High Output Track Renewals (HOTR) Survey Summary:

High Output Track Renewals (HOTR) uses state of the art factory like trains to renew rail, sleepers and ballast. Network Rail are responsible for delivering around 70% of the total volume of plain line renewals on the UK’s primary high-speed mainline routes.

Severn Partnerships role in HOTR is to provide a very accurate 3D plan of the railway track and all the associated railway assets along a proposed HOTR route.

One such project was on the Mainline in the Midlands area that lasted from November 2012 to October 2013 which involved surveying approximately 44 miles of track, across 32 separate sites on 10 different Engineers’ line reference (ELR) over a period of 12 months.

What do we do?

  • PGM Installation – At 200m intervals or less in places of safety.
  • Traversing – Survey control observations made using 1” total stations.
  • Levelling – All PGMs were levelled with double run sub-millimeter accuracy, using Leica DNA03 digital level and barcode staff.
  • Topographical Survey (Track) – Rails were surveyed at a general 10 metre interval throughout the project route unless specified otherwise (e.g. 5m intervals through Platforms, Tunnels, Bridges, and S&C units). This was carried out using total stations with radial observations to the running edge of both rails.

Instruments we use:

  • Dual frequency GNSS receivers
  • Total stations with an angular accuracy of ± 2″ and EDM accuracy of ±(2mm + 2ppm).
  • Conventional engineer’s or digital level with an accuracy of ±10mm per 1Km run of double levelling.

Site Safety:

Severn Partnership managed subcontractor Seaton Rail to provide:

  • Site safety staff.
  • Possession planning, track access & SSOW
  • Task Briefing Sheets

Standards:

All works were in line with the specification received by our client, and the following current Network Rail Standards:

  • NR/L2/TRK/3100 Topographic, engineering, land and measured building surveying – Strategy and General
  • NR/L3/TRK/3101 Topographic, engineering, land and measured building surveying – Track.
  • NR/GN/TRK/3103 Topographic, engineering, land and measured building surveying – Survey and Mapping
  • NR/GN/TRK/3105 Topographic, engineering, land and measured building surveying – Overhead Line Electrification
  • NR/L1/AMG/1010 Policy on working safely in the vicinity of buried services
  • NR/L1/AMG/1030 Working safely in the vicinity of buried services

Deliverables:

  • 3D digital CAD drawings (AutoCAD dwg & dxf Format)
  • Survey control station schedule and witness diagrams
  • Structure gauging information (SCO & SCP Format)