Bridge collapse on M20

[ALawson]

saaby93 said:

Anyone taking best bets on how long it takes to lift a lump of concrete off a truck and re-open a motorway?

I expect Keltbray or other demolition company are placing a crush concrete platform on motorway at the moment. Couple of 40t excavators with breakers will drop the remains of that footbridge in less than an hour, just need to breakup the dropped / demo footbridge and clean up,with an inspection of the road surface. Assuming the road is ok Tarmac or concrete? Then replace some safety fence.

That will be costing millions every hour to have it shut, so they will crack on and it cleared. Of course if the remaining section of footbridge is as it was constructed, which is likely they may just clear the dropped span.

Not a complex job in the grand scheme of things.

[Vaud]

ALawson said:

That will be costing millions every hour to have it shut, so they will crack on and it cleared. Of course if the remaining section of footbridge is as it was constructed, which is likely they may just clear the dropped span.

Who is it costing millions per hour?

[SilverSpur]

The insurance company will have insurance, and that insurance company will have insurance.

[The Nur]

SilverSpur said:

The insurance company will have insurance, and that insurance company will have insurance.

It's turtles all the way down.

[Vaud]

The Nur said:

It's turtles all the way down.

Wikipedia : A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise." The scientist gave a superior smile before replying, "What is the tortoise standing on?" "You're very clever, young man, very clever," said the old lady. "But it's turtles all the way down!"

[tumble dryer]

Vaud said:

The Nur said:

It's turtles all the way down.

Wikipedia : A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise." The scientist gave a superior smile before replying, "What is the tortoise standing on?" "You're very clever, young man, very clever," said the old lady. "But it's turtles all the way down!"

I liked this explanation:

The phrase is used to describe any system that appears to have dependencies that never end. For example, imagine accountability in a (hypothetical) police department. The citizens are policed by police, the police are policed by internal affairs, which might lead to the formation of an "internal internal affairs" to police internal affairs. Someone might describe this system of policing as "turtles all the way down", meaning that the system of policing never ends.

Every day, as they say...

[Nickyboy]

A few points that others have mentioned

Normal UK motorway bridge height is 5.1m.
Height limit applies to hard shoulders as well as main carraigeway, hard shoulders can be less but must be signed.
The artic crushed by the bridge is Polish registered so will be no more than 4m high




This pic shows the digger arm as nowhere near high enough to hit the bridge, it's also on one of the lowest trailers available, designed for carrying double deckers. The digger arm "could" however have been higher, knocked the bridge and the dumper truck also on the trailer being pushed back into the digger arm/bucket, thus bringing down the height of the arm. White markings on the tip of the arm would suggest it has hit the bridge so may make this feasible.

Why it was on the hard shoulder is a wonder though, it certainly wasn't travelling at speed otherwise the digger would have been wrecked or ripped off the trailer.

[TVR1]

Nickyboy said:

A few points that others have mentioned

Normal UK motorway bridge height is 5.1m.
Height limit applies to hard shoulders as well as main carraigeway, hard shoulders can be less but must be signed.
The artic crushed by the bridge is Polish registered so will be no more than 4m high




This pic shows the digger arm as nowhere near high enough to hit the bridge, it's also on one of the lowest trailers available, designed for carrying double deckers. The digger arm "could" however have been higher, knocked the bridge and the dumper truck also on the trailer being pushed back into the digger arm/bucket, thus bringing down the height of the arm. White markings on the tip of the arm would suggest it has hit the bridge so may make this feasible.

Why it was on the hard shoulder is a wonder though, it certainly wasn't travelling at speed otherwise the digger would have been wrecked or ripped off the trailer.

Is the bucket the wrong way around?

[cossy400]

TVR1 said:

Nickyboy said:

A few points that others have mentioned

Normal UK motorway bridge height is 5.1m.
Height limit applies to hard shoulders as well as main carraigeway, hard shoulders can be less but must be signed.
The artic crushed by the bridge is Polish registered so will be no more than 4m high




This pic shows the digger arm as nowhere near high enough to hit the bridge, it's also on one of the lowest trailers available, designed for carrying double deckers. The digger arm "could" however have been higher, knocked the bridge and the dumper truck also on the trailer being pushed back into the digger arm/bucket, thus bringing down the height of the arm. White markings on the tip of the arm would suggest it has hit the bridge so may make this feasible.

Why it was on the hard shoulder is a wonder though, it certainly wasn't travelling at speed otherwise the digger would have been wrecked or ripped off the trailer.

Is the bucket the wrong way around?

Yea they have it that way to back fill,

Im confused by this one as everyones saying hes hit the bridge but with nothing clearly screaming
"ITS ME"

As has been said in that last pic, the arms defo lower than the bridge.


Did he h/ it the one previous to this one and pulled over to check it and that's why he was on the hard shoulder?


Either way hes in for a rough bank holiday weekend, at least no one died then they d be a whole new world of poop

[hidetheelephants]

Flipatron said:

Looks to me like the dumper truck (on the low loader) has caught under the bridge at low speed. The dumper truck then tilts, lifting the bridge off it's foundation. The forward motion of the truck then moves the bridge a few meters clear and then collapses onto the low loader. There seems to be no clear evidence of an impact big enough to push it off its foundations.

