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Project Paper                                                  Bradley W Yates                                            ...
Project Paper                                    Bradley W Yates                                                   April 2...
Project Paper                                     Bradley W Yates                                                   April ...
Project Paper                                          Bradley W Yates                                                   A...
Project Paper                                   Bradley W Yates                                                   April 20...
Project Paper                                        Bradley W Yates                                                      ...
Project Paper                                        Bradley W Yates                                                  Apri...
Project Paper                                      Bradley W Yates                                                  April ...
Project Paper                                     Bradley W Yates                                                 April 20...
Project Paper                                     Bradley W Yates                                                  April 2...
Project Paper                                     Bradley W Yates                                                  April 2...
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
B Yates Operation Bridgeguard Paper Network Rail
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B Yates Operation Bridgeguard Paper Network Rail

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The purpose of this report is to illustrate the processes and functions with respect to the Bridgeguard 3 (BG3) Programme involving the inspection, assessment, protection and enhancement of Network Rail owned public road-over-rail bridges as a result of the UK Government’s agreement to allow 40T/44T Heavy Goods Vehicles (HGV) for international journeys on UK roads.
The report outlines the origins of BG3, from the initial European Council Directive and the UK Governments decision to undertake a risk management exercise to address the situation of allowing unchecked increases in HGV’’s since 1968 from 24T to 38T, through the challenges faced and ahead in order to close-out this massive enhancement operation.
Covering issues which caused delay in commencing the enhancement scheme, along with management and financial obligations by the stakeholders, the general impact of 40T/44T HGV’’s on bridges and safety responsibilities. Requirements will also be discussed with respect to inspections and working in the railway environment. Moving on to explain the assessment process, interim mitigation requirements, feasibility studies for works options such as permanent mitigation, which may involve permanent protection and/or strengthening or reconstruction. Then will examine the roles and responsibilities of the BG3 Coordinator plus a walking through a case study to illustrate the labyrinth of related tasks and decisions involved from receiving an assessment result through to a permanent solution that is acceptable to all stakeholders, both economically and in a practical sense relating to transport, environment and public interactions.
Finally, the current expenditure and status will be scrutinized in order to predict a date and cost of completion of the National BG3 Programme based on, and extrapolated from, the progress of the South East Territory.

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Transcript of "B Yates Operation Bridgeguard Paper Network Rail"

  1. 1. Project Paper Bradley W Yates April 2006 O P E R AT I O N B R I D G E G U A R D Bradley Yates, Bridgeguard 3 Coordinator, Structures Engineer, Network Rail, South East Territory, Civil Engineering, Structures, Waterloo, London, England, UK. 1. INTRODUCTION ABSTRACT Operation Bridgeguard, or Bridgeguard 3 (BG3), is the National Rail assessment and strengthening/reconstruction (or permanent mitigation) programme for public The purpose of this report is to illustrate road-over-rail ‘overline’ bridges. This was instigated by the UK Government’s reaction 12 the processes and functions with respect to adopting the European Council Directive 85/3/EEC , under the European Union to the Bridgeguard 3 (BG3) Programme (EU), that Member States must accept articulated vehicles and drawbar-trailer involving the inspection, assessment, combinations with 5 or more axles weighting up to 40 Tonnes (T – Metric) for protection and enhancement of Network st Rail owned public road-over-rail bridges international journeys on UK roads by 1 January 1999. as a result of the UK Government’s agreement to allow 40T/44T Heavy The applicable assessment code at that time was the Department of Transport (DoT), 6 Goods Vehicles (HGV) for international Roads and Local Transport Directive, Departmental Standard BD 21/84 and Advice journeys on UK roads. 5 Note BA 16/84 , which cover certain types of structures. Where assessment involves The report outlines the origins of BG3, a degree of engineering judgement, such as an acceptable method of assessing arch from the initial European Council 17 Directive and the UK Governments structures based on the modified ‘MEXE’ analysis which was the product of a 21 decision to undertake a risk management research programme led by Pippard , initially used for military purposes, but after the nd exercise to address the situation of 2 World War was adapted for civil use. The loading criterion for assessment was in allowing unchecked increases in HGV’’s accordance with the maximum gross vehicle and axle weight allowable under the since 1968 from 24T to 38T, through the 30 challenges faced and ahead in order to Statutory Instrument SI 1576/1982 . close-out this massive enhancement operation. However, the BG3 Programme did not commence at this time, due to considerable Covering issues which caused delay in debate and negotiation with regard to funding this national enhancement programme, commencing the enhancement scheme, which went on through the rest of the 1980’s and early 1990’s, until the DoT issued along with management and financial instructions to all ‘English’ Local Highway Authorities (LHA), stating they were obligations by the stakeholders, the expected to fund all assessment work starting from 1994/95 through use of money general impact of 40T/44T HGV’’s on 17 bridges and safety responsibilities. supplied through the Transport Supplementary Grant .* Requirements will also be discussed with respect to inspections and working in the Upon receiving this instruction a small few LHA’s commenced assessment work in railway environment. Moving on to 1993. However, this was a false start due to further debate and negotiation with regard explain the assessment process, interim to the position of the ‘Railway’, being only legally liable to provide and maintain this mitigation requirements, feasibility studies for works options such as permanent infrastructure to a capacity of 24 tons (t – Imperial). Which represented the level of 28 mitigation, which may involve permanent loads under the Motor Vehicles ‘Construction and Use’ Regulations 1969 at that 27 protection and/or strengthening or time, and under Section 117 of the Transport Act 1968 (S 117/68) , or as reconstruction. Then will examine the permanently weight restricted upon completion of the original ‘Operation Bridgeguard’, roles and responsibilities of the BG3 st Coordinator plus a walking through a or Bridgeguard 1 (BG1) Programme by 31 December 1968; stating, the ‘Railway’ case study to illustrate the labyrinth of was obliged to maintain unrestricted bridges to the standard of 24t, in accordance with related tasks and decisions involved from 16 the Ministry of Transport Technical Memorandum (Bridges) No. BE 4/67 , and receiving an assessment result through to 29 a permanent solution that is acceptable to Statutory Instrument 1705/1972 . These principles were accepted by the LHA’s in the all stakeholders, both economically and in end and adopted into a national agreement for a joint venture framework contract a practical sense relating to transport, (JVFC) in 1996. The programme was now finally in a position to commence in earnest. environment