Payload, who cares?

[Tracker]

There you go again Henry - always so dogmatic!!

 

I make it 645.3 kg + or - 2.10 kg!!

 

But I could be wrong??

[rupert123]

Tracker - 2012-11-25 6:33 PM

 

There you go again Henry - always so dogmatic!!

 

I make it 645.3 kg + or - 2.10 kg!!

 

But I could be wrong??

 

Ah, forgot the + or - bit, sorry about that

[Colin Leake]

pelmetman - 2012-11-23 8:11 PM

 

Tracker - 2012-11-23 8:09 PM

 

I thought a bag of cement was 25kg?

 

Well it was the last time I carried 4 of 'em out to my car!!

 

I thought they'd been reduced to 21 kg for elf & safety reasons :-S

 

Truth is the more you mix the heavier each one gets. I should know I've been mixing up enough lately. Unfortunately I've used all the bags up now and never thought to look at the weight but now you come to mention it I do seem to recollect that they seemed lighter than they used to be when loading them into the back of the car.

[crinklystarfish]

rupert123 - 2012-11-25 3:15 PM

crinklystarfish - 2012-11-24 7:01 PMOK dude, you repeatedly say a 100kg increase in mass over an arbitrary 3.500kg legal threshold makes no difference. You don't offer any explanation or evidence, so I assume it's just something you think sounds about right.

But you also acknowledge a 1000kg increase would make a difference.

At what exact point does extra weight over the plated limit of your average 3,500kg 'van actually become a problem then, and why?

654.3 kgs.

I take it you have nothing to back up your '100kg makes no difference' argument then, and that it is just based on pure conjecture pulled out of the air after a session in a pub.

[Mel B]

crinklystarfish - 2012-11-26 9:31 AM

rupert123 - 2012-11-25 3:15 PM

crinklystarfish - 2012-11-24 7:01 PMOK dude, you repeatedly say a 100kg increase in mass over an arbitrary 3.500kg legal threshold makes no difference. You don't offer any explanation or evidence, so I assume it's just something you think sounds about right.

But you also acknowledge a 1000kg increase would make a difference.

At what exact point does extra weight over the plated limit of your average 3,500kg 'van actually become a problem then, and why?

654.3 kgs.

I take it you have nothing to back up your '100kg makes no difference' argument then, and that it is just based on pure conjecture pulled out of the air after a session in a pub.

Crinkly ... that is a real insult to Rupert and I think you ought to apologies forthwith for that slanderous comment ... saying that he'd had a session in a pub ... 8-) you should of course have said the CLUB dear boy, the CLUB!!! :D

[Guest pelmetman]

To be honest as someone who once drove a bus and who's load was in a state constant flux ;-).............Sorry Crinkly I think your 100 kg is a bit of a red herring :D

 

Why?............well most campervanist's have their vehicle fully loaded most of the time.......so they are well use'd to the vehicles characteristic's ;-)...........indeed even loaded with the extra plonk when they head home is unlikely to make much difference to the handling...........I would even go so far as to suggest that snow and ice are far more dangerous than being a 100 kg overweight 8-).....

 

I suspect your average motorhome'ist would have enough experience, to be able to modify his driving for a slightly overloaded vehicle :D

 

 

[Tracker]

pelmetman - 2012-11-26 5:18 PM

 

To be honest as someone who once drove a bus and who's load was in a state constant flux ;-).............Sorry Crinkly I think your 100 kg is a bit of a red herring :D

 

 

Waddyamean -USED to drive a bus!!

[crinklystarfish]

Mel B - 2012-11-26 4:57 PM ...Crinkly ... that is a real insult to Rupert and I think you ought to apologies forthwith for that slanderous comment ... saying that he'd had a session in a pub ... 8-) you should of course have said the CLUB dear boy, the CLUB!!! :D

Pub, Club, Dubstep Bar, who knows?

What is clear is there isn't enough time left before the big-squeeze (or big-rip), to persuade Mr 123 / Mr Man.

