Part E - Bridge Inspection

Appendix: Guideline for Bridge Safety Management with clarification comments on grey background

4.1 - Scope

Each railway authority’s BSMP should provide for an effective bridge inspection program.

The railway authority should clearly define and document the different types of inspections to be undertaken for their bridges, including the frequencies of these inspections in their BSMP.

Section Analysis 4.1 – Scope

Bridge inspection is a vital component in BSMP. A bridge with undetected or unreported damage or deterioration can present a serious hazard to the safe railway operations. Bridge inspection and evaluation is a multi-tiered process, unlike many other types of inspection on a railway. While track, equipment and signal inspectors usually can compare measurements against common standards to determine whether the inspected feature complies with the standards, such is not the case with most bridges. The evaluation of a bridge requires the application of engineering principles by a competent person, who is usually not present during the inspection. It is therefore necessary that an inspection report should show any conditions on the bridge that might lead to a reduction in capacity, initiation of repair work, or a more detailed inspection to further characterize the condition.

Types of inspections include but are not limited to cursory, visual, detailed, mechanical, electrical, underwater, special, etc.

4.2 – Bridge & Overhead Bridge Inventory

The railway authority is expected to maintain an inventory of all bridges, located on its right of way. At a minimum, this inventory is expected to include the following information:

  1. Location (i.e. subdivision and mileage),
  2. Bridge type,
  3. Total length,
  4. Individual / average span length,
  5. Maximum height,
  6. Year built,
  7. Deck type,
  8. Obstacle being crossed (i.e. water body, roadway etc),
  9. Geo-referenced coordinates (i.e. longitude, latitude),
  10. Bridge rating, which may be expressed in terms of the individual bridge capacity or line capacity based on the governing bridge rating on the line segment,
  11. Line / load capacity,
  12. Date of line / load capacity evaluation, and
  13. The name of the party responsible for the inspection and maintenance of the bridge.

The railway authority is expected to have a complete inventory of all overhead bridges on its right of way, which at a minimum is expected to include the location (including geo-referenced coordinates) and, where available, the name of the party responsible for its inspection and maintenance.

4.3 - Scheduling of Bridge Inspections

  1. Each BSMP should include a visual inspection for each bridge in service at least once each calendar year with not more than 540 days between any successive inspections.
  2. Each BSMP should include a cursory inspection for each overhead bridge for which the railway authority does not have inspection and maintenance responsibilities, at least once each calendar year with not more than 540 days between any successive inspections.
  3. A bridge should be inspected more frequently when a Railway Bridge Engineer determines that such inspection frequency is necessary considering the conditions noted on prior inspections, the type and configuration of the bridge, and the weight and frequency of traffic carried on the bridge.
  4. Each BSMP should define requirements for the special inspection of a bridge, as per Section 4.5 of this Guideline.
  5. Any bridge that has not been in service and has not been inspected in accordance with this section within the previous 540 days should be inspected and the report of said inspection reviewed by a Railway Bridge Engineer prior to resumption of service.

Section Analysis 4.3 - Scheduling of Bridge Inspections

a. The railway authority should conduct regular comprehensive visual inspections of each bridge, at least once every year with not more than 540 days between any successive inspections, and maintain records of those inspections that include the date on which the inspection was performed, the precise identification of the bridge inspected, the items inspected, and accurate description of the condition of those items, and a narrative of any inspection item that is found by the inspector to be a potential problem.

Annual inspection of railway bridges has been an industry practice for over a century, and has proven to be an effective tool of bridge management. Even where a bridge sees very low levels of traffic, the potential still exists for damage from external sources or natural deterioration. This paragraph calls for one inspection per calendar year, with not more than 540 days between successive inspections. Both criteria apply. For example, if a bridge is inspected on January 3, 2011, it becomes overdue for inspection on June 27, 2012, 541 days later. If it is inspected on December 18, 2011, it becomes overdue on January 1, 2013, since it was not inspected in calendar year 2012.

b. The railway authority should carry out a cursory inspection of all overhead bridges, for which it does not have inspection and maintenance responsibilities at least once every year with not more than 540 days between any successive inspections, and maintain records of those inspections that include the date on which the inspection was performed.

