Project Description

Introduction

Project Name: Stockport Long Wheel Timber Bridge
Customer Organisation: CK Rail Ltd
Customer Contact Details: Matt Lees, Senior Project Manager

The contractor was commissioned to replace life-expired longitudinal timber bearers on EJN/7, Stockport Road in Cheadle. EJN/7 is a long-timbered structure at 1m 1370yds consisting of a skewed span carrying the single bi-directional Down & Up Main line over Stockport Road between Edgeley Junction and Northenden Junction. The line was non-electrified with existing line speed of 75mph and EMGTPA of 7 (due to increase to 20). Owing to the poor track quality there was an emergency speed restriction of 20mph in place over the structure.
The objective of works was to provide a solution to secure the vertical and horizontal movement of the longitudinal timbers as the horizontal wedges were insecure and requiring regular maintenance interventions.

Schedule of Works

  • Mobilise on site and prepare suitable compound and working area
  • Remove rails and store for re-installation
  • Remove all existing timbers and connection details, including chairs, waybeam packing and transom ties.
  • Replace existing long timbers and baseplates
  • Install packer plates, wedges and holding-down arrangement, including transom bars
  • Install track to line and level in accordance with Permanent Way AFC design
  • Construct a stiffness transition area either side of the structure, consisting of geo-web with rail-grid overlaid, with a minimum of 250mm of bottom ballast below sleepers
  • Supervise tamping of site

Risk Reduction Measures

  • The linespeed was raised in a staged manner to permit regular post-work inspections prior to re-opening to linespeed
  • Void meters were installed throughout the transition lengths to detect any areas of insufficient consolidation and follow-up works were planned to rectify any issues arising
  • The use of low-vibration hand-held plant was procured to minimise the exposure of the workforce to HAVs whilst drilling and fixing the ancillaries
  • S&T cables were identified and protected prior to works to prevent damage
  • Depth and location of structural elements were established prior to works so that transitional excavations could be controlled to prevent damage
  • Safe manual handling was achieved by identifying the weights of items at the planning stage and procuring adequate plant