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Tunnel Vision


With the date for energisation of the first new section of Electrified railway North of Bedford fast approaching a quantity of risks remained outstanding. The primary item of concern related to standing surface clearances (GL/RT1210) to the new, soon to be live, OLE equipment. Designer risk assessments had evidenced clearances at OLE supports and some over line structures but numerous features and ground profiles along the route remained un-assessed/un-evidenced.


Digitality Solutions created the product ‘Tunnel Vision’ to undertake the initial clearance sift. This tool created a clearance volume from the dynamic pantograph horn and allows the user to navigate the BIM model within the clearance volume. Non-compliant assets/features become evident as they are visible within the clearance volume. This allows the user to assess the validity of the intrusion and assess whether further assessment is necessary.

  • Tunnel Vision allowed the user to discount up to 90% of the identified locations of concern with the ability to assess 10+km of the rail corridor with a matter of hours. To undertake this activity manually would take numerous weeks

  • Tunnel Vision is run directly within the BIM model

  • The assessment accounts for the whole route and not limited to identified discrete locations. Guaranteeing all non-compliance's are captured

  • Tunnel Vision identified non-compliance which were not identified at the initial risk workshops

  • Tunnel Vision ensured all identified areas of concern were closed and evidenced efficiently to ensure energisation can proceed

  • Lesson learned is that Tunnel Vision should be employed earlier in the GRIP process to evaluate, identify and evidence standing surface clearances along the length of the project corridor

  • Full desktop assessment supports the boots off ballast

Potential Alternative Assessments

TunnelVision can also be configured to be utilised on existing Railway Infrastructure to assess the following:

  • Vegetation Clearance

  • For defining safe cess positions

  • Defining limited clearances to overline/lineside assets

  • Defining contact wire drop/fall zone

BIM Model Minimum Requirements

TunnelVision requires the following source data federated into a BIM Model. All this data is readily available within Network Rail's GeoRINM system

  • LiDAR/RILA Point Cloud Survey

  • Rail String Elements

  • Contact Wire String Elements

  • 3D Assets/Features


Exclusion Volume created from cess Horn of Dynamic Pantograph. Pantograph is modelled in accordance with UKMS and part of the DynaPan tool.


Navigation Tool to step through the exclusion volume. Elements of non compliance appear within the volume

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