Appendix A to Part 237 - Supplemental Statement of Agency Policy on the Safety of Railroad Bridges
49:4.1.1.1.31.9.125.1.70 : Appendix A
Appendix A to Part 237 - Supplemental Statement of Agency Policy on
the Safety of Railroad Bridges
A Statement of Agency Policy on the Safety of Railroad Bridges
was originally published by FRA in 2000 as Appendix C of the
Federal Track Safety Standards, 49 CFR Part 213. With the
promulgation of 49 CFR Part 237, Bridge Safety Standards, many of
the non-regulatory provisions in that Policy Statement have been
incorporated into the bridge safety standards in this part.
However, FRA has determined that other non-regulatory items are
still useful as information and guidance for track owners. Those
provisions of the Policy Statement are therefore retained and
placed in this Appendix in lieu of their former location in the
Track Safety Standards.
General
1. The structural integrity of bridges that carry railroad
tracks is important to the safety of railroad employees and to the
public. The responsibility for the safety of railroad bridges is
specified in § 237.3, “Responsibility for compliance.”
2. The capacity of a bridge to safely support its traffic can be
determined only by intelligent application of engineering
principles and the law of physics. Track owners should use those
principles to assess the integrity of railroad bridges.
3. The long term ability of a structure to perform its function
is an economic issue beyond the intent of this policy. In assessing
a bridge's structural condition, FRA focuses on the present safety
of the structure, rather than its appearance or long term
usefulness.
4. FRA inspectors conduct regular evaluations of railroad bridge
inspection and management practices. The objective of these
evaluations is to document the practices of the evaluated railroad,
to disclose any program weaknesses that could affect the safety of
the public or railroad employees, and to assure compliance with the
terms of this regulation. If the evaluation discloses problems, FRA
seeks a cooperative resolution. If safety is jeopardized by a track
owner's failure to resolve a bridge problem, FRA will use
appropriate measures, including assessing civil penalties and
issuance of emergency orders, to protect the safety of railroad
employees and the public.
5. This policy statement addresses the integrity of bridges that
carry railroad tracks. It does not address the integrity of other
types of structures on railroad property (i.e., tunnels, highway
bridges over railroads, or other structures on or over the
right-of-way).
6. The guidelines published in this statement are advisory. They
do not have the force of regulations or orders, which FRA may
enforce using civil penalties or other means. The guidelines
supplement the requirements of part 237 and are retained for
information and guidance.
Guidelines
1. Responsibility for safety of railroad bridges.
(a) The responsibility for the safety of railroad bridges is
specified in § 237.3.
(b) The track owner should maintain current information
regarding loads that may be operated over the bridge, either from
its own engineering evaluations or as provided by a competent
engineer representing the track owner. Information on permissible
loads may be communicated by the track owner either in terms of
specific car and locomotive configurations and weights, or as
values representing a standard railroad bridge rating reference
system. The most common standard bridge rating reference system
incorporated in the Manual for Railway Engineering of the American
Railway Engineering and Maintenance-of-Way Association is the
dimensional and proportional load configuration devised by Theodore
Cooper. Other reference systems may be used where convenient,
provided their effects can be defined in terms of shear, bending
and pier reactions as necessary for a comprehensive evaluation and
statement of the capacity of a bridge.
(c) The owner of the track on a bridge should advise other
railroads operating on that track of the maximum loads permitted on
the bridge stated in terms of car and locomotive configurations and
weights. No railroad should operate a load which exceeds those
limits without specific authority from, and in accordance with
restrictions placed by, the track owner.
2. Capacity of railroad bridges.
(a) The safe capacity of bridges should be determined pursuant
to § 237.71.
(b) Proper analysis of a bridge requires knowledge of the actual
dimensions, materials and properties of the structural members of
the bridge, their condition, and the stresses imposed in those
members by the service loads.
(c) The factors which were used for the design of a bridge can
generally be used to determine and rate the load capacity of a
bridge provided:
(i) The condition of the bridge has not changed significantly;
and
(ii) The stresses resulting from the service loads can be
correlated to the stresses for which the bridge was designed or
rated.
3. Railroad bridge loads.
(a) Control of loads is governed by § 237.73.
