When Rail Video and Event Data Don’t Align, Start with the Clock

A shared time reference helps railway teams find the onboard footage that corresponds to a recorded braking event.

Onboard NVR beside a playback screen showing railway video and a braking event at 14:32:08.
Illustrative example of onboard video and a braking record with matching timestamps.

Why the Records Can Be Hard to Match

In June 2026, two passenger trains collided near Elstow, England. In its interim report, the UK Rail Accident Investigation Branch (RAIB) said the recording devices used in the investigation did not all share a time source. Investigators used the signal data logger’s clock as the reference to align the records and reconstruct the sequence of events.

The same problem can come up in routine reviews. If a train event recorder logs a brake application at 14:32:08 and the video recorder’s clock is a few seconds off, the frame labeled 14:32:08 will show a different moment.

Reviewer comparing forward-facing rail footage, an event log, and operating data on three monitors.
Illustrative workflow for comparing onboard video with train operating records.

How the Data Gateway and NVR Work Together

A MegaFeis data gateway can use GNSS-based timing to provide a shared time reference for compatible onboard equipment. The onboard network video recorder (NVR) uses that reference to timestamp the footage it records.

When a braking event is logged, maintenance or safety teams can use its timestamp to locate the corresponding footage and review the signal indication and track conditions around that time.

Black onboard NVR mounted inside a rail vehicle equipment cabinet.
Illustrative installation of an onboard NVR used to timestamp recorded video.

Device processing, video buffering, and interruptions to synchronization can still affect how closely the records align.