and public interactions. Finally, the current expenditure and Had BG1 been completed, in which public funding was available, the ‘Railway’ would 14 status will be scrutinized in order to have been obliged to maintain all bridges to the standard of 24t . ** predict a date and cost of completion of the National BG3 Programme based on, This report will take a retrospective look at the issues, which have caused delay to the and extrapolated from, the progress of BG3 programme. Such as; changes to the above mentioned codes and directives, the South East Territory. including changes in ownership of the national rail network infrastructure, and my involvement in determining; the current status and close-out of the; assessments, risk KEYWORDS assessments of sub-standard structures and implementation of interim mitigation until Operation Bridgeguard; Bridgeguard 3; strengthening/reconstruction (or permanent mitigation) has been agreed and Network Rail; public road bridges; road- accomplished, including determining the likely challenges ahead and provide a over-rail bridges; ‘overline’ bridges; forecast estimate the final cost and completion of this programme. Bridge: inspection, assessment, protection, strengthening; Asset: infrastructure, enhancement, management * These instructions did not cover Scotland and Wales17. ** Bridgeguard 2 (BG2) was to be a programme of assessment and strengthening/reconstruction of railway Accommodation and Occupation ‘overline’ bridges during the late 1960’s and early 1970’s, but due to the withdrawal of the allocated funding, never eventuated14.Operation Bridgeguard 1 of 39
  2. 2. Project Paper Bradley W Yates April 20062. MANAGEMENT / BE 4 / SI 1705 assessments for these 10% of structures failing liabilityThe BG3 programme, and its expected to cost £3M, and funding forprinciples, was finally settled and a feasibility works options would requirenational JVFC agreement signed on an additional cost of approximately stthe 1 of April 1994. Later that year £13M, with financial contribution fromBritish Rail (BR) privatised and was the LHA’s, plus installation andthen taken over by a private company, maintenance of interim protectionRailtrack PLC (Rt PLC) in 1995, after measures of approximately £26M,successful negotiations with the Mitcham Goods Yard Bridge, Mordon again with financial contribution from 14 22County Surveyors Society (CSS) . mitigation, to be funded by the LHA’s the LHA’s .Rt PLC was to manage the until the assessment result has been Hence, the total cost for the BG3assessment phase under the Civil finalised, at which time a programme is estimated to be in theEngineering Directorate for project S117/BE4/SI1705 liability assessment region of £276M, of which £102M ismanagement. Procurement and is carried out, once the BD 21/93 expected to be funded by Rt PLC, seecommercial requirements pursued via assessment has been concluded and Appendix C, Table C.1.their Major Projects Division (MPD), if the final result does not achievewith final Technical Approval Authority 25/26T, or greater, HA loading Structures that were strengthened or(TAA) being from each of their Zone capacity. reconstructed in accordance with BS 22Structures Divisions . 5400 between 1975 and 1995, prior to Rt PLC to fund all the necessary S117 the JVFC being accepted in 1996, didAll assessment reports to be in / BE4 / SI1705 liability assessments to not required assessment . 25accordance with BD 21/93 and determine not only the level of‘reviewed’ by Rt PLC appointed contribution for any additional BD This reduced the number of structuresConsultants. The majority of 21/93 assessment work and interim to 5,500 being assessed under the 22assessment work being carried out by mitigation measures, but also funding JVFC and thus, revising thethe LHA’s, or their appointed of feasibility studies and future assessment cost estimate to £39M.Consultants. The remainder to be strengthening, reconstruction or However, due to previously low 25completed by Rt PLC appointed permanent mitigation works options . construction estimates, inflation andConsultants. In addition, the LHA is also entitled to general increases in welfare, materialHowever, LHA’s are expected to claim back 50% of the inspection and resource costs, the revisedmanage and install interim ‘temporary’ costs associated with the initial BD permanent mitigation costs climbed tomitigation measures upon receipt of 21/93 assessment if the S 117 / BE 4 / £539M.‘sub-standard’ results (less than 40T) SI 1705 result ‘failed’ to achieve Rt Consequently raising the total cost for 25and maintained until a permanent PLC liability obligations . the BG3 estimate to around £578M, ofsolution has been agreed and which £224M being funded by Rtimplemented to ensure the safety of 4. PROGRAMME PLC, see Appendix C, Table C.2. 25infrastructure and the general public . On the basis of accepting the EU In 1996, the European ParliamentPermanent solutions to be managed directive in 1985, the decision to adopted a revised European Councilby either Rt PLC or the LHA assess road bridges for 40T loads 13 Directive 96/53/EEC increasing thedepending on the whether the result was initially agreed in 1988, which if maximum allowable weight from 40Tof a liability assessment either commenced without delay, would to 44T for 6 axles.‘passed’ or ‘failed’ to achieve Rt PLC’s have allowed at least 10 yearslegal liability in accordance with S 117 Negotiations on the national completing assessments,/ BE 4 / SI 1705. That is, if ‘passed’, strengthening agreements strengthening and potentiallythe LHA to propose and lead the st commenced in 1997 and money was achieving the 1 January 1999 time‘agreed’ permanent solution to meet 14 identified for strengthening in the 1999 scale . 20the LHA’s aspirations, of either, Rt PLC business plan .strengthening or reconstruction to The ‘Railway’ owns approximately Also at this time, the Transportachieve 40T, and/or impose 6,500 public road bridges which Committee issued a report to thepermanent mitigation. This liability require assessment in accordance House of Commons in Session 1997-assessment also determined the level with BD 21/93 within in the BG3 22 98 suggesting that the assessmentof contribution by either party for programme . At a total estimated 25 and strengthening of the nation’sfunding the permanent scheme . cost of £42M, of which approximately bridge stock will not be complete by £27M worth to be delivered by Rt PLC 1999 and more likely to take at least and funded by the LHA’s. Of which an 153. FINANCE estimate of 10% of structures would until 2005 .The initial BD 21/93 assessment work require some form of permanent Since the UK was given 10 years towas to be funded by the LHA’s, as it mitigation, and an estimate of 10% ensure that its bridges were ready forhad been agreed not appropriate for would require some form of the introduction of 40T Heavy Goodsthe ‘Railway’ to fund an enhancement strengthening or reconstruction, at a Vehicles (HGV’s), the Government’spolicy to aid the transportation of total estimated cost of £195M to Rt response to this slow progress was 14 15freight by road . PLC. This left approximately 60% of disappointing . 14 the costs being funded by the LHA’s .Any additional assessment analysis Rt PLC was required to fund all S 117and/or investigations, including interimOperation Bridgeguard 2 of 39
