Caston Coastal Services

 Boat Transport & Trailer Specialists   (07787563357)  

General Towing Information and advice that you should read and be aware of before towing any trailer!

Towing Vehicle Compatibility

Most vehicles have the recommended towing weights for both braked and unbraked trailers, in the handbook. If it is not a commercial vehicle it is not illegal to exceed these weights within reason, but it may invalidate your vehicle warranty or insurance.

We are fortunate in the UK to have a large range of 4x4 towing vehicles, many of which are suitable for towing up to the legal maximum of 3500kg. Many larger cars can easily tow a horse trailer particularly if only loaded with one horse.

All commercial vehicles have a plate fitted either under the bonnet or in the passenger side door frame or step area. The top weight is the gross vehicle mass, the second is the gross train mass, which is the total permitted weight of the vehicle, trailer and loads. Subtracting the first weight from the second will give the maximum trailer weight that can be used with that vehicle.

Trailers can be ordered with the plated weights reduced to be compatible with your vehicle if required. Particularly for plant trailers don’t forget the weight of fuel and extra buckets, which may be better carried in the vehicle.

Driver's Licences

Holders of driving licences issued before July 1996 and providing that they have Group A or if after 1990, category B, are entitled to drive a vehicle and trailer combination up to a maximum train weight of 8.25 tons.

Holders of car licences issued after July 1996 can tow a 750kg unbraked trailer or if heavier trailers are towed, a vehicle and trailer combination of up to 3500 kg. Assuming that the trailer and its load are lighter than the towing vehicle. i.e. a 2000 kg. vehicle with a 1500 kg trailer.

Holders of new licences can upgrade to tow larger trailers by taking another test, B+E for trailers or a better option would be a C1 licence for 7.5 tonne vehicles which would allow them to use trailers up to 3500kg behind suitable vehicles or 750kg behind a 7.5 tonne vehicle.


A tachograph is required to be fitted to record the driver’s hours in a vehicle and trailer combination that exceeds 3500 kg. when used for commercial purposes.

Exempt from this requirement are vehicles used for the non-commercial carriage of goods for personal use, vehicles carrying live animals between a farm and a local market or from a local market to a slaughterhouse and vehicles carrying goods having a maximum weight not exceeding 7.5 tonnes if carrying materials or equipment for the drivers use, in the course of his work, within a 50km radius of the vehicle base.

There are other exemptions but they are not likely to be relevant to most trailer users.

Trailer Towing Speed

The maximum speed limit for trailers is 60 mph on motorways and dual carriageways, otherwise 50 mph unless a lower speed limit is in operation. Trailers are not permitted in the outside lane of motorways.

Maximum Size

The maximum width of a trailer must not exceed 2.3 metres (7’6”) or 2.5 metres (8’2.5”) when towed by a heavy goods vehicle. The trailer must not extend more than 305mm (12”) outwards each side of the towing vehicle, irrespective of allowable width.

The maximum permitted trailer body length without the tow bar is 7 metres but the overall train length must not exceed 18.35 metres.

Trailer Care

New galvanised trailers weather naturally and the shiny silver becomes dull grey, a protective coating forms that is very resistant to corrosion and the only maintenance required is occasional washing. However when the galvanised coating is new it is very vulnerable to surface corrosion from road salt and other acids, this makes the surface rough with what looks like black or white deposits. This does not damage the protection.New laws may come in as they are in the rest of Europe whereby trailers will have to have MOT's, something to be aware of especially if travelling abroad as you will need additional documentation.

Road Tax, Insurance and MOT

Road tax or excise duty does not apply to trailers and extra duty is not charged on vehicles towing trailers up to 3500kg.

Third party liabilities are normally covered by the towing vehicle insurance as long as the trailer is attached. Additional cover should be arranged if insurance for theft or damage to the trailer is required.
Surprisingly the law requires no vehicle safety tests and if the trailer was built to comply with all relevant construction and use regulations, it is legal to use in the U.K.

It is illegal to operate a trailer in an un roadworthy condition, it is the users responsibility to ensue that the trailer is maintained in first-rate condition particularly as many trailers are used infrequently. Once you are past a trailer weight of around 75% of the weight of the towing vehicle you are entering a critical zone regarding stability and safety and a correctly maintained trailer is essential.

Trailer Brakes

Trailers up to half the kerb weight of the towing vehicle do not require brakes up to a maximum limit of 750kg. Above this weight and up to 3500kg. Auto-reversing over-run brakes are required on all wheels and all equipment must comply with E.U. regulations.

Trailers with older braking systems are still legal to use as long as they complied with the regulations at the time that they were built.
Over-run brakes mean that the trailer brakes apply when the trailer begins to push a decelerating towing vehicle. Auto-reverse means that the trailer brakes disengage automatically when the trailer is reversed eliminating the need to mechanically stop the brakes applying when reversing.

1,2 or 3 Axles?

The principal reason for fitting more axles is to carry more weight. A single axle is usually fitted up to 1500kg. And twin axles up to 3 500kg.
A single axle trailer is easier to manouvre uncoupled and the tow bar height is not as critical, twin axle trailers can be more stable, the position of the load is not quite as important, they are certainly better for livestock where the load can move and they are more stable for loading.

Three axles are really only suitable for long trailers or where small diameter wheels are required where the tyre loading of two axles may not be enough. To fit three axles to a 3 500kg trailer that would normally have two increases the unladen weight therefore reducing its carrying capacity. Its initial cost is greater and maintenance costs increase by50%.

By example our 6OLT twin axle livestock trailer is 12 feet long and weighs about 1000kg. It will easily hold 2500kg. of livestock up to the 3500kg maximum weight limit. A longer trailer with three axles will be a lot heavier and legally hold considerably less.

Also our 35MD twin axle plant trailer is built as strong and as light as possible to accommodate the largest possible machines of about 2800kg. Building the trailer larger, stronger or with three axles would reduce its legal capacity.

Reversing a Trailer

Reversing a trailer is very difficult for the inexperienced. A long trailer with a short vehicle is the easiest. A trailer that is shorter than the wheelbase of the towing vehicles is all but impossible and it is always better to unhitch it and move it by hand.

With a longer trailer, turn the opposite way to push the trailer in the right direction then follow it, sounds easy and with practice it is!

All modern trailers have auto-reversing brakes so nothing has to be operated but slight drag may be felt. If this is a problem either in muddy conditions or on gravel, an optional mechanical interlock can be supplied. It is fitted to the coupling and can be engaged by hand to stop the brakes from applying; it will automatically disengage when the vehicle moves forward.

If you are unsure for any reason to whether you can tow or would like to hire our driver and trailer for a day or just a job please contact us and we can work something out for you on 01263862837 or 07787563357.