Safe Management of Structures

Transcription

1 Safe Management of Structures Synopsis This document mandates the requirements for managing the structural integrity of structures so that they do not present an unacceptable risk to safety as a result of their condition, use or location. Submitted by Paul Woolford Project Manager Authorised by Anne Blakeney Acting Department Head s Management This document is the property of the Rail Safety and Standards Board Limited. It shall not be reproduced in whole or in part without the written permission of the Department Head of Railway Group Standards Management, Rail Safety and Standards Board. Published by: Rail Safety and Standards Board Evergreen House 160 Euston Road London NW1 2DX Copyright 2004 Rail Safety and Standards Board Limited

2 This page has been left blank intentionally

3 Page 1 of 21 Contents Section Description Page Part A A1 Issue record 2 A2 Implementation of this document 2 A3 Scope of s 3 A4 Responsibilities 3 A5 Health and safety responsibilities 3 A6 Technical content 3 A7 Supply 3 Part B B1 Purpose 4 B2 Application of this document 4 B3 Definitions 5 B4 Principle 7 Part C C1 Administration of safe management of structures 8 C2 Listing and identification of structures 8 C3 Examination of structures 9 C4 Assessment of structures 15 C5 Evaluation of structural safety of structures 17 C6 Action following an evaluation 18 C7 Records 19 C8 Competency 19 C9 Structures owned by outside parties 20 References 21 RAIL SAFETY AND STANDARDS BOARD 1

4 Page 2 of 21 Withdrawn Document A1 Issue record Part A Issue Date Comments One May 1997 Replaced s GC/RT5121 Examination of Structures and GC/RT5141 Assessment of Structural Capacity. Two October 2000 Revised throughout. Requirements for buildings and assessments clarified. Responsibilities allocated to the duty holder. Three April 2004 Asset management clauses from GC/RT5123 incorporated. Various minor amendments made. Material changes have been marked by a vertical black line in the adjacent margin. This document will be updated when necessary by distribution of a complete replacement. A2 Implementation of this document The publication date of this document is 3 April This document comes into force on 5 June The dates by which compliance with the requirements of this document is to be achieved are set out in Part B2. Where those dates are later than the date on which this document comes into force, this is to give Railway Group members additional time to plan and commence implementation so as to achieve full compliance by the dates set out in Part B2. This document supersedes the following s, either in whole or in part as indicated: Railway Group Standard Issue No. Title RGS sections superseded by this document Date(s) as of which sections are superseded 2 Safe Management of Structures All 5 June 2004 GC/RT Safe Asset Management Coastal and Estuarial Defences Clause Clause Clause June 2004 GC/RT5123, issue 1, is withdrawn with effect from 5 June Parts of GC/RT5123 not superseded by this document are superseded by GC/RT5143, issue 2, which is to be issued at the same time., issue 2, is withdrawn with effect from 5 June RAIL SAFETY AND STANDARDS BOARD

5 Page 3 of 21 A3 Scope of Railway Group Standards A4 Responsibilities The overall scope of s is set out in Annex F of the s Code, issue 1, January The specific scope of this document is set out in Part B2. s are mandatory on all members of the Railway Group* and apply to all relevant activities that fall into the scope of each individual s Railway Safety Case. If any of those activities are performed by a contractor, the contractor s obligation in respect of s is determined by the terms of the contract between the respective parties. Where a contractor is a duty holder of a Railway Safety Case then s apply directly to the activities described in the Safety Case. * The Railway Group comprises Network Rail Infrastructure Limited, Rail Safety and Standards Board Limited, and the train and station operators who hold railway safety cases for operation on or related to infrastructure controlled by Network Rail Infrastructure Limited. Network Rail Infrastructure Limited is also known as Network Rail. Rail Safety and Standards Board Limited is also known as RSSB. A5 Health and safety responsibilities A6 Content Each Railway Group member is reminded of the need to consider its own responsibilities to ensure health and safety at work and its own duties under health and safety legislation. RSSB does not warrant that compliance with all or any documents published by RSSB is sufficient in itself to ensure safe systems of work or operation or to satisfy such responsibilities or duties. The content of this document has been approved by: Track and Structures Subject Committee on 29 January Enquiries should be directed to RSSB Telephone: or enquiries@rssb.co.uk. A7 Supply Controlled and uncontrolled copies of this document may be obtained from the Industry Safety Liaison Department, Rail Safety and Standards Board, Evergreen House, 160 Euston Road, London NW1 2DX or enquiries@rssb.co.uk. s can also be viewed at RAIL SAFETY AND STANDARDS BOARD 3

