Scheme Assessment Report As a Key Component
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Western Link Stage 2 - Bridges Feasibility Study 17 October 2017 Warrington Borough Council Mott MacDonald Spring Bank House 33 Stamford Street Altrincham WA14 1ES United Kingdom T +44 (0)161 926 4000 F +44 (0)161 929 8915 mottmac.com Warrington Borough Council New Town House, Buttermarket Street, Western Link Warrington, WL-MMD-07-XX-RP-S-0003 Cheshire, WA1 2NH https://mottmac.sharepoint.com/teams/pj-b1092/Shared Documents/10 - Stage 2 - Bridges/Documents/WLBridges Fe-MMDasibility-07-ZZ-RP-S -0003Study Stage 2 Bridges Feasibility Report.docx Mott MacDonald 17 October 2017 Mott MacDonald Limited. Registered in England and Wales no. 1243967. Registered office: Mott MacDonald House, 8-10 Sydenham Road, Croydon CR0 2EE, Warrington Borough Council United Kingdom Issue and Revision Record Revision Date Originator Checker Approver Description S2.0 17/10/17 O Lucas R Mathews R Langley First Draft S2.1 03/11/17 O Lucas R Mathews R Langley Client Issue Document reference: WL-MMD-07-XX-RP-S-0003 Information class: Secure This document is issued for the party which commissioned it and for specific purposes connected with the above- captioned project only. It should not be relied upon by any other party or used for any other purpose. We accept no responsibility for the consequences of this document being relied upon by any other party, or being used for any other purpose, or containing any error or omission which is due to an error or omission in data supplied to us by other parties. This document contains confidential information and proprietary intellectual property. 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Mott MacDonald | Western Link Stage 2 - Bridges Feasibility Study Contents Executive summary 1 1 Structures 5 1.1 Manchester Ship Canal 5 1.2 Walton Viaduct 11 1.3 West Coast Main Line Viaduct 19 1.4 Forrest Way 25 1.5 East Ditton Goods / Arpley Rail Viaduct 30 1.6 West Ditton Goods / Arpley Rail Viaduct 34 1.7 St Helens Canal 38 1.8 Sankey Brook 41 1.9 Ditton Rail and St Helens Canal Bridge 44 1.10 West River Mersey Viaduct 49 1.11 East River Mersey Crossing 57 1.12 Centre Park Link Chester Road Bridge 61 1.13 Chester Road Fixed Bridge 64 Appendix A - Drawings 67 WL-MMD-07-XX-RP-S-0003 | 17 October 2017 https://mottmac.sharepoint.com/teams/pj-b1092/Shared Documents/10 - Bridges/Documents/WL-MMD-07-ZZ-RP-S-0003 Stage 2 Bridges Feasibility Report.docx Mott MacDonald | Western Link Stage 2 - Bridges Feasibility Study WL-MMD-07-XX-RP-S-0003 | 17 October 2017 https://mottmac.sharepoint.com/teams/pj-b1092/Shared Documents/10 - Bridges/Documents/WL-MMD-07-ZZ-RP-S-0003 Stage 2 Bridges Feasibility Report.docx Mott MacDonald | Western Link 1 Stage 2 - Bridges Feasibility Study Executive summary Warrington Borough Council has received development funding from the Department for Transport (DfT) to develop an Outline Business Case (OBC) for the Western Link scheme. Mott MacDonald has been commissioned by Warrington Borough Council to produce the Western Link OBC, which includes a Scheme Assessment Report as a key component. This report comprises a bridges feasibility study that will inform the engineering assessment and cost appraisal that is to be carried out for each scheme option in the Stage 2 Scheme Assessment Report. Western Link consists of a new single carriageway link road between Sankey Way (A57) and Chester Road (A56) to the west of Warrington Town Centre. The rationale behind the development of this scheme is that it will address a range of transport issues within Warrington. These include alleviating town centre congestion, providing a faster and more direct north - south connection and unlocking land immediately south-west of the town centre for housing and employment development. A Stage 1 Scheme Assessment Report was completed in May 2017 with the Stage 1 Bridge Feasibility Study submitted as an accompaniment to that report. The Scheme Assessment Report detailed the methodology for refinement from 44 route options down to 6 feasible options that were to be taken forward to public consultation. This report pertains to Stage 2 of the Option Assessment Process. At this stage Mott MacDonald is to consider the 6 feasible route options and identify the preferred route option to be presented to the Department for Transport (DfT). It has been identified that there are 13 possible bridge crossings that form the 6 proposed route options – these structures are detailed in Table 1 overleaf. For each crossing, a brief report has been produced that lists indicative sizes, span options, possible construction types and any constraints that may impact its implementation. Additionally, for each structure, an outline general arrangement drawing has been produced showing a potentially feasible option suitable for costing purposes. These drawings are included in Appendix B. Based on the information available at this stage in the design process, it is not believed that there are any significant technical issues that would prevent the Western Link Scheme from being implemented from a structures only standpoint. However, each crossing has its own limitations and requirements that will need further investigations at subsequent stages in the design process. In particular the following risks and constraints have been identified as significant for this project: ● Interface with Network Rail for Walton Viaduct Underbridge, West Coast Main Line and Ditton Goods Line Overbridge. Any works that impact on Network Rail’s infrastructure will have to undergo a lengthy approval process. ● Clearance levels over the River Mersey - Establishing clearance levels for new structures spanning over the River Mersey is likely to involve several stakeholders and could be a lengthy process. ● Vertical sight lines for the existing Forrest Way Bridge have been assessed to be unsatisfactory to accommodate a 30mph or 40mph highway alignment. It is recommended that a replacement structure is constructed alongside the existing structure to accommodate the proposed Western Link highway alignment. WL-MMD-07-XX-RP-S-0003 | 17 October 2017 https://mottmac.sharepoint.com/teams/pj-b1092/Shared Documents/10 - Bridges/Documents/WL-MMD-07-ZZ-RP-S-0003 Stage 2 Bridges Feasibility Report.docx Mott MacDonald | Western Link 2 Stage 2 - Bridges Feasibility Study ● Existing 132kV electricity lines that run throughout the study area will require diversion to allow for safe construction of bridge structures along the route. ● To accommodate the proposed junction to the A57 Sankey Way, a new grade separated structure will be required. ● To accommodate the proposed junction to the A56 Chester Road, the proposed Manchester Ship Canal Viaduct may have to be widened at the southern end to accommodate the additional lanes necessitated by the junction.