-- Edited by yobarr on Saturday 18th of June 2022 07:15:54 PM
Mike Harding said
10:07 AM Jun 19, 2022
Axel steer: Thanks Jaahn and Yobarr, I understand now thanks.
It's got me wondering how the Al-Ko rubber torsion suspension in my Snowy River caravan reacts in such a situation, I do not have ESC or the like and never told at more than 90kph and the van always feels stable.
yobarr said
10:20 AM Jun 19, 2022
Mike Harding wrote:
Axel steer: Thanks Jaahn and Yobarr, I understand now thanks.
It's got me wondering how the Al-Ko rubber torsion suspension in my Snowy River caravan reacts in such a situation, I do not have ESC or the like and never told at more than 90kph and the van always feels stable.
Same principle Mike, as the arm from the rubber suspension unit to the axle still swings through an arc under compression, changing distance from towball, and moving axle from its 90 degrees to chassis stance. Perhaps not as severe as the brightly coloured flash 4 shock systems, but it'll eventually send you R-Sup if sway develops. Cheers
-- Edited by yobarr on Sunday 19th of June 2022 10:22:17 AM
yobarr said
12:13 PM Jun 19, 2022
Mike Harding wrote:
Axel steer: Thanks Jaahn and Yobarr, I understand now thanks.
It's got me wondering how the Al-Ko rubber torsion suspension in my Snowy River caravan reacts in such a situation, I do not have ESC or the like and never told at more than 90kph and the van always feels stable.
Hi Mike. Please note that I have composed this post only from my research, and not from personal experience, but it seems to me that all the adulation of this flash ESC gear is more a result of hype than of the system's effectiveness? It appears, from my research, that it loses its effectiveness at moderate speeds, and at highway speed it is absolutely ineffective.(Read "useless"). All reports of its effectiveness come from people with vested interests, whether they be companies marketing the product, retailers or consumers, who are highly unlikely to admit they've made a mistake forking out big dollars for said product. Seems to me to deserve inclusion in the same category as brightly coloured suspension with double shock-absorbers, which I admit initially had me sucked in too, until I did an analysis of the physics. BUT, let me say that after reading advice from Peter'n'Margaret I did fit heavy duty EFS XTR shocks to my van, with dramatic improvement on the "development" roads I often travel. No more broken springs either! This post will no doubt produce multiple howls of disapproval and anger from members with these gadgets that we survived for years without, but who's going to admit that they've spent mega dollars on this stuff? And Mike, there is no need to feel you've "missed out" by not having ESC. My van runs 3150-3200kg GTM and NEVER sways even when I try to flick it around a bit to check on the tyres, as is regularly done with Roadtrains, and I have no ESC or ABS or any other gadgets. Horror! Cheers
Mike Harding said
12:57 PM Jun 19, 2022
Interesting assertions Yobarr.
Although I do not have ESC on my van it is systems of this sort (complex embedded systems) which I have spent many decades designing and I would consider an ESC quite a challenge.
Some basic off-the-cuff thoughts:
A car and caravan travelling at 100kph covers about 28m/S
Activation time for an electrical breaking system on a van say 250mS
Time for the electronics to determine there is a "sway" condition occuring say 1S (maybe a lot longer - keep in mind the forward motion is 100kph but the sway motion will be very slow)
The really complex bit now is how to handle the caravan brakes and how to respond to changes in the detected sway condition, one would have to look at the rate of change of sway and respond to this data but, as mentioned, this is a slow change and at 28m/S perhaps far too slow?
Dunno? And I don't know how such a system could be tested to the level we require of, say, medical equipment. I suppose when caravans with ESC roll no one can prove the cause or whether the ESC did what it should. Indeed what are the limitations of the ESC, what are its specifications, what rate of change of sway can it tolerate?
This is not a trivial problem.
Bobdown said
01:47 PM Jun 19, 2022
Collo wrote:
Most caravans, if not all are equipped with electric brakes. There should be a controller inside the vehicle.