  3. 3. Project Paper Bradley W Yates April 20065. SAFETY engineering trains or on-track plant, This information is required to which are made at walking pace. produce bridge inspection Site Safety IMPLICATIONS And Condition (SSAC) Reports and The responsibilities of a COSS is to Risk Minimisation (RIMINI)The ‘Railway’ has an excellent safety make sure each person in the siterecord with particular respect to Possession Planning Reports in order inspection group has the correct to develop a COSS Record ofbridges and, along with Central and certification, make sure a safe systemLocal Government organisations, are Arrangement and Briefing Forms of work is in place and inform the which outline the safe system ofsatisfied that this will not be group about site specific hazards. Forjeopardised by the introduction of working, hazards, emergency 20 example; limited sight conditions, procedures and associated method40/44T HGV’s . limited clearances, poor underfoot statements as necessary.This statement is supported by conditions, noise from sourcesprudent asset management, as adjacent to the site and other local Working on the track, and the road forstructures are routinely examined features, which may affect the safe that matter, is a high risk business.throughout the year, formally system of work. Attaining a safe system of workexamined on an annual basis, and are requires in-depth knowledge of thegiven a detailed inspection every six railway and highway environments, ayears. By using the results and clear understanding of the rules andfindings of these inspections, and the ability to appropriately apply them.historical records, recommendations Getting it wrong is not an option andare made for maintenance, protection, safety is the number one priority at allstrengthening or reconstruction to times.ensure that safety is adhered to, andstructures are maintained ‘fit-for- This has been exemplified throughpurpose’ at all times. the inception of the Health and Safety at Work (HSW) etc. ActThe assessment reports are Queens Road Bridge, Hastingsundertaken by civil engineering 19742, of which most sections cameconsultants who had tendered for a into force in 1975, but some werenumber of bridges, including LHA ‘in- The COSS will also make the group not effective until 1978.house’ resources or consultancies, aware of generic hazards, including In more recent times, this has beenand made responsible for employing but not limited to; hazards associated enhancement by the implementationcontractors who supply rail safety with access and egress, overhead and enforcement of thepersonnel, plant and equipment for and/or aboveground electrification Construction (Design andbridge inspection work. lines, underground services, Management) (CDM) Regulations overgrown vegetation, scrap material 199434, which came in March 1995All consultants are given a complete and other trip hazards, particularly along with the Reporting of Injuries,site safety risk evaluation for each when working at night. Diseases and Dangerousbridge. Risk evaluations are obtainedthrough liaison with, and provision of Other risks people need to be aware Occurrences Regulations (RIDDOR)information from railway staff and of are hazardous substances. Such 199535, and came into force on Aprilcontractors, with expert knowledge of as; oil, grease, lubrication and effluent 1996.railway safety requirements and in from trains, dust and asbestos, To date, there have been no reportedconjunction with reference to the working at heights or near water, fatalities, major injuries or incidentsRailway Group Standard GE/RT/8000: falling objects, manual handling, with respect to work associated withRule Book . 26 vehicle and plant safety, as well as, the BG3 Programme. live traffic hazards.All individuals undertaking inspectionsmust have undertaken, and have Furthermore, these types of 6. HGV WEIGHTS ONpassed a Personal Track Safety environments are susceptible to BRIDGES(PTS) course and carry a valid PTS contact with pigeon and bat faeces and ‘leptospirosis’ or Weil’s disease The forces transmitted to a bridge by‘Sentinel’ Card at all times whilst where exposed to rats, bat or cattle a HGV are dependent on its totalworking on or near the railway and urine where in contact with canal, weight and how the weight iswear appropriate Personal Protection river, or drainage and sewage outlets. distributed via the axles.Equipment (PPE). These hazards are also relevant with Generally, spreading the load evenlyAll Inspections for Assessment (IA) regard to working on or near the to avoiding very heavy individual axlesrequire ‘touching-distance’ surveys roadway. reduces ‘static’ or ‘point’ loadings.and in order to do this from track/soffit Consequently, national regulations onlevel require Possessions or Reconnaissance inspections are weights and dimensions of vehiclesBlockades, called ‘Green Zones’, initially undertaken, with details from specify not only maximum weights butunder the responsibility of a Controller the track Sectional Appendix and also maximum axle weights andof Site Safety (COSS) in which there Hazard Directory information to 2 minimum spacing between axles , seeare no train movements, with the only confirm access arrangements, Appendix A, Illustration A.1.exception when an Engineering equipment required, identify siteSupervisor’s (ES) has been allocated specific safety hazards and risks with A further factor to reduce ‘dynamic’ orto the work site for movements of respect to the required inspection. ‘impact’ loadings on a bridge is the efficiency of the vehicle’s suspensionOperation Bridgeguard 3 of 39
  4. 4. Project Paper Bradley W Yates April 2006in preventing large axle loads from for assessment of arches. or the failure is only marginal, to meetbeing transferred to the structure by a the LHA capacity aspirations.moving vehicle. Vehicles fitted with a The assessment should take intosuspension system consisting of soft account all historical record Significant achievements are usuallysprings and good dampers reduce the information including use, condition, gained from more detailed distributionimpact considerably . 4 maintenance and repair, in of ‘grillage’ or ‘non-linear’ finite conjunction with full use of partial element analysis and/or ‘buckling’Hence, the loading caused by 44T safety factors. These calculations and analysis using software packagesvehicles on 6 axles with road friendly assumptions are considered to be such as SuperStress, Leap5 orsuspension, with a 10.5T axle weight conservative and do not make use of LUSAS for ‘flat’ slabs and using actuallimit and minimum axle spacing, any residual, characteristic strength of or worst credible strengths attainedwould cause no more loading than the materials used or the form of from material testing, as well as, usemost 38T vehicles on 5 axles, with a construction. of analysis for particular consideration10.5T axle weight limit which were of U-frame stiffness modelling. Bridgealready allowed, and considerably Following an assessment that fails to capacity enhancements can also beless than the 40T vehicles on 5 axles, achieve 40/44T Assessment Live gained through the application of 11with a 11.5T axle weight limit which Loading (ALL), BA 79 should be ‘Vehicle Swept Path’ analyses.were to be allowed from the 1 st used to appraise whether the 4January 1999 , see Appendix A, structure is monitoring appropriate For arches, modelling through use ofIllustration A.1. and can remain without any mitigation ARCHIE, ARCHIE-M, MULTI or measures until further detailed diaphragm analyses, and inspectionIn addition, the greatest loading for a assessment, works are carried out to to confirm backing type and depth ofgiven length of vehicle is produced by achieve full strength or increased to fill, provides significant benefits.certain types of 32T vehicles at 8.5 the desired capacity.metres (m) in length already in use, as Where marginal failures havethe number of these ‘nose-to-tail’ on a Consequently, if the structure is occurred, or to further improve thebridge would produce a higher total considered not monitoring above detailed methods, review of theloading than fewer 44T vehicles, at appropriate, owing to the brittleness of partial safety factors, conditions and10.5m long, occupying the same the materials or shear failure modes pavement factors, impact, volume and 4given distance , see Appendix A, which cause sudden and catastrophic speed of traffic and particular elementIllustration A.2. failure; then, weight limits, lane width characteristics, such as restraint or restrictions, and/or protection of the resistance to lateral-torsional buckling,Therefore, there is no reason why 44T footways/verges shall be applied, in can achieve enhanced results.HGV’s with 6 axles should not be any combination as appropriate, or inpermitted in line with the requirements deed partial or complete closure of the If the initial assessment, or detailedand specifications for 40T HGV’s and structure, in order to protect the analysis, does not achieve 40/44Tno need for any additional structure and safe guard the general ALL, then a Section 117 Assessment 27assessment. public, and road/rail users, until a Report (S117 AR) is undertaken to permanent solution is agreed and determine the ‘Railway’s’ legal live implemented. load bearing liability and contribution7. ASSESSMENT to fund previously undertaken However, if deterioration or the assessment work, interim measuresThe purpose of assessment is to conditions of the elements are of and for any future permanentdetermine the capability of public road concern, or a weight limit is requested solutions.highway bridges to carry the imposed above the BD 21 result, then the40/44T Gross Vehicle Weight (GVW) The ‘Railway’s’ legal live load bearing bridge shall be monitored at enhancedloadings. liability is undertaken in accordance intervals of no more than 6 months in 8 accordance with BD 50/93 , BD with SI 1705 for the elements whichNominal loads for assessment are 9 54/93 and BD 63/94 . 