Knowing exactly where every structure, sign, pole and platform edge is on a railway is very important. The position of any item can affect everything from gauge clearances to signal sighting.

The traditional method of capturing this information involved track walking with a trundle wheel and GPS receiver. However, this exposes staff to the potential safety risks of being on or about the line.

Gathering data by train

Therefore, Network Rail Signalling Innovations Group (SIG) changed the way in which asset inventory data was captured by utilising Network Rail’s track inspection vehicles to undertake train-based surveys. These are carried out on behalf of Signalling Design Group (SDG) projects.

The system used, OmniSurveyor3D®, accurately identifies the geographical and linear position and dimensions of an item, which is automatically assigned a unique ID. This information can be incorporated into a comprehensive geospatial database of assets with the ability to include condition/ inspection information. Details can be exported to assist with engineering reports and data gathering exercises.

At its most basic level, the software can be used to identify and understand the assets of a route and the surrounding environment. Height profile data can be interrogated for the creation of gradient information. Site reports and images relating to any asset can be added to the database. When the time comes for site visits, inbuilt aerial imagery combined with access points within the database allows for access route planning.

Experienced operators can use a further array of tools to make life easier. Measurements can be taken between two points in three dimensions, giving both direct distance and track distance to an accuracy of several centimetres. This information can be used to display lineside measurements, signal distances, level crossing widths, bridge height/length and the like. The signal sighting tool can be used to check driver’s line of sight to a signal. Also, with a bank of virtual asset and object models, OmniSurveyor3D enables users to overlay and manipulate objects for signal planning/sighting, new track layouts and station builds. The software can also be used for office-based driver route learning.

Extra features

The system developer, Omnicom, is currently working to extend the functionality offered within the software by including links and features already offered New Measurement Tool [online]in existing products OmniVision® and OmniInspector®HD. Adding these features, such as automatic image recognition, laser integration and support for SDEF (Signal Data Exchange Format), will greatly enhance the user experience. A new suite of models including signs, signals, speed boards, plant and machinery are also being developed to give users a 3D interactive environment to help improve efficiency, effectiveness and safety when working in the railway environment.

OmniSurveyor3D is widely used by Network Rail’s Signalling Design Group and it is an integral part of the production of base signalling plans and scheme plans. Importing data into the Intelligent Scheme Plan (ISP) software produces a geographic file. This displays the signalling and track data according to geographical position with overlaid Ordnance Survey topography and aerial imagery.

The geographic file is the centre-pin of ISP as this is the file into which all surveyed data is imported and from which all layout plans are generated. The imported files contain data for track centre lines, track connection, datum points, point nodes and the assets. ISP then converts the geographic data into a more familiar schematic or ‘as-is’ layout that depicts the track and signalling layout with sections scaled according to the user requirements and is linked to the static imagery associated with the assets.

Accurate plans

Recent projects delivered were East Coast main line and Durham Coast to the York SDG office and Cambridge to the Swindon office. Over the last 12 months alone, nearly 2,000 miles of the rail network have been surveyed for specific projects but, historically, the entire network was surveyed on a rotational basis so data is available for over 90% of the main line network. This data is available to all contractors from either SIG or Omnicom.

Richard Cooper of the Swindon SDG, involved in the pilot projects using ISP, said of the method: “As well as the saving in time and cost, we avoid exposure to the safety risks of being on or about the line. This new method of producing signalling plans is accurate, with digital images and position data readily available at the touch of a button and easily shared with other disciplines. Different disciplines can request additional survey assets such as telecoms, electrification, plant and civils which could prove to be very cost effective as only one set of data is required.”

Darren Leech, Project Manager of the Cambridge Resignalling Project, added: “The video has also proven to be beneficial for use with risk-based signal sighting, constructability assessments, driver route learning and training.”