Trains cancelled over fake bridge collapse image

Given the number of cctv cameras that operate in the UK, and their continued growth, I am surprised that the rail operator did not have access to a direct view of the bridge. I am also a bit surprised that there isn't technology to detect rail damage, especially the power lines that runs over the track.

Where I live it is not uncommon for rail to have detection for people walking on the rail, and bridges to have extra protection against jumpers. I wouldn't be that surprised if the same system can be used to verify damage.

This is the part that I find insane. What if the bridge had collapsed, and no one had bothered to post a picture of it to social media?

There is technology that could detect rail breaks, in the form of track circuits: feed a current into a rail, detect whether it gets to the other end (or bridge the two rails at the other end of the circuit and see if it gets back to the start of the other rail). A variation of this is commonly used in signalling systems to verify that the track is clear: if a pair of wheels is in the track section then the signal will short across the rails and make the circuit show 'occupied'.

Ultimately, though, this kind of stuff is expensive (semi-bespoke safety-critical equipment every few miles across an enormous network) and doesn't reduce all risks. Landslides don't necessarily break rails (but can cause derailments), embankments and bridges can get washed out but the track remains hanging, and lots of other failure modes.

There are definitely also systems to confirm that the power lines aren't down, but unfortunately the wires can stay up and the track be damaged or vice versa, so proving one doesn't prove the other. CCTV is probably a better bet, but that's still a truly enormous number of cameras, plus running power supplies all along the railway and ensuring a data link, plus monitoring.

I mean, you're supposed to call the police or Network Rail: there are placards on the (remains of the) bridge with the telephone number. But yes, it's not uncommon to have to send a train to examine the line (at slow speed, able to stop within line-of-sight) after extreme weather.

> Given the number of cctv cameras that operate in the UK, and their continued growth,

CCTV cameras are mostly in private ownership, those in public ownership are owned by a mass of radically different bodies who will not share access without a minimum of police involvement. Oh and of course - we rarely point the cameras at the bridges (we have so many bridges).

> Where I live it is not uncommon for rail to have detection for people walking on the rail, and bridges to have extra protection against jumpers. I wouldn't be that surprised if the same system can be used to verify damage.

This bridge just carries trains. There is no path for walking on it. Additionally jumping would be very unusual on this kind of bridge; the big suspension bridges attract that behaviour.

You mentioned twice that you are surprised by things which are quite common in the UK. I don't know where you're from, but it's worth noting that the UK has long been used as a bogeyman by American media, and this has intensified recently. You should come and visit, the pound is not so strong at the moment so you'll get a great deal to see our country.

Contrary to popular belief, not every single square inch of the UK is covered by state operated CCTV.

The saying/claims in the last 20 years or so is that London has the highest ratio of cameras to people in the world, through looking at what seems more correct statistics it is only the 12th most dense camera city in the world. how well that translate to the rest of the country is much less talked about.

Here in Sweden, people walking on the rails without permission is a fairly common problem, which cause almost 4k hours of accumulated delays per year. For people who often travel by train, the announcement of reduced speed because of the system has detected people on the tracks are one of the more common ones, only second to the catch-all announcement of "signal error", which simply mean the computer says stop for a reason that the driver don't know or don't want to say.

When it comes to suicide prevention on bridges, it is not just the big bridges. Suicide by train is a fairly talked methods in the news as a work hazard for train drivers, and the protection here is for small bridges that goes above the track. Similar issues exist with bridges over roads and highways. Those methods are to my read of the statistics more common than the movie version of a person jumping from a suspension bridge.

One of the more interesting ways of detecting rail damage, and subsidence in general, is optically detecting noise / distortion in fiber optic cables. An applied case of observables which are the basis for an evaluative (the "signal") being utilized originally to diagnose possible maintenance issues and then going "hey there, wait a sec, there's a different evaluative we can produce from this exhaust and sell".

https://fibersense.com/

http://www.focus-sensors.com/

People on tracks and suicide by train are, I suspect, way more common in London for us than elsewhere. I can't get solid figures though. But it seems to sit around 15k hrs of delays nationwide for people on tracks.

We had a big government inquest into suicide in 2018 which included asking national rail to justify it position and actions. Of the 30k rail bridges in the UK only the hotspots have any modern measures of suicide prevention; and the hotspots are mostly but not exclusively suspension bridges.

However, from your comment, I see that you might be meaning pedestrian bridges across tracks, which almost always have metal rails higher than an adult man here. Our older stone road bridges (which are very common) have thick and tall walls on the edge which serve a similar function if not as effectively.

However, I think to hark back to the original image and post - the bridge depicted is a train bridge going over a road. More like a viaduct tbh. Its highly unlikely that there is any normalised pedestrian access so it won't tank highly for assigning prevention and detection measures for either suicid, and its easily assessed from the busy public road so I doubt it makes the priority list for automated collapse detection.