6 Page 4 of 21 Withdrawn Document B1 Purpose B2 Application of this document Part B This document mandates the requirements for managing the structural integrity of structures so that they do not present an unacceptable risk to safety as a result of their condition, use or location. B2.1 To whom the requirements apply This document contains requirements that are applicable to duty holders of the following categories of Railway Safety Case: a) infrastructure controller b) station operator. At a station contractual arrangements (including a station lease) do not of themselves relieve the duty holder of his obligation to comply with Railway Group Standards that are relevant to the duty holder s licensed activities. This obligation is established by the duty holder s licence and his Railway Safety Case which has been submitted and accepted in accordance with the Railways (Safety Case) Regulations B2.2 Compliance requirements The requirements of this document shall be complied with no later than 5 June B2.2.1 Infrastructure Specifically the contents of this document apply to all structures within the areas of railway infrastructure indicated in the s Code, issue 1, January B2.2.2 Stations Specifically the contents of this document apply to all structures within the areas of railway infrastructure indicated in the s Code, issue 1, January B2.3 General compliance requirements After the compliance date or the date by which compliance is achieved, if earlier, Railway Group members shall maintain compliance with the requirements set out in this. Where it is considered not reasonably practicable to comply with the requirements, authorisation not to comply shall be sought in accordance with the s Code, issue 1, January B2.4 Exclusions from the application of this document This document does not cover all aspects of the safe management of structures. Health and safety and emergency evacuation requirements are not covered. B2.5 Related requirements in other documents GC/RT5122 sets out the requirements for the management of the risks to the operational railway from road vehicles or waterborne vessels striking bridges. GC/RT5143 sets out the minimum requirements for assessing and managing the risk to railway infrastructure from flooding, scour, wave and tidal action, and for the action to be taken when flood warnings are received. GC/RT5151 sets out requirements for the safe management of embankments, cuttings and natural slopes. GC/RT5152 sets out the minimum requirements for managing the risk from mineral extraction and landfill operations. 4 RAIL SAFETY AND STANDARDS BOARD

7 Page 5 of 21 GI/RT7014 sets out the requirements for the design and maintenance of stations to facilitate their safe use. GI/RT7016 sets out the requirements for the design and maintenance of station platforms for their safe interface with trains. GC/RT5180 sets out the requirements for maintaining the structural integrity of tunnels. GC/RT5212 sets out the requirements for monitoring and maintaining clearances. It also mandates requirements for new, altered and temporary infrastructure relating to clearances; gauging conditions for passage of exceptional loads; standard vehicle gauges; and data relating to gauging and clearances, to be provided to Railway Group members and their suppliers. GO/RT3411 identifies minimum actions necessary to identify and respond to exceptional weather conditions as an input to safe rail operation. B2.6 Supporting documents This document is supported by RSSB Approved Code of Practice GC/RC5511, issue 3, which sets out recommendations for the safe management of structures. B3 Definitions Assessment The determination of the safe load-carrying capacity of a structure, taking into account its physical condition, use and location. The term includes the use of quantitative methods, unless otherwise justified, checks, inspections and the use of historic data, where appropriate. Quantitative methods include: a) carrying out calculations b) carrying out documented and technically approved stress measurements c) the use of valid design documentation. Bridge A structure of one or more spans greater than or equal to 1800 mm, whose prime purpose is usually to carry traffic or services over an obstruction or gap. Building A permanent fixed roofed structure into which people can go and within which goods may be stored or within which plant or equipment may be installed. The term excludes train sheds and platform canopies. See also definitions for train shed and platform canopy. Coastal and estuarine infrastructure Particular sections of works that include both coastal and estuarine protection works and sea and estuarine defences. Coastal protection works A particular section of infrastructure which prevents erosion of coastal land and encroachment by the sea and performs no flood defence role. Coastal protection works exist seaward of the limits specified in the Fourth Schedule of the Coast Protection Act Culvert A structure with a span or diameter greater than 450 mm and less than 1800 mm, whose prime purpose is usually, but not exclusively, to permit water or services to pass under a railway or road. The term excludes effluent pipelines passing under a railway or road. Duty holder The Railway Group member responsible for the safe management of a structure under their Railway Safety Case. RAIL SAFETY AND STANDARDS BOARD 5

