When it comes to towing you'll hear a lot of talk about braked and unbraked trailers but what exactly is the difference between the two?
In this article we'll look at the difference bettwen braked and unbraked trailers, but also go into the details on what is a braked trailer, what is an unbraked trailer and a few bits around the legislation and laws, including some facts about breakaway cables and when you need one.
For more details on towing visit the page for individual towing limits for specific van models. It's also worth checking the payload of your van if you're towing as well, so there's a handing van weights section as well.
Right... onto the main event, details about braked and unbraked trailers.
It will come as no surprise that the clue is in the name. The main difference between an unbraked trailer and a braked trailer is that an braked trailer has its own brakes and and unbraked trailer does not.
For a braked trailer, the trailer's brakes are connected to the towing vehicle. This is done by a mechanical linkage. It allows the the trailer to apply its own brakes when towing. If the towing vehicle brakes, then the trailer's brakes are also applied. It's a seemless and instant process that sees the vehicle and trailer work as one.
The mechanical link is provided through the tow bar, which will be connected to the towing vehicle's braking system.
If it is an unbraked trailer, the towing vehicle does all the braking. That means that the weight of the trailer is being stopped entirely by the brakes of the vehicle.
When you need a braked or unbraked trailer will depend entirely upon how much weight you are carying.
Trailers with a total kerb weight over 750kg must have their own brakes. So if you have a trailer of 751kg you are legally required to have brakes.
Braked trailers also need a breakaway cable. This automatically applies the trailer's parking brake if it becomes detached from the towing vehicle. So if you're trailer becomes uncoupled, it's not going to keep rolling down the road and end up in someone's front room.
The rules also state that an unbraked trailer requires a secondary coupling. So that's another method of securing the trailer to the towing vehicle. A back-up plan. In case anything goes wrong.
Let's try and get really nerdy about this.
A braked trailer is wheeled vehicle that is pulled by another vehicle with a co-dependant braking system. That means it has brakes that will function when told do to so by the towing vehicle.
If you brake in your van, the brakes on the trailer will work at the same time. That means that you're not getting the weight and the momentum of the trailer forced upon the van, and that the brakes are not going to have to help stop the trailer all by themselves.
The braked towing capacity is the maximum weight a vehicle can tow when the trailer has its own brakes.
The amount it can tow will depend upon the gross train weight of the towing vehicle. This is a design weight that includes the overall weight of the towing vehicle, the trailer and its payload.
For vans the gross train weight will usally not exceed 3.5 tonnes. This means a 3.5 tonne van can tow a 3.5-tonne trailer. In other words a trailer that with its cargo weighs a maximum of 3.5 tonnes.
A braked trailer simply has mechanical brakes on the trailer's axle. A linkage from the towing vehicle connects the braking systems together - this is via the tow bar.
When the towing vehicle presses the brake pedals a hydraulic signal tells the brakes on the trailer to be applied as well.
Any vehicle can tow a braked trailer if they have a braked trailer coupling. This is a tow bar trailer coupling that enabled trailers with brakes to be connected.
Trailers will either have a 7 pin or 13 pin interface to connect to the towing van or car and the trailer.
It will also have a coupling head - this is the round ball you usually associate with towing.
Other components include a handbrake, handle, breakaway cable and dampers.
You can tell if a trailer is braked by simply looking at the inside of the rear wheels of trailer. If the trailer has brakes then it is a braked trailer.
If the axles doesn't have any brakes in the wheel hubs then it is an unbreaked trailer.
You can also look for a mechanical linkage that connects the trailer brakes to the tow bar.
Ad you can probably guess the unbraked trailer meaning is the opposite of a braked trailer. An unbraked trailer is a trailer without brakes.
That means it must conform to a different set of rules and regulations about its weight and what vehicle is towing it.
An unbraked trailer is most commonly used for small items and can be known as a car trailer, travel trailer, traveller trailer or single axle trailer.
With an unbraked trailer the towing vehicle is responsible for all the braking. That means the weight of the trailer will all have to be stopped by the braked of the car or van towing it.
Thr maximum unbraked trailer weight in the UK is 750kg. This is the safe limit that cars and vans are allowed to tow a trailer without the added addition of trailer brakes on the trailer being towed.
The unbraked trailer towing capacity is the maximum weight it can tow when the trailer doesn't have its own brakes and that's been set at 750kg.
The eagle-eyed amongst you (and those that know their vans) will see that 3.5-tonnes plus 750kg is equal to 4.25-tonnes. That's important because that is currently the permissible weight for electric vehicles to operate at with special dispensation for B-licence holders.
In other words, the government has looked at the trailer towing regulations and decided that a van towing a 750kg trailer is safe, so therefore a 4.25-tonne van with batteries and a full payload must also be a safe weight.
That means that a 4.25-tonne electric van cannot tow a 750kg trailer and still be driveable with a B-licence. That's despite large vans like the Ford Transit and Mercedes-Benz Sprinter having much higher towing capacities.
The Mercedes Sprinter van towing capacity is actually 3,500kg (7716 lbs) which will require a different category of licence. Read more on the licences needed to drive a van.
Most vans and other vehicles can tow a lot more weight with a braked trailer than they can with an unbraked trailer.
Another requirement for a trailer is to have a breakaway cable attached to the towing vehicle.
It is a secondary tether designed to secure the trailer in the event that it becomes de-coupled or unattached.
Most people will want to know "do you need a breakaway cable on my trailer" well the simple answer is 'yes' and here's why.
A breakaway cable is a legal requirement for all braked trailers and caravans. Unbraked trailers also need to have a breakaway cable as in the event of coupling detachment it is designed to apply the handbrake of the towed vehicle before allowing it to break away and come to a stop.
A secondary coupling is a legal requirement for all unbraked trailers.
The law in the UK requires all trailers and caravans with a weight of - or a maximum technically permissible laden mass (MTPLM) - between 750kg and 3500kg to be fitted with a safety device to provide protection should the towing vehicle and trailer separate.
Yes it is legal to fit your own towbar, however, the towbar itself must be an EC Approved towbar.
This will be apparent from a label or plate that displays the EC approval number.
Although you can install your own towabr, be warned, if a towbar is not installed correctly then it is both dangerous and illegal. For this reason, many people choose to use a professional fitting service instead.