In the event of sway...press the controller button. This will activate the caravan brakes independant of the tow vehicle. This will pull the caravan back straight.
No need to accelerate or definitely dont de accelerate.
Collo.
I have set my van brakes to come on a second or so earlier than the tug, and others have said "a short, sharp brake helps control the van", or just hit the van brake control button only.
I have used the van brakes only when going down a very steep descent in low gear, just a tap here and there to slow the rig down without overheating the tugs brakes.
It is good to practice occasionally in a safe area, to see if vans brakes are operating properly if anything else.
Cheers Bob
-- Edited by Bobdown on Sunday 19th of June 2022 03:54:56 PM
yobarr said
01:52 PM Jun 19, 2022
Mike Harding wrote:
Interesting assertions Yobarr.
Although I do not have ESC on my van it is systems of this sort (complex embedded systems) which I have spent many decades designing and I would consider an ESC quite a challenge.
Some basic off-the-cuff thoughts:
A car and caravan travelling at 100kph covers about 28m/S
Activation time for an electrical breaking system on a van say 250mS
Time for the electronics to determine there is a "sway" condition occuring say 1S (maybe a lot longer - keep in mind the forward motion is 100kph but the sway motion will be very slow)
The really complex bit now is how to handle the caravan brakes and how to respond to changes in the detected sway condition, one would have to look at the rate of change of sway and respond to this data but, as mentioned, this is a slow change and at 28m/s perhaps far too slow?
Dunno? And I don't know how such a system could be tested to the level we require of, say, medical equipment. I suppose when caravans with ESC roll no one can prove the cause or whether the ESC did what it should. Indeed what are the limitations of the ESC, what are its specifications, what rate of change of sway can it tolerate?
This is not a trivial problem.
Great post Mike, with the thoughts that I've highlighted above matching the information I found when doing research. Another con job, me thinks, but seems there's a sucker around every corner! Learn to load correctly with most weight over van's axle group, make sure the car has at least 10% more weight on its wheels than the van does, make sure your tyres are not more than 5 years old and get the tyre pressures right (do your research there too!), make sure towball weight is around 10% of ATM, set your brake controller appropriately with a higher setting on the open road, and don't believe all the hype that you'll hear from people whose primary interest is boosting their own bank account balance. These things will do more to ensure your safety than any gadgets will do. Cheers
Jaahn said
10:07 AM Jun 20, 2022
Hi Yobarr and Mike
I cannot argue against the fact that the primary safety is to correctly load your van, and balance it, and ensure that it is a weight that is appropriate for the tow vehicle. The drivers first responsibility, and then to drive in a safe manner at a safe speed.
But modern cars and utes are equipped with a several braking and stability technology devices which WORK WELL and are now after many many years, mature technology which is very reliable. They can 'kick-in' in a super short time frame to intervene and sometimes without the driver noticing. "Gee I wonder what happened then" type response. I do believe caravans could benefit from that expertise but currently I doubt they do use any really high tec solutions despite the sales hype. Probably a better hydraulic braking system would be a start. An ABS has an inbuilt pump to supply pressure and the smarts to run all the wheels individually braking as required. YAW sensors are fitted in all cars. These things are 20-30 years old.
I test out my system occasionally when it is appropriate. Sometimes in a incident. A while back after visiting a friend on the farm, returning at dusk I had a roo jump in front from nowhere, on a tight bend, down hill, gravel road. I braked hard, the technology took over and the car stopped short as the roo hopped off and my car never skidded or lost directional control ?? PERRRFECT. Try that in your old ute with no technology.
Jaahn
-- Edited by Jaahn on Monday 20th of June 2022 08:41:40 PM
Fast_Eddie said
11:23 AM Jun 20, 2022
Definitely do NOT accelerate - all you will do is waste time and have to deal with the problem at a higher speed - if you are still on the road.
When the van starts to weave it is already travelling faster then the car - because it is travelling a weaving path, but only going forward at your speed. So accelerating will most definitely not help.
