Guideline for Bridge Safety Management

Part D - Bridge Inspection

3.1 – Scope

The railway company BSMP should provide for an effective bridge inspection program. The railway company 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 3.1 – Scope

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. The evaluation of a bridge requires the application of engineering principles by a professional engineer or a competent person under the direction of a professional engineer, 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.

3.2 – Inventory

The railway company is expected to maintain an inventory of all bridges on its right of way, and should have a list of all third-party overhead bridges on its right of way.

3.2.1 – Bridges

At a minimum, the bridge inventory should include the following information:

  1. Location (e.g. subdivision and mileage),
  2. Geo-referenced coordinates (e.g. longitude, latitude),
  3. Obstacle being crossed (e.g. water body, roadway etc.),
  4. Maximum height,
  5. Total length,
  6. 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,
  7. Date of bridge rating completed,
  8. The entity, if other than the railway company, responsible for the inspection and maintenance of the bridge,
  9. Each bridge span should have the following information:
    1. Superstructure type,
    2. Substructure type,
    3. Span length,
    4. Year built, and
    5. Deck type.
  10. Identify bridge sub-structures that are vulnerable to scour, erosion or lateral stream migration.

Items (f) and (g), if not part of the railway company's bridge inventory, should be referenced in its BSMP as to where it can be found.

3.2.2 – Third Party Overhead Bridges

At a minimum the list of third-party overhead bridges should include the location and the entity responsible for inspection and maintenance.

Section Analysis 3.2 – Inventory

The inventory may be included as an appendix to the BSMP or referenced as a separate, stand-alone document.

3.3 – Types of Inspections

3.3.1 – Visual Inspection

A visual inspection is a documented inspection made by a Railway Bridge Engineer or a Railway Bridge Inspector under the direction of a Railway Bridge Engineer.

3.3.2 – Special Inspections

The railway company BSMP should include an appropriate procedure for the protection of traffic after an accident or during and after a significant natural event that may have affected the structural integrity of the bridge, and for the subsequent inspection of any bridge that might have been affected.

A significant natural event may include but not limited to flood, fire, ice flows, debris flows, sub-grade instability, rock instability, the effect of beaver dam failure, and earthquake.

3.3.3 – Underwater Inspections

The railway company 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 company BSMP should include provisions for routine 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 or poor visibility.

The railway company should be knowledgeable of the risks posed by scour, erosion and stream stability hazards, including those associated with spread footings.

Section Analysis 3.3.3 - Underwater Inspections

The condition of bridge components located underwater 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 a Railway Bridge Engineer to be susceptible to conditions that will require underwater inspections, provisions and procedures should be put in place.

3.3.4 – Vegetation and Drainage Channel Inspection

The railway company BSMP should incorporate inspection practices to monitor vegetation and drainage conditions to ensure conditions are compliant with the Rules Respecting Track Safety, do not negatively affect bridge safety or safe railway operations and enable a thorough bridge inspection to be carried out.

3.4 – Scheduling of Bridge Inspections

The BSMP should include:

  1. 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. An inspection for each third party overhead bridge as per the Rules Respecting Track Safety.
  3. A provision for inspecting bridges 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. A defined requirement for the special inspection of a bridge, as per Section 3.3.2 of this Guideline.
  5. A requirement that any bridge that has not been in service and has not been inspected in accordance with this section should be inspected and the report of said inspection reviewed by a Railway Bridge Engineer before the resumption of service.

3.5 – Bridge Inspection Procedures

  1. The BSMP should specify or reference the procedures to be used for inspection of bridges or classes and types of bridges.
  2. The bridge inspection procedures shallFootnote 6 be as specified by a Railway Bridge Engineer.
  3. The bridge inspection procedures should be designed to detect, report, and protect deteriorations and deficiencies before they present a hazard to safe railway operations.

