Overload caravan driver in serious trouble

[old Jack]

Is there a minimum mass that should be applied to a drawbar?

I have read 6% to 10%, but this is not the end of the matter. Having excess weight in the front or rear of a long trailer/caravan is asking for trouble, as this weight acts like a pendulum.
A trailer or caravan can be under ATM but if all the load is at the front or rear it can be dangerously unstable but legal. Conversely a trailer or caravan that is slightly over ATM but if the weight is concentrated over the axles can be perfectly safe and stable but not legal.

GVM on a vehicle is a legal limit, and most 4wds of the factory suspension will struggle to be above the minimum legal ride height when at GVM even though they are at or under the manufacturers recommended axle load limits, it is about time manufacturers should be forced to ensure that the vehicle at GVM, including the max towball mass is above the legal minimum ride height. This ensure sufficient suspension travel for the safe operation of the vehicle and the TC, ABS and ASC systems.

A stock vehicle can be at GVM and still allowed to tow 750kg of unbraked trailer load as long as the rear axle limit is not exceeded, so this indicates the vehicles braking system is capable of handling GVM +750kg!

A stock vehicle and braked trailer/caravan combination can be at GCVM as long as the axle load limits and towbar downloads are within the limits, so this indicates the engine, transmission, driveshafts and diffs are capable of handling these loads.

I can say without hesitation or doubt that my Challenger with upgraded suspension and tyres that can be 5% over GVM but at the axle limits is a lot safer than a stock vehicle loaded to GVM and towing a 750kg unbraked trailer.

OJ.

[nj swb]

I have read 6% to 10%, but this is not the end of the matter.

As OJ points out, the towball down-force is only part of the issue, as the dynamic effects of weight distribution is more significant than simple COG measurements.

Mitsubishi Motors Australia, in their infinite wisdom, allow a 10% ball weight for ATM up to 2500kg, but down to 6% at 3000kg. Some years ago I read an engineering report that suggested 6 - 7% is optimal, but that probably relies on sensible loading i.e. heavy items near the centre, not at each end. I recall somebody suggested Australia's 10% rule of thumb is partly because we love loading up draw bars and rear bars, so more weight on the rear of the tow vehicle is arguably a little safer in that scenario.

[jaffles]

Someone said or to the likes have the van or towed item confiscated if % overweight. Harsh but they impound cars for "hooning laws" these days. Kids kill themselves in fast cars, maybe there is a growing number to towing accidents deaths-injuries nowadays. Be nice if industry and the private sector could work out something, with Gov just there as the theoretical big stick.

It seems over the years car manufacturers have crept the tow weight up year after year, I bet cars are getting lighter due to emission targets. Someone is doing a bit of marketing me thinks.

[old Jack]

It seems over the years car manufacturers have crept the tow weight up year after year, I bet cars are getting lighter due to emission targets. Someone is doing a bit of marketing me thinks.

Cars generally have got bigger and heavier but have become safer, more comfortable and greater performance.
Gen 1 Pajero LWB kerb weight 1530kg to 1600kg. Ladder chassis and separate body.
Gen 2 Pajero LWB kerb weight 1950kg to 2035kg. Ladder chassis and separate body
Gen 3 Pajero LWB kerb weight 1950kg to 2050kg. Unibody/Monocoque construction.
Gen 4 Pajero LWB kerb weight 2150kg to 2250kg. Unibody/Monocoque construction.

I think all vehicle should have to pass a full axle load to ride height test. Simply load the vehicle up to the axle weight limits and measure the the suspension ride heights, a quick and simple test.

Before towing limits were introduced the general rule of thumb was the tow vehicle should be heavier than the trailer or caravan. Seems like a sensible idea to me. Some overseas countries limit tow weight the the vehicles kerb weight or a lower percentage of the vehicle GVM. May be once the trailer is heavier than the vehicle the speed is limited to 70kph, yes they would clog the roads up but they would be easier to get past than when they are travelling at 80kph!

