Do you really need ATC?
Comments
-
Your absolutely right Lutz but some info would perhaps be interesting. I'm sure that the UK police must have some statistics after carrying out accident investigation. All I can say is that when its been activated on my van it's been quite violent.
Is it set up correctly as it is only designed to place a light touch on the van's brakes, 40% capacity if I recall, and only till the van stabilises? In no way should it have knocked 25 % off your vehicles speed as you say. That level of drag, if sustained for any length of time is dissipating so much power that it is in real danger of starting a brake fire.
0 -
In a word, no, you don't need ATC. We have survived 30 years without, never had a snake, never had an accident of any kind with caravan, but if it is on there when bought then that's fine and we shall embrace progress.
0 -
In a word, no, you don't need ATC. We have survived 30 years without, never had a snake, never had an accident of any kind with caravan, but if it is on there when bought then that's fine and we shall embrace progress.
...Did you ever have a stabliser fitted?
0 -
Because my towing vehicle has TSA (Trailer Stability Assist) I just wonder if I had a caravan with ATC, if the two would 'fight' each other for control
Probably not but it could have the car doing its own thing to bring the caravan under control by braking individual wheels and the caravan reacting by slapping on its brakes.
So at the mo' I don't think I want ATC.
0 -
Fundamentally a device sensing directly and acting directly on the van is potentially far more effective to one that has to indirectly sense the van’s sway by its influence on the tow vehicle, then only has the tow vehicles braking system to control the van’s reaction.
I have LR’s trailer stability system, but would much rather the van checks itself, I suspect doing so long before the car can even detect it and initiate any indirect corrective action.
I doubt there can be any negative interaction as I suspect until the van has started to destabilised the car the car’s system will not react. Any criticism I might have of the ATC is it is too egar to act, coming in before I sense any undue sway through to the steering wheel.
It is comforting to know that should the ATC fail all is not lost, there is another device but not one IMO that sensing and operating indirectly will be as effective as addressing directly the issue.0 -
In a word, no, you don't need ATC. We have survived 30 years without, never had a snake, never had an accident of any kind with caravan, but if it is on there when bought then that's fine and we shall embrace progress.
I,m with TDA on this i,ve been towing wellover 35 years now with and without a stableiser and only once had a snake problem through poor weight distribution which was soon rectified so i dont concider ATC a must.
v9.
0 -
....
I,m with TDA on this i,ve been towing wellover 35 years now with and without a stableiser and only once had a snake problem through poor weight distribution which was soon rectified so i dont concider ATC a must.
v9.
I kinda agree with you both. I've not been towing quite as long as you, but, like you have towed here there & everywhere without ATC or stabiliser of any kind. But I also drove cars without ABS, but wouldn't consider a car now without (Rover P5B Coupe excepted
). Modern gizmos like ABS, EBA, ASC etc etc are all aids to modern driving and are a good thing. Our 'new' caravan came with ATC as standard but
was bought for other reasons, the fact that it had ATC was just extra icing.0 -
I never know what half these acronyms do.
0 -
I've been driving now for nigh on xx years, before seat belts came in, never had one ativate, but wouldn't dream (law or no law) of driving without one fastened. Door mirrors, never heard of them when I started driving, used to do a shoulder check, still
do after checking my mirrors, so do we really need them if you can still turn your head.ABS, only felt it activate once in all my driving years, but thank goodness it did!
Never felt the ATC system activate, but I hope it's there if needed.
You can argue against all modern safety features, but I for one wouldn't be without them, whether they come into action or not.
0 -
It's an excellent safety feature and you never know when a snake may occur even with a properly loaded van driven at moderate speed. A lorry or (more likely) a white van overtaking might just induce instability. It happened to me just once and it was a very
scary experience and totally unexpected. I actually managed to accelerate out if it (although many say this is impossible) but I was grateful when our next van had ATC fitted.People who say these features are unnecessary usually haven't experienced a problem. Most people don't have burglar alarms on their houses but speak to anybody who has been burgled and they will have alarms, CCTV, mortice locks, you name it.
