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Post Info TOPIC: WDH


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RE: WDH
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Peter_n_Margaret wrote:

Towing is not a static state and the forces involved can become very much larger when mobile, especially over undulating ground. Add to that, some vehicles have much less strength in the rear end than others which explains why some have much lower tow capacities and much lower ball weights than you would expect and some will not allow the use of a WDH.
Sometimes the weak link is the tow bar but more often I suggest the weak link is the structural strength of what it is attached to.
Exceed the specified limits at your peril.

ps... the design load capabilities for the approval of tow bars are:
Longitudinal (push and pull force) 1.5 x the rated tow capacity (= 5.25T for 3.5T tow capacity).
Vertical (up and down) and transverse (side to side) is half of the rated tow capacity (= 1.75T for 3.5T tow capacity).
Cheers,
Peter


 Thanks Peter, for providing these details and confirming my thoughts.

Instead of using a WDH in an effort to make a car do things for which it never was designed, surely it would be better, and safer, to purchase a more-suitable vehicle or a smaller van. Simple stuff. Cheers



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As we should know, there are many maximum ratings for various loadings for a car and trailer ie just a few- maximum towing weight, maximum tow ball weight, maximum tow bar weight and so on.

If WDH users load their vehicles and trailers so that none of the vehicle, trailer, tow ball, tow bar, axle loadings etc exceed the maximum rating of those items, I do not think those WDH users are doing anything with their vehicles beyond what the designers of the vehicle and trailer should have allowed in their design and build. Sure, some of those maximum ratings may mean a lower limitation on the allowable practical tow load for a pig trailer, rather than a maximum load allowable for a dog trailer. But that does not mean the vehicle is expected to be used beyond its design capability.

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Thanks for the positive feedback and to KJB as well.

yobarr wrote:
... undoubtedly there still will be a couple of members who refuse to learn.

Are you talking about members on this thread? I don't think there are. There are members who misunderstand others' posts. The fact you seem to think others are wrong puts you in this category.

Again, I ask does anyone think what I have posted is wrong?

Of course the inner workings and benefits are much in dispute, but I have flogged enough dead horses for now.

 

 



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yobarr wrote:
Brenda and Alan wrote:

The weight of the car is the issue to me as Yobarr thinks the car exerts less force downwards and conversely the van exerts more downwards when WDH is tensioned. This is the only was he can rationalise his belief that towball weight remains unchanged

You ask where this reduction in weight goes to look at the vans wheels for your answer.

Alan

----------------------------------------------------------------------------

Oh Deary me, talk about being  persistent, but wrong!

On the contrary, Yobarr does not THINK that the car exerts less force downwards, he KNOWS.

---------------------------------------------------------------------------------------------------------------------------------------------       

Yobarr 

What you are in fact saying is Newton is wrong. Now who shall I believe.



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If I was to sit a known weight (mass) on my kitchen scales and take note of the measurement, then start attaching helium balloons to the item, what would happen to the measurement?

I believe it would reduce (but the original mass is unchanged), eventually if enough balloons are attached the item would float off into LaLa Land where it may come to the attention of some of our members.

The balloons are adding a Force that opposes Gravity, reducing the apparent weight, but not changing the mass.

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BarneyBDB wrote:

If I was to sit a known weight (mass) on my kitchen scales and take note of the measurement, then start attaching helium balloons to the item, what would happen to the measurement?

I believe it would reduce (but the original mass is unchanged), eventually if enough balloons are attached the item would float off into LaLa Land where it may come to the attention of some of our members.

The balloons are adding a Force that opposes Gravity, reducing the apparent weight, but not changing the mass.


 This is just another red herring brought into this discussion.

Are there any hydrogen balloons attached to a car and caravan on a weigh bridge. No

The system of a car and caravan sitting on aweigh bridge is a closed system with no external influences. That is to say the total weight of the system remains the same.

Alan



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Brenda and Alan wrote:
The system of a car and caravan sitting on aweigh bridge is a closed system with no external influences. That is to say the total weight of the system remains the same.