Caravans have got heavier for any given size especially the "off road" type.
There are ADR's for vehicles so why not have ADR's for caravan design?
We crash test vehicles to get ANCAP ratings why not do stability testing of caravans?
Since caravans and campers can have custom fit outs then each caravan or camper should be weighed when empty and weighed again when fully loaded, axle weights and towball weights should done.

My Challenger straight off the factory floor has a GVM of 2710kg and can legal tow 3,000kg with a 300kg towball load. I can tell you the factory suspension is not above the minimum legal ride height with 300kg on the towball and the rear axle at the 1600kg load limit, and the engine and gearbox struggle to tow 3,000kg on anything but flat roads. 3,000kg to a work site or boat ramp where you are traveling at 60kph or less is doable but certainly not at 80kph or over especially is the road is not flat.

When testing Lockup and Auto Mate, we used just under 2,000kg and this seemed a comfortable touring towing weight so 75% of GVM.
This was with a dual axle trailer with a 2.4m wide x 3.0m long flat bed and a 2m long drawbar, loaded with 32 hard wood pallets.

OJ.

[wazznt]

There are ADR's for vehicles so why not have ADR's for caravan design?
We crash test vehicles to get ANCAP ratings why not do stability testing of caravans?
Since caravans and campers can have custom fit outs then each caravan or camper should be weighed when empty and weighed again when fully loaded, axle weights and towball weights should done.
OJ.

Not done because a great percentage would probably fail even a basic test .If anyone is in any doubt of the low standards in this country there is a lemons caravan website that has a long list of brands to avoid. The lengths that these sub standard manafacturers will go to shut up or discredit anyone publishing the truth is extrodinary, as the websites owner will attest ..
To anyone thinking of purchasing a caravan new or used , I suggest you become a member and spend some time reading.

[jaffles]

Cars generally have got bigger and heavier but have become safer, more comfortable and greater performance.
Gen 1 Pajero LWB kerb weight 1530kg to 1600kg. Ladder chassis and separate body.
Gen 2 Pajero LWB kerb weight 1950kg to 2035kg. Ladder chassis and separate body
Gen 3 Pajero LWB kerb weight 1950kg to 2050kg. Unibody/Monocoque construction.
Gen 4 Pajero LWB kerb weight 2150kg to 2250kg. Unibody/Monocoque construction.

SNIP

OJ.

well that will teach me for generalising. This means I will have very little to contribute.....better stick to the camp fire hey lol

[Dicko1]

well that will teach me for generalising. This means I will have very little to contribute.....better stick to the camp fire hey lol

hahaha.

[oldn64]

The worst case I have seen was while we were holidaying in our own van a bloke pulled up in the site next to ours and when he unhooked his single axle van he had to sit on the draw bar to stop the van tipping backwards while telling his wife to put some stands under the back.
Tom

The big problem that is happening here is that when we look back to licensing it really is Australians getting taught to pass a test. After this everyone can tow, use car trailers , horse floats and caravans. We have all been there. it is scary to think that very few of us get taught how to drive or even how to tow, then there is the whole safety around braking distances when towing.

i remember coming home from interstate with a car on a tandem behind me. there was nothing wrong with my weight or my towing but it took one idiot to jump in front of me and slam there brakes on. I ended up next to the numpty stopped behind the line on his right. if I didnt have that lane to jump into as I pulled up he would have been in the intersection mostly dead.

We need to become serious about our licensing and actually teach this stuff to people. Get the right education so that people who want to tow can back and know how to hook up etc etc. I get scared at how many times I have see a trailer leave a tow vehicle just because they didnt hook it up and clip it down properly so yes while it was on the first bump unhitches it.

[jaffles]

[QUOTE=oldn64;n1075752]

SNIP
We need to become serious about our licensing and actually teach this stuff to people. Get the right education so that people who want to tow can back and know how to hook up etc etc.
SNIP
[/QUOTE

I'd vote for across the board.

You can get a truck licence easy enough without any weight in it at all. Put a load on however and its a completely different beast. Be good if cars understood that as I'm sure anyone who tows knows. Brakes only do so much. Then if you add rain it starts to get very real pretty quickly.

I was once a boy wonder on a two stroke 250 roadbike, probably an advanced riding course saved my life until the sense to get off the dam thing matured.

