The Rail Accident Investigation Branch (RAIB) has published its final report on the track-worker near miss that occurred at 09:53 on 23 April 2024 at Chiltern Green, between Harpenden and Luton Airport Parkway. A telecommunications tester narrowly escaped being struck by a south-bound train travelling at 104 mph (167 km/h) when crossing an underbridge offering only minimal clearance.
Incident overview
RAIB’s investigation confirms that the worker had been returning from a welfare break and was unaware of a safe authorised route back to the worksite. The person in charge (PiC) had earlier escorted the tester across the same underbridge using an informal route not envisaged by the original project engineer. When the driver spotted the worker, he sounded the horn and made an emergency brake application before reporting the incident, uncertain whether contact had been made.
Principal findings
- Planning deficiencies – The PiC had taken little part in the work-planning stage and held incomplete documentation. As a result, the group’s access route did not align with the safe-work methodology intended by the project engineer.
- Inadequate safe system of work – No effective controls were in place for staff leaving or re-joining the group. The tester therefore crossed the bridge alone despite recognising the risk.
- Missing limited-clearance signage – Although Network Rail’s asset records flagged the structure as restricted, the bridge carried no ‘limited clearance’ signs, removing a key visual prompt.
- Incomplete asset management – Network Rail’s East Midlands route lacks a comprehensive inventory, inspection regime and maintenance schedule for warning signage, allowing hazards to go unflagged.
RAIB issues four recommendations:
- Keltbray Infrastructure Services – Strengthen work-planning processes so frontline staff receive unambiguous instructions covering walking routes and egress arrangements.
- Rail Safety and Standards Board (RSSB) – Review and, where necessary, amend industry standards governing warning signage at restricted-clearance structures.
- Network Rail (asset management) – Record all lineside signage assets and establish inspection and maintenance regimes.
- Network Rail (risk reduction) – Accelerate the fitting of warning signs to structures already recorded as restricted clearance.
RAIB highlights the need for:
- Clear shared understanding of walking routes during planning and site briefing stages;
- Precise identification of all intended access points where multiple sites of work are involved;
- Avoidance of any location offering reduced clearance while lines remain open;
- Agreed exit strategies for staff involved in a near miss, including liaison with the signaller.
Following the incident, industry rules were updated to prohibit holders of Personal Track Safety (PTS) competency from crossing restricted-clearance bridges unless a formally assessed safe system is in force.
RAIB investigations focus solely on preventing recurrence rather than attributing blame. The Branch liaises with duty-holders throughout an inquiry to ensure that emerging safety issues are communicated long before a final report is released.