0 -
..... and you never know when a snake may occur even with a properly loaded van driven at moderate speed. A lorry or (more likely) a white van overtaking might just induce instability. .....
I've been aware that Sprinter type vans have gone passed me at a rate of knots, but I've never had moments of instablity with either combintaion of my last car & caravan (about 80%) or my current car & caravan (nearer 90%)
0 -
In a word, no, you don't need ATC. We have survived 30 years without, never had a snake, never had an accident of any kind with caravan, but if it is on there when bought then that's fine and we shall embrace progress.
...Did you ever have a stabliser fitted?
Yes, the old blade type on our first van, and then the Alko hitch, which is what we have now on our 32 year old Cotswold. We have always towed with Land Rover and Jeep vehicles, big powerful engines, well up to towing up hill and down dale. OH is a skilled
driver, emergency vehicle trained as well. Towed most of his driving life, including horse trailers, much heavier than caravans, great deal of care required.I am not saying ATC is bad by the way, it is progress, if it is provided, then good. If it isn't, we aren't worried.
0 -
..... and you never know when a snake may occur even with a properly loaded van driven at moderate speed. A lorry or (more likely) a white van overtaking might just induce instability. .....
I've been aware that Sprinter type vans have gone passed me at a rate of knots, but I've never had moments of instablity with either combintaion of my last car & caravan (about 80%) or my current car & caravan (nearer 90%)
In general I do not find these vans a problem but we tow at 86%. Even at that level you can feel the odd one realy shifting and in close though. All combinations are different though and others may not be so lucky.
Not sure if your post is showing changing peoples ideas of the standard van as I would have said Transit.
0 -
In a word, no, you don't need ATC. We have survived 30 years without, never had a snake, never had an accident of any kind with caravan, but if it is on there when bought then that's fine and we shall embrace progress.
...Did you ever have a stabliser fitted?
Yes, the old blade type on our first van, and then the Alko hitch, which is what we have now on our 32 year old Cotswold. We have always towed with Land Rover and Jeep vehicles, big powerful engines, well up to towing up hill and down dale. OH is a skilled
driver, emergency vehicle trained as well. Towed most of his driving life, including horse trailers, much heavier than caravans, great deal of care required.I am not saying ATC is bad by the way, it is progress, if it is provided, then good. If it isn't, we aren't worried.
We also started out without a stabaliser and then OH fitted a blade, as others we have gone through the years 34+ towing caravans with no problems but as I said in my earlier post it only takes a second for a bad snake to happen and when it does it is a
frightening experiance. OH has also towed caravans and horse trailers for years, he had all his licenses when in the Army including track & HGV so years of experiance however we would not want to be without an ATC having had one and seen and felt the differance,
like ABS it works so fast much faster than a human being so anything that can make you safe while on the roads has to be a good thing.0 -
is there a way of 'talking' to an ATC?
ie how many times it's triggered or not?Write your comments here...My expeirence is that you will know when it operates , the van will start slowing ,not aggresivly but a smooth aplication of the caravan brakes . You dont really need to plug in to the control box tto know . Ours BPW chassis therefore
IDC . behaves the same as friend with a Bailey Alco chassis . Can tell you instances that trigger them but it takes to long . I'm certain that if LED does its stuff then the systems working .0 -
Your absolutely right Lutz but some info would perhaps be interesting. I'm sure that the UK police must have some statistics after carrying out accident investigation. All I can say is that when its been activated on my van it's been quite violent.