If, in future, they argue that black is white, for the sole purpose of not wasting any more life, I will graciously accept that they earnestly believe that black is indeed white.

[Guest pelmetman]

Miss read post :$..................I blame the drink *-)..................I should drink more before I post :D

[rupert123]

crinklystarfish - 2012-11-26 5:49 PM

Mel B - 2012-11-26 4:57 PM ...Crinkly ... that is a real insult to Rupert and I think you ought to apologies forthwith for that slanderous comment ... saying that he'd had a session in a pub ... 8-) you should of course have said the CLUB dear boy, the CLUB!!! :D

Pub, Club, Dubstep Bar, who knows?

What is clear is there isn't enough time left before the big-squeeze (or big-rip), to persuade Mr 123 / Mr Man.

If, in future, they argue that black is white, for the sole purpose of not wasting any more life, I will graciously accept that they earnestly believe that black is indeed white.

Not just me you need to persuade mr crinklecut, plenty of others agree that 100kg will make no differance at all. Now I understand that with your truck, which looks really top heavy, a 100kg stored high up may tip the whole thing over. Just buy a proper van and you will no longer have to worry about it.

[crinklystarfish]

With my water and fuel tanks full, and all the clobber we take with us, I still have a theoretical spare payload of 3,800kg so to be fair, if anyone should be in a position to argue that 100kg makes no difference, I'd be a good candidate. 

But it does. I accept you will never see that and hope you are never in a position where you prove yourself wrong.

[Mel B]

pelmetman - 2012-11-26 5:18 PM

 

To be honest as someone who once drove a bus and who's load was in a state constant flux ;-).............Sorry Crinkly I think your 100 kg is a bit of a red herring :D

 

Why?............well most campervanist's have their vehicle fully loaded most of the time.......so they are well use'd to the vehicles characteristic's ;-)...........indeed even loaded with the extra plonk when they head home is unlikely to make much difference to the handling...........I would even go so far as to suggest that snow and ice are far more dangerous than being a 100 kg overweight 8-).....

 

I suspect your average motorhome'ist would have enough experience, to be able to modify his driving for a slightly overloaded vehicle :D

 

 

Sorry Dave, but I disagree. We could feel quite a difference in handling when we'd come home from abroad in our Flash 04 with our booze etc on board - I hasten to add that we were no where near the 3500kg limit of the vehicle as it had a 700+kg payload less the weight of our chattels and extras fitted such as awning, bike rack and spare wheel, but still left a very healthy unused allowance. The stuff wouldn't have added more than 70kg which included some wine, beer, soft 'syrup' drinks (I love the lemon one) and of course my de-mineralised water too) and it was well distributed to prevent all the weight being in the garage, but it certainly was very noticeable even though it wasn't overloaded and we had air assistance suspension on the rear. What it would have been like if we had overloaded it I hate to think! *-)

[Guest pelmetman]

Mel B - 2012-11-28 12:13 AM

 

pelmetman - 2012-11-26 5:18 PM

 

To be honest as someone who once drove a bus and who's load was in a state constant flux ;-).............Sorry Crinkly I think your 100 kg is a bit of a red herring :D

 

Why?............well most campervanist's have their vehicle fully loaded most of the time.......so they are well use'd to the vehicles characteristic's ;-)...........indeed even loaded with the extra plonk when they head home is unlikely to make much difference to the handling...........I would even go so far as to suggest that snow and ice are far more dangerous than being a 100 kg overweight 8-).....