c. A bridge should be inspected more frequently than the period referenced in paragraph a. and b., above; when a Railway Bridge Engineer determines that such inspection frequency is necessary. The responsibility for adequate inspection remains with the railway authority, with the conditions prescribed by a Railway Bridge Engineer. The inspection regime for every bridge should be determined from its condition, configuration, environment and traffic levels.

d. Each BSMP should define requirements for the special inspection of a bridge to be performed whenever the bridge is involved in an event which might have compromised the integrity of the bridge, including flood, fire, earthquake, derailment, or other vehicular or vessel impact. It is essential that safe railway operations be protected from damage from an event caused by natural or non-railway agents. The railway authority should have in place a means to receive notice of such an event, including weather and earthquakes, and a procedure to conduct an inspection following such an event.

e. Any bridge that has not been in railway service and has not been inspected in accordance with this section should be inspected and the inspection report reviewed by a Railway Bridge Engineer prior to the resumption of railway service. The inspection frequency requirements of paragraph a. do not apply to bridges that are not in service, but that does not relieve a railway authority from responsibility for any damage to outside parties that might be caused by the condition of the bridge. If a bridge not in service has been inspected within the previous 540 days, the railway authority may accept that inspection and begin railway service, subject to any determination in that regard by a Railway Bridge Engineer. The inspection period would date from the last inspection, with no credit for out-of-service time.

4.4 – Bridge Inspection Procedures

  1. Each BSMP should specify the procedure to be used for inspection of individual bridges or classes and types of bridges.
  2. The bridge inspection procedures shall11 be as specified by a Railway Bridge Engineer who is designated as responsible for conducting and reviewing the inspections. The inspection procedures should incorporate the methods, means of access, and level of detail to be recorded for the various components of that bridge or class of bridges.
  3. The bridge inspection procedures should ensure that the level of detail in the inspection procedures are appropriate to the configuration of the bridge, conditions found during previous inspections, and the nature of the traffic moved over the bridge, including equipment weights, train frequency and length, level of passenger and hazardous materials traffic, and vulnerability of the bridge to damage.
  4. The bridge inspection procedures should be designed to detect, report and protect deteriorations and deficiencies before they present a hazard to safe railway operations.

Section Analysis 4.4 – Bridge Inspection Procedures

Each BSMP should specify the procedure to be used for inspection of individual bridges or classes and types of bridges. A Railway Bridge Engineer who is designated as responsible for conducting and reviewing the inspections should specify the bridge inspection procedures. The bridge inspection procedures should provide reasonable assurance that the level of detail and the inspection procedures are appropriate to the configuration of the bridge. Additionally, the bridge inspection procedures should be designed to detect, report and protect deterioration and deficiencies before they present a hazard to safe railway operations. The responsibility for adequate inspection remains with the railway authority, with the conditions prescribed by a Railway Bridge Engineer. The inspection regime for every bridge should be determined from its condition, configuration, environment and traffic levels. The instructions for a bridge inspection may be both general, as by bridge type or line segment and specific as needed by particular considerations for an individual bridge.

4.5 - Special Inspections

Each railway authority's BSMP should include a procedure for the protection of traffic and for the inspection of any bridge that might have been damaged by natural or accidental event, including but not limited to flood, fire, ice flows, debris flows, sub-grade instability, rock instability, effect of beaver dam failure, earthquake, derailment, vandalism, vehicular or vessel impact.

Section Analysis 4.5 - Special Inspections

It is essential that traffic be protected from possible bridge failure caused by damage from an event. The railway authority should have in place a means to receive notice of such an event, including weather conditions and earthquakes, and a procedure to conduct an inspection following such an event.

The Railway Bridge Engineer may be required to supplement his/her competencies with outside expertise to provide for a reasonable level of bridge safety, (e.g. geotechnical or Underwater Inspection).

4.6 – Underwater Inspections

Each railway authority's BSMP should include provisions for underwater inspections for the detection of scour or deterioration of bridge components that are submerged and where the foundation cannot be inspected due to the depth of water, high water flow or poor visibility.