Research shows that you have a max of ~4 sec to get it under control. Using the manual trailer brake is extremely hard to do in that time, but can be done, but only if you are sensitive enough to know what is happening the moment it starts.
Best to put a DSC on the van and let the electronics deal with it - much faster than a human can in this circumstance.
Are We Lost said
12:36 PM Jun 20, 2022
As Fast Eddie says, you have a maximum of ~4 seconds to regain control. I believe that in most cases by the time 4 seconds has elapsed it is already too late. Where I disagree with Eddie is the time it takes for a driver to react and hit the brake controller button. I believe most experienced drivers would hit that button in the first second from detecting the sway, which would be pretty well immediately it starts.
I just watched a few Youtube videos on caravan sway accidents and it seems each oscillation typically takes about a second from one side to the other ... until the swings become so wide that gaining control is impossible.
In the process of searching for videos I found this one that is promoting a solution combining mechanical and electronic means to limit sway.
I have no doubt the test was engineered to show a result, and real life situations may be very different. The speed is low, while in real life, sway accidents are usually at speed. But it does highlight that electronic systems can react quickly, because these oscillations are much faster than one second. There is also a mechanical component of the system that uses friction to inhibit sway. I can't see that doing much, but every little bit helps.
Hairyone said
07:20 PM Jun 20, 2022
bratboy wrote:
Hairyone wrote:
I mounted my brake controller in the middle of the dash for that exact reason, with specific instructions to the Mrs, that if things get a bit untidy.....hit the button!
So your not capable of confident in managing your vehicle without outside assistance ,,,,, I wonder what a licencing officer would think of that ?
what you suggest could be more dangerous then the original sway .
Dear Bratboy,
I drive heavy vehicles for a living and don't have an issue with confidence driving a car and caravan without assistance. Im 6ft3 and 125kg ,and if you've ever sat in a 79 series Landcruiser you'd realise it doesn't take much to fill the cab, and there isn't a lot of room down the right hand side to mount a brake controller with easy access........I would have no issue using the brake controller manually myself if needed, and would find it a lot more accessible where Ive mounted it if need be. But if in an emergency situation I found myself steering with ONE hand and needing to change gear with the other I would not be to much of a frign hero not to allow my passenger to help, or use it myself if the Mrs was driving. Landcruisers are also not known for there fantastic hand brakes eithe,r so in the situation of the vehicle rolling while the driver is out of the vehicle it also makes it very easy to pull it up (eg . a boat ramp).........I was going to ask a bit about your driving experience, but dont bother I just read enough of your know it all dribble to get a fair idea....Bwahahaha
yobarr said
07:38 PM Jun 20, 2022
Hairyone wrote:
bratboy wrote:
Hairyone wrote:
I mounted my brake controller in the middle of the dash for that exact reason, with specific instructions to the Mrs, that if things get a bit untidy.....hit the button!
So your not capable of confident in managing your vehicle without outside assistance ,,,,, I wonder what a licencing officer would think of that ?
what you suggest could be more dangerous then the original sway .
Dear Bratboy,
I drive heavy vehicles for a living and don't have an issue with confidence driving a car and caravan without assistance. Im 6ft3 and 125kg ,and if you've ever sat in a 79 series Landcruiser you'd realise it doesn't take much to fill the cab, and there isn't a lot of room down the right hand side to mount a brake controller with easy access........I would have no issue using the brake controller manually myself if needed, and would find it a lot more accessible where Ive mounted it if need be. But if in an emergency situation I found myself steering with ONE hand and needing to change gear with the other I would not be to much of a frign hero not to allow my passenger to help, or use it myself if the Mrs was driving. Landcruisers are also not known for there fantastic hand brakes eithe,r so in the situation of the vehicle rolling while the driver is out of the vehicle it also makes it very easy to pull it up (eg . a boat ramp).........I was going to ask a bit about your driving experience, but dont bother I just read enough of your know it all dribble to get a fair idea....Bwahahaha
Great post Sean, with lots of common sense explanations of your reasons for mounting your controller where it is. Could I also congratulate you on the great car you've chosen, although I can understand your comment "it doesn't take much to fill the cab". Must say that I also agree with your thoughts posted in the last couple of lines. Well done! Cheers
-- Edited by yobarr on Saturday 18th of June 2022 07:15:54 PM
Axel steer: Thanks Jaahn and Yobarr, I understand now thanks.
