No weeto you can feel the trailer pushing when you take your foot off just going stright down the road the traction on the drive axle keeps the truck ridged .Imagine the drive axle is a lock, release the lock and its like pushing a peice of string.
Mike-C:
weeto:
Cruise control! and if you want to see the evidence i will tell you were to find it, were trucks ended up jackknifed which wast not caused by braking.Ok fair enough, its not something i’d considered. But i’ve an open mind.
I wouldn’t mind seeing some evidence.
You would just need to, ring any truck manufacturer, and ask them, its one of the reasons why they put a warning in the cruise control section in the manual, but not all say what the actual dangers of inapropriate use is.
cruse control,they will blame the heated seat next,has anyone know of a jack knife when going up hill.
fuse:
cruse control,they will blame the heated seat next,has anyone know of a jack knife when going up hill.
now your just being a ■■■■!
Strewth is that the evidence we’ve been waiting for, Ring the bloody manufacturer?
Jesus wept.
Juddian:
Strewth is that the evidence we’ve been waiting for, Ring the bloody manufacturer?Jesus wept.
you didnt have to wait did you!
Does any body on here know of or heardd of a jack knife when going up a hill or even a small hill.
And to bust the myth about a brake induced jackknife! We shall quote VOSA! on how ABS operates for the non believers.
The ABS will operate on at least one front axle and on one rear axle. The system will
have a minimum of four sensors and two modulators (one for each axle). The system will
generally operate on a “select Low” control philosophy where modulation action will be
taken on the first wheel to lock. This system will protect the towing vehicle from brake
induced jack-knifing and enable the driver to steer during braking by preventing the
directly controlled wheels from locking.
If you want to argue against VOSA, like the guy in Mansfield will have to, be my guest.
Link found here
Quite right weeto as you say the exhaust brake idea wasn’t perfect by any means, on a different tack though I think that nowadays a lot of the feel has been lost , what with suspensions being so soft , plenty of horses under the bonnet and a quiet environment its quite easy to find yourself moving a lot quicker than you think. Add to that the trend to drive on the brakes instead of using the gearbox and your building problems. A good friend of mine who has worked in the moter industry research industry for years has told me on more than one occasion that we are fast approaching the point were new technology can / is causing an adverse on safety. On more positive note however I can state positively that a jacknife is when your hands start to sweat and you ar… hole goes from the size of a 50 pence piece to the size of a 5 pence piece in quick succession!
it does not mention cruse control there weeto
fuse:
it does not mention cruse control there weeto
I didnt say it did!
norfolk:
Quite right weeto as you say the exhaust brake idea wasn’t perfect by any means, on a different tack though I think that nowadays a lot of the feel has been lost , what with suspensions being so soft , plenty of horses under the bonnet and a quiet environment its quite easy to find yourself moving a lot quicker than you think. Add to that the trend to drive on the brakes instead of using the gearbox and your building problems. A good friend of mine who has worked in the moter industry research industry for years has told me on more than one occasion that we are fast approaching the point were new technology can / is causing an adverse on safety. On more positive note however I can state positively that a jacknife is when your hands start to sweat and you ar… hole goes from the size of a 50 pence piece to the size of a 5 pence piece in quick succession!
I know what you mean, high cabs on air suspension gives you absolutly no indication of what the trailer is doing, and that would probably explain the amount of roll overs that occur on a weekly/daily basis.
Some drivers dont seem to have any respect of the vehicle they are driving!
weeto:
Cruise control! and if you want to see the evidence i will tell you were to find it, were trucks ended up jackknifed which wast not caused by braking.
Oh just to add to this re a Brake induced jackknife, even VOSA has an official line on it!!
You’re not wrong. Cruise control should NOT be used in slippery conditions. But before you pat yourself on the back you started this thread by declaring that many of the other factors that could result in a jackknife were nowt but myth when clearly the weight of opinion voiced by these experienced “know-alls” would suggest otherwise. Now why don’t you explain to all the “know-alls” how exactly cruise control can cause a jackknife? Know-all… 
weeto:
And to bust the myth about a brake induced jackknife! We shall quote VOSA! on how ABS operates for the non believers.The ABS will operate on at least one front axle and on one rear axle. The system will
have a minimum of four sensors and two modulators (one for each axle). The system will
generally operate on a “select Low” control philosophy where modulation action will be
taken on the first wheel to lock. This system will protect the towing vehicle from brake
induced jack-knifing and enable the driver to steer during braking by preventing the
directly controlled wheels from locking.
If you want to argue against VOSA, like the guy in Mansfield will have to, be my guest.Link found here
http://www.transportsfriend.org/pdf_files/candu/abs.pdf
Not sure where anyone’s given any different definition of ABS operation, protect against is not the same as totally eliminate BTW.
