uk.news.yahoo.com/bank-holiday-travel--caravan-drivers-warned-as-highway-agency-released-horror-crash-footage-113121815.html#UPTPaun
However, that would appear to be a transit van pulling the large caravan. An unjustified assumption causes me to think "Well, that's one less".
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Looks like a close relative stops his van on lane one to go and assist. What an absolute bell end.
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agree there Alanović, that idiot was more dangerous than the caravan driver
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>> agree there Alanović, that idiot was more dangerous than the caravan driver
>>
Don't be coy, diddy
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Not enough tarmac in the van.
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Something wrong with the caravan, overload, tyre pressures too low or both. God people are idiots.
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>> God people are idiots.
The way that is punctuated, I couldn't agree more!
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>> The way that is punctuated,
Try to keep to the subject, Duncan. Sheeesh... one track mind some people.
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Something wrong with the caravan, overload, tyre pressures too low or both. God people are idiots.
Can't be certain, but the caravan looked nose down so it's possible the hitch load was way out of spec. I'd have thought a transit van was a pretty good tow vehicle, but I've never tried one.
Last edited by: Slidingpillar on Wed 16 Apr 14 at 15:04
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Saw a van flailing about on the M6, until the panels and the frame parted company. An explosion of fibre glass, suitcases, bedding and kitchen utensils. That's when the driver noticed....
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I have seen the aftermath of a caravan and a shogun, it wasnt nice.
I guess with the transit, if it was empty then it would have been dangerous towing a large caravan..... the 80% towing weight rule comes to mind
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>> I have seen the aftermath of a caravan and a shogun, it wasnt nice.
I read that as "the aftermath of a caravan and a shoTgun"
Was about to say that was an episode of the sweeney
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>> Saw a van flailing about on the M6, until the panels and the frame parted
>> company. An explosion of fibre glass, suitcases, bedding and kitchen utensils. That's when the driver
>> noticed....
I saw the remains of a similar event on the M62 many years ago, and only found out a few days later that it was a close friend and his family.
Last edited by: neiltoo on Wed 16 Apr 14 at 15:27
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Going South over the Forth Road Bridge there is a steady downhill stretch after Dunfermline for about 2 miles - Crop of overturned caravans April - October.
Instead of say 50 mph, they go at 60mph and downhill this becomes 70...........with the consequences of an overturned car/4x4 and a smashed up fibreglass/aluminium caravan.
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Not that I intend to lug a caravan, but what can be done to correct the "tank slapper", if anything can? I know what you're supposed to do on a two-wheeler, but that's single track obviously, and c'van lugging doesn't lend itself to taking hands off the bars:)
Last edited by: NortonES2 on Wed 16 Apr 14 at 16:01
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Just booked myself on a caravan beginners course. Feeling a bit daunted now!!
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There are two views about this among caravanners. One is to slow down gradually, the other is to speed up slightly and drive out of it.
The one thing you mustn't do it to touch your brakes once it starts to snake.
Of course, the easiest thing to do is to load it properly and avoid the situation in the first place.
Pat
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>> There are two views about this among caravanners. One is to slow down gradually, the
>> other is to speed up slightly and drive out of it.
>>
>> The one thing you mustn't do it to touch your brakes once it starts to
>> snake.
>>
>> Of course, the easiest thing to do is to load it properly and avoid the
>> situation in the first place.
>>
>> Pat
>>
The "accelerate out of it" idea is out-dated now most cars have some form of stability protection. Safest approach is to brake firmly and let the computer worry about fixing the problem.
I think Pat's advice of "load it properly in the first place" is the most important, though!
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>> I think Pat's advice of "load it properly in the first place" is the most
>> important, though!
>>
Would you go down to where those caravaners live and tell them?
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When I was young and foolish (younger and foolisher anyway) I towed a mini to a banger race meeting on a very heavy trailer, with a Ford Escort - I know - too heavy!
Going south on the M6 there's a steep downhill to a wooded section and right hand bend.
The approach is slightly uphill, and I didn't ease off the gas soon enough before the summit. So I was travelling a little fast when I started the descent. The weight of the trailer started to push me faster, and as I braked, it started to sway. If I left the brake, I speeded up.