It's got me wondering how the Al-Ko rubber torsion suspension in my Snowy River caravan reacts in such a situation, I do not have ESC or the like and never told at more than 90kph and the van always feels stable.
Same principle Mike, as the arm from the rubber suspension unit to the axle still swings through an arc under compression, changing distance from towball, and moving axle from its 90 degrees to chassis stance. Perhaps not as severe as the brightly coloured flash 4 shock systems, but it'll eventually send you R-Sup if sway develops. Cheers
-- Edited by yobarr on Sunday 19th of June 2022 10:22:17 AM
Hi Mike. Please note that I have composed this post only from my research, and not from personal experience, but it seems to me that all the adulation of this flash ESC gear is more a result of hype than of the system's effectiveness? It appears, from my research, that it loses its effectiveness at moderate speeds, and at highway speed it is absolutely ineffective.(Read "useless"). All reports of its effectiveness come from people with vested interests, whether they be companies marketing the product, retailers or consumers, who are highly unlikely to admit they've made a mistake forking out big dollars for said product. Seems to me to deserve inclusion in the same category as brightly coloured suspension with double shock-absorbers, which I admit initially had me sucked in too, until I did an analysis of the physics. BUT, let me say that after reading advice from Peter'n'Margaret I did fit heavy duty EFS XTR shocks to my van, with dramatic improvement on the "development" roads I often travel. No more broken springs either! This post will no doubt produce multiple howls of disapproval and anger from members with these gadgets that we survived for years without, but who's going to admit that they've spent mega dollars on this stuff? And Mike, there is no need to feel you've "missed out" by not having ESC. My van runs 3150-3200kg GTM and NEVER sways even when I try to flick it around a bit to check on the tyres, as is regularly done with Roadtrains, and I have no ESC or ABS or any other gadgets. Horror! Cheers
Interesting assertions Yobarr.
Although I do not have ESC on my van it is systems of this sort (complex embedded systems) which I have spent many decades designing and I would consider an ESC quite a challenge.
Some basic off-the-cuff thoughts:
A car and caravan travelling at 100kph covers about 28m/S
Activation time for an electrical breaking system on a van say 250mS
Time for the electronics to determine there is a "sway" condition occuring say 1S (maybe a lot longer - keep in mind the forward motion is 100kph but the sway motion will be very slow)
The really complex bit now is how to handle the caravan brakes and how to respond to changes in the detected sway condition, one would have to look at the rate of change of sway and respond to this data but, as mentioned, this is a slow change and at 28m/S perhaps far too slow?
Dunno? And I don't know how such a system could be tested to the level we require of, say, medical equipment. I suppose when caravans with ESC roll no one can prove the cause or whether the ESC did what it should. Indeed what are the limitations of the ESC, what are its specifications, what rate of change of sway can it tolerate?
This is not a trivial problem.
-- Edited by Bobdown on Sunday 19th of June 2022 03:54:56 PM
Great post Mike, with the thoughts that I've highlighted above matching the information I found when doing research. Another con job, me thinks, but seems there's a sucker around every corner! Learn to load correctly with most weight over van's axle group, make sure the car has at least 10% more weight on its wheels than the van does, make sure your tyres are not more than 5 years old and get the tyre pressures right (do your research there too!), make sure towball weight is around 10% of ATM, set your brake controller appropriately with a higher setting on the open road, and don't believe all the hype that you'll hear from people whose primary interest is boosting their own bank account balance. These things will do more to ensure your safety than any gadgets will do. Cheers
Hi Yobarr and Mike
I cannot argue against the fact that the primary safety is to correctly load your van, and balance it, and ensure that it is a weight that is appropriate for the tow vehicle. The drivers first responsibility, and then to drive in a safe manner at a safe speed.