10 failed to achieve 25/26T to BD 21, andderived from design loads contained 7 calculated in accordance with BE 4/67in BD 37 , as amended, and 25 Further detailed analysis may be or BS 153 for footway loadings andrequirements defined in SI 33 undertaken where it is considered a other relevant standards as required.1998/3111 , and reduced loadings in 6BD 21 , as amended, see Appendix B For unrestricted bridges the livefor tables. loading capacity used is 24t Gross Vehicle Weight (GVW).*The criteria for assessment of publicroad highway bridges are defined in For weight restricted bridges the liveBD 21, as amended, using simplistic load capacity is as ‘historically’ weightmethods of analysis. Such as, simple restricted under Sections 1, 6, 12 orstatics, simply supported members 17 of the Road Traffic Regulation Actand strip analysis for ‘flat’ deck 1967, and preceding Acts of 1930, 5structures. Along with BA 16 , as 1933 and 1960, when SI 1705 cameamended, for a simple method of load London Road, Mitcham (Station Signal into force, and Rt PLC’s liability Box in foreground)distribution and a simple empirical remains at the level of prohibition, as 16 substantial increase will be achieved,model of modified ‘MEXE’ method long as the prohibition remains * 24 tons (Imperial) = ~24.38 tonnes (Metric)Operation Bridgeguard 4 of 39
  5. 5. Project Paper Bradley W Yates April 2006continuously in force, whether in the control of their highway network. Thesame or altered form, until the bridge ‘Railway’ would also encourage this tois reconstructed. This is also applied reduce unnecessary assets of theto bridges listed in Schedule 3 of SI railway network, plus reducing liability1705 which were under consideration and maintenance, unless there is afor imposition of a prohibition at the commercial incentive and investmenttime the Act was drafted. not to do so. However, this scenario rarely occurs due to the obviousFor ‘flat’ decks, all elements are issues that arise.analysed simplistically by idealisingsimply supported members and There are four model worksmanual methods with loadings applied Sandilands Tunnel, Croydon agreements relating to these 22using ‘simple statics’ . scenarios where the LHA partially or entirely fund fully relating to ownershipPre-stressed and pre-cast bridges are and maintenance liabilities . 22not referenced in BE 4/67. However, 8. STRENGTHENING /S 117 assessments should have also RECONSTRUCTION A. The bridge fails to achieve thereferred to CP 114, CP 115 or CP 116 ‘Railway’s’ obligations and theas required, as these were in practice There are five probable outcomes as LHA requires the capacity higher 22at the time of SI 1705 . a result of a ‘sub-standard’ (less than than the ‘Railway’s’ liability. The 22 40/44T) assessment result . LHA carry out the work and takeComposite structures are also not over ownership and maintenancereferenced in BE 4/67. But, CP 117 1. The bridge fails to achieve the responsibilities.code of practise was in use at the time ‘Railway’s’ obligations and aof SI 1705 and should have been permanent weight limit is invoked B. The bridge fails to achieve the 22referred to in S 117 assessments . in accordance with the BD21 ‘Railway’s’ obligations and the result. The ‘Railway’ is to fund all LHA requires the capacity higherPost-tensioned bridges are also not associated costs. than the ‘Railway’s’ liability. Thereferenced in BE 4/67 and methods LHA carry out the work, but thefor assessment under S 117 need to 2. The bridge fails to achieve the ‘Railway’ retains ownership andbe agreed as no referenced is made. ‘Railway’s’ obligations and the maintenance responsibilities. LHA require the capacity to meetJack arches, hogging plates and tie- the ‘Railway’s’ liability. The C. The bridge achieves therods are assessed qualitatively under ‘Railway’ is to fund all associated ‘Railway’s’ obligations and theBE 4/67. costs. LHA requires the capacity higherFor arches, reference is made to the than the ‘Railway’s’ liability. The 22 3. The bridge fails to achieve the‘MEXE’ method of analysis . LHA carry out the work and take ‘Railway’s’ obligations and the over ownership and maintenanceSubstructures, foundations, spandrel LHA require a capacity higher responsibilities.walls, columns and piers are than the ‘Railway’s’ liability. Theassessed qualitatively under BE 4/67. ‘Railway’ and the LHA jointly fund D. The bridge achieves the the associated costs. Should ‘Railway’s’ obligations and theFootways, verges and jack arches reconstruction be necessary to LHA requires the capacity higherthat do not carry highway loadings achieve 40/44T ALL, the LHA is than the ‘Railway’s’ liability. The required to fund only 5% of the LHA carry out the work, but theshould only be assessed for self- necessary costs. ‘Railway’ retains ownership andweight only, unless crowd loadingswere considered at the time of maintenance responsibilities. 4. The bridge achieves, or exceeds,construction. However, footways the ‘Railway’s’ obligations and a There are also some rare casesconstructed after 1955 will require permanent weight limit is invoked where the LHA retains/gains 22assessment to BS 153 . in accordance with the BD21 ownership, but the maintenance result. The LHA funds all responsibilities remain with theCompletion of the assessment phase associated costs. ‘Railway’.should take between 2-3 years fromcompletion of an inspection for 5. The bridge achieves, or exceeds, Strengthening options include, butassessment, which includes additional the ‘Railway’s’ obligations and the definitely not limited to; replacementdetailed, liability and interim measure LHA require the capacity higher of defective elements, addition ofassessments. than the BD21 result. The LHA plates to increase the cross-sectional funds all associated costs. area, additional of stiffener plates overOnce the assessment stage has beenexhausted, either through analysis or the bearings, addition of angles and/or ‘Work’ referred to in these scenarios isagreed review, the LHA will confirm its stiffener plates to eliminate lateral- defined as; weight restriction, widthload bearing aspirations and torsional buckling and/or bracing restriction, resurfacing, realignmentsubsequently define the cost sharing frames for structures with steel (horizontal/vertical), footway/vergecriteria and permanent solutions to be elements. protection, strengthening orinvestigated within a Feasibility Study reconstruction of part, or whole, of the Repair of defects, replacement of(FS), identifying appropriate and structure. defective elements or installation ofeconomic works options to achieve carbon fibre reinforced plates tothe LHA’s long term objectives. LHA may wish to take over ownership increase strength of concrete or cast of structures in order to be more in iron elements.Operation Bridgeguard 5 of 39
