LNER AIVR flags a Retford track fault; overnight fix, zero delay

New Civil Engineer (6 Jul 2026) quoting LNER's 9 Apr 2026 announcement: after a January 2026 Cambridgeshire defect caused over 10,000 delay minutes, One Big Circle's AIVR identified a developing fa...

21ⓘ

AI system

System

Automated Intelligent Video Review (AIVR) front-of-train camera system with machine-learning analysis

Model

Not assessed

Release

Not assessed

Application developer

One Big Circle

Role

Not assessed

Configuration

Not assessed

Inputs and outputs

Not assessed

Autonomy

Not assessed

Workflow

Front-of-train cameras on scheduled passenger services covering the same track daily. Machine-learning review that raises possible defects to the infrastructure manager. A maintenance organization able to schedule overnight possessions.

Human oversight

Not assessed

Relation to AI

AIVR's analysis raised the fault report that Network Rail engineers acted on. No human had reported it. Whether the minor fault would have escalated is LNER's claim. Detection rates and false-positive rates are not published.

AI contribution

AIVR's analysis raised the fault report that Network Rail engineers acted on. No human had reported it. Whether the minor fault would have escalated is LNER's claim. Detection rates and false-positive rates are not published.

Benefits

Outcome identifiers

Not assessed

Benefit

an overnight repair with no delay to passengers and zero delay minutes

Category

Improved Organizational Efficiency

Status

Not assessed

Beneficiary groups

Organizations. Society. People.

Beneficiaries

Not assessed

Reach

Not assessed

Distribution and access

Not assessed

Duration

Not assessed

Expected?

Yes

Costs and harms

Not assessed

Measurement

Studies

Not assessed

Study design

Not assessed

Measurement

Not assessed

Setting and sample

Not assessed

Measures

an overnight repair with no delay to passengers and zero delay minutes

Comparison

a track defect reported by a train driver a week earlier (January 2026, Cambridgeshire)

Results

Reference: over 10,000 delay minutes, multiple cancellations, and led to a full day of disruption for customers. Result: an overnight repair, with no delay to passengers, and zero delay minutes caused.

Additional value from AI

Not assessed

Limitations

Not assessed

Denominators

Not assessed

Materials for replication

Not assessed

Money

Kind of value

Not assessed

Amount

Not assessed

Currency and prices

Not assessed

Period and unit

Not assessed

Realization

Not assessed

Recipients and payers

Not assessed

Gross or net

Not assessed

Included costs

Not assessed

Comparison

Not assessed

Method

Not assessed

Return and payback

Not assessed

People and places

Participants

Developer: One Big Circle. Operator: LNER (on-train cameras), with findings passed to Network Rail.

Jurisdictions

Benefit: Retford, United Kingdom. Developer: United Kingdom. Operator: United Kingdom.

Ownership and control

Not assessed

Dependencies

Not assessed

Cross-border connections

Not assessed

Geopolitical implications

Not assessed

Follow-up

Conditions for replication

Engineers triage AI reports promptly. False positives (such as the snake) do not swamp the reporting channel. The fault is visible from a train-mounted camera.

Replication attempts

1 follow-up entries. Benefit did not recur: 1.

Later findings

6 July 2026. The system was still running on LNER trains in July 2026, when it raised a snake crossing the line as a potential track defect; Network Rail said raising it automatically was standard practice.

Availability

Not assessed

Institutional decision

Not assessed

Grounds

Not assessed

Action and result

Not assessed

Success criterion

Not assessed

Evidence

Source numbers

AIBD-0255-source-0001–0002

Citations

Numbered references below.

Language

Not assessed

Source relationships

Independent, Operator

Original evidence

Not assessed

Access and versions

Not assessed

Supported findings

Not assessed

Evidence strength

Not assessed

Missing evidence

Not assessed

Grades

Assessed benefits

Organizations. Society. People.

Depth

Organizations: 2. Society: 1. People: Not assessed.

Reasons

Organizations: An overnight planned repair with zero delay minutes. The comparison is a defect the same month that cost over 10,000 delay minutes and a day of disruption. Society: Passengers were spared delay from this fault. The scale of avoided disruption is not quantified. People: No individual outcome is documented.

Observed or intended

Not assessed

Rubric

Not assessed

Assessor and date

Not assessed

Alternative assessments

Not assessed

Fill

Independently reported

Entry details

Kind

Not assessed

Field

Railway safety. Track inspection / defect detection.

Purpose

AIVR is built to capture and analyze front-of-train video with machine learning. The aim is to find and fix track and lineside defects before they cause disruption.

Dates

Date basis unassessed: 2026 (precision unassessed). Updated: 21 October 2026.

Stage

Not assessed

Version

SHA-256: c075807381a9…

References

Other identifiers

Not assessed

Category mappings

Not assessed

Brief

Not assessed

Revisions

5 revisions. Latest: 21 October 2026.

Sources

  1. News report Independent author

    Pashby T (6 Jul 2026). AI system on LNER train misidentifies snake as track defect. New Civil Engineer.

  2. Press release Deployer

    Network Rail (31 Oct 2022). Future Rail – how machine learning is improving your journeys.