Glossary › F

Bulkhead spoiler

Aerodynamic profile on a vehicle bulkhead. Improves fuel efficiency.

Fall catch

Component of a drop-side locking system.


Italian manufacturer of vehicle mounted loading cranes.


Floating Car Data. Method of assessing actual traffic situation whereby cars are used as sensors. As soon as a car is stopped in a traffic jam or slow moving traffic the vehicle automatically transmits information on the position and traffic situation at that particular location. Theoretically every car could be used as a mobile information source.


Chemical component of hard foam insulated vehicles and cooling liquids. Manufacturers are moving to full plastic construction and cooling liquids that are FCKW free.

Feeding trough

Found in the front of horse trailers.


Imperial measure of length used universally for container dimensions e.g. 20 foot container = 6096 mm in length.


Product name for insulated panel system from the German manufacturer Schmitz. Panels are foam filled with inner and outer steel skins.

Ferry shackles

Lashing equipment required on semi-trailers (4 per side) which are transported by ship.

Ferry-rail specification

Semi-trailers require special equipment for transport by sea and/or by rail. This includes roll-on roll-off equipment and grapple lift equipment, spare wheel winch in front of the axles etc.

Fifth wheel

Coupling for semi-trailer king-pin on a tractor unit.

Fifth wheel height

Distance from ground to top of tractor fifth wheel.

Fifth wheel height

Distance from the ground to the top of a fifth wheel. Varies from around 1m to 1.5m depending on semi-trailer type. Mega-trailers require an extremely low fifth wheel in order to maximise internal load height in the bodywork. Semi-trailer tractors with very low fifth wheels are known as low-trucks.

Fifth wheel load

The vertical load in tonnes applied by a semi-trailer to a tractor unit fifth wheel.

Filling aperture

The upper filling aperture and cap on tank and silo vehicles.

Final approval

Final approval by the manufacturer before a vehicle leaves the works.

Fine grain steel

High quality steel that is slightly more brittle than mild steel but is lighter and therefore useful for vehicle manufacture.

Finished component transporter

Semi-trailers with wheels which are at the side rather than under the bodywork. This allows the entire internal volume of the body to be used. The cargo is loaded on frames or flats and the vehicle can drive over the cargo when loading unloading. The vehicle uses air suspension to pick up and set down the cargo. Extensively used for glass plate and large concrete components.

Finishing brake

A light brake pressure is applied to the rear axle of a tipping semi-trailer via an electro-pneumatic valve in the cab that prevents the vehicle rolling away.

Fire extinguisher

Carried on many vehicles especially hazardous goods transporters where these are compulsory.

Fired painting

A particularly complex paint system for vehicle components which offers excellent corrosion protection

Fish belly supports

Term used to describe tipper body frames that slope toward the middle in a wedge shape. The middle of the body is also the centre of the load and must be reinforced at the point where the tipping mechanism is attached.


Body components that are generally used for fixing.

Five chamber lights

Common rear light clusters including brake lights, rear lights, indicators, reversing lights and fog lights.

Fixed axles

Term used for a single rigid axle.

Fixed body

Any bodywork which is not demountable.

Fixing hook

Hook that centres and holds the front of a demountable body on the vehicle chassis e.g. used on AWL system.

Fixing hook locking

Manual or hydraulic equipment which locks a roll-on container on a trailer.


Guidelines for the length of vehicles.


A demountable frame with support legs and floor but without bodywork.

Flat roof

Standard type of roof on dry-freight bodies and tilts. Offers maximum usable internal volume.


Small standardised container that can be transported with 2 other Flexboxes on a standard 20 ft flat.

Flexible air tunnel

Often used under the roof in a refrigerated vehicle to help circulation of air.


A system from the German manufacturer Schmitz which allows a semi-trailer to be adapted to suit different fifth wheel heights so that a higher internal body height can be achieved when using a tractor unit with low fifth wheel height i.e. height adjustable bodywork. The trailer’s air suspension is also adjusted to suit the tractor fifth wheel height.