 

I suspect your average motorhome'ist would have enough experience, to be able to modify his driving for a slightly overloaded vehicle :D

 

 

Sorry Dave, but I disagree. We could feel quite a difference in handling when we'd come home from abroad in our Flash 04 with our booze etc on board - I hasten to add that we were no where near the 3500kg limit of the vehicle as it had a 700+kg payload less the weight of our chattels and extras fitted such as awning, bike rack and spare wheel, but still left a very healthy unused allowance. The stuff wouldn't have added more than 70kg which included some wine, beer, soft 'syrup' drinks (I love the lemon one) and of course my de-mineralised water too) and it was well distributed to prevent all the weight being in the garage, but it certainly was very noticeable even though it wasn't overloaded and we had air assistance suspension on the rear. What it would have been like if we had overloaded it I hate to think! *-)

 

If your well within your payload I'd be surprised if it was in anyway dangerous ;-)........... I suspect you altered your driving accordingly, just as you would if you were driving through fog or ice?.................As any experienced driver would do ;-)....................so where's the danger? :-S

[Tracker]

I think the point the pedants are trying to make is that every 100 kg will make a difference to handling and braking.

 

That difference may not always be measurable but it will be there as the laws of physics and inertia cannot be denied.

 

The point about whether or not that difference can be deemed dangerous - or even consistently measurable - is hypothetical and always will be because it depends on so may other variables like speed, weather, surface type, driver ability, drive visibility.

 

I too can feel the difference between an empty van and a fully loaded van, particularly going uphill, and if it has an effect on pulling power it must obviously have an effect on handling and braking.

 

That said, I do have to say that I have not noticed 100 kg of load make any perceivable difference at all to hill climbing, handling or braking

 

So if the advocates of losing the extra 100 kg would like to lead by example and reduce their own van weights by 100 kg and let us all know the benefits they derive it might, or might not, provide an incentive for a few others to follow suit!

[Brian Kirby]

Driving in itself is relatively dangerous. That is the main reason why the inexperienced, sadly for them and their insurance premiums, have more accidents than the experienced. One has to learn to drive within one's own capabilities, and those of one's vehicle.

 

I would submit that it is perfectly possible, with care, for an experienced driver to drive a grossly overloaded vehicle with reasonable safety on level ground (though descending hills would be unwise to suicidal! :-)) but that would not make his action legal.

 

The point in relation to payloads, surely, is not danger, or risk, but legality. The obvious reason for establishing a legal limit to what a vehicle can carry, is that its design imposes limitations beyond which it becomes, by degrees, dangerous to drive. So, to protect the inexperienced from themselves, and to protect the rest of us from the foolish, the ignorant, or the over-confident, a legal limit is imposed. Break the limit and one breaks the law so, if one is caught, some form of retribution must be expected.

 

This is presumably the reason that driving licenses are also limited as to what it is permissible to drive. We have learnt that driving heavy vehicles requires more training, and greater experience, than driving light vehicles, so we set aside a licence category for driving such vehicles. The basis for the differing licence categories is experiential, but to keep the categories simple, the steps are relatively crude and abrupt.

 

So, back to legality. It is as illegal for a driver licensed to drive vehicles up to 3,500kg, to drive an empty vehicle plated at 4,000kg, even if it weighs than 3,500kg at the time, as it is for a vehicle plated at 3,500kg to be loaded to 4,000kg, whatever licence the eventual driver holds. Safety is not the issue here: only legality. If you break the law, you may not cause actual danger, but you are acting illegally.

 

For instance, driving a vehicle down plated to 3,500kg from 4,000kg, at an actual weight of 3,750kg is still well within its design parameters, so can be considered "safe", but it is definitely illegal.

 

So, arguing over whether 100kg does, or does not, make a difference, and whether or not that difference actually diminishes safety, seems to me wholly irrelevant to both cases. It is the driver's legal obligation to ensure that any vehicle they are driving is loaded within it's legal limits. If they don't, they risk fine or prosecution. They may also be driving a vehicle that is relatively dangerous. Two separate, unrelated, risks. It is the driver who decides whether to take them, and their consequences, or not.

[tonyishuk]

 

 

The only thing I can add to the thread, having lost interest after page three and after seeing this thread running for so long, has any one put into the mix ??

 

I have shifted my 100kg into a 750 kg non braked trailer, along with about another 350 kg will make no difference to my braking nor will my braked trailer of 2000 kg 'cause it has its own brakes.