Cruise control could cause a jacknife, but it needs one other thing for that to happen and that is a very slippery road surface, and I mean very slippery like ice, the camber of the road would cause the drive axle to shift to the left (in the UK) and momentum would take over and fold you in half. But, cruise control is also linked to the traction control system which uses a slight brake application to control a spinning wheel while disabling the cruise control at the same time, so on a dry or normal wet road you would NEVER jacknife with cruise control alone 
If a road is slippery enough to cause you to jacknife by using cruise control then you’d be stupid to use it in the first place, so again it wouldn’t actually be the fault of the cruise control, but the idiot that pushed the button, the cruise control itself would not cause a jacknife, however add an idiot into the equation and it may contribute to it 
Wow, quite some thread. All brought about I guess when I said:
In 22 years of part time driving across a broad range of vehicle types I’ve never come close to a jack knife situation. Including back in the days when airlines had taps. On the odd occasion I forgot to open the yellow line tap, you could always tell as soon as you did the moving brake check because the unit would nose dive. Now do please correct me if I’m wrong but every time I see a jack knife I think the trailer brakes must be ineffective or not even connected AND the driver has failed to pay attention to what’s happening ahead then had to panic brake. The unit brakes but the weight of the trailer continues its momentum thus pushing the unit round. With a properly set up and working braking system the trailer brakes should apply earlier/more force than the unit brakes thus pulling the dog back by its tail.
Having read through this thread I would agree that weight distribution and 5th wheel adjustment plays a big part in the likelyhood of a JK.
I’ve driven artics where the 5th wheel hasn’t been set properly and they are horrible to drive - all over the road.
Oh and can I just clear something up for future reference if you don’t mind chaps:
BREAK is when you take a rest from work. i.e a 45.
BRAKE is what the middle pedal is and does. 
having jack knifed - I can tell you in can happen on a straight road, and so quick you don’t have time to do much about it, when it happened to me it was before ABS/EBS etc , I was approaching a roundabout in the inside lane, , running empty with a flat trailer on steel suspension, the outside lane was queuing so backed right off and went up the inside as you do, when a car pulled out of the outside lane lane right in front of me , as I hit the brakes the arse end of the unit hit a slippery patch ( found out later it was spilt diesel) and started to slide towards the side of the road, as I tried to correct the unit (which I did) the trailer axles under braking hit the same slippery spot and locked up, the "flick " I had done to bring the unit into line swung the trailer which now had no traction at all , which pushed the unit sideways and the trailer then gained grip and momentum,but by now the unit was sideways and way past the point where you could steer out, I ended up with the trailer still in its lane , but the unit facing almost backwards with the trailer embedded in the passenger side rear quarter - time from the moment the trailer lost grip to ending up facing backwards , probably 2 seconds- if you can get out of that your a better man than me- it was a good 45 minutes later and with the Police we worked out what had happened and why- in those split seconds you have no chance of working out the actual cause and effect and taking effective action. For the record I don’t have a copy any more of the letter from the Police, but it was on the lines that after investigation the cause of the accident was due to a diesel spillage on the carriageway , combined with the need to brake harshly due to another road user that lead to the incident, as such the Police feel there should be no further action taken against the driver (me)
Any driver worth his weight could tell you it’s a no no to use cruise control in icy or slippery conditions so it whouldn’t have any bearing because any driver who selects cruise in such conditions is raving mad. Cruise control also slows the vehicle up when nearing another vehicle by applying the engine brake and in the case of my truck will apply the foot brake and so can cause a jacknife … There !
Never had a jacknife (touch wood) I have had the trailer start to slide but have regained control by either steering away from the side or accelertating gently.
In all cases it’s not really the icem snow, rain or any surface that causes the jacknife … it’s the driver and lack of control in every case.
Winseer:
If your trailer starts to swing around the side of you, then you floor the accelerator (in the dry and straight) and flick the trailer brake/handbrake to effectively “jerk the combination straight again”.If you’re going around a corner, it won’t work. If it’s icy it won’t work. If it’s wet, it might still not work.
There’s a reason of course that we have a yellow airline as well as a red one. You can drive it around on “only” the red, but I wouldn’t advise it. Shunters do it all the time, but even they run into the occasional bother come the rain and snow…
Are you for real?
Please enlighten me as to why we have a yellow airline,as well as a red one? you sound like a professional driver who i could learn a few things from. Flick the handbrake lol Wtf,i wouldn’t let you drive my dyson round the living room.
Shoshaye:
Winseer:
If your trailer starts to swing around the side of you, then you floor the accelerator (in the dry and straight) and flick the trailer brake/handbrake to effectively “jerk the combination straight again”.If you’re going around a corner, it won’t work. If it’s icy it won’t work. If it’s wet, it might still not work.
There’s a reason of course that we have a yellow airline as well as a red one. You can drive it around on “only” the red, but I wouldn’t advise it. Shunters do it all the time, but even they run into the occasional bother come the rain and snow…
Are you for real?
Please enlighten me as to why we have a yellow airline,as well as a red one? you sound like a professional driver who i could learn a few things from. Flick the handbrake lol Wtf,i wouldn’t let you drive my dyson round the living room.
It’s scary that some people don’t know basic things, Then naive people like Shoshaye try to take the mick out of someones obviously good advice, It’s the sort of thing that most drivers would already know.