"The Thinking Persons Driving School"

Berkshire Driving School, 63 Wheatley, Great Hollands, Bracknell RG12 8UG
01344 303132

http://www.berkshire-driving-school.co.uk
Trailer Tuition Enquiries : john@berkshire-driving-school.co.uk

Berkshire Driving School - Trailer Towing

Like all select occupations, trailer towing has its own jargon. This section attempts to explain these and add some practical knowledge on the subject. Please let us know if you think of something we have left out or if any errors have sneaked in. We have a minimum test vehicle to help you get through the driving test but we will provide training on your own outfit if required.

Trailer towing incurs a 25% surcharge over our standard rate - please check the home page for our current rates.

1. What is the MAM?
2. What is a Tonne?
3. What are ‘grandfather rights'?
4. Give an example of ‘grandfather rights'
5. What is the vehicle weight when pulling a trailer?
6. Does ‘fully comprehensive insurance' cover all damage done by a driver?
7. What are the current restrictions to car provisional license holders?
8. What are the restrictions applying to trailer drivers?
9. How does the car + trailer test differ from the car test?
10. How do I uncouple the trailer?
11. How do I recouple the trailer?
12. What is meant by ‘vehicle security' when recoupling?
13. What is an ‘anti-sway' device?
14. How is snaking avoided?
15. What compatibility issues are important?
16. Is the weight on the tow bar important?
17. What is a jack knife and how do I correct it?
18. What is ‘brake fade' and how do I avoid it?
19. When driving off, what is the most important safety concern?
20. What restrictions apply to trailer drivers?
21. How much is Car Tax?
22. Do I need a Trailer Licence?

1. What is the MAM?

The MAM is the maximum authorised mass (weight) also known as the gross vehicle weight. It is the weight of the trailer plus the weight of the maximum permitted payload.

2. What is a Tonne?

A tonne is a metric ton or 1000kg.

3. What are ‘grandfather rights'?

Grandfather's rights are the continued rights to drive vehicles although the law has changed. New drivers with the same license will not be permitted to drive certain vehicles which had hitherto been allowed if that person had passed the test at an earlier date.

4. Give an example of ‘grandfather rights'

Drivers who passed the test before 1 January 1997 are permitted to drive vehicle and trailer combinations up to 8.25 tonnes. They are also permitted to drive medium goods vehicles which have a MAM of 7.5 tonnes. Drivers who passed their test after this date are restricted to vehicle and trailer combinations of 3.5 tonnes MAM. They are also restricted to small trailers with a MAM of 750 kg, 3/4 metric ton.

5. What is the maximum weight a car or 4X4 may pull?

The DVLA states -
"Category B vehicles may be coupled with a trailer up to 750kgs MAM (allowing a combined weight up to 4.25 tonnes MAM) or a trailer over 750kgs MAM provided the MAM of the trailer does not exceed the unladen weight of the towing vehicle, and the combination does not exceed 3.5 tonnes MAM."

Reference is made to the maximum authorised mass (MAM) of vehicles and trailers. This should be taken to mean the permissible maximum weight, also known as the gross vehicle weight.

As for towing caravans, existing general guidance recommends that the laden weight of the caravan does not exceed 85% of the unladen weight of the car. In the majority of cases, caravans and small trailers towed by cars should be within the new category B threshold.

For example: Say that the unladen weight of a typical 4X4 may be 2 tonnes. The manufacturer may authorise a MAM of 2.75 tonnes. ie it may be permitted to carry a payload of 750kg max.
This leaves just 750kg for the trailer (ie a small camping trailer, usually unbraked.) Clearly the 4x4 is capable of drawing a far larger trailer than this but the driver must have a trailer licence entitlement to do so.

So, two requirements are needed. There are that the vehicle has a towing limit and also legal restrictions apply.

The vehicle weight is the maximum mass of the car plus trailer. Be aware of this so that you may comply with weight limit signs.
You should find that your trailer is marked with the unladen weight and payload. (Our present trailer has a payload of 1,000kg and an unladen weight of 276kg bringing the maximum authorized mass to 1276kg. This is just over the minimum driving test vehicle requirements.) Our BMW 120d has a maximum permitted towing mass of 1,200kg (as printed in the manufacturer's handbook) so is a good match for this trailer. When fully laden the trailer will weigh less than 80% of the car and therefore complies with the Code of Practice recommended by the Caravan Club.