                   Alan


 Although a while back I lost all interest in talking to a brick wall, and consequently have not read every post thoroughly, I do not recall ever seeing it  claimed that the total weight does not stay the same? Spare me.

Talk about stating the obvious.

Can we expect another brainstorm? Cheers



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Brenda and Alan wrote:
yobarr wrote:
Brenda and Alan wrote:

The weight of the car is the issue to me as Yobarr thinks the car exerts less force downwards and conversely the van exerts more downwards when WDH is tensioned. This is the only was he can rationalise his belief that towball weight remains unchanged

You ask where this reduction in weight goes to look at the vans wheels for your answer.

Alan

----------------------------------------------------------------------------

Oh Deary me, talk about being  persistent, but wrong!

On the contrary, Yobarr does not THINK that the car exerts less force downwards, he KNOWS.

---------------------------------------------------------------------------------------------------------------------------------------------       

Yobarr 

What you are in fact saying is Newton is wrong. Now who shall I believe.


 Alan, each day I grow more sure that you're simply being mischievous and stirring us up for your own amusement.

Instead of waffling-on, and confusing learners, why do you not carry-out the weighing exercise that I have many times outlined, and which Stephen drew diagrams of, to show how the a WDH works.

This will show you that you're being nonsensical, and may save us from having to endure more nonsense. Cheers.



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yobarr wrote:
Brenda and Alan wrote:
yobarr wrote:
Brenda and Alan wrote:

The weight of the car is the issue to me as Yobarr thinks the car exerts less force downwards and conversely the van exerts more downwards when WDH is tensioned. This is the only was he can rationalise his belief that towball weight remains unchanged

You ask where this reduction in weight goes to look at the vans wheels for your answer.

Alan

----------------------------------------------------------------------------

Oh Deary me, talk about being  persistent, but wrong!

On the contrary, Yobarr does not THINK that the car exerts less force downwards, he KNOWS.

---------------------------------------------------------------------------------------------------------------------------------------------       

Yobarr 

What you are in fact saying is Newton is wrong. Now who shall I believe.


 Alan, each day I grow more sure that you're simply being mischievous and stirring us up for your own amusement.

Instead of waffling-on, and confusing learners, why do you not carry-out the weighing exercise that I have many times outlined, and which Stephen drew diagrams of, to show how the a WDH works.

This will show you that you're being nonsensical, and may save us from having to endure more nonsense. Cheers.


 Your weighing exercise is pointless.

In your case you start with the false premise the towball weight does not change and end up with the result that Newtons gravitational equation is wrong.

I on the other hand take Newtons equation to correct and end up with the fact that towball weight is indeed reduced.

As I have asked you before give us your new gravitational equation,  but no one has seen hide nor hair of it.



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Maybe my workings went over the heads of some people, but the workings are senior high school applied maths and physics.

The attachment to my post at 10.29pm 19 January 2024 demonstrates how and some magnitudes of the forces when they occur internally in the system.

Maybe, I should not be surprised at all the posts still continuing.



-- Edited by watsea on Tuesday 30th of January 2024 10:48:33 AM

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Yobarr seems to have dropped out of this discussion, maybe he coudn;t come up with a new gravitational equation.

Two things are certain.

Ron and Watsea have both done similar calculations on the forces generated by a WDH and shown an Upwards force at the towbar equivalent to the increase in axle weight of the van.

Newton isn't wrong. His equations show that the force that a given mass exerts downwards is fixed. This means that the total weight of both car and van can't change. This accords with the findings that Ron and Watsea have shown. The reduction in towball download on car shows up as an increase in van axle weight thereby maintaining the total weight of the van.

If anybody has problems with this please give your reasoning And mathematics to justify tour caim

Alan

 



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Brenda and Alan wrote:

Yobarr seems to have dropped out of this discussion, maybe he coudn;t come up with a new gravitational equation.

Two things are certain.

Ron and Watsea have both done similar calculations on the forces generated by a WDH and shown an Upwards force at the towbar equivalent to the increase in axle weight of the van.

