It follows that it is most likely a great number of snaking accidents have been attributed to tyre failure ( see also 6a and 11e), when it can now be seen that in a very considerable number of cases it will now be possible to prove that the snaking causes the tyre failure.
It can also be seen from my diagram that I have estimated that each side of the van could, in turn, lift over 5 feet. Each time that this happens the van would therefore lift the rear of the tow car off the road. I have seen the result of this happening to a large Volvo Estate car. The latter had come to rest on the hard shoulder with the van on its side, still fixed to the tow car with the latter's wheels well clear of the ground.
I circulated this information via RTA Investigators.com some considerable time ago, but judging by the length of time it takes to resolve these matters it is far too early for anyone who has dealt with a similar case to be free to communicate.
Referring back to the caravan snaking marks shown above, if the caravan brakes are working the thickness of the rubber on the road should decrease slightly as the marks approach the crash site. I predict that what you will see on the road in these cases is clear evidence that the snaking trailer is making a mark as it comes to the outside of its swing so that the thickness of the rubber on the road will be at a maximum nearest to the centre of the trailer and will decrease to zero as the trailer stops swinging.
I would also predict that the thickness of the rubber on the road will remain constant as the caravan has moved forward indicating that the brakes are not working. As I explained in Section 4 (Over run Brakes), if the tyre marks ( or absence of same altogether) indicate that the brakes are not working, this is either due to a mechanical fault or is accounted for by my explanations, and if the latter is the case it could apply to all over run brakes on the road. The fact that the driver of the tow car may not have applied the brakes should not really be an issue. What use are brakes that drivers dare not apply at the critical moment?
A Typical Caravan Chassis is quite robust and the parts that Investigators need to examine in this connection are likely to survive most accidents in good enough condition for there to be "proof" that the brakes were in good mechanical order at the time of the accident.The most likely item to be damaged is the telescopic arm of the brake actuating mechanism, but even if there is serious damage to this item due to the van breaking free from the towing hitch, a well greased arm free of rust or paint, should prove that it was in good order before the accident .
(17b)
Over Loading of Caravans
This in my view is likely to be a very common problem because in the past manufacturers of caravans have given insufficient attention to the matter. I currently have a small and a large touring caravan ( similar to photos in www.caravanaccidents2.wordpress.com) I have had the small van 9 years and the large van 15 years. The largest weight that is allowed on my Land Rover Discovery towing bracket is 75kg, but both the vans have "design" locations for the battery, spare wheel, two gas cylinders and a hot water cylinder near the front of the van and their combined weight (counting the smallest gas cylinders available) is about 75kg. There are six store cupboards forward of the axle, which is the main space apart from the wardrobe for keeping bedding and clothes. I cannot load any item inside the van forward of the axle/axles, without a change in position of the previously mentioned items. The first procedure I carry out before each journey is to empty the hot water cylinder (about 25kg); this is most irritating as I have to fill it up again when reaching the next stop, having first fetched the water some distance on a trolley. (I have located my spare wheel as in photo "N".) I next secure the battery in the back of the Discovery, placing it in a plastic bowl first. Finally, I very often have to secure the full gas cylinder inside the caravan at the back ( but I am concerned that this is a safety hazard in the event of an accident). I then check the nose weight to see whether any other items have to be moved inside the van. It is hardly surprising that police doing road side checks find many incorrectly loaded vans.
On safety grounds there should be government regulations which compel all caravan manufacturers to address these problems during manufacture, and place a duty on retailers to check that vans they are selling meet these requirements. I have learned recently that some manufacturers are solving this problem by having an "all electric" van. This eliminates the battery and the gas bottles; an electric heater is much lighter than a gas appliance. They have overlooked the fact that hardly any caravan sites have electric points that will cope with the load, unless, for instance, the electric heater is not used at the same time as the electric kettle.
Furthermore, at busy times most caravan sites do not have enough electricity points for all customers. Installing extra capacity is most expensive and electricity companies cannot always meet requirements outside urban areas. Expensive transformers are needed aswell as miles of wire on poles. This causes a further road hazard as purchasers of the "all electric" vans will soon realise that they have to have a gas system aswell.
If the latest temporary repair kits for repairing tyres by inserting a suitable substance through the tyre valve meet general approval and pass EU tests, at least the spare wheel can be eliminated safely ( in due course), but I can see no future for replacements for the other items. If an electric braking system is fitted to the caravan, as I understand the situation the regulations will require a battery in the caravan to facilitate operation of the caravan brakes if the caravan becomes detached from the tow car.(17c)
Insurance
In 2003 I had to "tick a box" on my boat insurance application form to signify that I did in some instances sail on the sea ( coastal waters only) "single handed." As a result I was requested to out line in great detail where I was sailing before my insurance was granted. In 26 years of towing caravans and sailing cruisers on the road my insurers have never asked about the weight of the trailer plus load; the maximum nose weight allowed by the tow car manufacturers, or the vehicle I was using as a tow car. I am sure that if this was pointed out to Insurers by a "well qualified organisation" they would see that it was in their own interests to make these checks, which would make our roads safer as everyone would be compelled to address seriously the complicated procedure to be carried out to ensure that you are towing a suitable and correctly loaded trailer. It will be seen from the photographs mentioned above ( and the photo of a caravan chassis), that manufacturers are now beginning to make safer provision for some essential items of touring equipment.(17d)
Overloading of the back of a Tow Car
The serious consequences of overloading the back end of a vehicle have previously been reported in "Impact." In this case the accident resulted in a fatality, but I have been unable to obtain a back copy to read about this. I only have the information by word of mouth.
Too much weight on the back end of a tow car will make its steering "light." The vehicle will thus have a tendency not to respond to the steering wheel; ie, it may go straight on although the wheel has been turned. Accident Investigators may find evidence of this from the tyre marks on the road. Too much weight on a tow cars' towing bracket will have a much greater effect than is observed when viewing the stationary vehicle as on a moderately uneven road the caravan will "pitch" so that one feels considerable bounce on the rear suspension of the tow car. Some types of stabiliser make a contribution to reducing "pitching," but it will always occur and in an accident situation could be an important destabilising factor.
Another instance of problems arising from too heavy a load on the towing bracket is damage to the latter and its fixings. Too much weight on the nose of a caravan can also damage the over run mechanism or other structural items at the front of the van, but I have not known of any manufacturer giving a value for the maximum nose weight. It is usually considered that it must not exceed 7% of the total loaded weight of the van.