Wednesday, October 29, 2025

Safety Message – Temporary Jumpers and Bridges

Incorrect isolation or installation of temporary jumpers/bridges

Temporary jumpers or bridges are electrical wires railway signalling personnel use to bypass or isolate portions of signalling apparatus, circuitry or equipment to enable rail construction or maintenance works.

The potential risks to safety associated with using temporary jumpers/bridges include:

• train-to-train collisions or collisions with rail safety workers.
• collisions with road vehicles or pedestrians at level crossings.
• derailments.

These can occur if temporary jumpers/bridges, which bypass critical signalling safety systems (e.g. level crossings, points), are incorrectly installed or connected. In this safety message, we will cover:

1. General precautions
2. Use
3. Design
4. Verification and testing
5. Security
6. Documentation and communications.

General precautions

The use of temporary jumpers/bridges should be the exception rather than the norm when undertaking maintenance and construction activities.

Due to the inherent risks, ONRSR expects that rail infrastructure managers (RIMs) establish procedures and engineering solutions which minimise, if not eliminate, the use of temporary jumpers/bridges, especially at level crossings and points. Examples of engineering solutions include:

• Individual point end detection and point isolation maintenance switches in multi-end point arrangements.
• Line isolation switches or maintenance switches at multi-line level crossings.
• Use and installation of approved stage-work alteration signalling circuit designs to safeguard the signalling system.

Avoid using temporary jumpers/bridges across any relay contacts where:

• Signalling equipment is prevented from properly returning to a more restrictive or locking position
• Unprotected signalling equipment is functioning unsafely under a less restrictive or unlocked position.

Use

Good practice regarding using jumper wires includes:

• Systems and procedures: Including all documentation and authorised approvals. This ensures the use of temporary jumpering or bridging is adequately controlled and managed.
• Notification: Using applicable authorisation forms, designs and work instructions to ensure all parties are aware of where jumpers or bridges are to be installed and by who.
• Authorisations: These are limited to appropriately competent signal engineers and ensure all applicable reviews, approvals and mitigations are in place.
• Competence requirements: Limiting use of jumper wires to authorised, competent and qualified railway signalling personnel.
• Close connections: Connecting jumper wires as close as possible to the equipment concerned without them being disturbed by the works taking place. Generally, this should be the closest equipment housing to works being undertaken.
• Time limits: Limiting use of temporary jumpering/bridging to the period covering the work documented on the authorisation form.
• Extensions: Only allowing extensions of time limits if authorised by a signalling engineer in consultation with the responsible competent asset maintenance signal engineer or the signalling engineer responsible for the integrity of the system.
• Returning jumper wires: Ensure all jumper/bridge wires issued in conjunction with the approved authorisation are removed and returned to secure storage.
• Network rules and Procedures: Booking out of use, isolating and disconnecting signalling equipment in accordance with the appropriate Network Safeworking Rules and signalling procedures.

Design

Good practice regarding the design of jumper wires includes:

• Length and colour: Enable clear identification amongst all other wires and conductors contained within signalling equipment rooms, enclosures, housing and location cases.
• Insulation: Should be clearly defined in standards e.g. 0.6/1 kV.
• Lugs, plugs and clips: Connecting lugs, plugs or clips at each end of the jumper wire are insulated (as far as practicable) and suitable for application.
• ID numbers: Numbered consecutively and permanently fixed to each end as identified in the authorised circuit diagram. This includes labelling of the jumper wires and their owner.
• Conductors: Utilisation of appropriately rated flexible multi-stranded cables (preferred due to their flexibility and resistance to fracture).

Verification and testing

Good practice includes but is not limited to the following checks:

Installation

• Correlation and visual checks: Preinstallation circuit correlation and visual checks together with applicable testing undertaken at the location where jumper wires are to be installed.
• Circuit diagrams: Cross-check that affected circuit/s in the approved circuit design diagrams reflect what is installed (including circuit correlations).
• Verification and validation: Undertaken by the independent applicably competent railway signalling engineer or technician, examine, test and certify the installation to ensure jumpers are correctly installed and labelled as per authorisation forms, circuit diagrams and work instructions.
• Contacts: Verify and test the entire circuit/s during installation of jumpers to ensure:
  - all contacts in the circuits (including the contacts in any equipment) are effective and that
  - signalling systems and equipment function normally for all routes and train movements.
• Loose wires: Ensure that no potential exists for wires to become loose, fall out or inadvertently connect across adjacent circuit terminals.
• Documentation and certification: Undertaken by the authorising signalling engineer, and including authorisation forms, details on the circuit diagram (including test markups), amd work instructions. Check that all verification, testing and endorsements have been completed and are certified in accordance with the applicable standards and procedures.