Floor load

Load capacity of the vehicle floor usually measured per square metre. For swap bodies the European Standard EN 283 requires a floor load of 5460 kg/m².

Floor sump

When the floor of a refrigerated vehicle is taken a short distance up the walls and sealed to provide a waterproof area and also to increase strength.

Floor valve

Found on tank trailers e.g. for discharge.


Usually multi layer phenol coated plywood panels that are hardwearing and able to carry point loads.

Flush rear frame

The rear end of a container chassis may finish flush with the container so to allow easy reversing to loading bays.


Classification of insulation values less than 0.7 W/m²K, wall thickness of 45mm.

Foam padding

Found in furniture vehicles and other box bodies which transport sensitive goods e.g. artwork.

Foldable posts

Foldable posts on long material transporters that allow side unloading of goods (tree trunks).

Foldable side extension

Generally used on low loaders and semi-trailers which transport over-size construction equipment and machinery. Extensions may be folded out to give 3m overall width. Requires special approval.

Folding handrail

Folding handrails are usually found on waLKWays above tankers.

Folding lift system

Equipment used to raise the upper load deck of a car transporter.

Folding-wall bodies

Dry freight bodywork, which have multi-leaf concertina like folding side doors that allow access over the entire length of the body.

Foodstuff box-body vehicles

Trailers and semi-trailers that have box bodies to suit the requirements of the food industry. Easy to clean in order to meet hygiene requirements and lightly or heavily insulated to prevent temperature increase. Have a lower internal height than standard box bodies.

Forklift truck protection buffer

Rubber or steel buffers on side raves that protect drop-sides from forklift truck damage when loading.

FRC classification

Sets the insulation values as less then 0.4 W/m²K where insulation thickness of walls is 40mm. An ATP test is necessary for the material and the bodywork.

Freight exchange

A load exchange organisation for hauliers. Many companies are connected on-line for fast access to consignments.

Freight pallet

Term used by many manufacturers for BDF standard demountable base-frames without bodywork.


Manufacturer of retarding brakes for trailers.

Fresh air shutter

Found on bulkhead or rear frame of refrigerated vehicles to allow fresh air into body.

Fresh produce construction

Dry freight bodywork on rigids, trailers or semi-trailers for transport of foodstuffs or other temperature sensitive goods. The body materials are temperature resistant.


Product name for fresh produce bodywork from the German manufacturer Ackermann-Fruehauf.

Friction steering

A type of steering which depends on adhesion between road and tyres.

Friction strengthened parabolic suspension

A smoother trailer ride is achieved by the thick material and layered leaf ends.


Leading manufacturer of vehicle temperature control equipment.


A type of temperature recorder for refrigerated vehicles. The recorder has variable recording periods.

Front lifter

Tipping cylinder in front of a body bulkhead and tip the body to the rear. The cylinder may have a operating pressure from 150 to 250 bar.

Front loading

The draw bar of container trailers can be pneumatically lowered allowing the tractor unit to reverse very close to the front of the trailer in order to load a skip over the front of the trailer.


Leading supplier of aluminium vehicle bodywork components.


Leading manufacturer of trailer tyres.

Funnel system

At the rear of walking floor trailers funnels are used to direct goods into containers or onto conveyors.


Commonly used in the floor of grain transporters for discharge into underground grain silos.

Guide rollers

Used on swap body chassis and on demountable bodies. On swap body trailers these rollers are used to locate the swap body on the trailer. On demountable bodies the rollers are fitted beneath the body so that the body rolls up the chassis to the correct location.

Serial number

Every vehicle is identified by a unique serial number from the manufacturer usually on the front right bottom corner of trailers. This number is included in German trailer licence documents.

Spring controlled parking brake

Alternative to a hand brake. A spring is operated by air pressure. In the brake cylinder the spring load is applied to the wheel brake. Can only be released using air pressure.

Suspension centres

The distance between the centre of suspension springs – often the same distance between V-drawbar blocks.