scope:

This Guidance Note provides guidance on surveying activity for which a co-ordinated engineering, land, topographic or measured building survey is required.

The concept of a survey risk register is covered in NR/L2/TRK/3100.

NOTE 1 It is important to consider the accuracy of the survey required and also the commercial and technical risks involved with a survey.

NOTE 2 As an example consider a track renewal site where a decision has to be made as to which technique is appropriate. This very much depends on the type of route. In general terms, a decision has to be made between the options of a Hallade survey (NR/L3/TRK/3101 Section 5.11) or Total Station (electronic theodolite and EDM) detail survey (NR/L3/TRK/3101 Section 5.8). All planned works in the area need to be considered (track and other disciplines). Where adjacent tracks (alongside or close by on the same track) are to be renewed a topographic survey would be advantageous. When other works such as level crossing renewals, platform reconstructions, or certain types of drainage work, are required, then a topographic survey has distinct advantages.

When new and innovative techniques not covered by this standard are developed and are appropriate for use, these techniques can be presented to the Network Rail Senior Survey Engineer for consideration and approval.

Purpose

This Guidance Note standard has been written to enable a general understanding of the techniques that may be used to collect survey data for Topographic surveys requiring a positional accuracy of better than Plus or Minus 100mm. It provides detailed project processes for track monitoring and surveying for slab tracking as Appendices.

Such surveys are not an automatic requirement for all projects.

It specifically excludes ground investigation, geotechnical, building condition, dilapidation surveys and surveys associated with Network Rail owned and operated measurement trains.

It is intended to be used in conjunction with the suite of Network Rail Topographic surveying standards. Parts of NR/L2/TRK/3100, Topographic, engineering, land and measured building surveying - Surveying and general specify information to enable a specification for survey data collection to be developed for the disciplines of Track (specified in NR/L3/TRK/3101), Civils (specified in NR/L2/TRK/3102, in development), OLE, Signalling and Commercial Property (all with standards to be developed).

This Guidance Note provides guidance and recommendations on the GRIP stages that the various techniques are best suited for.