El Deano:
Captain Caveman 76:
Warning, the following post contains half remembered facts and ■■■ packet maths.
I’m pretty sure that double decker busses can lean up to 30 degrees before tipping over. Given the height of them, you’d need a kerb about 2 foot high to get to that angle.
Of course, speed and weight distribution will alter that dramatically.
28 degrees as demonstrated here
youtu.be/C-fZA1NJtPA
Thats a fair old tilt though but imagine the upper deck being full and apply same to a diuble beck trailer.
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Totally. And that’s in a static condition. Even a double decker bus with full upper deck actually has an amazingly low centre of mass for its appearance. 20 People don’t weigh much. All the drive train, engine and axles are very low slung on them. Lorries have a much much higher centre of mass. As Conor mentioned, even a normal height trailer can roll when you hit a kerb.
And that’s without moving. Consider speed and it changes things up a gear. You can tip over various ways. Side slam into the outside kerb on a right bend and the kerb acts as a fulcrum and the momentum carries the wagon over the top. Or another way is hitting a kerb in a straight line. The suspension soaks up the impact, rebounds and the energy puts the lorry into a bank angle. The centre of mass already high only has to pass the fulcrum (tyre contact point). When they roll the downside suspension squashes under the weight, further leaning it over and then the tyre sidewalls collapse under the lorry which pushes the fulcrum point further towards the mid line.
The other aspect is the torsional nature of roll overs. When a roll over starts, the chassis will twist, perhaps the rear of the trailer tilting furthest. This twist in the chassis creates stored energy. Energy that finally is released and screws over the rest of the lorry, including the unit.
Harry Monk:
Where’s that video of the Downton’s truck going over in a brewery somewhere because the driver dragged the trailer wheels over a kerb?
I thought that was quite surprising how easily that went over unless the video camera didn’t make it look as steep as it was in reality.
Skippy70:
Putting it on its ribs isn’t the only reason to avoid kerbs,the rims are made of chocolate. This one was left in the yard & the driver denied all knowledge when asked. I also stopped a subby, who was reversing onto a bay one day to tell him his wheel looked like the photo. He also said he hadn’t hit anything…
Not sure if that’s been caused by the kerb itself. It looks like quite a lot of worked on when they’ve been over those plastic bell things councils put down to stop corner cutting, they seem to be very effective at mangling rims.
El Deano:
Captain Caveman 76:
Warning, the following post contains half remembered facts and ■■■ packet maths.
I’m pretty sure that double decker busses can lean up to 30 degrees before tipping over. Given the height of them, you’d need a kerb about 2 foot high to get to that angle.
Of course, speed and weight distribution will alter that dramatically.
28 degrees as demonstrated here
youtu.be/C-fZA1NJtPA
Thats a fair old tilt though but imagine the upper deck being full and apply same to a diuble beck trailer.
Sent from my SM-G903F using Tapatalk
What a bloody faff. Although, fair play to the chief tester he’s got some confidence walking under it to straighten the ropes and climbing on the top deck.
I know a farmer who drives around a field in an artic at 30 mph over a railway sleeper to tip a full load of round bales off .
You most certainly can tip over by hitting a kerb. I recently posted some pics of a lorry that overturned at less than 20mph on a roundabout, he went over.
Thanks so much for all the feedback so far - it’s so useful to get all that. Conor’s story and the Turner video are particularly scary!! Does anyone have a link to this Downton rollover? I’ve never seen it.
wanderingstar:
Does anyone have a link to this Downton rollover? I’ve never seen it.
I remember at the time they were very aggressive in trying to get all trace of it removed from the internet, I haven’t been able to find it but someone might know.
Harry Monk:
Where’s that video of the Downton’s truck going over in a brewery somewhere because the driver dragged the trailer wheels over a kerb?
just for harry
m.youtube.com/watch?v=DNrPEfiJRTk
Harry Monk:
wanderingstar:
Does anyone have a link to this Downton rollover? I’ve never seen it.
