MTPLM AND NOSE WEIGHT

[Elwynhorton]

Not sure how to ask this question, so I apologise if it makes no sense.
My query arises as I believe my Spanish caravan has been plated at higher than the axle plate due to a breakdown in communication, at the build stage. That is, they underestimated the impact of the required disability adaptions and by the time the adaptions had been fitted the weight was higher than anticipated, leaving very little payload, based on axle weight, so they just added a bit in the plated weight.
Not wanting to be overweight and in a bid to carry an extra few kilo, I am wondering if there is technically a difference in the caravan weight and the maximum axle load.
The axle is plated at 1350 kilo and vehicle tow ball weight/nose weight is 85 kilo.
Would it be an offence therefore to load the caravan to say 1400 kilo.
The majority of our things will go in the car a Sedona 2.9 CRDi.
Train weight etc is not an issue, as the car is capable of carrying 900 kilo and towing 2000 kilo.
At this stage I do not want to have a higher rated axle fitted. But will consider if it is the only option.
Any advice or comments will be appreciated.

 

[otherclive]

Not sure how to ask this question, so I apologise if it makes no sense.
My query arises as I believe my Spanish caravan has been plated at higher than the axle plate due to a breakdown in communication, at the build stage. That is, they underestimated the impact of the required disability adaptions and by the time the adaptions had been fitted the weight was higher than anticipated, leaving very little payload, based on axle weight, so they just added a bit in the plated weight.
Not wanting to be overweight and in a bid to carry an extra few kilo, I am wondering if there is technically a difference in the caravan weight and the maximum axle load.
The axle is plated at 1350 kilo and vehicle tow ball weight/nose weight is 85 kilo.
Would it be an offence therefore to load the caravan to say 1400 kilo.
The majority of our things will go in the car a Sedona 2.9 CRDi.
Train weight etc is not an issue, as the car is capable of carrying 900 kilo and towing 2000 kilo.
At this stage I do not want to have a higher rated axle fitted. But will consider if it is the only option.
Any advice or comments will be appreciated.

You have asked a question that drew lots of comment on this website forum quite recently and also linked back to a very long thread on Caravan Talk forum.

Whilst your logic is fine regarding the fact that noseweight will offload the weight on the axle whilst being towed. However after reading all of the various posts associated with the threads referred to above I still haven’t decided whether there is a firm legal definition. What I do subscribe to is that the caravan maker is responsible for the whole vehicle design and as such sets the MTPLM. I’ve always taken MTPLM to be the literal meaning of maximum. When I was stopped for a random weight check the caravans overall weight and it’s axle and noseweights were measured along with its tyre load index. The car weights were measured too.
Some U.K. makers wil upgrade the payload after manufacture but never in excess of axle specification.

What I don’t know is how the Spanish authorities view the legislation on caravan weights. Can you not load the car to maximum and keep caravan weight (axle plus noseweight) below axle specified weight? As that would be the crucial safety aspect.

I recently explored having a higher rated axle fitted but Alko would not consider suppling unless Swift formally agreed the change and were to update their records accordingly. Needless to say I decided to fit a straight replacement axle as mine was damaged.

 

[Lutz]

I presume that because the caravan was custom built to your requirements it is relatively new (post-2014?), in which case it was subject to European type approval. That being the case, there must be a statutory plate somewhere (often in the front locker) stating the MTPLM, the max. allowable noseweight and the permitted axle load all on that same plate, What are the figures displayed there?
Whatever that type approval plate shows, these are all absolute limits which must not be exceeded. If the MTPLM is less than the plated max. axle load you should get in touch with the manufacturer and ask whether it is possible to replate the caravan so that the two values are the same. It would be an offence to exceed the plated MTPLM.
If the plated max. axle load, and ultimately the MTPLM, are too low for your requirements, then the only option would be to have a heavier duty axle fitted, but this again would only be possible if the manufacturer has had the caravan with such a heavier duty axle type approved in the first place.

 

[ProfJohnL]

Hello Elwyn,

I spotted your post late last night, but was too tired to answer it. Since then two other well informed contributors have responded and covered most of what I believe the situation would be. Whilst I agree with their answers, I am a little concerned that you didn't give us all the figures for the caravan, for example you did not tell us the plated MTPLM , and I'm not sure where you got your nose load figure from as 85kg . This looks more like the maximum for the car, not the caravan.

Caravans under go a multiple stage manufacturing process, using a combination of stock items like the caravan chassis usually from different supplier, and bespoke parts such as body panels, and decorative parts. The caravan monufacturer is responsible for specifying the final assembly and importantly will decide what the safe working loads for the whole caravan will be. Obviously they have to chose parts from suppliers that will never be over stressed, so it's very common to find a caravan fitted with an axle with a greater load capacity, than the caravans MTPLM. However that does not necessarily mean there is scope for the caravan manufacture to increase the MTPLM, because other components used in the construction may already be at their safe working limits. It's the same principle as the weakest link in a chain.

