Surprised no o e has put this up yet.
m.youtube.com/watch?v=uOnwlkRo1TY
Just remember, it’s NOT a training video!
When I drove DD’s, for Halfords and for Palletforce, I was surprised at how stable they were. Both companies were pretty strict about not overloading the top deck, and the small wheels helped keep the CG low. In fact, the biggest cause of problems was drivers ripping tyres off by screwing trailers round on concrete.
The most dangerous place for rollovers is roundabouts. You swing left, then right and then left again. If you get the harmonic right, you don’t need to be hugely heavy or going fast to lay it on its side.
When I was at wavin we had a very windy night and the next morning came a call from hazlehead. “One of the dd’s has fallen over” My boss told me to go and see what the hell they were on about and get some pictures [emoji23]
Lower the suspension right down and go under slowly and I reckon you’d rescue that.
wanderingstar:
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!!
Yes but… pay attention to how fast he took that turn. If he’d turned in slowly, there was plenty of space to use to avoid that kerb and even if he had hit it, he probably would have just bumped up it embarrassingly instead of in a P45-inducing manner.
You can tip over a trailer without a kerb.
A high C of G makes tipping easier. Higher speeds, sharper corners, adverse cambers, braking in corners, unstable loads that shift, liquid loads, shorter trailers, (20’ box on short skelly worse than centre if long one) all makes tipping over easier.
And yes a kerb can be another factor.
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wanderingstar:
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!!
The speed at which you hit the kerb, the height of the kerb, and the extent and duration of the mounting, is always a factor however.
Ironically, sweeping bends, in which it is possible for all three trailer wheels to fully mount the kerb quickly and almost simultaneously, and stay mounted for an appreciable distance, and which entice the driver to approach them at higher speeds, are actually considered more dangerous than simply cutting over a kerb corner.
But no minor misjudgment or misplan - which sometimes involves deciding to allow a low kerb to be mounted rather than stopping dead to recover - is capable on its own of turning a wagon over.
wanderingstar:
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!!
I would bet a pint thats one of them proper high industrial type kerbs and not your std jobby.
Just drive it and dont worry.
cav551 that is very interesting about how the right speed to roll over can sometimes be slow. I do roundabouts at about 14mph in the double decker and think I’m therefore safe but it sounds maybe not!
Santa I didn’t know ripping tyres off by screwing trailers round on concrete was a ‘thing’. I’ll bear that in mind when I’m on the small tyres! And I hadn’t thought about the small wheels helping with the CG either.
nomiS36 food for thought that picture!! Esp. with bridges…
And thanks everyone else for the brilliant info and advice. I knew TN would sort me out with this!
One should also remember when clipping a kerb that this will cause trailer flex/twist which can be enough for a load shift as strap tension will be affected.
Speed/angle/kerb height/camber so many factors involved, sometimes all you can do is take the speed right off or stop and try and adjust the angle.
Occupational hazard even the best of us can find ourselves in a situation when a controlled mounting is inevitable.
Dipper_Dave:
One should also remember when clipping a kerb that this will cause trailer flex/twist which can be enough for a load shift as strap tension will be affected.Speed/angle/kerb height/camber so many factors involved, sometimes all you can do is take the speed right off or stop and try and adjust the angle.
Occupational hazard even the best of us can find ourselves in a situation when a controlled mounting is inevitable.
All true. And as you infer it’s uncontrolled mounting that causes the most problems.
Edit to fix quotes
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As someone who until recently pulled double deckers around Id say yes, you can tip one over by mounting a kerb. More likely though, and a major ■■■■ boiler fir your employer, those smaller tyres are so easy to blow out by catching a kerb. So, yes, caution is always advisable around corners.
wanderingstar:
cav551 that is very interesting about how the right speed to roll over can sometimes be slow. I do roundabouts at about 14mph in the double decker and think I’m therefore safe but it sounds maybe not!
!
It doesn’t take much energy to send some wagons over. Santa mentioned roundabouts left/right/left. Common places for it. Shipping containers on skele trailers loaded with high centre of gravity and/ or room for load to shift and also high sided scrap tippers are quite vulnerable.
A heavy vehicle travelling at any speed has energy. Even hitting a low kerb redistributes that energy. All that is needed is for the overturning moment to exceed the righting moment.
Found this for you chief. It’s an easy read too
Excellent attachment Freight Dog, now that’s the sort of thing that should be included in the DCPC !! 
Super document Freight Dog! I will read that thoroughly.
wanderingstar:
Super document Freight Dog! I will read that thoroughly.
No worries dude, cracking question btw.
Oh thanks! When this guy said it it kept niggling at me for weeks so in the end I thought I’d come and ask the experts 
wanderingstar:
Oh thanks! When this guy said it it kept niggling at me for weeks so in the end I thought I’d come and ask the experts
Non of us are experts 
. Well a few might be. (Def NOT me 
)
Santa:
When I drove DD’s, for Halfords and for Palletforce, I was surprised at how stable they were. Both companies were pretty strict about not overloading the top deck, and the small wheels helped keep the CG low. In fact, the biggest cause of problems was drivers ripping tyres off by screwing trailers round on concrete.The most dangerous place for rollovers is roundabouts. You swing left, then right and then left again. If you get the harmonic right, you don’t need to be hugely heavy or going fast to lay it on its side.
That’s the pendulum effect.
papermonkey:
As someone who until recently pulled double deckers around Id say yes, you can tip one over by mounting a kerb.
Do you say this from, er, painful experience?