Write your comments here...Mines come on very smoothly and progressively , Its happened on a bumpy road and a cross wind on a motorway each time I had it well covered anyway didnt need it . But my wife was towing and unfortuanatley got into an driver induced
swing and before I could reach for the wheel the IDC came on and even the Vw anti lock brakes momentarily came on dropped of about 5mph and everything straightened up . She hasnt done it again . Brilliant . Theres another post here that says they should come
on at a maximum of 40% I think .If yours are a bit violent I should check cable adjustments or get someone to do it for you .0 -
It's an excellent safety feature and you never know when a snake may occur even with a properly loaded van driven at moderate speed. A lorry or (more likely) a white van overtaking might just induce instability. It happened to me just once and it was a very
scary experience and totally unexpected. I actually managed to accelerate out if it (although many say this is impossible) but I was grateful when our next van had ATC fitted.People who say these features are unnecessary usually haven't experienced a problem. Most people don't have burglar alarms on their houses but speak to anybody who has been burgled and they will have alarms, CCTV, mortice locks, you name it.
Write your comments here...In the old days . I'm going to have to be careful now not to mention speed or reckless , But you are right the only way is Pedal to the metal as the yanks say . works every time particulaly down hills over a bridge were keeping
the van pulling keeps it inline stops a sway developing ,Laws of Physics and all that ! Our van is 7.4 and a single axle and its nice to know IDC is fitted and works when necersary0 -
It's an excellent safety feature and you never know when a snake may occur even with a properly loaded van driven at moderate speed. A lorry or (more likely) a white van overtaking might just induce instability. It happened to me just once and it was a very
scary experience and totally unexpected. I actually managed to accelerate out if it (although many say this is impossible) but I was grateful when our next van had ATC fitted.People who say these features are unnecessary usually haven't experienced a problem. Most people don't have burglar alarms on their houses but speak to anybody who has been burgled and they will have alarms, CCTV, mortice locks, you name it.
Write your comments here...In the old days . I'm going to have to be careful now not to mention speed or reckless , But you are right the only way is Pedal to the metal as the yanks say . works every time particulaly down hills over a bridge were keeping
the van pulling keeps it inline stops a sway developing ,Laws of Physics and all that ! Our van is 7.4 and a single axle and its nice to know IDC is fitted and works when necersary...The way your post reads it seems you have an inherantly unstable set up ? if you say it works eveytime in the nigh on 50 years of towing,I have only once had a problem that needed a clench of the buttocks
0 -
That is not necessarily so JVB, Martin may be just taking preventative action. We have only had one incident in 11 years and that on our current Unicorn with ATC, which activated and resolved the crisIs. However, still very frightening. Our snake was induced
by a panel van passing at high speed on a downward grade. So now in such situations I keep a very close eye on the rear view mirror and if I see a large van about to pass very fast, gently accelerate as it does so, which definitely increases stability over
not doing it.1 -
That is not necessarily so JVB, Martin may be just taking preventative action. We have only had one incident in 11 years and that on our current Unicorn with ATC, which activated and resolved the crisIs. However, still very frightening. Our snake was induced
by a panel van passing at high speed on a downward grade. So now in such situations I keep a very close eye on the rear view mirror and if I see a large van about to pass very fast, gently accelerate as it does so, which definitely increases stability over
not doing it....A gentle accelerate is not as martin says "pedal to the metal"which has been proven will probably make the situation worse
0 -
Scientifically measured tests by Bath University, confirm that speed, weight distribution and tw vehicle v trailer weights have a profound in trailer snaking. However the notion that increasing speed, in a snake will improve the situation is not born out
in practical tests - largely because the towing vehicle is unlikely to have sufficient power reserves to make enough difference. Much better to compromise a little trailer coupling tension for a reductiion in speed so as to move the trailer out of its self
induced oscillation range. If you had enough power to accelerate then you are likely to find that snaking would become worse well before the benefits of acceleration were felt. In short, scientific tests show that you can't drive through it, your best remedy
is to reduce speed.0 -
We have all heard about accelerating to pull the outfit straight whilst in a snake.
Some people also say the way to get out of a tank slapper on a motorcycle is to accelerate.
Don't believe a word of any of it. You are only going to crash at a higher speed and with more accrued energy. The law of the conservation of energy simply and in plain English means it's going to hurt / cost more
0 -
It's an interesting question do you need ATC? The is hopefully not but there might be an occasion when you are glad that you do have it.
