Widths and weights of trailers

[R Cubed]

Hi all, here is another stupid question, not MV related but could be.

 

Does the weight of the tow vehicle affect the legal width of a trailer towed by it, I know the max width is 2.55mtrs but have heard ref to 2.3mtrs ?

 

At what point does a trailer have to be plated (mot) is this by its size or weight if so what is it ?

[croc]

from "The Traffic Officer's Companion. 18th edition. Gordon Wilson"

 

Construction and use.

 

Maximum width.

A trailer drawn by a motor vehicle other than a motor cycle = 2.55 metres.

Trailer drawn by motor cycle = 1.5 metres.

 

It is an offence to use, cause or permit the use of an unbraked wheeled trailer if -

i, its laden weight exeeds its maximum gross weight.

ii, it is drawn by a vehicle of which the kerbside weight is less than twice the weight of the trailer plus its load.

 

Documentation.

 

Goods Vehicles (Plating and Testing) regulations 1988.

includes for annual testing "Other trailers, the weight of which, unladen exceeds 1,020kg"

 

 

There are numerous clauses and exemptions like living vans and stuff manufactured pre 1960. Because of the way the regulations are writen I don't believe it is possible to give a simple answer. So much depends on what the vehicle is, when it was built and how it is being used.

You need to take your specific vehicle and trailer, decide how you intend to use it, then apply the regulations to decide if it would be legal to use.

As well as the width and test issues, remember driver licence weight limits and the potential need for a tachograph to be fitted.

[Paul Dodd]

What Croc has said is correct, and equally it is complicated. The usual starting point is to determine what licence you have for towing. If you held a normal Cat B (with B+E) licence before 01/01/97 you are pretty much OK for most things, after that it gets trickier. Next if the towing vehicle has more than 8 seats you need to check if you require any additional licence categories. For Unbraked trailers IE below 750kg Max Mass the max weight of the trailer cant exceed more than 50% of the Mass in running order of the tow vehicle. If the trailer is braked it cannot exceed the mass in running order of the Towvehicle In any case it cannot exceed the towing limit set by the manufacturer of the Towing vehicle. The Tow vehicle also has a maximum allowable Gross train weight (GTW), this is set by the manufacturer of the tow vehicle, but in any case for a licence before 97 it is limited to 8250kg, it is a lot less for later licences. It wouldn't be possible to make a true determination without knowing what your proposed combination consisted of. Incidentally the documentation always refers to the max permitted weight of the trailer, and people have been prosecuted for exceeding the combination of these weights even though the actual weight was no where near. I have a VOSA document that clearly states its the actual weight not the possible weights that is important.

[utt61]

Prior to April 2010 a vehicle with an MAM under 3500kg was allowed to tow a trailer no wider than 2.3 metres, whilst a vehicle with an MAM exceeding 3500kg could tow a trailer up to 2.55 metres.

 

Since April 2010, the limit has been 2.55 metres irrespective of MAM, to bring the UK into line with Europe.

 

Anything wider than 2.55 metres requiers Special Types authorisation.

[radiomike7]

Anything wider than 2.55 metres requiers Special Types authorisation.

 

Not quite, a refrigerated trailer can be up to 2.6m :cool2:

 

The whole system is just far too complicated.

[R Cubed]

What Croc has said is correct, and equally it is complicated. The usual starting point is to determine what licence you have for towing. If you held a normal Cat B (with B+E) licence before 01/01/97 you are pretty much OK for most things.

 

This is of interest to me and several friends, old license ie before they changed so we have B+E, C1+E with code 107 (so limited to gross train weight of 8250Kgs) and D1+E as I have heard lots of stories about what you can and cant do, so I was hoping to try and clarify as much as possible with regards to our situations, ie: general towing over 750Kgs.

 

Next if the towing vehicle has more than 8 seats you need to check if you require any additional licence categories. For Unbraked trailers IE below 750kg Max Mass the max weight of the trailer cant exceed more than 50% of the Mass in running order of the tow vehicle. If the trailer is braked it cannot exceed the mass in running order of the Towvehicle In any case it cannot exceed the towing limit set by the manufacturer of the Towing vehicle. The Tow vehicle also has a maximum allowable Gross train weight (GTW), this is set by the manufacturer of the tow vehicle, but in any case for a licence before 97 it is limited to 8250kg, it is a lot less for later licences.

 

This I can see, all ok there.

 

It wouldn't be possible to make a true determination without knowing what your proposed combination consisted of. Incidentally the documentation always refers to the max permitted weight of the trailer, and people have been prosecuted for exceeding the combination of these weights even though the actual weight was no where near.

 

I have a VOSA document that clearly states its the actual weight not the possible weights that is important.