 

 

or am I :D ing ?

 

Rgds

[Brian Kirby]

tonyishuk - 2012-11-28 7:46 PM

 

 

 

The only thing I can add to the thread, having lost interest after page three and after seeing this thread running for so long, has any one put into the mix ??

 

I have shifted my 100kg into a 750 kg non braked trailer, along with about another 350 kg will make no difference to my braking nor will my braked trailer of 2000 kg 'cause it has its own brakes.

 

or am I :D ing ?

 

Rgds

Interesting question, that provoked a bit of research. First, I'm going to re-state the questions, Tony, to try to get greater clarity.

 

If I tow an unbraked trailer (max MAM 750kg) laden to 350kg, will adding a further 100kg increase my stopping distance?

 

Answer: yes. Because the load is added to the trailer, and not to the tow vehicle, the tyres cannot adapt as below to additional load, so will have a reduced contact patch relative to the total mass they are required to stop. So, the tyres are unable to develop their maximum potential efficiency for the prevailing road conditions, your stopping distance increases, and you hit the car in front! :-(

 

If instead, you add the 100kg to the tow vehicle, rather than to the trailer, the answer should be no, and you should not hit the car in front. :-) The exception would be if the tow vehicle was already overloaded. Generally, adding mass to a vehicle will increase the contact patch between tyre and ground. So, (sort of! :-)) more weight = bigger tyre footprint = greater friction = the same stopping distance. However, this increase in the size of the contact patch with mass is not linear: it begins to diminish once the tyre passes its design threshold. So, if the vehicle is overloaded, it is probable the tyres would also be overloaded, and the contact patch would not respond optimally. Therefore, it is probable your stopping distance would increase - and you would still hit the car in front. :-(

 

If I tow a braked trailer weighing two tonnes, will this increase my stopping distance?

 

Answer: yes. This is because the trailer brakes (assuming a normal "single axle" trailer) work only on the over-run principle. When the tow vehicle brakes, the trailer, in effect, tries to catch it up. In so doing, it operates the mechanism that applies its own brakes. However, its brakes only operate for so long as the tow vehicle continues to decelerate. To maintain braking, therefore, the trailer must continually "push" at the tow vehicle. However, as above, the tow vehicle's tyres gain virtually no added load from the trailer, so their contact patch does cannot grow proportionately to the total mass to be stopped, meaning the tyres cannot develop their optimum performance for the prevailing road conditions, and you again hit the car in front. :-(

 

In short, there is no free lunch! :-D

[BGD]

Brian - just a thought, but I don't see any mention of Inertia in your analysis.

 

 

 

Sure, the additional weight will be affected by gravity, and thus will have some (very small, but some) effect on tyre contact patch.

 

But I'd have thought that, at any sort of decent speed, the effect of any addition to weight will, upon braking ( and particularly if heavy/emergency braking), have a much greater inertial force than gravitational force..........thus that additional weight is effectively trying to continue forwards at unbraked speed, thus the brakes have to work harder to overcome that load inertia.

 

Imagine a 100kg object moving towards you, on a trolley say, and you have to stop it. Think of the contra-inertial force you have to use in order to do so.

Now imagine the same trolley, but carrying 200kgs, approaching you at the same speed. The force which you have to use in order to stop the forwards movement of that trolley in the same stopping distance are, I would suggest, a lot greater.

 

Thus it seems to me that the increase in inertial force associated with each additional kg of weight added to a wheeled vehicle when braking from speed, is much greater than the additional gravitational force.

 

Thus, all other things being equal, it seems to me that it WILL take a greater distance to stop when 100 kgs is added to the total vehicle train-weight (whether that extra weight is added to the car or the trailer).

 

 

 

 

[Guest 1footinthegrave]

Blimey it's still running........................................................................

 

Definitely too many people walled up with too much time on their hands ( me included )

[Mel B]

BGD - 2012-11-30 5:00 PM

 

Imagine a 100kg object moving towards you, on a trolley say, and you have to stop it. Think of the contra-inertial force you have to use in order to do so.