8 Page 6 of 21 Withdrawn Document Estuarine defence A particular section of infrastructure which protects the railway or low-lying areas from flooding by estuarine waters and which falls inland of the Fourth Schedule of the Coast Protection Act Estuarine protection works A particular section of infrastructure which prevents erosion of estuarine land and encroachment by estuarine waters and performs no flood defence role. Estuarine coastal protection works exist inland of the limits specified in the Fourth Schedule of the Coast Protection Act Evaluation The appraisal of all relevant reports, information, assessments and circumstances relating to a structure to establish whether further action is required to ensure that it does not pose an unacceptable risk to safety as a result of its condition, use or location. Failure The situation where a structure is no longer capable of performing the function required of it. Minor retaining wall Any retaining wall that does not support vehicular loadings and that retains material to either: a) a height of 600 mm or less, or b) a height of 1 m or less, provided it is less than 5 m long. Outside party Any person or organisation other than a Railway Group member. An outside party also includes a Railway Group member acting outside the scope of its Railway Safety Case. Platform canopy A station roof (including its supports) that does not span across operational railway lines. See also definition for train shed. Sea defence A particular section of infrastructure which protects the railway or low-lying areas from flooding from the sea and which falls seaward of the Fourth Schedule of the Coast Protection Act Significant This term is used to describe anything that measurably changes the safety of a structure. Structure Something built to support or retain a load. The term includes: bridges; viaducts; tunnels; culverts; retaining walls (including minor retaining walls); coastal and estuarine infrastructure; gantries, posts and stanchions carrying overhead line equipment, lighting, signals etc; trainsheds; platform canopies; platforms; buildings and water retaining structures. The term includes any permanent access facilities provided. For the purposes of this document the term excludes earthworks. Train shed A station roof (including its supports) that spans across operational railway lines. See also definition for platform canopy. Tunnel A structure provided to allow a railway to pass under higher land and which has been excavated without removing the surface of that land. The term includes 6 RAIL SAFETY AND STANDARDS BOARD

9 Page 7 of 21 any shafts, adits or portals. Other types of construction are also classified as tunnels if the structure requires examination as a tunnel. Viaduct A bridge containing five spans or more. B4 Principle This document supports HMRI Railway Safety Principles and Guidance, Principle 7 in that structures supporting the track should be capable of carrying and transferring the forces exerted by the trains and Principle 8 in that structures above or adjacent to the railway should be capable of supporting the loads imposed upon them and afford protection to the railway. RAIL SAFETY AND STANDARDS BOARD 7

10 Page 8 of 21 Withdrawn Document C1 Administration of safe management of structures Part C The duty holder shall have in place procedures that ensure for each structure: a) its location and identity are known and recorded (see section C2) b) examinations are carried out to identify any significant change in condition, loading or environment that may indicate or cause deterioration (see section C3) c) assessments are carried out to establish the safe load-carrying capacity of the structure, taking into account its physical condition, use and location (see section C4) d) evaluations are carried out to establish whether further action is required to ensure that the structure does not pose an unacceptable risk to safety as a result of its condition, use or location (see section C5) e) a suitable course of action is taken following an evaluation of the structure (see section C6) f) records are available to substantiate these requirements (see section C7) g) a competent person or organisation is appointed to manage the structural integrity of the structure (see section C8) h) significant changes in use are recorded i) significant structural alterations are approved and recorded j) the limits of the responsibilities between maintainers of the track and the structure are defined where the structure supports track(s). Where the structure is owned by an outside party, the requirements of section C9 apply. C2 Listing and identification of structures C2.1 Listing of structures C2.1.1 General requirements The duty holder shall have procedures in place to: a) list all structures in a register (but not necessarily all in a single register) except as described below b) ensure that the listing of structures is complete and maintained c) ensure that each new structure is included in the register as soon as construction work within the scope of this document begins. The register shall clearly define the location, type of structure, owner, type of use of the structure and, where appropriate, the start and finish of the structure. It is permissible to omit minor retaining walls, as defined in section B3, from the register. 8 RAIL SAFETY AND STANDARDS BOARD