 

Now we are getting a bit juicy !!!! so what you are saying here then is all the licensing categories ect refer to max weights,

 

but in reality, say you had a car which weighed 1200Kgs (guessing the average tow car) and was able to tow a train weight of 2000Kgs (this would be load and weight of trailer) but the trailer was designed to have a train weight of 3000Kgs (this would be load and weight of trailer) but you only had a train weight of 1000Kgs (this would be load and weight of trailer)

 

So in this situation you have 1200Kgs car plus a train weight of 1000Kgs making GTW of 2200Kgs

 

and not 1200Kgs car plus train weight of 3000Kgs making GTW of 4200Kgs

 

Would this be legal or not :nut:

 

Also with reference to trailer widths this I gather is now 2.55 regardless of what is towing it obviously you need wing mirrors to be able to see down the sides though.

[Paul Dodd]

Ok, now this always gets contentious, so it is important to understand what all the various terms mean. (And to put the record straight I have heard of cases going both ways, so don't take as gospel what I say here will keep you out of court) Trailer and vehicle legislation refer to a number of terms some of which mean the same thing. For the Towing vehicle MRO or Mass in running order (sometimes called Kerbweight or Kerbside weight) refers to the weight of a vehicle usually defined by the vehicle manufacturer, it is calculated and their are various formula used but generally means A vehicle normally, with 90% full tank of fuel; an adequate supply of other

liquids incidental to the vehicle’s propulsion; the driver but without any

passengers; without any load, except tools and equipment with which the car

is normally provided; but without the towing bracket. The MAM or Maximum Authorised mass (sometimes called the Gross vehicle Weight GVW or Max Permissable weight MPW) is the weight of the Tow vehicle complete with passengers, luggage, the dog and the imposed noseweight of any trailed load.

Within this the manufacturer will specify Two other weights that these days are found the VIN plate: The Gross Train Weight (GTW) and the Maximum Permissable Towing Mass MPTM) For the Trailer you will generally see the following MiRO (Mass in running order) this is the ex works unladen weight of the trailer, and the Maximum Technically Permitted Laden mass (MTPLM), which is the maximum weight the trailer can physically weigh when loaded, IE the difference between the MTPLM and the MiRO is the Payload. Now the confusion arises with the difference between a Payload Trailer and A non payload trailer. So a non payload trailer such as a caravan is likely to plated with its MTPLM it may say 2000 kg and that is what it will weigh. But a Payload trailer has to be able to say on the plate what it can carry so for example a trailer could say on the plate 2000kg but this is only the max allowed. People have been summonsed for this because the plated weight is greater than the allowance for the tow vehicle even though the actual weight is less. There is a VOSA document however that states quite unambiguously that it is the actual weight that counts not the potential. So to give an example , I have a Vauxhall Zafira, the manufacturers figures for this are that the MRO is 1628kg the MAM as 2175 kg the Maximum Permissable Towing Mass as 1500kg and the Gross Train weight as 3550kg.My trailer has a MiRO 700kg and a MTPLM of 2200kg, so theoretically I have a payload of 1500kg. So assuming I don't carry any passengers or luggage I could theoretically only load a payload of 800kg (IE 700 + 800 = 1500 (the towing limit for the car) onto the trailer and still stay within the limits. This still gives me a total GTW of 3128 kg (1500 + 1628 well within the limits) so again I could load the car up with a payload of 422kg (3550 GTW- 1628 MRO ) providing the payload does not either take the car over its MAM (which it doesn't in this case) or overload the individual axle loads of the car. Hope this helps , bit long winded I know but there isn't an easier explanation. :cheesy:

[N.O.S.]

I think that has to be one of the most helpful and useful replies to a legislation question we've had! :thumbsup:

 

If you have any spare time, Paul - do you fancy tackling a few of the other grey areas identified on the Forum? :whistle:

[John Comber]

Superb Paul , great reading with my sandwich, I think you have answered many questions in one hit, thanks.

[Paul Dodd]

 

do you fancy tackling a few of the other grey areas identified on the Forum? :whistle:

If I can help I will, my areas of expertise are Type approval, IVA and Licensing requirements, If you know of any specific "grey areas" let me know.

[R Cubed]

Thanks you very much, this is just what I was hoping to hear. So good to know VOSA have it right.

 

Very well put for a complicated question.

 

Could you just clear the last bit, that provided you have suitable mirrors it does not matter what sort of vehicle you have you can still tow a trailer or caravan which has a 2.55 max width ? (ignoring of coarse the weight issues)

[Paul Dodd]

Providing we are only talking about vehicles that are driven on B licenses and have less than 8 seats then there shouldn't be a problem.

 

You should however always refer to the manufacturers data for the tow vehicle as some have surprisingly low towing weights and/or allowable imposed loads on the axles.

 

The total towable width is 2.55m and the loading length of the trailer is 7m (the drawbar length is not counted)

 

As for mirrors the minimum requirement is for using the tow vehicles mirrors however if the width of the trailer or more likely any load on it reduces the rear / side visibility (there are figures which I cant remember at the moment) then extension or supplementary mirrors must be used. These mirrors must be type approved.