably practicable - as per the Rail Safety National Law.

While not exhaustive, given the range of operational environments within the Australian rail industry, the following examples of good practice should be noted.

RTOs must consider a range of factors, including the likelihood of a hazard and the degree of harm to determine what management practices 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).

A good safety management system should contain key details across six key areas:

  • Asset details
  • Indicative risks and controls
  • Systems and procedures / detailing
  • Structural standards
  • Inspection records
  • Defect management

> Asset details

Asset details (such as an asset register) provide information about the bridge itself. Information that asset details should cover includes, but is not limited to:

  • Structure and location name, and location rail kilometrage (normally given at the "Up" end of the bridge)
  • Structure description including number of spans, lengths of spans, super-structure type, sub-structure type, and deck configuration, for example, transom, ballast top or direct fix.
  • Structure drawings and photographs including design railway loading (original design live load and current live load rating (LA) equivalent), structural details of any modifications or strengthening.
  • Current operational railway loading details e.g. showing maximum axle loads, load or speed restrictions, and typical operational rollingstock type in use.
  • Current operational speed and temporary speed restriction (if any).

> Indicative risks and controls

Documenting the risks and controls for bridges demonstrates that risks are being monitored and managed effectively. Risks can include:

  • Structural collapse due to:
    • overloading of the bridge,
    • deterioration of a bridge member (rust, rot, split, crack, fatigue, insect attack).
    • deterioration of the bridge due to an external event (scour at supports, landslip, wind event, flood or earthquake damage, bridge struck by road or rail vehicle damage to the bridge due to derailment of train on approaches or on the bridge.
  • Railway staff or passengers falling from the bridge.
  • Bridge inspection staff or repair crews struck by road vehicle or train.

Each of these risks should have controls in place to ensure the safety of the bridge so far as is reasonably practicable. These controls can include:

  • Design based on appropriate standard and performed by a qualified bridge engineer.
  • Design is verified, and construction certified.
  • Bridge design load recorded and current train load effects are less than design capacity.
  • Current structural condition is checked by routine and special inspections, defects are recorded, risks evaluated and monitored with interventions made before defects become safety critical.
  • Special engineering inspections in the event of earthquake, flood or other damage - to confirm adequacy of structure or initiate necessary repairs.
  • Maintaining the track and rollingstock to standards.
  • Adequate design clearance, signposting of any reduced clearance, addition of crash beams to protect the bridge structure, adoption of active monitoring and warning system for over-height vehicles (as required by risk analysis).
  • Train loading standards, competency of personnel and inspections.
  • Workplace safety procedures and worksite protection for road and rail traffic.

> Systems and Procedures

Procedures underpin the overall process for maintaining bridges. They can include:

  • Competency requirements for bridge inspectors, and bridge engineers.
  • An identified responsible and competent person to make asset decisions.
  • Clearly defined responsibilities of Inspectors and Engineers.
  • Inspection types, frequency and methodology required.
  • Previous report and photographs of defects on site to ensure consistency and capacity to review any deterioration.
  • All structural areas to be inspected, access proximity and any tests required for inspection types.
  • Defects to be checked for (depending on structure type and materials) including their priority rankings, defect criticality limits (with triggers for higher inspection type)
  • Clearly defined safety critical structural defect limits that inform restriction to, or suspension of, railway operations.

> Structural standards

Standards define the criteria for how bridges should be maintained. They can include:

  • Australian Standards (e.g. AS 5100 Bridge Design and relevant material standards)
  • RIM assets systems, bridge inspection standard and procedures
  • RIM bridge maintenance procedures
  • RIM structural defects management process
  • RIM and road authority Safe Working Standards
  • Clear and defined defect acceptance and rejection criteria
  • Priority ranking system for defects
  • Technical maintenance plans

> Inspection records

Undertaking inspections of bridges helps understand their condition and what repairs or maintenance may be required. Documentation in relation to inspections can include:

  • Type of inspections:
    • Level 1 (routine visual inspections)
    • Level 2 (detailed inspection and testing)
    • Level 3 (detailed engineering inspection and load rating).
    • Special engineering inspection triggered by external events.
  • Structural areas to be inspected, access proximity and any tests required for inspection types including whether they meet standards.
  • Triggers for L2 and L3 inspections e.g. significant defects, deteriorated bridge condition.
  • Special inspection report triggers e.g. storm damage, train derailment, landslip, increased loading or operational speed proposed
  • Copies of all previous inspection reports (L1, L2, L3 and special)
  • Timing for inspections e.g. when next inspections are due (L1, L2 and L3)
  • Inspection forms to be used.

> Defect management

Defect management is about ensuring defects or non-conformances are accurately recorded, criticality assessed, tracked, monitored and actioned, ensuring traceability from defect to rectification.

Information in relation to defect management can cover:

  • Itemised current defects (as per TMP)
  • Defects referenced to specific structural element as per description/numbering system adopted in standards.
  • Key details about the defect including:
    • date found, inspection type (L1, L2, L3, or special), defect type, detailed location, photographs
    • current criticality assessment
    • programmed future action (monitoring frequency, correction date, more detailed inspection if nearing intervention limits)
  • Next inspections due (L1 and L2)
  • Documented changes made by structure’s manager to inspector’s draft
  • Defect criticality and draft correction date, with reasons and any additional risk controls deemed relevant.
  • Records of repairs made and assurances these can be related and traceable to the relevant defects and non-conformances


Proper bridge maintenance can have additional benefits as well as improved operational safety including:

  • Better use of resources, with more programmed repairs and fewer reactive repairs.
  • More efficient management of bridge assets and understanding of on-going resource requirements including future asset replacements.
  • Fewer overdue inspections or repairs.
  • Better risk-based responses to repairs.

Operators may benefit from reviewing their SMS. The following list includes, but is not limited to, those systems and procedures likely to be most relevant for review:

  1. Technical Maintenance Plans
  2. Management of change process
  3. Monitoring processes and procedures
  4. Defect management systems
  5. Competencies and Training processes

Please see ONRSR Guideline - Safety Management System Guideline for more information.

Safety Management System Guideline

The Safety Management Guideline provides accredited rail transport operators, and those seeking accreditation, with guidance on the legislative requirements for safety management and what the National Rail Safety Regulator (NRSR) looks for when assessing the safety management system, and how to prepare a safety management system that complies with the legislative requirements.

All RTOs managing railway bridges may benefit from reviewing this guideline.

A comprehensive collection of ONRSR Safety Messages is available to view here.

Last updated: Dec 14, 2023, 9:11:39 AM