  6. 6. Project Paper Bradley W Yates April 2006Replacement of the backing ‘fill’ with a This involves, encouraging the LHA to The BD 21/97 AR was issued in thstructural material, repointing, undertake and complete outstanding January 2000 and approved on 30stitching, and/or installation of initial assessments, implement and November 2001.reinforcement rods or ties, horizontally review interim mitigation until furtheror vertically, for arch structures. assessment and investigation work is The structure is a single span, half - finalised, facilitate the pursuit of through plate-girder bridgeAs well as, installing concrete feasibilities for permanent solutions constructed in 1894, with concretereinforced slabs or steel plates over based future maintenance, whole life abutments and wing-walls. Thethe entire deck, or just over affected costing economic analysis, and parapets are formed by the upperareas for any applicable type of progression of suitable and agreed portions of the outer girders with astructure. works options. clear span of 11.65m and a skew of o 48 , see Appendix F.1-4 for historicalCompletion of works should occur plan, elevations and sections.within 2-3 years from completion of anassessment, which includes The bridge consists of 2 No. mainfeasibility, possession planning and outer girders, with 13 No. transversedesign of the agreed option. riveted girders spanning from abutment to a main outer girder, with9. BRIDGEGUARD 3 only 1 No. central girder spanning between the main outer girders. COODINATOR The transverse riveted girders areThe BG3 Coordinator is responsible Wickham Market Bridge, Wickham constructed of steel, with wrought ironfor accepting assessments, as the hogging plates and tie-rods backfilledTechnical Approval Authority (TAA) on with plain concrete under thebehalf of the ‘Railway’, then notifying 10. CASE STUDY carriageway, and wrought iron camberthe relevant LHA of the assessment plates beneath the footways.results, requesting proposals for The name of the bridge and the LHAinterim measures and/or long-term shall not be identified, as the purpose Two of the original transverse rivetedaspirations, as required. of this case study is not to single out a girders have been replaced with rolled LHA or Consultant for any particular universal girders, as well as, aSuitability and appraisal of interim motive, which might be construed as number of hogging and camber platesmeasures are undertaken and deliberate delay tactics. There are have been replaced with cast-in-situreviewed periodically, until either others examples that would be more concrete slabs.assessed out or a permanent solution appropriate for that. But, to addresshas been implemented. processes, resources, approval and The bridge carries an unclassified decision making issues by all (urban) two-way road, carriagewayAgreeing or proposing where further width of 6.05m with 1.80/1.90m wide stakeholders, which have in effectdetailed analysis and intrusive footways on each side, and 9.75m delayed solutions being implementedinvestigation work, and what types, between parapets, which are 2.44m by more than 10 years from provisionare of value in pursuing in either deep. The bridge also has a 4t of a completed BD 21/97 Assessmentattaining the ‘Railway’s’ legal liability, (Imperial) weight limit with a permitted Report (AR), as opposed to the 2-3achieving the LHA aspirations or speed of 30mph. However, the traffic years from initial expectations.where likely to significantly is high flow with a poor surfacereduce/minimise the scope of This is a typical scenario and not an condition.necessary interim mitigation or isolated case where substantialpermanent works. strengthening is required to achieve The Inspection for Assessment (IR) the LHA aspirations of 40/44T was carried on under a T3 possessionLiaise with the LHA’s, Department for th capacity. This case study describes of the line for engineering work on 26Transport (DfT), Transport for London April 1998 and access to the the key factors, apart from the delay(TfL) and London Bridge Engineering underside of the bridge deck was of some LHA’s in completingGroup (LoBEG) regarding achieved by use of mobile scaffolding assessment reports, which areprogramming and progress, status of and ladders from track level.* causing delay to the closeout of thework, costs, technical and liability BG3 programme. An overall condition factor of 1.0 wasissues, as well as, changes to codesof practice and ‘best’ practises with The AR was undertaken with respect used in consideration of individualrespect to assessment, interim to the findings of the inspection defects, section losses at criticalmeasures and strengthening or th undertaken on the 26 April 1998 and sections of the longitudinal andreconstruction work. in accordance with the standards transverse beams, taken into account detailed in the BD 21/97 Approval in from the inspection.The main objective is to facilitate the Principle (AIP) issued July 1998 and The deck was analysed as a numbercloseout of the assessment th approved on 10 March 1999. of single span, simply supportedprogramme and management ofinterim mitigation. girders, see Appendix F, Drawings F5-6. The deck is heavily skewed with * A T3 Possession is where arrangements are made to block the line completely from normal passage of trains. The only authorised equipment, plant or engineering trains are allowed to pass through this type of possession at walking pace, as arranged with the Engineering Supervisor.Operation Bridgeguard 6 of 39
  7. 7. Project Paper Bradley W Yates April 2006the transverse girders typically Accidental Wheel Load (AWL) effects. A Complementary Review (CR), orspanning between an abutment and a The hogging plate tie-rods located Sensitivity Analysis (SA), waslongitudinal main outer girder. Live beneath the carriageway and undertaken by the same Consultantload was applied using two methods: footways were themselves capable of as the S117 AR and was completed insimple ‘statics’, using real vehicle sustaining 40/44T ALL. However, the November 2003.single axles specified in BD 21/97 connections were rated at 0T DLO.Appendix D, to determine the limiting These elements are rated at 0T DLO The purpose of a CR/SA was tovehicle, and; simple ‘distribution’, due to the connection details are not identify any reserve strength or causeusing single axles applied in in accordance with current design of the initial lack of capacity in theaccordance with BA 16/97 Chapter 2, standards, which result in reduced elements failing BD 21/97, and thus,to determine the limiting factor and loading capacities in comparison to identify any potential consideration forassessed rating and engineering current standards. However, this is a further analysis to improve the overalljudgement is used to arrive at the final theoretical result and in practise have capacity. A more sophisticatedassessed rating should the two a high capacity than the designated grillage analysis of the deck couldmethod give rise to differing results, 0T DLO. have been undertaken at the time, butas well as; BD 56/96 and ‘L-frame’ is was claimed that it would not giveidealised structure for analysis of the The abutments, wing-walls and significant improvements in the loadlongitudinal girders. foundations were qualitatively carrying capacity of the bridge, which assessed, and as there were no was stated by the original ConsultantThe main outer girders were assessed significant signs of distress or defects in the BD21/97 AIP.as having 3T Allowable Live Loading observed, were considered adequate(ALL), limited by the bending capacity in accordance with BD 21/97. The scope of the work was toat mid-span due to the effects of estimate the capacity of the edgeUniformly Distributed Load (UDL) A Section 117 Assessment Report girders assuming some partialtogether with a Knife Edge Load (S117 AR) was then undertaken by restraint of the compression flanges to(KEL). The likely reason for failure is another Consultant to determine the enhance resistant to ‘lateral-torsional’the effective length used in calculating ‘Railway’s’ legal live loading bearing buckling and the transverse girders,the bending resistance. This is low as liability in accordance with SI assuming parts of the hogging platesa result of the lack of restraint and 1972/1705 for the elements which assist in supporting the girderlack of stiffness due to slenderness of failed to achieve 25T to BD 21/97, sections, as well as, consideringsuch deep girders with narrow which is calculated in accordance with composite action between the girdersflanges. However, the beams are BE 4/67 and other relevant standards and the surrounding concrete and thecapable of withstanding the full effects detailed in the BE 4/67 AIP, both tie-rods to recommend any benefit inof footway live loading at Ultimate documents were issued in April 2003 undertaking a Non-Linear Finite thLimit State (ULS). and approved 6 May 2003. Element Analysis (NLFEA) to enhance the current capacity of thisAlso, one of the transverse girders, For unrestricted bridges the live bridge.the one which spans centrally across loading capacity used is 24t Grossthe deck, from outer girder to outer Vehicle Weight (GVW). However, this The assessment had conservativelygirder, was found to have an particular structure has a 4t weight assumed that k4, which is a factor thatassessed rating of 0T (Dead Load limit and in accordance with this allows for warping stiffness and isOnly), limited by bending at mid-span ‘historical’ weight limit imposed under defined in Clause 9.7.2 of BD56/96, isdue to the effects of axle loading. The the Road Traffic Act 1960, Section 41, equal to 1.0. By assuming a lowerlikely reason for this failure is due to of the Road Traffic Regulation Act value for k4 and assuming partialsection loss from corrosion. The 1967, and subsequently the live effectiveness, of semi-rigid transverseremainder of the transverse beams loading used was 4t GVW.