If the trailer has no brakes it may have a maximum authorized mass of 750kg and may be driven by car drivers. 'L' plates and a supervising driver are not required. However the trailer must weigh less than half the weight of the towing vehicle's kerb weight.

Trailers with overrun brakes may have a maximum authorized mass of 3.5 tonnes if permitted by the manufacturer (as denoted by the plate). They usually have a maximum authorized mass exceeding 750kg and restrictions apply if the driver does not have grandfather rights to draw such a trailer - namely the front and rear of the vehicle must display 'L' plates and the driver must be supervised by a qualified driver. The trailer when loaded must not exceed the car manufacturer's design limit (see handbook). Note that although the vehicle may easily pull the trailer, legal considerations should be observed. Failure to do so would invalidate the insurance. For example a car plus trailer license will not allow the driver to draw a combination greater than 4.25 tonnes (3.5 tonne vehicle drawing a 750kg trailer). Above this mass a medium or large driving license is required to be held by the driver.

6. Does ‘fully comprehensive insurance' cover all damage done by a driver?

No, for example, if a driver overloads a bridge, this is not likely to be covered by the vehicle insurance.

7. What are the current restrictions to car provisional license holders?

These include not pulling a trailer and not driving on the motorway. They should also display ‘L' plates and be accompanied by a suitably qualified driver.

8. What are the restrictions applying to trailer drivers?

These include not using the third lane of motorways and lower speed limits on many roads:

• Motorways and dual carriageways,60mph,
• other roads, 50mph.

9. How does the car + trailer test differ from the car test?

• The test is longer,
• The test centre has a manoeuvring area,
• No manoeuvres are conducted on the road,
• There is no emergency stop,
• The ‘controlled stop' is conducted on the manoeuvring area,
• The examiner will ask the candidate to perform a manoeuvring exercise,
• The examiner will ask questions on vehicle safety
• An uncoupling and recoupling exercise is performed,
• The candidate is expected to drive to a higher standard.

10. How do I uncouple the trailer?

• Select a suitable place to leave the trailer. This should be level and convenient for others.
• Leave the car is a safe condition and apply the trailer handbrake.
• Disconnect the safety cable and electrical plug,
• Lower the jockey wheel and disconnect the trailer cup from the tow ball,
• Move the car away,
• Check the trailer brakes.
• Check the trailer security.

11. How do I recouple the trailer?

• Check that the trailer handbrake is applied,
• Reverse close to the trailer tow cup and leave the car is a safe condition.
• (A stick by the trailers tow cup could be used or check visually.)
• You should consider repositioning the car if needed. (It is easier to swing the trailer round rather than to pull it up to the car. A tandem axle trailer is easier to swing round if the jockey wheel lifts the front wheels off the ground))
• Wind down the jockey wheel so that the tow cup is slightly higher than the car tow ball.
• Release the trailer handbrake carefully and swing the tow cup over the tow ball, be prepared to reapply the trailer handbrake if the trailer threatens to move too quickly,
• Raise the jockey wheel to lower the tow cup onto the car tow ball.
• ENSURE THAT A SAFE COUPLING HAS BEEN EFFECTED. Raise the back of the car by lowering the jockey wheel down a little.
• Raise the jockey wheel completely and lock it up, making certain that it does not interfere with the brake actuator.
• Make certain that the green plug or handle has sprung out,
• Connect break-away cable and the black electrical plug. (The drain hole is at the bottom)
• Release the trailer brake,
• Make certain that the slack in the cables is sufficient to allow manoeuvring yet will not let them drag on the ground.
• Check lights, tyres and vehicle security. (The brake lights need the ignition to be switched on, have a handy stick which can be wedged between seat and brake pedal if you are on your own.)
• Adjust any retrofitted mirrors.
• Check the coupling and brakes before leaving the yard by accelerating and braking.