My gut instinct proved to be correct. I gently pressed the accelerator, which straightened me up.
As we reached the bottom, and a slight uphill section, I allowed the speed to rub off naturally. I think I was doing 85 - 90mph at the bottom.
I felt quite fortunate, when I dried off the sweat etc.
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And I should think there was quite of bit of "etc."!
Lucky escape.
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Many new caravans are now fitted with a device called ATC, (active trailer control), which detects when the van starts to snake and applies the caravan brakes none-too-subtly to slow the whole rig down.
Works well as I found out in Spain last January after a gust of about force 12 caught me broadside going through the mountains. I was doing less than 50 and I guarantee it was correctly loaded, it's just that some rare incidents are unavoidable. Witness the big artics that get blown over by freak gusts.
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Having caravanned on and off for the last 30 years I can see various factors added up to cause this:
- Heavy caravan probably with bad weight distribution inside
- Lightly loaded van probably with a lower kerb weight than the caravan
- You cannot tell, but the stretch of road was probably down hill
The other questions is:
- Did the caravan have a tow hitch stabiliser and was it working properly? That alone can avoid snaking getting out of control by exerting damping movement on the towball.
All in all the driver should be strung up for being so irresponsible and giving the caravanning community a bad name.
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I've seen a few rollovers in my time. Caravans don't stand up to being interfaced with the tarmac very well !
I have the normal Alko hitch stabiliser and I also fit a Scott ' blade type ' one.......'cos I've already got one. 17' Elddis and Grand Vitara......rock steady !
A bad roll I attended a long time ago was a horse box with one horse pulled by a.........Marina 1.3 ! It was on it's side on the motorway and a vet had to be called who put the poor animal down in situe.
A popular film clip..........www.youtube.com/watch?v=e_Xygo2054Q
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>> A popular film clip
Amazing Horatio. The world's worst drivers of expensive cars... losing control under wheelspin with all those pedestrian spectators up against concrete walls too. Surely a couple of deaths and maimings must have been left out for humanitarian reasons?
It's simply beyond belief that someone can lose control under wheelspin in a Veyron - 4wd remember. Did they just put drunk non-driving teenagers in them to see what would happen? It looked a bit like that because they seemed very slow and coarse in their steering inputs to put it mildly.
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>> - Did the caravan have a tow hitch stabiliser and was it working properly? That
>> alone can avoid snaking getting out of control by exerting damping movement on the towball.
>>
>> All in all the driver should be strung up for being so irresponsible and giving
>> the caravanning community a bad name.
If you put two and two together, looking at the vehicles involved, I suggest it is unlikely that the drivers would have invested in tow hitch stabilisers.
I don't think this was Mr and Mrs Featherstonhaugh on their way to a Caravan Club site.
Last edited by: Duncan on Wed 16 Apr 14 at 17:24
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Old Paddy there had probably just nicked it anyway...
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I thought that about the ' hillclimb' failure, Simon. A 19 foot twin axle van, favourite for a living van. Passing by in a Renault 5 with a towbar and just took a chance the owners weren't watching....................hmmmmm
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Hmmm. Not members of the Caravan Club in all probability.
Looks downhill, which would be typical - that stretch of the M5 where there always seems to be a caravan accident is the downhill stretch IIRC. I have always inferred that having some tension in the drawbar helps, which would also explain the common assertion that accelerating helps with a tank slapper. You can however see the basic problem with that, as (in)stability is also speed related.
I researched this a few years ago, having a vested interest. Bath University did some tests, sponsored by Bailey.
Broadly, there is a speed at which any outfit will become unstable, when the oscillation set up by a bump or sway for example overcomes the damping in the system. A number of things help to control it -
- stiffer suspension, better damped ,on the back of the towcar is better than softer, less well damped.
- a short overhang is better than a long one.
- the longer the drawbar, the better. UK caravns tend to have shorter drawbars than continental ones.
- dampers on the caravan are likely to help. Historically, many UK caravans have not had dampers at all, just compressible rubber springs. European caravans use the same makes of chassis, but but nearly always have dampers.
- load the caravan payload centrally, and low.