The railway authority should have in place an underwater inspection program to identify which bridges to inspect, the items to inspect, and the frequency of underwater inspections to provide reasonable assurance of the foundation’s integrity.

The railway authority should be knowledgeable of the risks posed by scour, erosion and stream stability hazards.

Section Analysis 4.6 - Underwater Inspections

Each railway authority's BSMP should provide for the detection of scour or deterioration of bridge components that are submerged or subject to water flow. The condition of bridge components located under water is usually not evident from above. Means to determine their condition might be as simple as using measuring rods from the surface, or might call for periodic or special diving inspections. Advanced technology might also provide devices that can be used to determine underwater conditions.

It is recognized that not all bridges require an underwater inspection, nor will every part of a bridge over water require an underwater inspection. The intent in this section is that if a bridge is deemed by the Railway Bridge Engineer to be susceptible to conditions that will require underwater inspections, provisions and procedures should be put in place.

4.7 – Inspection of Brush and Drainage Channel Conditions

  1. Each railway authority's BSMP shall12 include provisions for the inspection of brush conditions under and adjacent to bridges and ensure that vegetation is controlled to reduce the fire hazards to bridges and enable a thorough bridge inspection to be carried out.
  2. Each railway authority's BSMP shall13 include provisions to ensure each drainage or other water carrying facility under or immediately adjacent to the bridge is maintained and kept free of obstruction, to accommodate expected water flow for the area concerned.

4.8 – Bridge Inspection Records

  1. Each railway authority should keep a record of each inspection that has been performed on those bridges under this part.
  2. Each record of an inspection under the BSMP described in this part should be prepared from notes taken on the day(s) the inspection is made, supplemented with sketches and photographs as needed.
  3. Each BSMP should specify that every bridge inspection report should include, as a minimum, the following information:
    1. A precise identification of the bridge inspected, (including geo referenced coordinates);
    2. The date(s) on which the inspection was carried out;
    3. The identification and written or electronic signature of the inspector;
    4. The type of inspection performed, in conformance with the definitions of the inspection types in the railway authority's BSMP;
    5. An indication on the report as to whether any item noted thereon requires expedited or critical review by a Railway Bridge Engineer, and any restrictions placed at the time of the inspection; and
    6. The condition of components inspected, which may be in a condition-reporting format prescribed in the railway authority's BSMP, together with any narrative description necessary for the correct interpretation of the report.
  4. Each railway authority's BSMP should specify the retention period and location for bridge inspection records. The retention period should be no less than five years following the completion of the inspection, or until the completion of the next two inspections of the same type, whichever is greater.

Section Analysis 4.8 - Bridge Inspection Records

a. Each railway authority should keep a record of each required inspection that is to be performed on those bridges under this part.

b. A bridge inspection has little value unless it is recorded and reported to the individuals who are responsible for the ultimate determination of the safety of the bridge. Railway Bridge Inspectors may use a variety of methods to record their findings as they move about the bridge. These include, but are not limited to, notebooks, voice recordings, having another individual transcribe notes, and photographs. These notes and other items are usually compiled into a prescribed report form at the end of the day or at the conclusion of the inspection.

c. Delineates the essential elements that should be addressed and reported in any bridge inspection.

d. This provision was drafted with the intent that the actual conduct of the inspection should be reported and recorded, showing the fact that the bridge was actually inspected on a certain date, the type of inspection performed, by whom it was performed, and whether or not any critical conditions were detected. Inspection and reporting procedures vary widely among different railway authorities and circumstances. In many cases, a Railway Bridge Inspector may prepare the report before leaving the bridge. The reports might be forwarded by mail, by electronic means, or by hand delivery. They might be forwarded daily, weekly, or even less frequently. In other circumstances, a consulting engineer might be engaged by a railway authority to inspect all of the bridges on all or part of the line, and the final report might be prepared by the engineering firm after all of the inspections are completed. Similarly, a railway authority might begin a comprehensive inspection and evaluation of a large bridge that will take several weeks to complete.