Now imagine the same trolley, but carrying 200kgs, approaching you at the same speed. The force which you have to use in order to stop the forwards movement of that trolley in the same stopping distance are, I would suggest, a lot greater.

 

Wrong Bruce! 8-) I have done a massive jump to get out of the way before the thing got near me ! :D

[Brian Kirby]

BGD - 2012-11-30 5:00 PM

 

Brian - just a thought, but I don't see any mention of Inertia in your analysis.

...................................

All I can say in response Bruce, is that what I wrote was an unscientific precis of what seemed the accepted theory of how it works. Under ideal conditions, the apparently accpted theory says that the additional downforce on each tyre, coupled with its increased footprint, generates sufficient friction with the ground to counter the added inertia of the moving mass. So, given no overload, the same vehicle, on the same tyres, with the same brakes, on the same road, under the same driving conditions, will stop from the same speed, within the same distance, whatever its weight.

 

The further :-) proviso is that the brakes must be capable of stopping the wheels rotating, and must be applied to the point at which the wheels nearly, but not quite, lock. So, ABS, I think!

 

That, of course, discounts the possible effect of any trailer. Interesting, innit! :-)

[Derek Uzzell]

No, BGD is correct - this iwill be immediately evident from the information on this file:

 

http://www.asociacionideatica.com/The%20braking%20effect.pdf

[crinklystarfish]

Brian Kirby - 2012-11-30 10:29 PM... The further :-) proviso is that the brakes must be capable of stopping the wheels rotating, and must be applied to the point at which the wheels nearly, but not quite, lock. So, ABS, I think!That, of course, discounts the possible effect of any trailer. Interesting, innit! :-)

Bang on. Crinkly test-rode his touring pushbike unladen, then toured fully loaded, when fully laden the extra mass easily overcame the ability of the brakes to retard progress and an ignominious meeting with level crossing barriers ensued.

The crucial point in all this though, that many seem wilfully blind to, is driver competence.

Larger / heavier vehicles require higher standards of driving competence, it's why we have LGV test.

Nothing chills me more than a grandfather rights 7.5t truck driver bearing down on me whilst cycling. Some other 'user groups' come close in the fear factor. Motorhome drivers very often demonstrate their lack of awareness of vehicle length / width. The very last thing any sane cyclist would want to see is these vehicles becoming larger / heavier still. 

Quite simply, many motorhome drivers are already in over their head - before they overload their vehicles.

[Tracker]

crinklystarfish - 2012-12-01 10:34 AM

The crucial point in all this though, that many seem wilfully blind to, is driver competence.

many motorhome drivers are already in over their head - before they overload their vehicles.

 

Driver competence and other variables are points that have been well made several times so the many who are wilfully blind do not seem to be on this forum?

 

Can't speak for non forumite motorhome owners though but insurance rates do suggest that overall motorhomes and their drivers present significantly less risk to themselves and to others than many other combinations of driver and vehicle?

 

Which suggests that if that were not so the cost of insuring these very expensive to buy and hideously expensive to repair behemoths would be considerably higher than the relatively modest premiums we all pay when compared to many other classes of driver and vehicle!

[Guest 1footinthegrave]

Give us a break Crinklystarfish, as Tracker say's, Insurers are not stupid and that's reflected in risk and claims, and why those who have grandfather rights enjoy such low premiums, and incidentally all who insure M/homes enjoy significantly lower premiums as a whole.

 

Just for the record I have been in the past both HGV class one, and PSV trained and licensed but oddly NEVER asked by insurers, but I would not set myself up as being a better driver as a result.

 

You'll witness many a HGV driver using the phone whilst belting down a motorway with a 38 tonner, just because they have a license for competence does not mean they are not idiots and downright dangerous, so given the choice a grandfather rights driving his pride and joy or one of them guys I know which I'd sooner have bearing down on me.