- pay attention to hitch load (noseweight). It should be at least 4% of the trailer weight, and up to 7% if the maximum hitch / towbar loads allow.
- subject to not overloading, put the heavy stuff in the car, not the caravan.
I believe Pat disagrees on the last one. Maybe (she can speak for herself) because that's how an articulated LGV works, but they have semi-trailers where half the weight is on the fifth wheel (and hence the prime mover) anyway. If it was a wagon and drag, would you still put the weight in the trailer by preference? Unlikely. Artics also have proper service brakes. A caravan is a different case, where the load is on the central trailer axle(s) with a nominal hitch load, and the brake are overrun type.
However - I think the most overlooked factor is actually tyre pressures. My pet theory is that overheated, failing caravan tyres account for a lot of upsets. Make sure the car and caravan tyres are at the right pressures, get the noseweight in the right zone, load sensibly, keep the speed <=60mph (the highest legal limit on UK roads anyway) and you will be very unlucky to have a problem unless you make stupidly violent control inputs.
Incidentally, the Bath research concluded that hitch dampers made no material difference to the speed at which instability occurred. All they did was damp out oscillations faster at sub-critical speeds, which could in fact lead to over-confidence.
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And change tyres fairly frequently as caravans tend to be static most of the time, particularly during storage, and in all weathers.
Tyres soon develop flat spots and sidewalls crack. Tread my appear good.
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>> Bath research concluded that hitch dampers made no material difference to the speed at which instability occurred. All they did was damp out oscillations faster at sub-critical speeds, which could in fact lead to over-confidence
I think that's been repeated incessantly, but how many caravanners read it?
Decades ago, I lost a caravan wheel on the M6. I slowed gently onto the hard shoulder,which ground away the bottom of the damper on that side. Refitting the wheel, I could definitely feel the absence of the damper on that side until I got it replaced.
Last edited by: bathtub tom on Wed 16 Apr 14 at 23:50
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One of our jobs this weekend is to ackle the caravan. A good wash and some minor work including fitting a new pump inlet. I'll be calling at the national Tyre depot tomorrow while I'm out to try and blag a bogof on a pair of tyres.
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>>I believe Pat disagrees on the last one.<<
Not at all, just with the way it's interpreted in relation to an HGV.
Putting heavy stuff in the car would be like putting the first four packs of timber in the cab!
Putting heavy stuff just forward of the caravan axle in creases the noseweight slightly and for us, gets much more stability.
Putting the heavy stuff in the car means the car sits down low at the back and takes traction from the front wheels. It also looks like an inverted V at the towbar pivot point. The whole thing should look completely level when loaded to go.
It's not an exact science, although numbercruncher won't agree with that!
We've towed with a number of different cars, we never check the noseweight, but look at the whole outfit from a distance. If it looks level then the next step is to find out if it 'feels' right during the first five miles or so and that, again for us, is the crunch test.
Pat
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I've done quite a lot of towing of different things over the years, all with older cars or landrovers, no modern stabilty aids. Caravan, horse trailer, army trailer, dinghy.
I think the key things are;
1) familiarise yourself with the combination, and learn its characteristics and safe speed. eg 40 mph absolute maximum with a horse on a flat open road, usually no more than 30 mph
2) load the car in preference to the caravan. Keep the weight low down, distribute so there is some but not too much nose weight. I don't agree about concentrating the weight near the axle. I think even distribution damps down pitching. (Like carrying milk pails on a long pole rather than balancing something on your head)
3) adjustable tow hitch height is vital. All vehicles and trailers differ, and differ again with load. As Pat says, the whole combination should be level.
4) speed is of overwhelming importance, and the cause of all problems. Anything is safe if you drive slowly enough.
5) you have to concentrate 100% on the towing all the time. No distractions, no radio etc, watch and feel the trailer like a hawk. Be alert to the tiniest hint of a wobble, and slow down by easing off. The only circumstances where the "accelerate to cure" holds I think is if approaching a hill and wanting to built up speed to shoot it. In those circumstances alone foot down at the bottom of the hill is safe because it will quickly slow down under gravity as you hit the hill.
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Right, having discovered that you have to crawl to your destination and are not even allowed to listen to the car radio, I think we have confirmed that shed dragging is holiday misery and Hotel / Cottage rental wins hands down every time.