Newton isn't wrong. His equations show that the force that a given mass exerts downwards is fixed. This means that the total weight of both car and van can't change. This accords with the findings that Ron and Watsea have shown. The reduction in towball download on car shows up as an increase in van axle weight thereby maintaining the total weight of the van.

If anybody has problems with this please give your reasoning And mathematics to justify tour caim

Alan


 Alan, the only thing I've given up on is talking to a brickwall. Visit a weighbridge and conduct the tests I've many times outlined.

Otherwise, continue enjoying your time in LaLa Land. Cheers



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I have not posted on this forum for some time but I see you guys are still "debating" this topic which has been beaten to death on this and other forums.

A Weight Distribution Hitch does exactly that......it distributes the weight on the tug rear axle from the downward force on the towball that is applied.

It is distributed to the front axle and a small percentage to the van axles.

The downward force on the towball does not change.

 



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montie wrote:

I have not posted on this forum for some time but I see you guys are still "debating" this topic which has been beaten to death on this and other forums.

A Weight Distribution Hitch does exactly that......it distributes the weight on the tug rear axle from the downward force on the towball that is applied.

It is distributed to the front axle and a small percentage to the van axles.

The downward force on the towball does not change.


 Hi Monty, wondered what had happened to you! 

Alan persists with his mis-guided waffle, which doesn't particularly bother me as everybody is entitked to an opinion.

However, I do despair that newbies, and others, may take his "advice" on board, to their detriment. Cheers



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I am not sure if people noticed or not, but I can point out that in my workings of 18 January 2024, because the tension chains are further out from the towball, more torque and uplift is given to the rear of the vehicle than a simple reduction in weight to the hitch.
In fact, for the loads and dimensions in my example, the change in rear axle load is about 2.1 times higher in magnitude than a simple transfer of weight from the tow hitch.
That is:
In my example 50kg was distributed to the van axle by the WDH, and the change in rear axle load is 154kg.
If a simple 50kg reduction in tow hitch load occurred, then the rear axle load reduction is 72.7kg.
So clearly, the torque applied by WDH provides a greater distribution of the loads than simple repositioning of loads.



-- Edited by watsea on Sunday 4th of February 2024 10:20:10 PM

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Brenda and Alan wrote:

Yobarr seems to have dropped out of this discussion, maybe he coudn;t come up with a new gravitational equation.

Two things are certain.

Ron and Watsea have both done similar calculations on the forces generated by a WDH and shown an Upwards force at the towbar equivalent to the increase in axle weight of the van.

Newton isn't wrong.. His equations show that the force that a given mass exerts downwards is fixed. This means that the total weight of both car and van can't change. This accords with the findings that Ron and Watsea have shown. The reduction in towball download on car shows up as an increase in van axle weight thereby maintaining the total weight of the van.

If anybody has problems with this please give your reasoning And mathematics to justify tour caim

Alan


 Alan, as always I had decided to treat your "advice" with the contempt, in my opinion, it so richly deserves, but a communication from another GN member prompted me to respond.

This member asked me did I know what sort of caravan Newton owned, but I don't really know. . Can you help? 



-- Edited by yobarr on Sunday 4th of February 2024 10:57:32 PM

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watsea wrote:

I am not sure if people noticed or not, but I can point out that in my workings of 18 January 2024, because the tension chains are further out from the towball, more torque and uplift is given to the rear of the vehicle than a simple reduction in weight to the hitch.
In fact, for the loads and dimensions in my example, the change in rear axle load is about 2.1 times higher in magnitude than a simple transfer of weight from the tow hitch.
That is:
In my example 50kg was distributed to the van axle by the WDH, and the change in rear axle load is 154kg.
If a simple 50kg reduction in tow hitch load occurred, then the rear axle load reduction is 72.7kg.
So clearly, the torque applied by WDH provides a greater distribution of the loads than simple repositioning of loads.


For clarity, here is that sheet of workings. I rotated it vertical and increased the contrast for easier reading.

Watsea.jpg

But I don't think many on here will want to get into the detail of the calculations.

 



Attachments
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OMG!!!!

Much easier to refer to the Hayman Reece website where it is clarified.
From a practical perspective it's useless information anyway. It can't be measured, can only be calculated.