TC recognizes the wide range of time periods required for these various inspections and reporting procedures, so this provision is recommended as a means for the railway authority to track inspection progress, bridge by bridge, with a simple line item showing:

1. The identification of the bridge inspected;

2. The date(s) on which the inspection was carried out;

3. The identification of the Railway Bridge Inspector;

4. The type of inspection performed; and

5. An indication on the report as to whether any item noted thereon requires expedited or critical review by a Railway Bridge Engineer, and any restrictions placed at the time of the inspection.

d. Further proposes that each BSMP specify the retention period and location for bridge inspection records. There are several good reasons for retaining bridge inspection reports over the period of several years or inspection cycles. First, a comparison of successive reports can reveal any accelerating rates of deterioration or degradation of bridge components. Second, an audit or review of the effectiveness of a bridge inspection program requires comparison of previous inspection reports with the actual condition of a bridge included in the audit. It provides a valuable factor in determining the effectiveness of a BSMP.

4.9 - Review of Bridge Inspection Reports

Each railway authority's BSMP should specify the manner and timeline in which bridge inspection reports will be reviewed by the Railway Bridge Engineer to:

  1. Determine whether inspections have been performed in accordance with the relevant schedule and specified procedures;
  2. Evaluate whether any items on the report represent a present or potential hazard to safety;
  3. Require any modifications to the inspection procedures or frequency for that particular bridge;
  4. Schedule any repairs or modifications to the bridge that are required to maintain its structural integrity; and
  5. Determine the need for further higher-level review.

A Railway Bridge Engineer shall14 review potentially imminent failure conditions identified during bridge inspections prior to the next train movement.

A safety evaluation should be carried out in accordance with timeline identified in the Bridge Safety Management Program. Records of a safety evaluation should identify, at a minimum, the bridge evaluated, the date of the evaluation, the responsible Railway Bridge Engineer, and the conclusions and recommendations resulting from the safety evaluation.

Section Analysis 4.9 - Review of Bridge Inspection Reports

A Railway Bridge Engineer should review inspection reports and determine whether bridges are being inspected according to the applicable procedures and frequencies, and review any items noted by a Railway Bridge Inspector as exceptions and would require higher-level or engineering review. The record of safety evaluation need not necessarily be a stand-alone document.

4.10 – Bridge Hazard Identification and Risk Assessment

A railway company is required to implement and maintain processes for the identification of safety issues and concerns15, evaluating and classifying risks by means of a risk assessment16, and necessary control strategies17.

Section Analysis 4.10 - Bridge Hazard Identification and Risk Assessment

Railway Safety Management System Guide February 2001 (TP13548)

Part E) Risk Management Process

2. (e) a process for

i) identifying safety issues and concerns, including those associated with human factors, third parties and significant changes to railway operations, and

ii) evaluating and classifying risks by means of a risk assessment

Risk management does not mean taking risks, but rather it means identifying risks and working to mitigate or eliminate them. The Safety Management System should include a formal risk management process that includes the following steps:

Step 1 – Identification of Safety Issues and Concerns

  • Mechanisms for employees to identify safety issues and concerns on a routine, ongoing basis that have high levels of visibility and participation
  • Input from incident/accident investigations and safety data collection and analysis
  • Analytical methods such as failure mode and effect analysis, hazard and operability studies, and fault-tree analysis and event-tree analysis for new equipment, systems, practices and procedures where experience and a safety history are not available
  • Special consideration of safety issues and concerns related to human factors, third-party interfaces and the introduction of significant changes to operations
  • Feedback from Safety Management System processes such as incident and accident investigation, safety data collection and analysis, proficiency testing, and internal audit
  • Safety monitoring technology such as hotbox detectors, wheel impact detectors, high water detectors and on-train monitoring systems
  • Input from the public (1-800 numbers), customers (complaint monitoring) and regulatory agencies (findings of non-compliance or unsafe situations)

Railways are expected to do a thorough analysis of both new operations and significant changes to existing operations. In the case of new equipment, systems, operations, practices and procedures where experience and a safety history are not available, formal analytical techniques should be applied. These techniques are more demanding in terms of data, time, effort and expertise; however, this extra effort is justified for new equipment, systems, operations, practices and procedures and should be considered a normal part of the process of implementing change.

Examples of significant changes requiring a risk assessment process include

  • railway company mergers,
  • major organizational transitions,
  • the introduction of new technology (e.g., Light Emitting Diodes), and
  • major operational changes (e.g., new commuter lines, speed changes).