Removal

• Certification and Validation: Examination and testing of the installation undertaken by the independent and competent railway signalling engineer or technician to certify and ensure that:
  - jumpers have been correctly removed as per the details and requirements in the authorisation form, circuit diagram and work instructions
  - all safeworking documents and work instructions, verification, testing and endorsements have been completed and are certified in accordance with the applicable procedures and standards.

• Contacts: Verify and test the entire circuit/s following the removal of jumpers to ensure that:
  - all contacts in the affected circuits (including the contacts in any equipment) are effective
  - signalling systems and equipment function normally.

• Loose wires: Ensure that no potential exists for wires to become loose, fall out or inadvertently connect across adjacent circuit terminals.
• Omissions/errors: Investigate any omissions, issues or errors including:
  - endorsements and dates of installation written on authorisation form
  - completions of all documents on the register and whether the applicable records have been retained on site
  - test markups on authorised circuit diagram of affected circuits are correct and not missing or incomplete.
  - all applicable verification tests associated with the removal of the jumpers/bridges have been completed.

Security

Good practice regarding the security of jumper wires includes:

• Storage: Systems and procedures to ensure jumper wires are adequately stored.
• Responsibility: Defining, in documentation, who is responsible for jumper wires
• Oversight: Systems and procedures for oversight
• Documentation: Ensuring documents authorising the installation of jumper wires are in place
• Registers: Having registers which list the status and location of jumper wires, and updating such registers when jumpers are installed and disconnected
• Lost jumper wires: Procedures to manage lost or stolen jumpers and how the jumper wire register is updated
• Tampering: Systems and procedures to ensure jumper wires cannot be tampered with.

Documentation and communications

Good practice regarding communication and documentation for jumper wires includes:

• Records: Maintain a record of all activities undertaken in relation to jumpers.
• Tracking numbers: Use a unique identification number which is assigned for each authorisation and can be tracked to a single work activity e.g. a consecutive numbering system.
• Mark-ups: Mark up circuit diagrams e.g. mark-ups on the authorised circuit diagram/s, preferably in different colours, applicable for each person, and each test and verification stage.
• Circuit diagrams: Show operational circuits, position and points where temporary jumpers/bridges are to be connected, installed, disconnected and isolated, and any other temporary bridging arrangements.
• Work Instructions: Use specific work instructions detailing each task and activity associated with the use of the temporary jumpers/bridges.
• Procedures and standards: Systems and procedures covering how works will be performed.
• Verification and testing documents: Systems and procedures covering verification and testing such as inspection and test plan (ITPs) and test certificates.
• Authorisations: Systems and procedures to ensure documents have appropriate signatures, signoffs and endorsements for using and carrying out tests on temporary jumpers/bridges
• Awareness and notification: Ensuring signalling maintenance staff are aware of who is responsible for the equipment and who to contact.
• Handover: Ensuring details of the status of the temporary jumpering/bridging arrangements are discussed and documented on the authorisation form endorsed by all parties involved in the handover process.

Key documents and actions

Reasons for the acceptance or rejection of controls should be documented in any assessment of the risks (Section 100 RSNL)

Guidance material that can assist you include:

• AS 7702 Rail Equipment Type Approval
• AS 7716 Signal Testing Process
• AS 7717 Signal Testing and Commissioning
• RISSB Code of Practice -Type Approval – Signalling
• ONRSR Guideline Meaning of duty to ensure safety so far as is reasonably practicable
• ONRSR Guideline Safety Management Systems
• Safety Message: Installing, Upgrading and Commissioning Signalling Assets
• Safety Message: Managing your signalling assets
• Safety Message: Management of change
• Safety Message: Type Approval
• ONRSR Safety Alert Non-operation of level crossings on live lines due to incorrect isolation 16-December 2020
• ATSB Adelaide level crossing near miss highlights importance of rigorous inspection and testing during signal works
• ATSB Level crossing irregularity involving freight train 1MP9 at Torrens Road, Ovingham, South Australia, on 7 December 2020