Glossary › A

A1 to A3 Classification / FL to AT Classification

Term used to classify the transport of flammable liquids from petrol to heavy heating oil (old: A1, new: FL / old: A3, new: AT).


Anti-skid braking system (as ABV). Compulsory over 3.5 tonnes gross weight.


see ABS

Access platform

This is a platform on the bulkhead of tipping semi-trailers from which rolling top covers can be operated. The term may also apply to other platforms.

Acrylic paint

Type of paint used for commercial vehicles.

Adapter cable

An adapter that makes a connection between 7 and 13 pole plugs.

Adapter frame

Component of the Ackermann-Fruehauf short coupling system.

ADR classification

Vehicles transporting hazardous material have an ADR classification. European agreement on transport of hazardous materials by road (see Gehargut- hazardous materials).


General requirements for German Road Hauliers.

Aeroquip tracks

Longitudinal components for cargo control.


Old Ackermann term for all plastic bodywork.


Dry freight bodywork from Ackermann-Fruehauf.


Old Ackermann term for insulated bodywork.

Aggregate adapter

Aggregate which can be additionally fitted to a vehicle.

Air bag

Cargo control system e.g. for glass etc.

Air bag – ring type

Alternative air bag for air suspension which function like a concertina.

Air bags – rolling type

The rubber bags inflated and deflated for air suspension. The bags roll apart/together when inflated/deflated.

Air brake

Air operated braking system for trailers.

Air discharge accelerator

Found in the discharge outlets of silo vehicles to accelerate discharge.

Air leak rate

The amount of air ingress/loss from a box body with lipped seals on the rear doors. Especially important that this is as small as possible in refrigerated vehicles.

Air outlet

Outlet on a silo vehicle fitted with an air system that allows discharge without loosening.

Air pressure stabiliser

For example to control a steering axle when driving straight on.

Air suspension bellow

Rubber bellows used for air suspension which replace traditional mechanical springs.


Lightweight version of air suspended axle from manufacturer BPW.


Term used for the air hose between trailer and tractor unit.

Airfreight vehicle

Airfreight transporter.


Anti-swing trailer coupling from manufacturer AL-KO, for trailers up to 3.5 tonne total weight.


Manufacturer of vehicle components and axles.


Manufacturer of aluminium wheel rims.

Alignment rollers

Used to align and centrally position a swap body when being loaded onto a swap body chassis or prime mover.

Alignment wedges

Used to align and centrally position a swap body when being loaded onto a swap body chassis or prime mover.

All steel floor

Found in tipper vehicles where no wood is used in the floor.

All wheel steering

Steering of several parallel axles usually hydraulically operated and especially used on heavy low bed loaders.


Vehicle construction using aluminium materials and components wherever possible to save weight and maximise payload. Aluminium components include wheel rims, axle supports, etc. Expensive to manufacturer.


Rail approval certificate for roll-on and skip containers.


Light aluminium bodywork from Ackermann Fruehauf.

Aluminium alloy

Aluminium alloy – quality feature

Aluminium axle pads

Axles and their components can also be manufactured in aluminium for lightweight vehicles.


Advanced Mobile Telephone Systems. Analog mobile phone system that is widely used in the USA and Canada.


Manufacturer of sliding roof systems.


Manufacturer of cargo control equipment.

Anodised drop-sides

Aluminium drop-side sections are available in an anodised finish that looks very good and avoids painting.

Anti theft lock

Anti-theft equipment for towing jaws, hooks and eyes and for king pins.

Anti theft lock

Anti theft devices which are fitted to the king-pin of semi-trailers or towing eye of drawbars.

Anti-flame safety device

Safety equipment on petrol tankers which prevent explosion.

Anti-swing safety coupling

Car trailer coupling which offers better side swing stability and prevents lurching of the trailer. The coupling has two integrated side braces with dampers which stabilise the side loads.

Aperture height

This is the clear opening height from top of side rave to underside of cantrail or top rear frame member.

Argus connection

Hydraulic coupling fitting used on the connections between oil carrying pipes between tractor unit and trailer.

Asbestos free brake linings

The use of asbestos is forbidden in brake linings.


Test certificate for refrigerated vehicles. Approval plate is located on the front bulkhead of a vehicle. ATP classification is in accordance with international guidelines for the transport of temperature sensitive foods and covers classification of temperature control (cooling and heating) equipment. Vehicles for frozen foods must also have FRC certification.

Auger compressor

Used on container vehicles for pneumatic unloading of bulk loads e.g. from silos. Manufactured by e.g. RHH-Rand.

Automatic brake wear adjustment

Brake adjustment system that automatically compensates for brake lining wear by sensing the amount of brake movement required.

Automatic brake wear adjustment

System that automatically adjusts the brakes to allow for wear of the brake linings.

Automatic jockey wheel

A jockey wheel that automatically retracts when wound into the travel position.

Automatic reverse

Equipment on trailers with over-running brakes which allows the vehicle to be reversed.


Ackermann demountable body system – developed by Ackermann-Fruehauf.

Axial load

The permissible load on a turntable is the axial load. Load is applied vertically and horizontally. These apply only in load direction. For vehicles with speeds up to 105 km/h. Vehicles with lower speeds up to 30 km/h may have an axial load up to 25% higher.

Axle bogie

Term used for two or more axles grouped together.

Axle brackets

Fixing brackets on axles for fitting suspension components.

Axle data plate

The axle data plate provides several items of information e.g. load capacity, year of manufacture, single or tandem wheels, material thickness, etc.

Axle load

The load capacity of an axle.

Axle load increase

Increased axle load capacity approved by the manufacturer.

Axle nuts

Used to secure vehicle wheels.

Axle packer

Height balancing component between two or more axles.

Axle restraint rope

On air suspended axles which are used for road/rail combined transport vehicles the axles are bound with restraining ropes so that when the vehicles are lifted the air suspension is not allowed to hang down, fully extend and possibly be damaged.

Axle spacing

The longitudinal distance between the centre of axles.

Axles for trailers

Leading manufacturers : BPW, SAF, Knott, ROR, Fruehauf, Meritor, DB-Discos, SNB, Gigant, AL-KO, GFA, Warstein, Rotos, Valx

Waste disposal containers

Waste disposal containers, which are set down and picked up via a cable system.

Weight reduction

The total allowable weight of trailers and semi-trailers may be downgraded by their owner. For example if a tractor unit has a maximum towing capacity of only 12 tonnes a 16 tonne trailer can be downgraded to 12 tonnes. In Germany this requires a TÜV certificate in accordance with paragraph 19 of the German Regulations. Trailers with load sensitive brakes require no technical action. The total allowable weight is changed in the vehicle registration document.