11 Page 9 of 21 Temporary structures or significant temporary works attached to a structure shall be considered for inclusion in the register, taking into account their use, the risk of failure, and their expected life. Where buried or hidden structures are known to exist, or there is evidence that they are likely to exist, they shall be included in the register. Action shall be taken to confirm whether the structure exists or not, to the extent determined by the particular site circumstances and the potential risk that the buried or hidden structure poses to the safety of train operations (for example as a result of deterioration in the condition of the buried or hidden structure). C2.1.2 Additional requirements for coastal and estuarine infrastructure For coastal and estuarine infrastructure, the type and function of the infrastructure (that is, coastal protection works, estuarine protection works, sea defence or estuarine defence) shall be listed. C2.2 Unique identity for structures Each structure, which is required to have either a visual or a detailed examination, shall have a unique identity. This shall be recorded in the register and on any records relating to the structure. C2.3 Identification of structures on site Each structure shall be identifiable on site using a method that ensures that there is no ambiguity between the register, the records of the structure and the identification of the structure on site. Bridges, viaducts and other structures about which members of the public and outside parties are likely to report defects shall be provided with a marking clearly visible to members of the public. The marking shall include the identity of the structure to enable observed defects to be reported without doubt as to the structure involved and to permit identification of the structure by those responsible for its maintenance. For complex structures, consideration shall be given to identification marking of individual elements of the structure. C3 Examination of structures C3.1 Principles of structures examination C3.1.1 General principles Unless otherwise excluded by this document, each structure shall be examined to identify any significant change in condition, loading or environment that indicates or causes deterioration. The frequency and quality of examination shall be such that timely and appropriate action can be taken to ensure the continuing safety of the structure. The following examinations shall be undertaken to meet the above requirements: a) detailed examinations, as set out in section C3.2, to identify the primary information needed for the safe management of structures b) visual examinations, as set out in section C3.3, to identify defects which may have developed or worsened since the last examination, particularly since the last detailed examination, where appropriate c) any necessary additional examinations to suit particular circumstances, as set out in section C3.5. Additional information from observation of structures shall be received and recorded, as set out in section C3.6. RAIL SAFETY AND STANDARDS BOARD 9

12 Page 10 of 21 Withdrawn Document The duty holder shall ensure that all persons engaged in the examination process are aware of the action to be taken when they perceive a defect or situation that they believe is likely to endanger users or others. C3.1.2 Particular principles for coastal and estuarine infrastructure All examinations shall be carried out at low water to enable examination of the maximum area of the coastal or estuarine defence, unless the prevailing site conditions prevent this. Where an examination at low water is prevented by the prevailing site conditions, this shall be recorded and justified. Where appropriate, consideration shall be given to arranging for an underwater examination to be carried out of those sections that are permanently under water or under water at the time of the examination. C3.2 Detailed examination of structures C3.2.1 Structures requiring detailed examination The following structures shall receive detailed examinations at regular intervals: a) bridges and viaducts b) buildings c) culverts whose primary method of providing support is other than by arching action d) tunnels e) retaining walls (other than minor retaining walls) f) coastal and estuarine infrastructure g) structural parts of any other type of structure (except culverts) which are under water in a water course, and the depth of water prevents a visual examination h) water retaining structures i) structures which support buildings and span over operational railway lines but excluding the supported buildings j) train sheds k) platform canopies l) signal gantries. The duty holder shall identify any other structures requiring a detailed examination. C3.2.2 Normal interval between detailed examinations The normal interval between detailed examinations of a structure, listed in clause C3.2.1, shall be commensurate with its use, its type, its condition and deterioration, its accessibility and the effectiveness of the visual examinations required by section C3.3. The normal intervals between detailed examinations of structures shall not be greater than those specified in column A of Table 1, unless a risk assessment has been carried out. Where an increased interval between detailed examinations has been justified by a risk assessment it shall not exceed twice the normal interval specified in column A of Table RAIL SAFETY AND STANDARDS BOARD