Specific training for any thing that uses the road is not a bad idea.

[pharb]

[QUOTE=jaffles;n1075758]

SNIP
We need to become serious about our licensing and actually teach this stuff to people. Get the right education so that people who want to tow can back and know how to hook up etc etc.
SNIP
[/QUOTE

I'd vote for across the board.

You can get a truck licence easy enough without any weight in it at all. Put a load on however and its a completely different beast. Be good if cars understood that as I'm sure anyone who tows knows. Brakes only do so much. Then if you add rain it starts to get very real pretty quickly.

I was once a boy wonder on a two stroke 250 roadbike, probably an advanced riding course saved my life until the sense to get off the dam thing matured.

Specific training for any thing that uses the road is not a bad idea.

Heavy vehicles have to be loaded to minimum of 80% of their legal capacity when undertaking certified training and testing.

[jaffles]

In sunny ol Qld, the yearly certificate of inspection is unladen. To get a bodied truck licence is unladed. To up grade to a semi or b double is also unladen.

Specialist advanced training may be 80% loaded ?, but that would be voluntary with no legal requirement at all.

The brake bias also makes a huge difference on how they behave. Full-empty, Wet-dry. Cant adjust it on the fly however, well not in mine anyway.

[pharb]

In sunny ol Qld, the yearly certificate of inspection is unladen. To get a bodied truck licence is unladed. To up grade to a semi or b double is also unladen.

Specialist advanced training may be 80% loaded ?, but that would be voluntary with no legal requirement at all.

The brake bias also makes a huge difference on how they behave. Full-empty, Wet-dry. Cant adjust it on the fly however, well not in mine anyway.

What do you mean by yearly certificate of inspection ? Roadworthy? Yes, all roadworthies unladen.

All NSW heavy vehicles for licence testing have to be laden. I thought 80%, but this says 75%
https://www.rms.nsw.gov.au/business-...nce/index.html

Maybe my mind was thinking 80% because the trainers we use (Victoria) use 80% to keep a good margin above the 75%.

Maybe Qld are unladen

Brake bias has not been adjustable since the '80s. Haven't seen one of these since I was an apprentice
https://www.ebay.com.au/itm/PBR-STYL...-/143150215564

[jaffles]

yeh COI Certificate of Inspection. Its a yearly roadworthy to check brakes, suspension bushes, tyres, lights, indicators etc while looking for mechanical faults. My understanding its a National thing under the National Heavy Vehicle Register NHVR.

Doesn't surprise me it falls apart from there with the States. But I can guarantee you its all unladed in Qld. Which is dumb.

Just how dumb or free market forces is in one perception. My staff member and I are from residential construction. We both got a bodied truck licences (cement mixer size) and I moved into transport. That simple.

The next week I flew to Tasmania and drove a truck home to Qld. I can tell you parking it on the Spirit of Tasmania and through Melbourne traffic was a growing moment. Unladen the brakes work but are way overpowered in the wet. It rails around corners as the suspension is rock hard. However put 22.5T on and it and its a different beast that doesn't like direction change,. Brakes are good but like all drum brakes you only get so much before there gone. So you learn quickly to drive it slow with plenty of room. Learn not to get phased by traffic and what happens in front of you. Its like breathing, all part of the day.

Still think I will find and fork out for some advanced training. Imagine when the semi starts to slide cause the traffic of the highway jumps of the red for no reason, I'd like to have more of an idea of what to do with 42T than what I have.

Gets back to driver training for towing. Horses, caravans, cars you name it. Mine is just a lot bigger.

[Jasonmc73]

Still think I will find and fork out for some advanced training. Imagine when the semi starts to slide cause the traffic of the highway jumps of the red for no reason, I'd like to have more of an idea of what to do with 42T than what I have.

You may live longer than some Jaffles , sounds like you don't let your agility get carried away with your ability

[jaffles]

mate I'm not a smart man, but I enjoy getting old. By nature I'm pretty loose and thoughts are few.

But I'm open the what contributors on places like here have to say. If I can use their experiences and knowledge to be better mine than it works for me. Its often said you lean from your mistakes, but I'd rather learn from others.