How much does it cost to raise a railway bridge?

[droopsnoot]

None of these things are difficult, but there seem to be all sorts of reasons mentioned in this thread alone why they are a not a comprehensive solution. Flashing lights are too easy to ignore, static signs even more so. A barrier would work, but would be detrimental to traffic flow as it would have to be down all the time, but open for each suitable vehicle, there's no way you could have something that would drop when it senses a high vehicle coming. What if there's not enough gap between it and the vehicle in front to drop the barrier and safely stop?

I believe (though I'm not 100% sure) that proper truck sat-nav systems also include bridge height data and will route the vehicle to avoid things it cannot fit under, but some cheapskates just use a car one. A local chap once designed an built an in-cab low bridge warning using GPS, that sold quite well, but still these things happen. (That's not to suggest that I am happy about it, just to say that it's clearly not that easy). Perhaps in-depth interviews with drivers as to how they managed to hit a signposted low bridge might give some insight, but I suspect in that situation the driver will be mainly concerned with not incriminating themselves.

Edited by droopsnoot on Monday 11th June 11:06

[mcdjl]

Pacman1978 said:

Exactly how difficult is it to come up with a fairly cost effective solution to stop this problem.

How hard is it to install some laser sensors that are linked to a barrier or bollard or similar. All installed at a distance so as to prevent bridge strikes.

Or install sensors on the highest part of the vehicle which alerts the driver. Again a laser will surely be able to do its thing with ample space to avoid any problems.

(if I can think up the above ideas

I'd get a more powerful laser and slice the offending part of the roof off. it might still hit but just slide off nice and easily

[P924]

just put a structure up, 10 foot before the bridge, thats the same height, let people drive into that first.

[Foliage]

Hydraulically lift the bridge up when no trains are coming, when a trains coming drop barriers and lower the railway into position.


Turning any often hit bridges into a pseudo level crossings

[ZymoTech]

To bring things up to date a bit....last night (28th June) was the GWSR Plc's AGM and after the close of formal business the evening was thrown open to the floor for some Q & A. There was much discussion about Station Road bridge encompassing signage, over-height vehicle detection, red lights, flashing signs, a cctv system, vibration detection, who would pay for it all etc, etc.

Apparently the last straw (if you'll pardon the pun coming up) was on the 18th June when a lorry carrying a baler passed underneath the bridge - the lorry made it through to the other side but the baler didn't. If I can find a photo online I'll post a link.

To cut a long story short signs and lights can be ignored but a physical barrier can't. Hence an order has gone in for crash protection beams. These will be composed of box section steel filled with concrete, to create mass, and will be affixed to the bridge abutments. If I heard correctly the bottom edge of each beam will sit 20mm below the edge of the bridge span. Installation will be at some point in August but I don't know exactly when.

One nugget of information that cropped up was that Station Road bridge is in the top 15 of the most bashed railway bridges in the UK.

[saaby93]

ZymoTech said:

One nugget of information that cropped up was that Station Road bridge is in the top 15 of the most bashed railway bridges in the UK.

That being the case youd have thought there'd be some process for getting bridges off that list
Isnt reducing the height by 20mm going to move it further up the list not down it

[mcdjl]

saaby93 said:

That being the case youd have thought there'd be some process for getting bridges off that list
Isnt reducing the height by 20mm going to move it further up the list not down it

If who ever put the signs up was sensible they'll have marked it as 2m whens is actually 2.02m anyway. That 20mm will soon very lost in a lorry bouncing, being high on its springs or just sloping up as it as angles through the dip.
Alternatively the beam will just slice whatever a bit lower protecting the bridge.

[saaby93]

mcdjl said:

If who ever put the signs up was sensible they'll have marked it as 2m whens is actually 2.02m anyway. That 20mm will soon very lost in a lorry bouncing, being high on its springs or just sloping up as it as angles through the dip.
Alternatively the beam will just slice whatever a bit lower protecting the bridge.

Is that legal
How low are they allowed to place 'slicers' before being taken to task

We've seen in other threads eg bus lanes, that it's possible to place signs in places that are perfectly obvious in photographs but where you'd hardly notice them while driving.
( and since we're talking about railways - we know signals can be placed where train drivers dont see them too)

[mcdjl]

saaby93 said:

Is that legal
How low are they allowed to place 'slicers' before being taken to task

We've seen in other threads eg bus lanes, that it's possible to place signs in places that are perfectly obvious in photographs but where you'd hardly notice them while driving.
( and since we're talking about railways - we know signals can be placed where train drivers dont see them too)

If the slicer (big concrete filled steel beam) would be illegal then so would the bridge. So long as it's signed and higher than the sign says, it's function is to stop stuff hitting the bridge. The only difference being at least the trains will still run, even if the road is just as shut.

