Trailers - Category C/E.

Trailers

A trailer is a vehicle that is designed to be towed by another vehicle. A trailer combination is a car with an attached trailer vehicle.

Trailers are categorised into:

A trailer primarily designed for the transport of persons or goods.

A semi-trailer designed primarily for the carriage of persons or goods and coupled to the towing vehicle in such a way that the semi-trailer and its load rest partly on the vehicle.

A trailer implement (subject to registration) that is a trailer other than a trailer or semi-trailer, such as a caravan, gravel spreader, pump, cable car or similar.

A large trailer is a trailer with a maximum authorised gross weight of more than 750 kg.

Trailers/semi-trailers are categorised according to their permissible gross vehicle weight/axle load as follows:

O1 with a permissible gross vehicle weight for semi-trailer and trailer with rigid drawbar and a total axle load not exceeding 750 kg.

O2 with a permissible gross vehicle weight for semi-trailer and trailer with rigid drawbar with a total axle load of more than 750 kg, but not more than 3500 kg.

O3 with a permissible gross vehicle weight for semi-trailer and trailer with a total axle load of more than 3500 kg, but not more than 10,000 kg.

O4 with a permissible gross vehicle weight for semi-trailer and trailer with a total axle load of more than 10,000 kg.

- (Trailers O3 and O4 with a rigid drawbar are called a CART).

1. Steering wheel

Swivelling crane
The steering system on a trailer and implement usually consists of a turntable that allows the front wheels to turn.

The turntable consists of an upper and a lower ring, between which a series of spheres are placed.

Semi-trailers and trailers do not have an actual steering system. Semi-trailers can be equipped with mechanically activated rotation of one or more axles.

Checking the steering unit

Swivelling wreath
There must be no significant play at the swivelling rim. This is checked by applying the trailer's parking brake and making small, jerky movements with the connected lorry (rocking test).

The mounting bolts of the turntable are checked for tightness, which is assessed during the turntable test and/or by any rusting around the bolts.

Play at the swivel can be a sign of wear in the swivel itself or a sign that the mounting bolts for the swivel are loose.

Legal regulations
Significant play in the steering system as a whole or in its individual parts must not occur.

REMEMBER!
The helper must have a driving licence for the vehicle combination.

Possible steering for semi-trailer consists of:

• A swivel ring (same as on a trailer)
• A mechanical connection that extends under the fifth wheel. At the front of this is a "block" that fits snugly into the "gap" in the fifth wheel stool