A question about snaking
 

I know a caravan can cause car and caravan to go into a snake, but, if the tow vehicle is heavy enough am I right in thinking the caravan can swing around as much as it likes, the tow vehicle will stay put. Also am I right in thinking a very heavy tow vehicle does not guarantee that the caravan but is much lighter will not swing from side to side perhaps even going onto its side?

macafee2

If the train is badly set up (as in weight in the wrong places) the weight of the tow vehicle is irrelevant, it’ll still throw it about. The advantage of a heavier tow car is it is more resistant to swaying, but it can still swing about.
If you’ve got a 2t vehicle and your towing a 1t caravan then you’ll likely not notice a bit of sway, you might feel it if it builds a bit of momentum. But weight isn’t the main factor, tyres, suspension, length and width of tow car, weight distribution of tow car can all have unusual outcomes to stability.

If you take the same set up and put a large proportion of weight at the rear reducing the nose weight, obviously it’ll swing a lot and it will be felt even in a large car. I had this when I was rescuing My 75 a few years back. My terrano weighed a smidge over 2t, and when I loaded the car up it was a bit too far back on the trailer. It was all over the place and it was really felt in the tow car. So rather than moving the car I moved the spare wheel from the well to the passenger seat and some bags of clothes on the drivers and that was enough to stabilise the trailer.

If you set the nose weight up correctly and distribute the weight in the caravan correctly it shouldn’t sway unless the outfit is mismatched. A heavy tow car isn’t an excuse for a bad set up but it can certainly help!

Sort of, My thinking is that it does not matter how heavy the tow vehicle is, the caravan can still swing even if the tow vehicle does not sway

macafee2

I would say it would still swing yes, but I also think that the tow car will feel it, no matter how big it was. The suspension initially will be what dampens the effect on the tow car, with the mass of the tow car only coming into effect once its suspension has reached maximum effect.

The more it swings too, the more the tow vehicle will be effected by it. It is a pendulum effect. The caravan as it is connected to a a single point (the tow ball) in a three plane fulcrum, will always have the potential to swing, and bounce.

Also the wider the arc, the stronger it becomes against the tow car, think of it in terms of how a breaker bar works.

It's all down to how you load the caravan and having everything mechanical on both car & caravan in perfect working order.

Keeping to a safe speed (especially on downhill sections) is also important, a fact lots of "experienced caravanners" seem to forget sometimes to their peril.

I've been towing for a few years and the only snaking I can remember was with the 75 towing south on the M6.
It later turned out that a suspension bolt on the rear upper arm had come loose more than a year after my suspension overhaul. I picked up on this months later when preparing for the MOT

The reason for the question, I got the impression on a caravan forum that someone was suggesting a heavy tow vehicle would make everything ok but I did not think that would stop the trailer from swinging side to side.

It may keep the tow vehicle from going from side to side but not the trailer.

macafee2

I have towed, for almost as long as I have driven...

....and I have been in a car where the caravan snaked on a downhill section and turned over - not driven by me.

The higher the tug to trailer weight, the less of a problem the trailer snaking will be, but it is not an absolute. 'A wheel at each corner' tug, makes for a generally more stable tug. Going downhill is the worst possible snaking situation, try braking with the snake in the wrong position and it can make it much worse, the swing wider. Snaking uphill, then you can simply ease of and it will all slow down and stabilise.

Dampers have a very noticeable effect, the best in my opinion is a separate spring type damper, which also helps take some weight off the tugs rear wheels. I now use a much more convenient Alko hitch with built in damper. I wasn't impressed at first with it, but I have been pleasantly surprised at just how effective they can be.

I run with a measured 75/80Kg nose weight, max for car is 150kg, max for caravan is 100kg.

To help avoid a snake, when towing - I ban any loose liquids in the caravan, all high cupboard contents are transferred to floor cupboards, all heavy weights are placed on the floor, heaviest over the axle lighter between axle and front. Nothing, even clothes in the wardrobe, are allowed to be able to swing about. I tend to set up the nose weight once, then when I get what I want, make a mental note of what belongs where, to get that weight.

I always check my car and caravan tyre pressures before I tow.

I have never had the slightest hint of a snake towing my Pageant with my 75, at any speed and I have toured the UK with them over several years. It is a brillliant, stable tow car, but could do with a lower first gear to make it perfect.

some caravans are more stable then others. Our Swift did not care how it was loaded it never gave a hint of movement except when being over taken by a lorry or coach. Our Lunar likes to be nose heavy, until I got to know this it was a bit of a cow to tow and even now I would not like to push the boundaries when it comes to speed I am much more conscious that it is not as stable.

Best part of 30 years ago I was towing a caravan, was over taken and then brake checked. No idea why. Swerving to avoid the fool the car and caravan went into one heck of a snake. All my caravans have had some form of device to help reduce the risk of a snake.... boy that was scary, never again.

Alko ATC seems to do an exceedingly good job at controlling snakes.

macafee2

I notice that modern caravans (even without extra stabiliser gadgets) do seem much more stable anyway. My Bailey seems completely unperturbed by being overtaken by the express coaches. I used to always feel the wash from them with previous caravans, I would feel the tub as they began coming alongside, then it would get worse as the got slightly ahead of the van and be pushed sideways then.

The Alko seems to offer much less friction and a lot less leverage for the friction to work on, so I was quite surprised to find they work so well. I kept my old spring stabiliser for several years after moving to an Alko, until my confidence built in it.