People in the north west of Bristol who were up at around 1am in the early hours of this morning could have been excused for wondering if there was some kind of alien invasion in the offing, as a mystery blue light moved around the sky over their heads.
These images were captured on camera by a slightly concerned resident of Sea Mills, Ross-Jayh Crane, who said he watched the blue lights on the base of clouds passing near his home from just before 1am to around 1.30am this morning, Friday, November 11.
The lights have been seen multiple times over Bristol before, and caused quite a stir when they first appeared in 2018, but by 2019 there was rational and slightly bizarre explanation for the source of the lights.
Read more: It's not a UFO, it's one of our very high tech trains, admits Network Rail
The blue light comes from a bright yellow train that's run in the dead of night by Network Rail, as part of its maintenance of the line and the tracks.
It trundles along the recently-electrified railway lines around Bristol and shoots a blue light up into the night sky, to check for wear and tear on the overhead electrified wires. A Network Rail spokesperson said the New Measuring Train - they’ve even abbreviated it to NMT - often gets mistaken for UFOs.
A spokesperson for Network Rail confirmed its bright yellow train was operating on the lines around Bristol, and in Gloucestershire where it also caused a stir overnight. "Yes indeed it was from one of our measurement trains which records the tracks and the structures to the sides, above and below them to make sure they're in full working order," he said.
"The measurement trains plays a vital role in maintaining the railway – helping us to spot potential faults before they affect services,” he explained back in 2019. "The train travelling in the Bristol area last night is certainly one of the most advanced on the network, but it’s not quite out of this world,” he added.
For those who really want to know the details, the blue light is beamed from the roof of the train is part of a measurement system that monitors the amount of wear and tear on the overhead line created by the train pantographs that slide along the underside of the contact wire.
The data that bounces back of the wire is used to prevent something Network Rail call ‘dewirements’, caused by the overhead line braking as a result of the wire wearing too thin. It also scans the entire around around the railway lines to make sure there's no obstructions.
The blue light train is out and about on a fairly regular basis, but it appears the weather conditions have to be right for the light to be seen, with fairly low cloud that is thick enough to reflect back the eerie blue light. If the train passes by on a clear night, few people notice.
Read next:
From Bristol to the world - all the things the city invented, in chronological order
TV riots and bingo machines - the amazing story of Bristol's most famous tower block
How Bristol's famous 'Cry of the Poor' still resonates 150 years on
The story of 'the other Clifton and Ashton' and their remarkable links to Bristol
Want our best stories with fewer ads and alerts when the biggest news stories drop? Download our app on iPhone or Android