* beam connections, in ‘U-frame’ action,were rated at 3T ALL, limited by the capacity of the main girder could All elements were analysed as simply be raised to 7.5T + G1FE ALL. Inbending at mid-span due to the effects supported members by manualof axle loading. The likely reasons for addition, due to inherently methods with loadings applied using conservative calculations andthese failures are due to the simple ‘statics’. The hogging platesinadequacy of section sizes for the assumptions, in consideration of the and tie-rods were assessed bearing stiffeners at the supports, acurrent loading requirements. qualitatively, as these elements areHowever, the beams are capable of reduced effective length for ‘lateral- not covered in BE 4/67. The footways, torsional’ buckling the main girderswithstanding the full effects of footway substructure and foundations are notlive loading at ULS. are likely to achieve 40/44T ALL. assessed under BE 4/67. Also, theThe hogging plates beneath the footways do not require assessment If the hogging plates and thecarriageway areas were assessed as to BS 153 as the structure was surrounding concrete are consideredhaving a rating of 0T DLO, limited by constructed before 1955. to contribute to an increase in area forthe load intensity the effects of axle the tension flange of the transverse The only elements, which failed to girders, then the capacity is increasedtype loading. The hogging plates achieve the S117 AR, were five of thebeneath the footway areas were also to 3T ALL. centrally located ‘longer’ transverseassessed as having a rating of 0T beams limited by bending at mid- Using Current Information Sheet (CIS)DLO, limited by the load intensity of span. 35, for assessment of metal hogging * 4 tons (Imperial) = ~4.06 tonnes (Metric)Operation Bridgeguard 7 of 39
  8. 8. Project Paper Bradley W Yates April 2006plates, the plates under the in the CR/SA, see Appendix F, In total, accumulative delays of up to 3carriageway are rated at 7.5T ALL, Drawing F.8. years were associated with Rt PLC /but this does not apply to the footway. NR in not approving documents in aThe footway hogging plates could be The NLFEA concluded in January timely fashion; and further delaysrated at 40T ALL in consideration of 2006 with the recommendation of between Rt PLC / NR and the LHA incomposite action with the concrete undertaking a Feasibility Study (FS) to agreeing and instructing work, addinginfill slabs. However, the strength of consider strengthening options for the up to another 3 years.the concrete and the bonding would edge girders, suggested that initialneed to be confirmed. studies indicated a favourable option Now, considering it should only take would be to strengthen by adding approximately 2-3 years fromIt is overly conservative to consider edge angles to the top flanges of the instruction of a FS, through the designthe tie-rods as 0T DLO due to the edge girders to achieve 40/44T, and phase, until implementation of a worksconnections only, as this does not undertake a feasibility study to option; a period of some 9 years havetake into account any restraint offered consider other strengthening options past since the initial BD 21/97 AR wasby the hogging plates and the for the other elements. The NLFEA completed until implementation of an rdconcrete infill slabs, which would was approved on 23 February 2006. option to achieve 40/44T ALLresult in a rating of 40/44T ALL. capacity; 11 years since the However, considering this inspection for assessment wasHence, a Non-Linear Finite Element Consultant’s track record of undertaken, provided the FS isAnalysis (NLFEA) was recommended recommendations with this structure, instructed and undertaken in 2006,to be viable option and likely to along with them neglecting to this year.achieve a substantial increase in the comment on the other elements thatcurrent overall loading beading require strengthening, a ‘second’ Inclusive within this delay period, 3capacity of this structure. opinion and alternate consultation years may be associated to the would have been advisable prior to Consultant’s recommendations forA NLFEA AIP was completed by the undertaking the FS. further assessment work, and lack ofsame ‘other’ Consultant in September engineering judgement by both, RT nd2004, and approved on 2 November The BD 21/97 AIP was issued in July PLC / NR and the LHA in progress2004, 2 months later. 1998, but not signed until March 1999; this work. 8 months delay.The bridge was modelled using If a FS was undertaken upon‘LUSAS’ with ultimate limit state stress The BD 21/97 AR was issued in completion of the S117 AR in 2003,loading conditions, see Appendix F, January 2000, but not signed until we could be carrying outDrawings F.7-8. December 2001; almost 2 years strengthening, or reconstruction, work delay. in 2006, this year.The NLFEA raised the capacity of theedge girders from 3T to 7.5T ALL, A further period of 12 months went by Furthermore, if the BD 21/97 AR wasusing heavy traffic and poor surfacing until the S 117 AIP & Report were approved in a timely manner alongconditions, limited by ‘lateral-torsional’ issued in April 2003. with the S117 AR, that is bothbucking due to the slenderness of the completed and approved in 1999,main girders. From completion of the CR/SA, 12 months went by until the NLFEA AIP work could have been implement inThe central transverse girder, completed and approved. 2003 and we could have had a 40/44Tspanning from outer girder to outer ALL capacity bridge for 3 years,girder, was still limited to 0T DLO due Then, a further 2 years elapsed until instead of ‘maybe’ having a fullto bending at mid-span, and no the NLFEA was completed and capacity bridge in 3 years from now.increases to any of the other approved. One very important aspect has beentransverse girders or associate overlooked during this process, atelements due to distribution of load, least on a formal basis, which is thewere not mentioned. Also, the appraisal for interim measures inhogging plates and the tie-rods were accordance with BA 79/98 uponstill rated as 0T DLO with no completion of a failed BD 21/97 AR toadditional comments to substantiate protect the structure until a permanentany of the additional analysis, or solution is implemented.comments involving any engineering Fortunately, the saving grace with thisjudgement. structure is that it has an existing 4tThere were no supporting comments weight limit ‘historically’ in place.to substantiate the marginal increase However, the signage actually relatesin capacity, in respect of the to axle weights and actually relates torecommended substantial increases 8.13T GVW with 2 axles, andpreviously proposed; no comments therefore a weight limit sign of 7.5Twere made to address this, other than would comply to current standardsstating that the NLFEA confirmed the and regulations. In general, Weight Restriction Sign fortunately most ‘drivers’ will likelyouter girders were susceptible tolateral torsional bucking. Temporary and Permanent relate the 4t limit to the overall vehicleConsideration to the slenderness of Weight Restrictions for weight anyway.the edge girders should have been substandard bridges.identified and taken into considerationOperation Bridgeguard 8 of 39