(b) Authority for exceptions. Equipment exceeding the nominal
weight restriction on a bridge should be operated only under
conditions determined by a competent railroad bridge engineer who
has properly analyzed the stresses resulting from the proposed
loads and has determined that the proposed operation can be
conducted safely without damaging the bridge.
(c) Operating conditions. Operating conditions for exceptional
loads may include speed restrictions, restriction of traffic from
adjacent multiple tracks, and weight limitations on adjacent cars
in the same train.
4. Railroad bridge records.
(a) The organization responsible for the safety of a bridge
should keep design, construction, maintenance and repair records
readily accessible to permit the determination of safe loads.
Having design or rating drawings and calculations that conform to
the actual structure greatly simplifies the process of making
accurate determinations of safe bridge loads. This provision is
governed by § 237.33.
(b) Organizations acquiring railroad property should obtain
original or usable copies of all bridge records and drawings, and
protect or maintain knowledge of the location of the original
records.
5. Specifications for design and rating of railroad
bridges.
(a) The recommended specifications for the design and rating of
bridges are those found in the Manual for Railway Engineering
published by the American Railway Engineering and
Maintenance-of-Way Association. These specifications incorporate
recognized principles of structural design and analysis to provide
for the safe and economic utilization of railroad bridges during
their expected useful lives. These specifications are continually
reviewed and revised by committees of competent engineers. Other
specifications for design and rating, however, have been
successfully used by some railroads and may continue to be
suitable.
(b) A bridge can be rated for capacity according to current
specifications regardless of the specification to which it was
originally designed.
6. Periodic inspections of railroad bridges.
(a) Periodic bridge inspections by competent inspectors are
necessary to determine whether a structure conforms to its design
or rating condition and, if not, the degree of nonconformity. See §
237.101. Section 237.101(a) calls for every railroad bridge to be
inspected at least once in each calendar year. Deterioration or
damage may occur during the course of a year regardless of the
level of traffic that passes over a bridge. Inspections at more
frequent intervals may be required by the nature or condition of a
structure or intensive traffic levels.
7. Underwater inspections of railroad bridges.
(a) Inspections of bridges should include measuring and
recording the condition of substructure support at locations
subject to erosion from moving water.
(b) Stream beds often are not visible to the inspector. Indirect
measurements by sounding, probing, or any other appropriate means
are necessary in these cases. A series of records of these readings
will provide the best information in the event unexpected changes
suddenly occur. Where such indirect measurements do not provide the
necessary assurance of foundation integrity, diving inspections
should be performed as prescribed by a competent engineer.
8. Seismic considerations.
(a) Owners of bridges should be aware of the risks posed by
earthquakes in the areas in which their bridges are located.
Precautions should be taken to protect the safety of trains and the
public following an earthquake.
(b) Contingency plans for seismic events should be prepared in
advance, taking into account the potential for seismic activity in
an area.
(c) The predicted attenuation of ground motion varies
considerably within the United States. Local ground motion
attenuation values and the magnitude of an earthquake both
influence the extent of the area affected by an earthquake. Regions
with low frequency of seismic events produce less data from which
to predict attenuation factors. That uncertainty should be
considered when designating the area in which precautions should be
taken following the first notice of an earthquake. In fact,
earthquakes in such regions might propagate their effects over much
wider areas than earthquakes of the same magnitude occurring in
regions with frequent seismic activity.
9. Special inspections of railroad bridges.
Requirements for special inspections of railroad bridges are
found in § 237.105.
10. Railroad bridge inspection records.
(a) The requirements for recording and reporting bridge
inspections are found in § 237.109.
(b) Information from bridge inspection reports should be
incorporated into a bridge management program to ensure that
exceptions on the reports are corrected or accounted for. A series
of inspection reports prepared over time should be maintained so as
to provide a valuable record of trends and rates of degradation of
bridge components. The reports should be structured to promote
comprehensive inspections and effective communication between an
inspector and an engineer who performs an analysis of a bridge.
(c) An inspection report should be comprehensible to a competent
person without interpretation by the reporting inspector.