FYI the measured ball weight at the coupling of the unhitched loaded van must not exceed the lesser of the following:

1) The tug's rating

2) The van's rating (if it has one)

3) The towbar manufacturer's rating.

That is the legal requirement........and it doesn't change with the fitment of a WDH.

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yobarr wrote:


 Alan, as always I had decided to treat your "advice" with the contempt, in my opinion, it so richly deserves, but a communication from another GN member prompted me to respond.

This member asked me did I know what sort of caravan Newton owned, but I don't really know. . Can you help? 

----------------------------------------------------------------------------------------------------------------------------------------------------------------
Again waffle that does not address the issue of you saying Newton is wrong. Why do you think owning a caravan is relevant to the law of universal gravitation. Try actually reading and digesting my posts .

 



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montie wrote:

OMG!!!!

Much easier to refer to the Hayman Reece website where it is clarified.
From a practical perspective it's useless information anyway. It can't be measured, can only be calculated.

FYI the measured ball weight at the coupling of the unhitched loaded van must not exceed the lesser of the following:

1) The tug's rating

2) The van's rating (if it has one)

3) The towbar manufacturer's rating.

That is the legal requirement........and it doesn't change with the fitment of a WDH.


 The legal requirement is to assess the towball load in the condition in which the van is towed

Cars hitched weight minus cars unhitched weight gives the towball load .

Alan



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Brenda and Alan wrote:
montie wrote:

OMG!!!!

Much easier to refer to the Hayman Reece website where it is clarified.
From a practical perspective it's useless information anyway. It can't be measured, can only be calculated.

FYI the measured ball weight at the coupling of the unhitched loaded van must not exceed the lesser of the following:

1) The tug's rating

2) The van's rating (if it has one)

3) The towbar manufacturer's rating.

That is the legal requirement........and it doesn't change with the fitment of a WDH.


 The legal requirement is to assess the towball load in the condition in which the van is towed

Cars hitched weight minus cars unhitched weight gives the towball load .

Alan


 Alan,

As I previously stated you cannot measure the ball weight of a hitched van you can only calculate it as you did.

This can be verified by measuring the downward force at the coupling by unhitching the van.

Unless there has been a recent change in the regulations the "measured" weight is the standard required. 

 

 



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Brenda and Alan wrote:
yobarr wrote:


 Alan, as always I had decided to treat your "advice" with the contempt, in my opinion, it so richly deserves, but a communication from another GN member prompted me to respond.

This member asked me did I know what sort of caravan Newton owned, but I don't really know. . Can you help? 

----------------------------------------------------------------------------------------------------------------------------------------------------------------
Again waffle that does not address the issue of you saying Newton is wrong. Why do you think owning a caravan is relevant to the law of universal gravitation. Try actually reading and digesting my posts .


1) "Waffle" Learned a new word have you, Alan?

2) You obviously missed the fact that my tongue-in-cheek question about what caravan Newton owned was originally put to me in private communication from another well-respected GN member.

3) Rather than your posts being hard to "digest",  I find that those posts have an entirely different effect on my digestive system.



-- Edited by yobarr on Monday 5th of February 2024 08:57:05 PM

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yobarr wrote:
Brenda and Alan wrote:
yobarr wrote:


 .


1) "Waffle" Learned a new word have you, Alan?

2) You obviously missed the fact that my tongue-in-cheek question about what caravan Newton owned was originally put to me in private communication from another well-respected GN member.

3) Rather than your posts being hard to "digest",  I find that those posts have an entirely different effect on my digestive system.



-- Edited by yobarr on Monday 5th of February 2024 08:57:05 PM


 1. Waffle is what you do when you can't address a question. It is impossible for the car to weigh less than it's mass dictates.

2. You posted it. not the other person so you must have thought it relevant. It isn't.

3 If you took the information from my posts you might understand that the overall weight of a car or caravan can't change because their mass does not change.