13 Page 11 of 21 A B Type of structure Tunnels (excluding shafts) and coastal and estuarine infrastructure Structural parts of structures (except culverts) which are under water in a water course, and where the depth of water prevents a visual examination Type of structures identified in clause C3.2.1 except as otherwise specified in this table Normal interval between detailed examinations Maximum permitted tolerance on intervals between detailed examinations 12 months 3 months 3 years 6 months 6 years 6 months Table 1 Intervals between detailed examinations For other structures identified by the duty holder as requiring a detailed examination, the interval between detailed examinations shall be determined according to the circumstances, and the justification for the interval documented. C3.2.3 Maximum permitted tolerance on intervals between detailed examinations The interval between detailed examinations, whether it is based on the normal interval set out in column A of Table 1, or based on an increased interval justified by a risk assessment, shall not be extended beyond the determined interval plus the tolerance set out in column B of Table 1. The permitted tolerance, set out in column B of Table 1, shall not be used to increase the interval between detailed examinations on a regular basis. C3.2.4 Risk assessment to increase intervals between detailed examinations Where a risk assessment is required to determine an increased interval between detailed examinations, it shall take into account: a) the age of the structure b) the current condition and predicted rate of deterioration of the structure c) the presence of any materials likely to be subject to rapid failure d) the presence of fatigue-prone details or materials e) the likelihood of any current restrictions in its use being exceeded f) the results of any monitoring or measurements that have been carried out g) known or predicted external influences which may cause rapid deterioration or failure h) the likelihood of significant defects not being detected during a visual examination RAIL SAFETY AND STANDARDS BOARD 11

14 Page 12 of 21 Withdrawn Document i) the results of an evaluation of structural safety j) the quality and extent of examinations carried out k) the likely mode and consequences of failure l) the likelihood of any significant changes in use of the structure or in the traffic passing beneath the structure. The risk assessment shall be recorded and records retained until superseded by a subsequent review of the detailed examination interval. The validity of the risk assessment shall be confirmed after each detailed examination and when any other relevant changes become apparent. C3.2.5 Structures subject to rapid changes in condition or circumstances Where it is known, or suspected, that a structure is subject to a rapid change in condition or circumstances, the interval between detailed examinations shall be reduced to ensure that any significant change in condition or circumstances can be identified and assessed to maintain an adequate level of safety. C3.2.6 Quality and content of detailed examinations Except for hidden, obscured or buried parts of structures, the detailed examination shall be of sufficient quality to produce a record that includes the condition of all parts of the structure; the uses to which it is being put; recommendations for remedial action and any other relevant facts, so that: a) the extent of any change or deterioration since the last examination can be established b) the scope and urgency of any action needed before the next examination can be ascertained c) any changes required to the intervals between examinations can be identified d) the need for any further special investigation or other action can be determined. The examination shall generally be carried out from a position where the examiner is within touching distance of the part being examined unless otherwise justified (for example, by using closed circuit television equipment for the examination of tenanted arches that are clad or for underwater examinations). Where a load-bearing part, whose condition is critical in establishing the continuing safety of the structure, is hidden or obscured, the examination shall be sufficient to enable its condition to be verified. The scope of examination, and the extent to which the condition of safety-critical load-bearing parts could be verified, shall be recorded. For partially buried parts such as bridge abutments, and for completely buried parts such as foundations, the detailed examination shall be sufficient to identify whether such parts are likely to be suffering distress and whether further investigation (for example, monitoring or additional examination) is required. The likelihood of damage to the structure as a result of exposing the structure shall be taken into account in deciding whether or not to expose a hidden or obscured part. Where hidden, obscured or buried parts are exposed, consideration shall be given to obtaining dimensions of the part of the structure for assessment purposes. 12 RAIL SAFETY AND STANDARDS BOARD

15 Page 13 of 21 Where fire protection or other protection is removed to expose a structural element for examination, the protection shall be reinstated following the examination. For structures subject to traffic loads, the behaviour of the structure under normal traffic shall be observed and recorded, unless otherwise justified because of the particular site circumstances. C3.2.7 Reports of detailed examinations After every detailed examination a formal report shall be produced which: a) confirms that all accessible parts of the structure have been examined b) records the extent and severity of any defects found c) identifies the extent and severity of any changes in condition, use or environment since the last examination d) draws attention to any observed factors which may affect the safety of the structure e) identifies all hidden, obscured or buried parts that have not been examined f) identifies whether further investigation (such as monitoring or additional examination) is recommended g) for structures supporting traffic loads, identifies whether the structure was observed under traffic load and, if not, why it was not reasonably practicable to do so. For buildings, the report shall also include a recommended prioritised programme of planned maintenance, repair and renewal (if such work is required) until the next detailed examination. C3.3 Visual examination of structures C3.3.1 Structures requiring visual examinations All structures shall be visually examined at regular intervals. It is permissible to exempt buildings and minor retaining walls from regular visual examinations. C3.3.2 Interval between visual examinations The interval between visual examinations of each structure shall be commensurate with the following: a) its deterioration b) its vulnerability to accidental or deliberate damage or misuse c) its history of damage or misuse. The normal interval between visual examinations of structures shall not, however, be greater than 12 months, with a maximum permitted tolerance to the normal interval of three months. The permitted tolerance to the normal interval shall not be used to increase the normal interval on a regular basis. When a detailed examination coincides with a visual examination, it is not necessary to undertake a separate visual examination. C3.3.3 Quality and content of visual examinations The examination shall be of sufficient quality to detect and report any significant visible changes or evidence of impending changes since the last visual and detailed examinations, and in particular: RAIL SAFETY AND STANDARDS BOARD 13

