Background

Possessions and line blocks are essential when access to an earthwork cannot be gained by staying more than two metres away in a Separated Safe System, mainly due to narrow cess widths or pinch points preventing access in an open line scenario.

In CP7 Year 1, the Southern task list included 6,711 sites. Of these, 116 required a possession and 1,664 required a line block due to access constraints. To successfully deliver this volume of restricted access examinations, GeoAccess deployed a dedicated in-house planning team with strong local knowledge and established Network Rail contacts.

By combining comprehensive desk studies, early planning, and proactive stakeholder engagement, GeoAccess ensured efficient booking and high acceptance rates for possessions and line blocks across the Southern region.

Method

Planning and desk study were central to the success of the project. After an initial check for early non-compliance, the team carried out a desk study using previous exam data and the workbank from Network Rail. Using several years of information from the Earthworks Database and planning team experience, sites were identified where access limitations meant a possession or line block would be needed.

The Southern region planning team consisted of a Planning Manager, a Possession Planner, and a Safe Work Planner. Once the desk study was completed, the team reviewed the list and confirmed that these sites could be delivered using these access methods, then began the formal planning process.

Possessions had to be booked at least three months in advance through the PPS system, although late access requests could be submitted for high-risk sites. After submitting requests, the team attended all relevant Network Rail meetings within required timescales, including deconfliction meetings, to ensure work could proceed alongside other planned activities.

Line blockages had to be booked at least one week in advance, with each request accompanied by a Track Access Request Form. Submitting requests earlier increased the likelihood of acceptance by GZAC.

Innovations & Solutions

• Specialist depot access procedures managed for sites on the BPJ line located within a train depot, which had its own possession-booking procedure. In-house planners with strong local knowledge contacted the depot and followed individual requirements.
• Weekly depot meetings attended leading up to possessions, with staff names provided well in advance and all personnel completing required inductions before their shift.
• Drone survey capability deployed to survey sites ahead of possessions, allowing identification of potential access issues or other blockers in advance.
• Strong local knowledge and established contacts enabled quick resolution of issues, increasing acceptance rates and right-first-time completions.

Results & Conclusion

Through effective possession and line block planning, GeoAccess achieved:

• High acceptance rate for possession and line block requests across 1,780 restricted access sites.
• Increased use of possessions and line blocks, enabling examinations that would otherwise be impossible under open line conditions.
• Right-first-time site completions through comprehensive advance planning and pre-work surveys.
• Quick issue resolution via in-house planning team with local knowledge and established Network Rail relationships.

This project demonstrates how the GeoAccess in-house planning expertise provides Network Rail with reliable, efficient methods for railway earthwork inspections in restricted access environments across the Southern region.