12. What is meant by ‘vehicle security' when recoupling?

• The trailer used by us is small and light. Ensure that the tipping mechanism is locked down and that the lid catches are secure.
• Larger trailers may need an anti sway (or stabiliser) devices to be attached after the towing vehicle has been coupled.
• Caravans require more attention. Drawers and cupboards must be locked, gas bottles stowed, stop cocks, windows and skylights closed, chemical toilets emptied, electrical appliances made safe, loose items secured.
• The number plate may need to be changed. The trailer should be serviceable which is important if it has been standing for a long period.

13. What is an ‘anti-sway' device?

These are sometimes used on higher trailers to stop them swaying or snaking in the wind. They dampen the movement between trailer and towing vehicle.

14. How is snaking avoided?

Increasing the nose weight, fitting an anti-sway device, increasing the trailers tyre pressures and travelling slower will reduce this effect. Should this occur, braking will exacerbate this. Drive sympathetically and lift off the accelerator should this should occur. Consider accelerating if a transitory gust is the cause of the problem.

15. What compatibility issues are important?

• Old trailers may have a smaller non-metric tow cup which is incompatible with modern cars.
• Some trailers may have a tow eye which needs a tow pin on the towing vehicle
• Older trailers may need to have the over run brakes disabled when reversing, a collar is slipped over the spring arm.
• Non-standard lighting plugs may be used on older equipment.
• The tow hitch must be the correct height, especially if the trailer has more than one axle.

16. Is the weight on the tow bar important?

The weight should be such so that it can be coupled up to the car without too much effort. Excessive weight on the tow bar will set the car head lights too high and make the steering dangerously light.

Too little weight will make the combination snake the coupling may bang when going over bumps and the rear of the car will be excessively bouncy.

A nose weight of between 50 to 100kg should be considered. The load on the trailer may be re-distributed to achieve this.

17. What is a jack knife and how do I correct it?

Jack knifes come in two forms. Firstly, when reversing, the angle of the trailer can become so acute that the driver will not be able to recover when on full lock. Driving forward and straightening will sort this out.

A second type is a dangerous condition caused by the driver slowing down too sharply when cornering. The trailer goes straight on and pushes the back of the car round. If the driver had braked on the straight and accelerated gently when cornering, this could have been avoided. If the driver is lucky and catches the situation in time then accelerating might restore stability.

18. What is ‘brake fade' and how do I avoid it?

Hot friction material may lose its efficiency when hot or metal parts distort slightly. Old hydraulic fluid may produce bubbles if subjected to heat, air is squashy.

Cars have disk brakes which do not suffer brake fade since they offer superior cooling and brake disks expand towards the pads. Trailers have drum brakes which can overheat causing the drums to expand away from the brake shoes.

When approaching long descents trailer drivers should keep their brakes cool by –

• Slowing before the descent,
• Selecting a low gear to increase engine braking.

19. When driving off, what is the most important safety concern?

Visibility is restricted so be vigilant with your observation by checking ALL mirrors and looking round effectively, covering all sides of the vehicle. Watch out for pedestrians stepping over the tow hitch!

20. What restrictions apply to trailer drivers?

• Don't use the outside lane of a three lane motorway
• Don't exceed 60mph on the motorway
• Don't exceed 50 on other roads
• Watch out for weight limit signs since the vehicle now includes the trailer.
• Height and width restrictions may apply to your outfit.

21. How much is Car Tax?

For current rates of car tax (Vehicle Excise Duty) click here

http://www.vcacarfueldata.org.uk/ved/ then please come back

For additional useful information on vehicle taxation click here

22. Do I need a Trailer Licence?

If you wish to tow a larger trailer, the kind that have brakes fitted, and you do not have 'grandfather rights' (see questions 3 and 4 for explanation) then you will probably need to get your entitlement by passing the trailer test.

For additional useful information on trailer regulations click here

Please note all information on this site is as correct as best endeavours can make it (Errors and Omissions excepted). Please report website problems to webmaster Neil Manuel

Website created on Sunday 30th November 2003 and last edited on Sunday 13th September 2009.

We have welcomed visitors to our site. Thanks for browsing.

Useful Links...

BMW 120D - Our training vehicle - click on the above picture to visit the BMW site to see it's specifications.

http://www.touchreading.com, Touch Reading local business directory