16 Page 14 of 21 Withdrawn Document a) significant cracks b) any signs of loose, displaced or fallen material c) significant vandalism or accidental damage d) signs of significant subsidence or ground movement e) flooding or evidence of flooding f) changes in condition or in the deterioration of known defects g) changes in the nature or extent of use h) changes in the environment that could lead to rapid deterioration or affect safety i) significant changes in the readings of any monitoring systems currently being used. C3.3.4 Reports of visual examinations In the report of a visual examination, written evidence shall be produced which: a) confirms that the examination has been completed b) lists any significant defects or changes that have occurred or worsened since the last visual and/or detailed examinations c) identifies whether any changes to the intervals between examinations are required d) identifies whether there is a need for further special investigation or other action. C3.4 Annual review of planned maintenance, repair and renewal programme for buildings In place of an annual visual examination, the duty holder shall have procedures in place to ensure that the programme of planned maintenance, repair and renewal for each building, identified as a result of the detailed examination, is reviewed annually. The duty holder shall ensure that appropriate action is taken to overcome any shortfalls or take into account changes to the planned programme, whether or not the work was originally identified in the detailed examination report. C3.5 Additional examination C3.5.1 Structures requiring additional examinations An additional examination shall be carried out in the following circumstances: a) where the detailed examination, together with the assessment, where available, provides insufficient information to evaluate the safety of the structure b) after flooding, scour, wave action, tidal action, gales or earthquakes which could have affected the structure. c) following significant accidental or deliberate damage to a structure or parts of a structure. 14 RAIL SAFETY AND STANDARDS BOARD

17 Page 15 of 21 Consideration shall also be given to carrying out an additional examination when: d) a report is received that indicates that the safety of the structure has been compromised (for example, as a result of an exceptional event) e) understanding of the safety of the structure is altered as a result of new technical knowledge. C3.5.2 Content and reports of additional examinations The extent, method and purpose of additional examinations and the method of reporting shall be determined according to the circumstances, and the reasons documented. C3.6 Receiving and recording of observations of structures The duty holder shall have procedures in place to receive and record reports of: a) observations of details of the condition of structures which might affect the safety of persons on or about the structure b) observed changes in the condition of structures, including loose, displaced or fallen material, new defects or changes to existing defects c) observations of other situations which might affect the safety of train operations and the integrity of structures. The duty holder shall have procedures in place to investigate reported changes in the condition or situations to establish whether the reported change in the condition or situation is significant. GC/RT5021 sets out requirements for track inspections, including a requirement that, to the extent that it is reasonable to do so in the course of track inspections, faults and defects in bridges, viaducts, tunnels and other lineside structures are to be identified, recorded and reported. C4 Assessment of structures C4.1 Structures requiring assessment C4.1.1 Specific types of structures requiring assessment An assessment shall be carried out on the following structures: a) bridges and viaducts b) culverts whose primary method of providing support is other than by arching action c) structures which both support buildings and span across operational railway lines but excluding the supported buildings d) train sheds e) other types of construction classified as tunnels by the duty holder for the purposes of examination, but which support traffic loads. C4.1.2 Assessment of platform canopies An assessment on platform canopies shall also be carried out unless otherwise justified by appropriate criteria, including the following: a) knowledge of its condition, deterioration, repairs and problems exist b) there are no significant active defects c) the aerodynamic effects of passing trains are not severe and there are no plans for the speed of passing trains to increase significantly RAIL SAFETY AND STANDARDS BOARD 15