I did look at another thread of yours about increasing the tyre size, and I assume this is for the same reason.
.
For clarity, you need to be clear about the differences between measured weights and weight or load limits. MTPLM is the maximum permitted weight of the whole caravan. The Nose load figure you told us of 85kg looks like the nose load LIMIT for the car. The limit for most caravan chassis is usually 100kg.

The nose load is only produced by the imbalance of the caravan about its axles, the actual nose load produced on the car is variable and dependant on how you load the caravan. It's therefore only possible for a manufacturer to publish the S value (static vertical nose load limit) which you must not exceed. The driver is responsible for ensuring the vehicle is fully road legal before driving it on the roads, and that includes making sure the nose and permitted axle loads are within their limits and the whole caravan does not exceed it's MTPLM.

As you have not given us all the figures for your caravan, I cannot work out if you have any chance of being road legal,. But what seems to be clear is it would at best be a very narrow set of margins you would need to work with, with the strong possibility the modified caravan might be overweight.

All in all, this looks to be complex matter, which has been brought about by the modifications to make the caravan accessible for a disabled person. If this work was planned and performed by a professional converter, then they should have either advised you about these problems and done all that was necessary to ensure the conversion was both safe and fully compliant with the weights and loads legislation. They should not have produced an illegal trailer, and it's is their responsibility, In the UK such an outcome would have been covered by the Consumer Rights Act or SoGA if before 2015. As the goods are not fit for purpose. However I do not know if Spain has any consumer protection laws

 

[Lutz]

You state that the manufacturer has plated the MTPLM of the caravan greater than the permitted axle load. As both figures must appear on the same type approval plate I fail to understand how this is possible without such an error becoming immediately obvious during type approval.

For this reason it is important to know exactly what the details are that are shown on the statutory plate.

I recently explored having a higher rated axle fitted but Alko would not consider suppling unless Swift formally agreed the change and were to update their records accordingly. Needless to say I decided to fit a straight replacement axle as mine was damaged.

I presume that was the reply you got from AlKo UK. However, AlKo do offer a service to increase the permitted MTPLM and axle loads beyond what the caravan manufacturer allows. It's not cheap, upwards of 1599€ on the Continent for a component exchange (Stage 3) and over 4500€ if replacement of the entire chassis (Stage 4) is involved, but it is technically possible.

This is what they advertise:

 

[ProfJohnL]

You state that the manufacturer has plated the MTPLM of the caravan greater than the permitted axle load. As both figures must appear on the same type approval plate I fail to understand how this is possible without such an error becoming immediately obvious during type approval.

Hello Lutz,

It is possible to have an MTPLM that is greater than the permitted axle load, becasue it is expected that a trailer will have a nose load, and its the combined loads of axle and nose load that summed must be less than the MTPLM.

I'd agree its unusual, but it does fall within the protocols.

 

[Hutch]

This is getting very interesting, Elywn, Originally posted about tyres and quoted this.

Thanks for your reply.
The caravan is a bespoke Spanish import, which the manufacturer has adapted for a wheelchair user, hoist, lift etc. It is plated at 1600kg, the Alko chassis is stamped at 1600kg. But the tyres are rated at 650kg each.
I am assuming the tyres would be fine, before the added weight of the adaptions.
On a weigh bridge it is coming in at 1320kg.
So to be safe I am looking to upgrade to higher load index tyres.
I have crawled under but cannot see a plate on the axle, whereabouts should I be looking.
Any advice is appreciated.
Thanks.

I have a strange feeling that the axle of the caravan has been replaced at some time with a lower rate one. Or am I thinking too deeply.
Elywn, what make of caravan is it and did you buy it new or second hand.

 

[Raywood]

If the tyres are rated at 650 each than they are clearly below what is required and need replacing with some with a higher rating.
Not sure what you can do about the axle, but I am not clear what makes you think it has been changed. Possibly the best bet is to consult ALKO as to any specialist in the area who might be able to check it out and identify exactly what you have.

 

[Lutz]

Hello Lutz,

It is possible to have an MTPLM that is greater than the permitted axle load, becasue it is expected that a trailer will have a nose load, and its the combined loads of axle and nose load that summed must be less than the MTPLM.

I'd agree its unusual, but it does fall within the protocols.

Yes, you are correct. I should, of course, have said the MTPLM may not exceed the sum of the maximum permitted noseweight and axle load, although in practice I have never come across a case where it is greater than the max. axle load because that would seriously limit the load distribution in order to be able to make full use of such an MTPLM.