Last edited by: Zero on Thu 17 Apr 14 at 09:00
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I think we are probably missing out on the fun and sense of freedom that having your very own chemical toilet brings.
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>> I think we are probably missing out on the fun and sense of freedom that
>> having your very own chemical toilet brings.
According to this you need to rearrange the weight, not keen on the chemical toilet in the car
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>> According to this you need to rearrange the weight, not keen on the chemical toilet
>> in the car
>>
It might come in useful if the tail-swing becomes excessive...
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Agree that there is a right speed for any outfit. That speed can be very low if good practise isn't used. Also agree re high level of concentration.
Most cars will not have any means of adjusting tow ball height and no type approved option available to do it.
"Some nose weight but not too much" well, yes. But what is that? Bath say 7% but that may be reduced by limits. My little caravan is 1200kg, 7% is 84, but the limit for the fitted Al-Ko hitch is 75, so that's what it gets near enough. The limit for the car / tow bar is 120kg so not an issue but some cars have quite low limits.
Loading over the axle keeps down yaw inertia, so I'll keep doing it.
www.towingstabilitystudies.co.uk/stability-studies-game.php
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Modern caravans are inherently stable if loaded correctly and towed with a suitable vehicle. The Caravan Club suggest the caravan should be no more than 80% of the weight of the towing vehicle. My caravan has the Alko hitch stabiliser, as well as the Alko Automatic Traction Control, which senses any instability and brings it under control. However, I doubt if either of these would control a snake if none of the above applied and the vehicle was exceeding the speed limit.
Usually, high sided vehicles passing a caravan will cause some instability, but my 'van is not affected in any way by these. My tow car is a 4th gen Honda CR-V 2.2 I-DTEC EX which is above the minimum recommended weight.
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I've towed different things for decades up until a couple of years ago. Thankfully hardly any caravans because they are all pig to tow from the stability point of view once you press on. It's no wonder really with the wheels in the middle creating a dumbbell effect...
www.kampeertenten.nl/media/images/fendt.jpg
In many ways it's similar to the balance wheel on a small clock which only needs a tiny energy input to keep oscillating once started.
My favourite thing to tow was always an Ifor Williams horse trailer... particularly on the run home without the horse in. They have minimal rear overhang and a long effective drawbar length so track the car with great stability...
www.kampeertenten.nl/media/images/fendt.jpg
The other thing is that 90% of our towing has been done either with self levelling rear suspension or Land Rovers where the springs are so stiff a large load can be carried in the vehicle without dipping at the rear. From my experience this increased (within sensible limits) tow vehicle load greatly increases stability. Also with the aforementioned vehicles it enabled loading noseweight to absolute maximum which similarly improved stability.
Finally huge benefit to properly setting up the over run brakes so they neither allow the trailer to give the vehicle a shove in the rear nor come on with a rearwards snatch.
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>>> we are probably missing out on the fun and sense of freedom that having your very own chemical toilet brings.
Oh agreed.. so much so mine from the old days (not caravanning) is in no.2 garden shed set up and ready to go... so to speak.
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Just use the compost heap.
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You mean you do or I should?
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Ahh well as we are no longer true Fenlanders such delights are not entirely appropriate. Modernish house & smallish garden so no compost heap. Going to be hard to balance on steps over the green wheelie bin while the increased height enables me to smile sweetly into next door's sunroom.
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isn't that how you get a compost heap started?
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>> isn't that how you get a compost heap started?
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Don't know - its you who owns the Lancer.
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I judge nose weight by whether I can lift the coupling onto the ball. It should be heavy but reasonably easy.
<
I don't get that, and it's not my observation.
Try walking carrying a long heavy plank and it has incredible yaw stability.
Contrast staggering along carrying the same load close to you and if you stumble you fall over.
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>>Try walking carrying a long heavy plank and it has incredible yaw stability.
There is an important difference Cliff; there is some springing involved, provided by the lateral stiffness of the trailer tyres, and the lateral stiffness of the back and of the towing vehicle.