A complete analysis of existing operations is not required provided that current risk mitigation strategies are documented (see component 2(f)). Input from accident and incident investigation, safety performance data collection and analysis, and complaints, inspections and audits should be used to identify areas of existing operations that require a thorough analysis.

Step 2 – Risk Estimation

Assessment of the probability and severity of the safety issue/concern either qualitatively or quantitatively

Quantitative estimates of the probability and severity of the safety issue/concern can sometimes be developed from safety performance data, illness and injury records, etc.

Probability estimates based on historical data assume that future conditions will mirror those of the past. Where no relevant historical data are available, other methods such as fault-tree or event-tree analysis may be used to generate estimates.

Severity is normally measured in terms of the number of deaths or injuries, the value of property damage, or the cleanup costs and environmental impact, either as an average based on the experience of the company or industry over a certain time period or as a range. Other types of losses associated with accidents and incidents that are less easily measurable, such as damage to the company’s reputation and degradation of the quality and timeliness of service to customers, should also be evaluated in assessing the severity of risks. Where quantitative probability and severity estimates cannot be derived due to a lack of relevant data, qualitative estimates based on expert judgment may be substituted.

Step 3 – Risk Evaluation

Evaluate and determine whether the associated risk is tolerable, tolerable with mitigation or unacceptable using a predetermined company risk classification methodology
Risk evaluation is the process of assessing the significance of risks and determining which risks are tolerable, tolerable with mitigation or unacceptable.

Part F) Risk Control Strategies

2. (f) risk control strategies;

Risk control strategies are required for risks that have been classified as unacceptable or tolerable with mitigation. In generic terms, these strategies can focus on

  • eliminating the situation, substance, condition or activity that generates the risk;
  • reducing the probability of occurrence; or
  • mitigating (reducing) the consequences.

It is expected that railways will identify some or all of the risks included in the table on the following pages as unacceptable or tolerable with mitigation. This list is not exhaustive, but it is intended to exemplify common risks and typical control strategies and to indicate the process each railway company should undertake.

For existing operations, many of the risks will have already been considered and risk control strategies will form part of the railway’s current rules, standards, procedures and operating practices. In this case, the risk assessment process would document this link and then focus on the results of accident and incident investigations, safety data analysis, complaint follow-up, inspections, and audits to ensure that the risk is being mitigated to an acceptable level. This analysis should point a railway company to areas where they could undertake initiatives beyond their current practices in an effort to improve their overall safety performance.

For new operations, or for changes to technology, staffing levels, types of operation or other areas where a railway company lacks historical data and experience, a formal risk management process as described in component 2(e) should almost always be undertaken.

The Safety Management System should include procedures for the development of the required strategies, approval at an appropriate management level and effective implementation. Employees and their organizations should be involved in the development of risk control strategies, particularly for risks that they have identified, and they should be informed of the actions that are being taken or that are planned.

Railways are expected to do a thorough analysis of both new operations and significant changes to existing operations. In the case of new equipment, systems, operations, practices and procedures where experience and a safety history are not available, formal analytical techniques should be applied. These techniques are more demanding in terms of data, time, effort and expertise; however, this extra effort is justified for new equipment, systems, operations, practices and procedures and should be considered a normal part of the process of implementing change.

Examples of significant changes requiring a risk assessment process include:

  1. railway company mergers,
  2. major organizational transitions,
  3. the introduction of new technology (e.g., Light Emitting Diodes), and
  4. major operational changes (e.g., new commuter lines, speed changes).

A complete analysis of existing operations is not required provided that current risk mitigation strategies are documented. Input from accident and incident investigation, safety performance data collection and analysis, and complaints, inspections and audits should be used to identify areas of existing operations that require a thorough analysis.

11 Section 11 of the Railway Safety Act
12 Track Safety Rules part II B.II(a)
13 Track Safety Rules part II B.I
14 Section 11 of the Railway Safety Act
15 Section 2(e) of Safety Management System Regulations
16 Section 2(e) of Safety Management System Regulations
17 Section 2(f) of Safety Management System Regulations

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