11. Railroad bridge inspectors and engineers.
(a) Bridge inspections should be performed by technicians whose
training and experience enable them to detect and record
indications of distress on a bridge. Inspectors should provide
accurate measurements and other information about the condition of
the bridge in enough detail so that an engineer can make a proper
evaluation of the safety of the bridge. Qualifications of personnel
are addressed in subpart C to part 237.
(b) Accurate information about the condition of a bridge should
be evaluated by an engineer who is competent to determine the
capacity of the bridge. The inspector and the evaluator often are
not the same individual; therefore, the quality of the bridge
evaluation depends on the quality of the communication between
them. Review of inspection reports is addressed in § 237.111.
12. Scheduling inspections.
(a) A bridge management program should include a means to ensure
that each bridge under the program is inspected at the frequency
prescribed for that bridge by a competent engineer. Scheduling of
bridge inspections is addressed in § 237.101.
(b) Bridge inspections should be scheduled from an accurate
bridge inventory list that includes the due date of the next
inspection.
13. Special considerations for railroad bridges.
Railroad bridges differ from other types of bridges in the types
of loads they carry, in their modes of failure and indications of
distress, and in their construction details and components. Proper
inspection and analysis of railroad bridges require familiarity
with the loads, details and indications of distress that are unique
to this class of structure. Particular care should be taken that
modifications to railroad bridges, including retrofits for
protection against the effects of earthquakes, are suitable for the
structure to which they are to be applied. Modifications should not
adversely affect the serviceability of neither the bridge nor its
accessibility for periodic or special inspection.
14. Railroad implementation of bridge safety
programs.
FRA recommends that each track owner or other entity which is
responsible for the integrity of bridges which support its track
should comply with the intent of this regulation by adopting and
implementing an effective and comprehensive program to ensure the
safety of its bridges. The bridge safety program should incorporate
the following essential elements, applied according to the
configuration of the railroad and its bridges. The basis of the
program should be in one comprehensive and coherent document which
is available to all railroad personnel and other persons who are
responsible for the application of any portion of the program. The
program should include:
(a) Clearly defined roles and responsibilities of all persons
who are designated or authorized to make determinations regarding
the integrity of the track owner's bridges. The designations may be
made by position or by individual;
(b) Provisions for a complete inventory of bridges that carry
the owner's track, to include the following information on each
bridge:
(1) A unique identifier, such as milepost location and a
subdivision code;
(2) The location of the bridge by nearest town or station, and
geographic coordinates;
(3) The name of the geographic features crossed by the
bridge;
(4) The number of tracks on the bridge;
(5) The number of spans in the bridge;
(6) The lengths of the spans;
(7) Types of construction of:
(i) Substructure;
(ii) Superstructure; and
(iii) Deck;
(8) Overall length of the bridge;
(9) Dates of:
(i) Construction;
(ii) Major renovation; and
(iii) Strengthening; and
(10) Identification of entities responsible for maintenance of
the bridge or its different components.
(c) Known capacity of its bridges as determined by rating by
competent railroad bridge engineer or by design documents;
(d) Procedures for the control of movement of high, wide or
heavy loads exceeding the nominal capacity of bridges;
(e) Instructions for the maintenance of permanent records of
design, construction, modification, and repair;
(f) Railroad-specific procedures and standards for design and
rating of bridges;
(g) Detailed bridge inspection policy, including:
(1) Inspector qualifications; including:
(i) Bridge experience or appropriate educational training;
(ii) Training on bridge inspection procedures; and
(iii) Training on Railroad Workplace Safety; and
(2) Type and frequency of inspection; including:
(i) Periodic (at least annually);
(ii) Underwater;
(iii) Special;
(iv) Seismic; and
(v) Cursory inspections of overhead bridges that are not the
responsibility of the railroad;
(3) Inspection schedule for each bridge;
(4) Documentation of inspections; including:
(i) Date;
(ii) Name of inspector;
(iii) Reporting Format; and
(iv) Coherence of information;
(5) Inspection Report Review Process;
(6) Record retention; and
(7) Tracking of critical deficiencies to resolution; and
(h) Provide for the protection of train operations following an
inspection, noting a critical deficiency, repair, modification or
adverse event and should include:
(1) A listing of qualifications of personnel permitted to
authorize train operations following an adverse event; and
(2) Detailed internal program audit procedures to ensure
compliance with the provisions of the program.