But modern cars and utes are equipped with a several braking and stability technology devices which WORK WELL and are now after many many years, mature technology which is very reliable. They can 'kick-in' in a super short time frame to intervene and sometimes without the driver noticing. "Gee I wonder what happened then" type response. I do believe caravans could benefit from that expertise but currently I doubt they do use any really high tec solutions despite the sales hype. Probably a better hydraulic braking system would be a start. An ABS has an inbuilt pump to supply pressure and the smarts to run all the wheels individually braking as required. YAW sensors are fitted in all cars. These things are 20-30 years old.
I test out my system occasionally when it is appropriate. Sometimes in a incident. A while back after visiting a friend on the farm, returning at dusk I had a roo jump in front from nowhere, on a tight bend, down hill, gravel road. I braked hard, the technology took over and the car stopped short as the roo hopped off and my car never skidded or lost directional control ?? PERRRFECT. Try that in your old ute with no technology.
Jaahn
-- Edited by Jaahn on Monday 20th of June 2022 08:41:40 PM
Definitely do NOT accelerate - all you will do is waste time and have to deal with the problem at a higher speed - if you are still on the road.
When the van starts to weave it is already travelling faster then the car - because it is travelling a weaving path, but only going forward at your speed. So accelerating will most definitely not help.
Research shows that you have a max of ~4 sec to get it under control. Using the manual trailer brake is extremely hard to do in that time, but can be done, but only if you are sensitive enough to know what is happening the moment it starts.
Best to put a DSC on the van and let the electronics deal with it - much faster than a human can in this circumstance.
As Fast Eddie says, you have a maximum of ~4 seconds to regain control. I believe that in most cases by the time 4 seconds has elapsed it is already too late. Where I disagree with Eddie is the time it takes for a driver to react and hit the brake controller button. I believe most experienced drivers would hit that button in the first second from detecting the sway, which would be pretty well immediately it starts.
I just watched a few Youtube videos on caravan sway accidents and it seems each oscillation typically takes about a second from one side to the other ... until the swings become so wide that gaining control is impossible.
In the process of searching for videos I found this one that is promoting a solution combining mechanical and electronic means to limit sway.
Van sway being controlled
I have no doubt the test was engineered to show a result, and real life situations may be very different. The speed is low, while in real life, sway accidents are usually at speed. But it does highlight that electronic systems can react quickly, because these oscillations are much faster than one second. There is also a mechanical component of the system that uses friction to inhibit sway. I can't see that doing much, but every little bit helps.
Dear Bratboy,
I drive heavy vehicles for a living and don't have an issue with confidence driving a car and caravan without assistance. Im 6ft3 and 125kg ,and if you've ever sat in a 79 series Landcruiser you'd realise it doesn't take much to fill the cab, and there isn't a lot of room down the right hand side to mount a brake controller with easy access........I would have no issue using the brake controller manually myself if needed, and would find it a lot more accessible where Ive mounted it if need be. But if in an emergency situation I found myself steering with ONE hand and needing to change gear with the other I would not be to much of a frign hero not to allow my passenger to help, or use it myself if the Mrs was driving. Landcruisers are also not known for there fantastic hand brakes eithe,r so in the situation of the vehicle rolling while the driver is out of the vehicle it also makes it very easy to pull it up (eg . a boat ramp).........I was going to ask a bit about your driving experience, but dont bother I just read enough of your know it all dribble to get a fair idea....Bwahahaha
Great post Sean, with lots of common sense explanations of your reasons for mounting your controller where it is. Could I also congratulate you on the great car you've chosen, although I can understand your comment "it doesn't take much to fill the cab". Must say that I also agree with your thoughts posted in the last couple of lines. Well done! Cheers