Surely at its simplest a snake is caused by the caravan travelling faster than the car. Unfortunetely a towing vechicle doesn't have the ability to accelerate fast enough so you are putting energy into a situation where that is the last think that you want
to do. By easing off hopefully you are diffusing the situation. And if you have ATC that selectively slows the caravan which corrects the speed difference.0 -
Even if the van has started snaking, by slowing down you will, at least, be applying the brakes.
0 -
My experience with ATC is that always seems to activate when I'm accelerating uphill, so the van certainly isn't going faster than the car. It may be the cause is an uneven road surface but on the times when it has activated there has been no danger to
the car or van, so it's a puzzle. If it was offered as an optional extra I think I would decline.0 -
Two different things when the ATC comes on and a snake Got to say mine always feel something is holding it back when I accelerate up hill I put it down to the almost 2T weight on the back
Mine always activates 50yds from storage on a speed bump. I can be doing as much as 3 miles per hour never had it work for real I'm glad to say
0 -
It's an interesting question do you need ATC? The is hopefully not but there might be an occasion when you are glad that you do have it.
Surely at its simplest a snake is caused by the caravan travelling faster than the car. Unfortunetely a towing vechicle doesn't have the ability to accelerate fast enough so you are putting energy into a situation where that is the last think that you want
to do. By easing off hopefully you are diffusing the situation. And if you have ATC that selectively slows the caravan which corrects the speed difference.Write your comments here...
Baily in conjunction with Bristol University, regularly demonstrate snaking on a model with a conveyer belt on which runs a car and a loaded trailer. The conveyer belt is horizontal so there's no question of the trailer travelling faster than the car, yet
snaking still occurs. If you do a little searching on the web, there's lots of factual information to be found.0 -
Hi Jenny C,
I read all the posts on this subject and the impression I get is that non actually know what is going on when a snake is occurring. A snake or uncontrolled sway occurs when there is a force acting on the side of the combination, this could be a number of things - wind or wind vortices from vehicles passing or being passed, rutting in the road surface, erratic driving. Whether it results in an uncontrolled sway depends on a number of factors - speed, loading/balance of either tow or trailer. As to how uphill or downhill affects this result is again as a result of any of the aforementioned details. The thing to understand about the latter is that as soon as a sway of any magnitude starts the trailer is accelerating towards the tow by the action of the tyres resisting the sway ( this can be seen by using calculus to work out the forces) This implies that the overrun brakes would sooner than later be applied which it does momentarily after the damper has compressed. This is where the problem starts. If the force is great enough it pushes the van so quickly that the tires steer the van into the tow at an angle and if the driver does not act correctly the combination can get out of control in just three swings as resonance forces multiply the swings.
This can be prevented if the outfit is fitted with a pro active control system.
ATC is not pro active and not fast enough to cope with all situations it only activates after a sway has started by which time it may be to late.
0 -
A snake can never be the result of the caravan travelling faster than the towcar. For a start the two are interconnected so how can the caravan travel faster? If you mean that the caravan by virtue of the swing is trying to overtake the car, then how do you explain why the caravan will try to swing back like a pendulum? Surely it would then swing out just once and that's it.
"ATC is not pro active and not fast enough to cope with all situations it only activates after a sway has started by which time it may be to late." is simply not the case. It most definitely is pro-active. It is true that it relies on recognising a sway in order to deploy, but I am not aware of any evidence that its deployment is not sufficient to bring the outfit under control. On the contrary, there have been numerous complaints, even in this forum, that some consider that it deploys too readily, such as when negotiating a roundabout. If the onset of an actual pendular sway is not going to be the criterion which determines whether it deploys, then what is? There is no need to intervene if the caravan only swings out once and then recovers of its own accord as it is more than unlikely that the amplitude of the initial sway constitues a threat to the safety of the outfit. Only if the amplitude increases with each swing is there any point in reacting.
1