3.6 – Bridge Inspection Records

  1. The railway company should keep a record of each inspection.
  2. Each inspection record should be prepared from notes taken during the inspection, supplemented with sketches and photographs as needed.
  3. Each inspection record should specify, as a minimum, the following information:
    • Precise identification of the bridge inspected, ( e.g., geo-referenced coordinates);
    • The date on which the inspection was completed;
    • The identification and written or electronic signature of the inspector;
    • The type of inspection performed, in conformance with the definitions of the inspection types in the railway company BSMP;
    • 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
    • The condition of components inspected, which may be in a condition reporting format prescribed in the railway company BSMP, together with any narrative description necessary for the correct interpretation of the report.
  4. The railway company should specify the location where inspection records are kept.
  5. The retention period for inspection records 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 3.6 – Bridge Inspection Records

Item d.

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 valuable information for determining the effectiveness of the BSMP.

3.7 – Review of Bridge Inspection Reports

The railway company BSMP should specify the process by which bridge inspection reports are reviewed by a Railway Bridge Engineer.

The purpose of this review is to:

  1. Ensure that inspections have been performed in accordance with the relevant frequency 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 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 a Higher Level Review.

The timeline between the inspection and review should not be longer than 365 days. The review should be recorded and identify at a minimum the bridge reviewed, the date of the review, the responsible Railway Bridge Engineer, and the conclusions and recommendations resulting from the review.

However, a Railway Bridge Engineer shallFootnote 7 review potentially imminent failure conditions identified during bridge inspections before the next train movement.

3.8 – Higher Level Review

A higher level review is conducted by a Railway Bridge Engineer to ensure that a bridge is safe for its intended use. The review may include an assessment of all existing bridge inspections, evaluations, reports, information and circumstances relating to a bridge. Additional inspections or evaluations may be required to complete the higher level review.

Records of a higher level review 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 higher level review.

3.9 – Bridge Hazard Identification

  1. The railway company should develop, implement and maintain processes for the identification of safety issues and concerns, to evaluate and classify risks, and implement necessary control strategies.
  2. The railway company should be aware of the risks posed by scour, erosion and lateral stream migration. The railway company should implement measures to ensure safe railway operations over the bridges during and after severe weather.
  3. The railway company should be aware of the risks posed by load and distortion induced fatigue on steel bridges. It should maintain documentation of bridges where fatigue cracking has been observed. Where necessary the railway company should implement mitigating measures to minimize the probability of failure as a result of fatigue crack growth.

Section Analysis 3.9 - Bridge Hazard Identification

Item b.

Severe weather events that result in flooding or high flows frequently damage or wash out railway bridges and culverts, which can threaten safe railway operations when the risks are not recognized or adequately mitigated.

Items that should be considered include, but are not limited to, the following:

  • Identification of bridges which are susceptible to scour or lateral stream migration;
  • Identification of areas known to be subject to flooding or high flows;
  • Identification of bridges that have experienced damage as a result of a previous event;
  • Identification of critical bridges to determine whether, when, and where projected flooding or high flows might be consequential;
  • Awareness of snowpack conditions and impact on spring runoff;
  • Awareness of the effects of ice flow dams and other debris accumulation on the substructure;
  • Develop and implement acceptable methods of protecting bridges before, during, and after a flood or high flow event;
  • Develop and implement monitoring technologies that could provide advance warning of pending failures due to the effects of an event;
  • Use of sonar, sensors, and other smart technologies to monitor scour-critical bridges;
  • Define qualification and training requirements for inspectors to monitor bridges during an event;
  • Develop processes for monitoring the occurrence of severe weather events;
  • Define the frequency and scope of inspections to be performed during a flood or high flow event; and
  • Determine acceptable methods of performing an underwater inspection when divers cannot be used.

Item c.

Information regarding fatigue in railway bridges is available in the AREMA Manual for Railway Engineering, Volume 2. It is recognized that alternative methods and standards exist and are employed by some railway companies.