  9. 9. Project Paper Bradley W Yates April 2006Upon review in accordance with BA Currently, there are 261 (25%) of79/98, the main carriageway elements structures that require interimare monitoring appropriate, due to the measures to be installed to protect thetypes of materials and failure structure and mitigate risks until amechanisms not being brittle or permanent solution is agreed andsudden in nature. Conservative implemented. However, 143 (13%) ofcalculations and assumptions along these structures do not have any orwith reserves in strength and design acceptable/appropriate interimfactors of safety, an enhanced mitigation in place at this stage.monitoring regime would beacceptable, focusing on the sub- Copnor Road Bridge, Portsmouth 12. CHALLENGESstandard elements, to substantiateallowing a weight limit of 7.5T, above Within the South East Territory… Challenges of the past…the BD 21/97 AR result, and notclosing the bridge from vehicular st By the 1 January 1999, the number The initial agreement to assess wasaccess. of bridges in the South East Territory acknowledged in 1988, 4 years after (SET) was in the region of 1,100 and the EU Directive was issued in 1984,However, since it has been over 6 the number of completed assessment and a further 8 years of negotiationsyears since the BD21/97 AR had been reports received by Rt PLC was went by until the JVNF was signed incompleted, and at least another 3 approximately 220 (20%). 1996.years until a permanent solution isimplemented, the current weight limit Some works had commenced prior to As a consequence, reducing theshould be replaced with a 3T sign in the national works agreements being potential 10 years programme down staccordance with current regulations st finalised and by the 1 January 1999, to 4 years to achieve by the 1and to justify further continuation of approximately 15 (1.4%) structures January 1999.the enhanced monitoring to allow a had been strengthened or As much as the principles weremitigated use of the bridge, as the reconstructed and 20 (1.6%) have signed and agreed, as well as, thestructure is not subject to any adverse been partially strengthened and/or directive and commitment to fund thisor accelerated deterioration, at this permanent mitigation installed. work by the National Government tostage. st the LHA’s, there was still an Currently; by the 1 January 2006, the number of bridges in the South East unwillingness of LHA to fund and11. PROGRESS Territory (SET) is 1,097 and the progress the programme for the number of completed assessment ‘Railway’ owned bridges, which alsoWithin the National Programme … contributed in putting the scheme reports received by NR is now stBy the 1 January 1999, the number approximately 1064 (97%), see behind schedule.of structures reduced even further Appendix D for flowchart. Furthermore, the ‘Railway’ which hadfrom 5,500 to 5,187 as bridges that became privatised from the outset of In total, 364 (34%) of structures so farwere either weight restricted under the this programme and was forced to have failed to achieve 40/44T ALLRoad Traffic Regulation Act 1967 (and adopt the scheme under sufferance, capacity for all elements of which; 87preceding Acts of 1930, 1933 and as it was actually in the business of (8%) of structures have ‘failed’ to1960) when SI 1705 came into force, making money from the railway and achieve the ‘Railways’ liabilityor listed in Schedule 3 of SI 1705, was not inclined to assist the highway obligations.were removed from the scheme network with this enhancementunless the LHA Local Transport Plan Some 122 (11%) require substantial programme. Lengthy delay periods(LTP) now required these structures strengthening or reconstruction to occurred between the TAA receivingto have 40/44T capacities. achieve 40/44T ALL capacity of both and signing-off documents and further the carriageway and the delays arose in agreeing andAlso, if it was established that a tunnel footways/verges. instructing the next step forward.was of bored construction or the depthof cover (or overburden) is greater While 116 (11%) achieved 40/44T The decision of the ‘Railway’ tothan 7 metres, no assessment was ALL carriageway capacity, but only undertake S 117 AR’s on the basis ofrequired, as the effect of live loading required strengthening and/or draft or initial BD 21 AR ‘failed’as a proportion of the loading reduces permanent mitigation of the results, as opposed to after anywith depth, and it is reasonable to footways/verges. further assessment work had beenassume that the highway loading may finalised, was also caused forbe ignored . 23 To date, approximately 31 (3%) of additional delay, due to the LHA’s structures have been strengthened or stBy the 1 January 1999, the number encumbrance of undertaking or reconstructed, 30 (3%) have hadof completed assessment reports agreeing to further assessment work some form of partial strengtheningreceived by Rt PLC was while debating the interpretations of and/or permanent mitigationapproximately 1,050 (20%) and the the S 117 and BE 4/67 results. Which implemented on the carriagewayassessment programme predicted to were often open to opinion and and/or footways/verges, and 42 (4%) stbe complete by 1 January 2002 . 20 debate, when determining liability and have had some form of partial subsequent contribution, to current strengthening and/or permanent and progression of further mitigation implemented on the assessment work, as it was in the footways/verges only. interest of the LHA’s to try and ‘fail’ achieving the ‘Railways’ liability andOperation Bridgeguard 9 of 39
  10. 10. Project Paper Bradley W Yates April 2006conversely the ‘Railway’ trying to requiring further detailed assessment procurement via NR’s Major Projects st‘pass’ it’s obligations. work 6 years after exceeding the 1 and Investment (MPI) Division January 1999 milestone. And, only 31 continues to be of hindrance inThus, raising the need for a more (3%) of structures have been relation to processing commercialconsistent approach to the national strengthened or reconstructed to date requirements, and is currently a majoragreement, not just through guidance of an estimated total of 125 (11%). As cause of delay in the South Eastand technical notes produced by Rt well as, only 72 (7%) have had some Territory which needs to bePLC’s, which is only one point of view. form of partial strengthening and/or addressed, along with their lack ofIf ‘proper’ engineering judgement was permanent mitigation implemented, at finance and project management inmade to progress further assessment this stage, out of an estimated total of raising invoices and addressingwork at the time, most of the 250 (23%). Not to mention the risk of progress with LHA’s with respect toarguments and delay would have having 138 (13%) ‘sub-standard’ moneys owed for completed work, orbeen taken out of the picture, which structures which still do not have any paid upfront some time ago forwould have save time and money by acceptable or reasonable mitigation in uncompleted work yet to beboth parties, as well as, being closer place and therefore, much effort is progressed, which is of great cause ofto completing the programme expended in trying to encourage the concern. As well as, the lack of abilityobjective. LHA’s to respond to this matter in a to quantify exactly what has been responsible and timely fashion is already been spent on BG3 by NRChallenges at this stage… required. and Rt PLC, and the fact that onlyRebuilding relationships, confidence some 31 (3%) of structures have beenand cooperation with the LHA’s from strengthened or reconstructed and 72the days of Rt PLC, as well as, more (7%) have had some form of partialuse of ‘sound’ engineering judgement strengthening and/or permanentand experience in decision making, mitigation implemented in 12 yearswithout reliance been largely based since the programme officiallyon recommendations of Consultants, commenced in 1996.and often tactical for political leverageor delay purposes being adopted by 13. EXPENDITUREboth parties. For the South East TerritoryMajor tasks involve reducing; the Assessments…lengthy delay between the TAAreceiving and signing documents, and The estimated cost of the 1064 initialhurdles in agreeing and instructing the BD 21 Assessments completed isnext step forward. This should be Brettal Lane Bridge, NW London approximately £7M, with £0.15Mdone through technical and open reimbursable from the ‘Railway’dialog with the LHA’s to facilitate regarding Inspection For Assessmentprogress and move forward