More likely the jib arm of the digger caught the notch in the edge of the bridge deck and pivoted about its rear axle and levered upwards as the truck moved forward, lifting the bridge deck beyond the expansion guides and then the outer end has come down onto the stepframe. Presumably the 'middle' end of the deck remained more or less in place until the other lorry hit it, at which point the whole shooting match has come down. The bed on stepframe trailers is usually about 3' and the digger with the arm where it is shown in the pics is perhaps 4-4.5m high, so this is likely the fault of the driver. He can't have been going very fast otherwise it seems possible that the digger may have come off the back of the trailer, the truck would certainly have gone much further down the road before stopping, 40 tonnes doesn't stop quickly from 50~mph.

[red_slr]

I also agree with the above poster who says the pics don't look right.

Looking at the damage and the photos its not clear what happened.

There is no doubt the bridge is lower at that point on the HS though. I wonder if he stopped for some reason just at the bridge and then got wedged. Then attempted to drive under and ended up dragging the bridge off its mounts. Either way that must be 50-60 tonnes of concrete... if not 2 or 3 times that?

[saaby93]

red_slr said:

I also agree with the above poster who says the pics don't look right.

Looking at the damage and the photos its not clear what happened.

There is no doubt the bridge is lower at that point on the HS though. I wonder if he stopped for some reason just at the bridge and then got wedged. Then attempted to drive under and ended up dragging the bridge off its mounts. Either way that must be 50-60 tonnes of concrete... if not 2 or 3 times that?

The weight doesn't matter too much if the bridge is just sitting one lump of concrete on another and just waiting to be tapped sideways.. You can see some white stuff on the digger elbow but that may be secondary.
Similarly on the bridge abutment you can see where the deck has fallen off the edge.
The dumper truck doesnt look as big in that last photo

[red_slr]

I understand that. One of my curtain siders (26t) hit a tree limb c.15mph and it basically destroyed / bent every part of the truck. Forces involved are crazy and moved down the entire bed bending everything. However I am just saying it looks odd. I think its pretty clear something hit the bridge - just don't think it was a full on 56mph smash - that 360 would have more damage - IME. The fact he was on the HS is also odd.

I suspect the HA are going to take a lot of flack for this one - the Armco - IMHO - should have come out and reduced the risk to zero. I guess there is a policy of keeping the HS open though along that route given its towards the ports.

The M6 certainly used to have plenty of sections where the HS is reduced to nothing for a few hundred yards.

[red_slr]

You can clearly see the boom is above the top of the cab in this photo by some way...

I reckon that pushed the bridge off its mount down onto the dumper and then the trucks forward motion carried the bridge off its other mount along with the artic in L1 which is by this point also in contact with the bridge.

[turbobloke]

Vaud said:

The Nur said:

It's turtles all the way down.

Wikipedia : A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise." The scientist gave a superior smile before replying, "What is the tortoise standing on?" "You're very clever, young man, very clever," said the old lady. "But it's turtles all the way down!"

That's a great phrase.

As to Russell, he may have been giving the lecture and the topic may have been as described but he was a mathematician, philosopher, logician, as well as something of a historian and political activist.

IIRC his interest in science was on the philosophical side, applying the scientific method to aspects of philisophy including how a 'scientific society' might avoid many of the problems of his day including war.

A highly distinguished academic, he was elected FRS but likely not for waving test tubes in anger. His view on the bridge collapse would be invaluable

[red_slr]

Driver will also probably say view of bridge obstructed by gantry which looks very close.

[saaby93]

Nickyboy said:

A few points that others have mentioned

Normal UK motorway bridge height is 5.1m.
Height limit applies to hard shoulders as well as main carraigeway, hard shoulders can be less but must be signed.
The artic crushed by the bridge is Polish registered so will be no more than 4m high

This pic shows the digger arm as nowhere near high enough to hit the bridge,

It might be camera angle
That arm is about a metre or more higher than the white artic.
From that angle the bridge parapet will be a metre or more lower than it looks
It looks like there is nothing in the bridge mounting from preventing it from sliding sideways

Edited by saaby93 on Sunday 28th August 08:14

[saaby93]

CAPP0 said:

Here's the "before" shot. As I said above, the path on the bridge has quite a fair gradient on it. There's a bit of an optical illusion going on, the underside of the bridge slopes less so, but it does look low at the (alleged) point of impact, if the truck with the digger was travelling on the shelf for any reason.

look at the fence line and the height of the gantry above it and the height of the bridge above the fence
Thee bridge is a good metre or more lower. Those fence panels are what 2.4metres?

[croyde]

A lot of holidays now feked this weekend.

Amazing no one hurt apart from the poor fella on the bike.

[FlyingMeeces]

croyde said:

A lot of holidays now feked this weekend.

Amazing no one hurt apart from the poor fella on the bike.

Looking at the pics of where the bike ended up (from the Beeb article) that motorcyclist is a very very lucky boy/girl to 'only' have broken ribs. Wishing them a swift recovery all the same- ouch!