This combination of an inertia and a stiffness is enough to provide a means of energy exchange, i.e., the conversion of the yaw kinetic energy into the potential energy in the springs. This gives rise to the possibility of a vibration. Increasing the yaw inertia of the trailer reduces the natural frequency of this vibration, which in turn reduces the road speed where it is strongly excited. So, to improve the yaw stability of the outfit, to allow the largest range of stable speed, it's best to reduce the yaw stability of the trailer.
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I defer to your expertise, of course. But why then does this site, for example,
www.m.driving-test-success.com/vehicleloading/vehicleloading.html
say
"When loading a trailer spread the load evenly." ?
A quick browse of other sites say the same thing.
Or are they making a distinction between the act of loading a parked trailer, and actually pulling it? Having spread the bricks, say, evenly over the floor of my trailer, does it mean they should then be moved into a pile over the axle?
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Just realised I had included a horrid error
>> best to reduce the yaw stability of the trailer.
I should have said;
...best to reduce the yaw inertia of the trailer.
The problem with a surprising amount of motoring wisdom and advice is that it isn't based on any solid evidence - so, sites saying spread the load evenly, aren't basing their advice on evidence. You only need to read HJ, or even worse the road tests by Andrew English to see this effect.
The long running research by Bath/Bailey is worth reading carefully - they have looked at this in theory, and have backed it up with testing - both trailer only, and full vehicle.
So, to your practical question, instead of having bricks, say one deep all over the area of the trailer, better to have them 2, 3, or 4 deep centred on the axle.
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Yep and this fits in with my hands on experience of shifting farm equipment and similar in horse trailers and on Ifor Williams open trailers. Try and put the heavy items together just over and a fraction in front of the axle so the weight is concentrated and maximum acceptable noseweight is reached (with regard to any existing load in the rear of the tow vehicle).
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>> Just realised I had included a horrid error
>>
>> >> best to reduce the yaw stability of the trailer.
>>
>> I should have said;
>>
>> ...best to reduce the yaw inertia of the trailer.
Yes it was a horrific error, now 100 lines: I will not mix up yaw stability and yaw inertia.
;-)
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>> So, to your practical question, instead of having bricks, say one deep all over the
>> area of the trailer, better to have them 2, 3, or 4 deep centred on
>> the axle.
>>
>>
Thanks N-C, I'll do that in future. It feels counter-intuitive though.
It makes me wonder now about the similar process when ballasting a boat. The accepted wisdom is that if you concentrate the weight in the middle it gives a very unpleasant choppy pitching, and difficulty holding the boat on course. Spreading the load dampens down the motion.
Or is that wrong too?
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>>Or is that wrong too?
Sorry!, can't help with that. Filling the back of a postage stamp with my meagre knowledge of boats would be challenge.
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You're right Cliff but the actual tech design info is beyond my experience. I do know though for example slightly spread ballast (as in side to side) will help produce a more comfortable roll rate compared with all ballast centrally along the keel line.
These days we are only smallcraft users so I just get Mrs F to move where the outfit feels most balanced.
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>> slightly spread ballast (as in side to side) will help produce a more comfortable roll rate compared with all ballast centrally along the keel line.
I think I can visualise that. Imagine a metronome, it has a faster 'beat' the closer the mass is to the pivot. The boat's pivoting about the keel, move the ballast further from the keel and it will roll slower - I think.
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My only experience of towing anything heavy was back in the mid 90's.
An exhibition trailer and the tow vehicle was a Daihatsu Fourtrak LWB.
It had a stabiliser damper, but didn't seem to make much difference the thing was so heavy.
Happy at 35mph, OK upto 40, but incredibly unstable beyond that. I was told at the time this was due to the trailer having 4 wheels? Don't know how true that was?
I had forgotten all about that Fourtrak till now. A very capable 4WD even if the 2.8TD seemed underpowered.
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>>
>> Happy at 35mph, OK upto 40, but incredibly unstable beyond that. I was told at
>> the time this was due to the trailer having 4 wheels? Don't know how true
>> that was?
>>
That's where the weight of the towing vehicle comes in. With 4 wheels the trailer will want to plough on in a straight line. Fine if that's where you want to go, but not so great if it's thrown off course by something.
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Pulling a caravan.... - Alanovich