18 Page 16 of 21 Withdrawn Document d) there have been no significant increases in the loading on the canopy since it was built. All such justifications shall be documented. C4.1.3 Assessment of other structures For other structures, an assessment shall be carried out where information, in addition to that obtained from the examination process, is required by the duty holder to confirm the safe load capacity of the structure. C4.2 Reviewing validity of assessments A procedure shall be in place for reviewing the validity of assessments. The procedure shall take into account the factors identified in section C4.3, together with: a) the results of the most recent assessment b) the interval since the most recent assessment C4.3 Action plan for carrying out initial assessments Where no previous assessment exists, an action plan shall be created for prioritising, setting timescales and carrying out the initial assessments. The prioritisation of assessments shall take into account: a) the type and frequency of the loading to which the structure is subjected b) the type of structure c) the condition and deterioration of the structure d) the vulnerability of the structure to accidental damage e) any proposals for significant changes in the type and frequency of loading to which the structure will be subjected f) any strengthening or repairs g) the consequence of failure of the structure. C4.4 Method of assessments C4.4.1 Assessments requiring the use of quantitative methods Assessments using quantitative methods shall be carried out for: a) the superstructures of all viaducts and multispan bridges b) the superstructures of all single span bridges, except single span bridges with an effective span of less than 2 m, whose primary method of providing support is by arching action c) culverts whose primary method of providing support is other than by arching action d) structures which support buildings and span across operational railway lines but excluding the supported buildings e) train sheds. 16 RAIL SAFETY AND STANDARDS BOARD

19 Page 17 of 21 C4.4.2 Assessments of substructures requiring the use of quantitative methods Assessments using quantitative methods shall be carried out for the substructures of all bridges and viaducts, and for the substructures of culverts whose primary method of providing support is other than by arching action, where: a) the substructure is showing signs of distress to the extent that the structural integrity of the substructure cannot be established by examination alone b) significant changes to the loading are proposed (for example, as a result of higher speeds, heavier traffic, heavier superstructure following reconstruction) c) there is a significant weakening to the support of the substructure (for example, as a result of road lowering beneath a bridge, scour). C4.4.3 Assessments using qualitative methods For other structures or parts of structures (for example, the substructures of viaducts and bridges to which clause C4.4.2 does not apply), whether or not the types are specifically identified in clauses C4.1.1 or C4.1.2, it is permitted for qualitative methods to be used for all or part of the assessment as determined by the duty holder. C4.5 Technical approval of assessments Appropriate technical approval procedures for the assessment and checking thereof shall be in place for all assessments. Where structures are of complex or unusual form and the methods of analysis contained in current British, European or industry standards cannot be used or are inappropriate, the validity of the method of assessment shall be confirmed by a competent person within an organisation that is independent of the organisation carrying out the assessment. C5 Evaluation of structural safety of structures C5.1 Structures requiring evaluation of structural safety The structural safety of each structure other than minor retaining walls shall be evaluated. C5.2 When evaluations of structural safety are required The evaluation of the structural safety of a structure shall be carried out: a) after a report is received of a significant defect or a situation that is likely to affect the safety of train operations or the safety of a building b) after a visual, detailed or additional examination report is received c) after an assessment d) when there is a significant change in condition e) after significant accidental or deliberate damage f) when a significant change in the nature or extent of use or loading is apparent g) before a significant change of use or loading is introduced h) before significant structural repairs or alterations are carried out i) when new knowledge indicates safety may be affected RAIL SAFETY AND STANDARDS BOARD 17