in a Challenges of the future… costs relating to 87 (8%) of structurespragmatic and proactive approach, which ‘failed’ to achieve the ‘Railways’ Although much progress has been liability to S 117 / BE 4 / SI 1705.with emphasis on achieving their accomplished through the rebuilding(LHA’s) aspirations, in a timely and of relationships, confidence and However, this does not account foreconomic manner. While adequately cooperation with the LHA’s, more use further assessment and investigationmitigating provisional risks associated of ‘proper’ engineering judgement with work completed on 40 structureswith any resulting ‘sub-standard’ the ‘big picture’ in mind is still being £0.8M and formal interimhighway structures, without any required, as some LHA’s still base a measure appraisals undertaken on 40unnecessary delay or debate on lot of decision making on the reliance structures being £0.4M, with £0.12Msemantics or insignificant issues. on recommendations of Consultants, of these costs coming from theThe overall assessment progress had or the results of S 117 Assessments, ‘Railway’. As well as, liabilitybeen restrained largely due to which often only attributes minor assessments on 212 structures beinginsufficient funds being available benefit, but by no means achieves the £0.53M and funded entirely by thewhen required. This had either been long term desired capacity, and is ‘Railway’. This figure does notspent or allocated elsewhere, due to a often for only tactical delay and included associated costs for updatingvariety of agendas and priorities by political leverage, particularly with formal interim measure appraisalboth parities. As a result, slow regard to liability, interim measures reports required periodically, asdecision making and progression of and permanent solutions. This often necessary, but not likely to increasean acceptable solution. change depend on the liability to cost significantly. contribute to funding.This was emphasised in the South Thus assessment costs to date for theEast Territory by the fact that there Fortunately though, this now only SET are approximately £8M, withare still 33 (3%) of structures applies to a few LHA’s and is being £0.8M cost to the ‘Railway’, seeremaining to be assessed, due to lack pursued by the London Bridge Appendix C, Table C.4.of resources and motivation of the Engineering Group (LoBEG) and the With 33 structures remaining to beLHA’s in question, and they were County Surveyors’’ Society (CSS) to assessed, the total assessment costsgenerally ignorant of their safety progress with more determination. for the SET are estimated to be in theobligations. This is evident as an Progress of further assessment and region of £8.5M, with £1M worth ofestimated 45 (4%) of structures still investigation work identified forOperation Bridgeguard 10 of 39
  11. 11. Project Paper Bradley W Yates April 2006costs to the ‘Railway’, see Appendix approximately 1,100 structures being resources, materials, welfare andC.5 for table. £2.8M and funded entirely by the safety. ‘Railway’. This does not includedAt the current rate of assessing the associated costs for updating formal At the current SET rate ofremaining structures at approximately interim measure appraisal reports implementation of permanent3 (0.3%) structures per annum, the required periodically as necessary, solutions the estimated completionestimated completion date is but not likely to increase cost date is somewhere in the region ofsomewhere in the region of 2016, see significantly. 2030+, see Appendix E, Graph E.2.Appendix E, Graph E.1. Therefore, the assessment costs for Again, these predictions made on theFor the South East Territory National Programme are extrapolated the National Programme are expectedStrengthening/Reconstruction… to be in the order of £40M, with £4.5M from the progress of the SET, which cost to the ‘Railway’, see Appendix C, as previously mentioned is somewhatWith permanent works complete on more advanced than other Territories,102 structures at an estimated cost of Table C.7. and more likely to be in the region of£61M, of which £28M (45%) coming And at the current SET rate of 2070+, see Appendix E, Graph E.2.from the ‘Railway’. completion, the estimated date forHowever, this does not account for, completing the assessment work is 14. CONCLUSIONfeasibility studies costing an additional somewhere in the region of 2016+,£2.5M, or interim mitigation on 95 see Appendix E, Graph E.1. In 1961, the Ministry of Transportstructures costing approximately £4M, thought it advisable to consult the However, these predictions on theof which £4.5M of these costs ‘Railway’ on allowing 24t heavy National Programme are extrapolatedaccountable from the ‘Railway’. continental vehicles passing over their from the progress of the SET, which is 12,200 public road bridges.Thus, the interim and permanent somewhat more advanced than otherworks costs to date in the SET are Territories, and as such, is very much The Ministry of Transport felt such aapproximately £67.5M, with £32M of an over-optimistic prediction and more decision was in the best interest of thethese costs liable from the ‘Railway’. likely to be in the region of 2060+, see economy and agreed to provide full Appendix E.1 for graph. financial assistance, involving a sumWith a prediction of another 273 of almost £7M, on the proviso that thestructures requiring permanent works programme was complete before theand 143 structures requiring Transport Bill became law in 1969.temporary mitigation, the total worksforecast for the SET is expected to in Thus became known as ‘Operationthe region of £250M, with a value Bridgeguard’, due to the huge task or£120M coming from the ‘Railway’, see ‘mission’ of completing this immenseAppendix C, Table C.6. assessment and enhancement programme in 8 years in order toAt the current rate of implementation avoid the having to contributeof permanent solutions, approximately financially.10 (3%) structures per annum, theestimated completion date is The assessment results indicated thatsomewhere in the region of 2030, see 1,104 structures required some formAppendix E, Graph E.2. Bishop’s Bridge, Paddington of permanent works, of which 390 were accepted for permanentFor the National Assessment restriction and the remaining 714Programme… For the National structures scheduled to be bought up Strengthening/Reconstruction… 24t strength capacity....extrapolated and interpolation fromthe progress of the SET… ...extrapolated and interpolation from The average length of time from initial the progress of the SET… planning to completion of a road-over-The estimated final cost forecast forthe 5,200 initial BD 21 Assessments is With an approximately 1,800 rail bridge was estimated to be in theapproximately £34M, with £0.7M structures requiring some form of order of 4 years, and involvedreimbursable from the ‘Railway’ permanent works at an estimated anything up to 22 separateregarding inspection for assessment value of £1.07B with £480M (45%) stakeholders to be satisfied beforecosts relating to approximately 430 coming from the ‘Railway’. construction could begin. The main(8%) of structures ‘failing’ to achieve tasks were to increase output ofthe ‘Railways’ obligations in Plus, feasibility studies costing an assessment and construction, as wellaccordance with to S 117 / BE 4 / additional £42.5M, and interim as, reducing the completion period toSI 1705. mitigation in the order of £71.2M, of about a quarter of the normal time. which £80M (70%) of these costs areAlso, further assessment and reimbursable from the ‘Railway’. So, to pilot a bridge scheme toinvestigation work on approximately completion from 4 years down to 1,240 (5%) of structures being about Therefore, the works costs for the meant something had to go.£2.4M and formal interim measure National Programme are expected to be in the order of £1.2B, with £560M The source of all problems,appraisals undertaken on 520 (10%) foreseeable and unforeseen, wasof structures of around £1M, with £1M cost to the ‘Railway’, see Appendix C, Table C.7. This takes no account of essentially the concertina effect to thepaid by the ‘Railway’. Including, time scales.liability assessments required on inflation or rising costs in relation toOperation Bridgeguard 11 of 39

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