Alan



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the gross weight of the car + van combined (as a unit) does not change, the distribution of weight on the cars AXLES does as the weight is distributed to van axle(s) and the front axle of car, as per earlier weight bridge example the more pressure on WDH the less weight on bridge with car only on bridge the car may weight the same but it exerts less downward force on weight bridge as weight is move to van (not on bridge)

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dogbox wrote:

the gross weight of the car + van combined (as a unit) does not change, the distribution of weight on the cars AXLES does as the weight is distributed to van axle(s) and the front axle of car, as per earlier weight bridge example the more pressure on WDH the less weight on bridge with car only on bridge the car may weight the same but it exerts less downward force on weight bridge as weight is move to van (not on bridge)


 That's how a WDH works.....distributes the downward force applied to the towball. and subsequently applied to the rear axle.

The weight is distributed to the tug front axle and a small percentage to the van axles from the tug's rear axle.

The downward force applied to the towbar does not change. There also seems to be confusion amongst some posters as to how actual ball weight is determined. It can't be guessed, assessed, estimated or otherwise, it has to be weighed at the coupling with the van unhitched.

Weighing the tug hitched and unhitched give a good estimate but the nice enforcement officer will probably want to use his calibrated ball weight scales.  Both dealers and manufacturers all use a calibrated ball weight scales.  

 



-- Edited by montie on Tuesday 6th of February 2024 02:47:45 PM

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dogbox wrote:

the gross weight of the car + van combined (as a unit) does not change, the distribution of weight on the cars AXLES does as the weight is distributed to van axle(s) and the front axle of car, as per earlier weight bridge example the more pressure on WDH the less weight on bridge with car only on bridge the car may weight the same but it exerts less downward force on weight bridge as weight is move to van (not on bridge)


 The car weighs exactly the same (re Newton), what is changing is the force applied by the caravan towbar.

Weigh bridges work because Newtons law holds true. A mass of say 3000 Kg weighs precisely 3000 Kg Wt. This applies to all spring and load cell scales. Beam balances do direct comparison of two masses. If as Yobarr claims the car becomes lighter then the whole basis for these scales  is Kaput.

Alan



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montie wrote:

.

Weighing the tug hitched and unhitched give a good estimate but the nice enforcement officer will probably want to use his calibrated ball weight scales.  Both dealers and manufacturers all use a calibrated ball weight scales.  

 



-- Edited by montie on Tuesday 6th of February 2024 02:47:45 PM


 The scallies would certainly not use ball weight scales. They would use a certified set of pad scales or a certified weighbridge. Ball weight scales are notorious for inaccuracy and repeatability.

Refer to my post to dogbox re how weigh bridges work.

Alan



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Brenda and Alan wrote:
montie wrote:

.

Weighing the tug hitched and unhitched give a good estimate but the nice enforcement officer will probably want to use his calibrated ball weight scales.  Both dealers and manufacturers all use a calibrated ball weight scales.  


 The scallies would certainly not use ball weight scales. They would use a certified set of pad scales or a certified weighbridge. Ball weight scales are notorious for inaccuracy and repeatability.

Refer to my post to dogbox re how weigh bridges work.

Alan


For heaven's sake Alan, when people discuss weights they generally are referring to the weight applied through the wheels of a vehicle to the ground, not "mass" or "force" or any other  term that you may choose to use to make yourself appear to be knowledgeable. You're not.

When we are discussing WDHs there is NO disputing or denying that the total weight applied to the ground through the wheels of the car is reduced when a WDH is tensioned, and at the same time the total weight applied to the ground through the wheels of the van is increased. Nobody is interested in "mass" or "force" or whatever. They're just caravanners trying to understand their weights.

This all is simple stuff but in an effort to appear to be knowledgeable you persist with your rubbish-talk that causes only confusion for those among us who simply are trying to learn.

 

 



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i think he is laughing at us!

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dogbox wrote:

i think he is laughing at us!


 Presumably you're referring to Alan? If so, I agree completely, and several times I have suggested that he is simply being mischievous for his own amusement. I can't understand how someone can see fit to unnecessarily complicate something that is so simple.

A WDH DOES NOT CHANGE TOWBALL WEIGHT.     Never has.    Never will. Cheers



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