20 Page 18 of 21 Withdrawn Document j) when a significant change in environment occurs k) where existing records are insufficient to confirm its continuing safety. C5.3 Factors to be considered in the evaluation of structural safety For all structures the nature and extent of the evaluation required shall be determined, taking into account the risk from failure of the structure. The evaluation shall consider the effects of the loads likely to be imposed upon the structure and, taking into account the available data, confirm or otherwise its structural safety as a result of the condition, use or location of the structure. The evaluation of a structure shall also take into account, where applicable: a) its condition as revealed by examination b) its form and dimensions c) the strength and fatigue characteristics of the materials used d) the likely mode of failure e) the maximum permissible loading, including dynamic effects f) the likelihood of any imposed restriction on its use being exceeded g) the likelihood of deliberate damage occurring to the structure from vandalism h) the risk from damage occurring due to flooding, scour or other environmental effect (see also GC/RT5143) i) the risk from and/or to derailed trains at bridges spanning over the operational railway lines j) the risk from and/or to derailed trains at bridges supporting operational railway lines, including the need for guard rails or other methods of derailment containment on viaducts and other long span bridges k) the risk from road vehicles or waterborne vessels striking structures (including the risk of debris falling onto the railway as a result of the strike) l) the aerodynamic effects from passing trains m) the results of the most recent assessment, where available. The amount of information required shall take into account the degree of uncertainty about construction details and/or material strengths. Particular attention shall be given to establishing the level of protection provided by the coastal or estuarine defence. C6 Action following an evaluation The duty holder shall have procedures in place to: a) enable a suitable course of action to be determined following an evaluation of the structure b) carry out the course of action that has been determined c) check that such action has been carried out fully and to the required standard of workmanship 18 RAIL SAFETY AND STANDARDS BOARD

21 Page 19 of 21 d) report back on the results of any action taken. In all cases, suitable action shall be taken before the risk to the safety of train operations or the integrity of the structure becomes compromised. C7 Records Where applicable, the following records for each structure shall be retained for as long as the structure exists: a) as-built drawings of all new structures and any subsequent repairs to them b) as-built drawings of existing structures and any subsequent repairs to them where such drawings are known to exist c) examination reports and other records relating to structural condition d) the documented results of any assessments or equivalent e) the unique identity of the structure f) the safe load capacity of the structure g) the written or otherwise documented results of any evaluation of the structure h) the details and written or otherwise documented results of any risk assessment used to determine the scope of examinations or assessments i) details of any repairs or other action specified, with reasons for requiring such action, and confirmation or otherwise that the actions have been satisfactorily completed. The requirements for managing safety related records of elements of the infrastructure are set out in GI/RT7001. Details of the skill, knowledge and experience of all persons employed in the management of structures, and records of their appointment or approval, shall be retained for the period of validity of any work they have carried out. C8 Competency The duty holder shall have procedures in place that ensure that all persons or organisations with responsibilities for managing structures: a) have the necessary skill, knowledge, professional qualifications and experience to carry out those responsibilities commensurate with the type and complexity of the structures to be managed b) are fully aware and understand the extent of their responsibilities c) have sufficient resources to undertake their responsibilities d) understand to an appropriate level the mechanisms of structural failure and deterioration and can judge when urgent or immediate action is necessary for safety reasons. Additional requirements for competence management for safety-critical work are given in GO/RT3260. RAIL SAFETY AND STANDARDS BOARD 19

22 Page 20 of 21 Withdrawn Document C9 Structures owned by outside parties For each structure owned by an outside party the location, identity and, where it can be established, the owner of the structure shall be recorded and included in a register of structures held by the duty holder. For such structures, procedures shall be in place to determine whether the structure owner is competent to manage the safety of the structure. Where the duty holder is not satisfied that the structure is being managed safely, the structure shall be subjected to an external visual examination so far as is lawful and the owner advised of any significant defects observed. Appropriate action shall be taken to control any risk to the safety of train operations that is perceived or advised as a result of the presence or condition of any such structure. 20 RAIL SAFETY AND STANDARDS BOARD

23 Page 21 of 21 GC/RT5021 GC/RT5122 GC/RT5143 GC/RT5151 GC/RT5152 GC/RT5180 GC/RT5212 GI/RT7001 GI/RT7014 GI/RT7016 GO/RT3260 GO/RT3411 References s and Other Railway Group Documents The s Code, issue 1, January Track System Requirements Bridge Strikes from Road Vehicles or Waterborne Vessels Scour and Flooding, including Wave and Tidal Action Managing the Risk Safe Asset Management - Embankments and Cuttings Mineral Extraction and Landfill Managing the Risk Safe Asset Management of Infrastructure Tunnels Requirements for Defining and Maintaining Clearances Safety Related Records of Elements of the Infrastructure Infrastructure Requirements at Stations Interface between Station Platforms, Track and Trains Competence Management for Safety Critical Work Exceptional Weather Conditions - Managing the Risks The Catalogue of s and the s CD-ROM give the current issue number and status of documents published by RSSB. This information is also available from Other References Coast Protection Act 1949 HMRI Railway Safety Principles and Guidance RAIL SAFETY AND STANDARDS BOARD 21