[Rick101]

[gothatway]

How difficult/expensive would it be for all vehicles over a certain height to be required to be fitted with a satnav which knew the heights of all low bridges and could warn the driver of those in the vicinity ? Low loaders, hay/straw wagons, etc. would need some facility to enter the height of their load. Truckers' road atlases already contain low bridge info so the data is certainly available. I assume that all modern HGVs are already fitted with satnavs or trackers.

[saaby93]

gothatway said:

How difficult/expensive would it be for all vehicles over a certain height to be required to be fitted with a satnav which knew the heights of all low bridges and could warn the driver of those in the vicinity ? Low loaders, hay/straw wagons, etc. would need some facility to enter the height of their load. Truckers' road atlases already contain low bridge info so the data is certainly available. I assume that all modern HGVs are already fitted with satnavs or trackers.

One problem is many of the indicated heights are inaccurate
The local school double decker bus in theory shouldnt be able fit under the local railway bridge
However they brought it out, measured it up, took it under, checked there was a decent clearance and it's in service, presumabley lower when it's laden

[Evanivitch]

Foliage said:

Hydraulically lift the bridge up when no trains are coming, when a trains coming drop barriers and lower the railway into position.


Turning any often hit bridges into a pseudo level crossings

It's not a bad idea at all, and mechanically quite simple (hydraulic screw lift wouldn't be impossible for a few foot lift).

The biggest issue IMO would be doing it with a suitable safety factor as the bridge staying high is not a fail-safe scenario.

Effectively trains would be required to stop/severely slow before all approaching all such crossings. I'm not sure this would be suitable.

[saaby93]

Evanivitch said:

Foliage said:

Hydraulically lift the bridge up when no trains are coming, when a trains coming drop barriers and lower the railway into position.


Turning any often hit bridges into a pseudo level crossings

It's not a bad idea at all, and mechanically quite simple (hydraulic screw lift wouldn't be impossible for a few foot lift).

The biggest issue IMO would be doing it with a suitable safety factor as the bridge staying high is not a fail-safe scenario.

Effectively trains would be required to stop/severely slow before all approaching all such crossings. I'm not sure this would be suitable.

They could put a ramp either side

[Evanivitch]

saaby93 said:

They could put a ramp either side

You facetious tart.

[gothatway]

saaby93 said:

gothatway said:

How difficult/expensive would it be for all vehicles over a certain height to be required to be fitted with a satnav which knew the heights of all low bridges and could warn the driver of those in the vicinity ? Low loaders, hay/straw wagons, etc. would need some facility to enter the height of their load. Truckers' road atlases already contain low bridge info so the data is certainly available. I assume that all modern HGVs are already fitted with satnavs or trackers.

One problem is many of the indicated heights are inaccurate
The local school double decker bus in theory shouldnt be able fit under the local railway bridge
However they brought it out, measured it up, took it under, checked there was a decent clearance and it's in service, presumabley lower when it's laden

But that's fine, it errs on the side of safety. And it's simply a matter of updating the data for any that are found to be in error.

[saaby93]

two bridges being raised by a foot
https://www.bbc.com/news/uk-wales-45501434

[mcdjl]

A lot then. And in those cases it appears as much as a consequence of the bridge being life expired as much as to avoid being hit.

[Frank7]

saaby93 said:

two bridges being raised by a foot
https://www.bbc.com/news/uk-wales-45501434

I could have done with that maybe 40 years ago.
I was delivering a 60’ yacht, overland from Reading Marina to Cannes, France, on a 54’ artic.
Somewhere a few kms before Grasse, Alpes-Maritimes, I came to a railway bridge, it was well sign posted with the height, but I hope-guessed that I might make it.
The English kid (hired at a job Centre), who was driving the rented escort car, with Convoi Exceptionnel on a tarp spread across the bonnet, (a legal requirement), drove under the bridge, come back, and climbed up to the wheelhouse.
I edged through like a snail, until he called, “HOLD IT FRANK!”
I climbed up, and the yachts steering wheel, which was a wheel, not one of those spoke things, was touching the brickwork of the bridge.
I tried to unscrew it, or unbolt it, but I couldn’t budge it, I looked behind, and there were dozens of vehicles, impatiently waiting for me to move.
I had no chance of reversing, so I tied some rope around the wheel, and told the kid to pull down on it as hard as he could, then inched forward until I was through.
When we took a look, the leather steering wheel cover had brick scratches, but the wheel looked okay.
I got to Cannes late afternoon, and was told that the yacht would be offloaded in the morning.
3 or 4 guys looked it over, Christ knows if they saw anything, but they signed off on it, and I was out of there like a greyhound, en route to Le Havre.

[Rick101]

Network Rail said:

We’re responsible for the 30,000 bridges, tunnels and viaducts on Britain’s rail network.

At 4.25 million per bridge that's a big figure. I'm some will make an argument it should be done cheaper.

Regardless. I think drivers knowing the height of their vehicle and reading the signs would be the best solution to this.