I remember at the time they were very aggressive in trying to get all trace of it removed from the internet, I haven’t been able to find it but someone might know.
Yes I worked there when happened and the company was going mental about it been online,they were very touchy with videos showing the firm in bad light…
But they were more than happy to show videos of other trucks doing wrong/getting stuck etc in there training videos 
slightly 2 faced that I reckon
Continuing on the theme of Downton videos, isn’t there one where the load, I think it was big rolls of paper, was sticking out of the curtains ?
harrawaffa:
https://www.youtube.com/watch?v=kllMekpmy4g
I reckon if he had a decker on he’d have gone over due to the extra weight up top.
He’d mounted the high kerb.
Looks like he’s going to the Tesco RDC. It looks like the roundabout that you come to on the way out of frieghtliner at Carr hill. Mega slippery in the wet and always have traction loss fun in my RWD car going round and coming off it [emoji4]
OMG that video is so scary! So that pretty much drives the answer to my question home. Kerbs are way more dangerous than I had given them credit for. Thanks for finding it Fingermissing!!
Own Account Driver:
Skippy70:
Putting it on its ribs isn’t the only reason to avoid kerbs,the rims are made of chocolate. This one was left in the yard & the driver denied all knowledge when asked. I also stopped a subby, who was reversing onto a bay one day to tell him his wheel looked like the photo. He also said he hadn’t hit anything…
Not sure if that’s been caused by the kerb itself. It looks like quite a lot of worked on when they’ve been over those plastic bell things councils put down to stop corner cutting, they seem to be very effective at mangling rims.
Straight out of 1 rdc,onto the motorway,off the motorway into ours.
Skippy70:
Putting it on its ribs isn’t the only reason to avoid kerbs,the rims are made of chocolate. This one was left in the yard & the driver denied all knowledge when asked. I also stopped a subby, who was reversing onto a bay one day to tell him his wheel looked like the photo. He also said he hadn’t hit anything…
The trouble with steel rims. Alloy rims like Alcoas are 4 times as strong and wont buckle like that…
Skippy70:
Own Account Driver:
Skippy70:
Putting it on its ribs isn’t the only reason to avoid kerbs,the rims are made of chocolate. This one was left in the yard & the driver denied all knowledge when asked. I also stopped a subby, who was reversing onto a bay one day to tell him his wheel looked like the photo. He also said he hadn’t hit anything…
Not sure if that’s been caused by the kerb itself. It looks like quite a lot of worked on when they’ve been over those plastic bell things councils put down to stop corner cutting, they seem to be very effective at mangling rims.
Straight out of 1 rdc,onto the motorway,off the motorway into ours.
Wonder if a forkie pranged into it and drove off. Otherwise it seems like one for Mulder & Scully.
Back in the 1970s IIRC there was an organisation called the road research laboratory which did some investigations into lorry rollovers. Bearing in mind that virtually everything was on steel suspension back then, they came to the conclusion that there were critical speeds which could trigger a rollover - which could be remarkably slow, several instances had been recorded of artics falling over at 12 mph on the exit of roundabouts.
wanderingstar:
Someone told me recently it would be possible to tip over a double decked trailer by striking/mounting a kerb. Would this really be possible? I ask as I’ve started driving them including 16’3" trailers and as a newish driver I want to know how much fear of kerbs I need to have! Thanks.
Years ago a Ford fleet driver driving a D1000 with a 33 ft trailer loaded with 18 tons of pig iron drove into Toddington services at speed and hit the high kerb,it flipped the outfit upside down and killed him.
sidestrap:
wanderingstar:
Someone told me recently it would be possible to tip over a double decked trailer by striking/mounting a kerb. Would this really be possible? I ask as I’ve started driving them including 16’3" trailers and as a newish driver I want to know how much fear of kerbs I need to have! Thanks.
Years ago a Ford fleet driver driving a D1000 with a 33 ft trailer loaded with 18 tons of pig iron drove into Toddington services at speed and hit the high kerb,it flipped the outfit upside down and killed him.
The operative words there … " at speed !
