Glossary › R

Friction steering

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

Radio control?

A remote system to immediately stop the loading of hazardous goods vehicles

Rail approval

Swap bodies, containers and trailers must be fitted with special lifting and securing equipment and tested before being approved for transport by rail.


A roof railing e.g. on a car trailer which is fitted with a cover.

Raise/lower equipment

Pneumatic or hydraulic equipment on trailers which allows the deck height to be raised or lowered to suit loading ramps or similar.

Ramp lifter

Equipment used to help lift and lower loading ramps.

Ramp wedges

Used between the deck steps of low loaders to provide a sloping running surface.

Raw material semi-trailer

Tipper or fixed body with discharge from beneath the vehicle. Open topped over full length with covers or flaps. For transporting grain, malt and similar loose products. An alternative to silo vehicles.

Rear discharge hatch

Hatch found in the rear walls of tippers. A 300 x 300 mm opening allows a uniform discharge of goods. Commonly used when discharging on to conveyor belts.

Rear doors

Box bodies, curtainsiders and some tilt vehicles are fitted with full height and full width rear doors.

Rear light covers

Moving floor vehicles may have covers that protect the rear lights against damage from cargo when unloading.

Rear loading

Term used for demountable waste disposal equipment that may be picked up/set down from front or rear.

Rear mounted

Refers to cranes fitted at the rear of semi-trailers e.g. for loading of building materials.

Rear ramp

Rear wall of animal transporters may be hinged at the bottom and used as a ramp. May also be equipped with lifting aids and non-slip surface.

Rear reflectors

Compulsory on new trailers.

Rear supports

Simple tubes used to support the rear of a trailer during loading/unloading.

Rear underrun

The rear of vehicle must be fitted with underrun protection according to international standards. May be folded away on tipping semi-trailers for road finishing.

Rear wall

Rear wall may be solid or have doors, barn doors, container doors, gull-wing doors or curtains.

Rear wall lock

Tippers employ a system of levers to aid opening and closing of the trailer rear when tipping.

Recessed locking gear

Door locking gear that is built into the door panels. The doors are closed by top and bottom cams and keepers and a handle set in the door panel.

Refrigerated vehicles

General terms for box bodies that can be cooled to -30 ºC for transport of deep frozen foods.

Remote control

Used for many vehicle applications e.g. to operate walking floors or cranes.

Remote control steering

Long material transporters may have the axle controlled on curves via remote control from the tractor unit.

Remote thermometer

Usually found on the bulkhead of refrigerated vehicles. Used to the show the temperature inside the bodywork.


Retarder brakes ensure high brake performance with minimal wear. Also known as eddy current brakes. Electricity is provided by the tractor unit. When used, magnetic fields and magnets brake rotating rotors. ABS braking systems are connected to the retarder brakes and when ABS is activated the retarder is immediately turned off. On air suspended trailers the retarder brake can also be activated via the ALB. Disadvantage : excess weight. On hazardous goods vehicles an additional cooling system is required.

Retractable ladder (1)

Often fitted at the rear of vehicles to allow easy access into the body. The ladder is pulled in and out as required.

Retro reflective

Markings on vehicle sides and/or rear which are reflective when illuminated. Increases traffic safety.


Radio Frequency Identification. Transponder technology for automatic identification and data collection. The transponder is contacted by central stations and transmits a signal back. Passive system not requiring electrical supply. Energy is provided by the reader’s impulse and is thus maintenance free.

Ribbed trough

Term used to describe tipper troughs that have vertical or sloping U-profiles to reinforce the flat side walls. Also known as a Jet-profile.


Leading manufacturer of trailer couplings.

Road railer

A semi-trailer with fittings for rail transport using adapter bogies that are fitted between the trailers. The trailer suspension is used to raise the chassis that is then connected to the rail bogies. This system is intended to reduce road congestion. Used in the USA and elsewhere since 1991.

Rocker foot on landing legs

Curved foot on semi-trailer landing legs that compensates for uneven ground or any movement caused by air suspension.


Leading German manufacturer of trailer and semi-trailer couplings.

Rod steering

Steering system used mostly on semi-trailers where the rear axle(s) are steered from the kingpin area via a system of rods and a turntable. The system operates both forwards and in reverse.


A basic box body kit as offered to bodybuilders.


Abbreviation for rolling highway. This is the loading of complete road trains onto rail wagons.

Roll containers

Term used for steel waste disposal containers that are rolled on and off the carrying vehicle.

Roll over plate

Lowering bodies may use plates to make driving on easier. Such plates may also be used to bridge the gap between vehicle deck and loading ramps.

Roll over protection

Tankers may have a round or square bar around the loading aperture to protect it from damage should the vehicle roll over in an accident.

Roll-on Container

Container that is set down and picked up via a roller and hook system.

Roll-on container rope

Rope used with Roll-on container system

Roll-on roll-off specification

Specification for semi-trailers which can be carried by rail for long haul travel which includes special air suspension, foldable rear underrun, front bumpers and heavy duty lashing shackles on the chassis.

Roll-on safety stop

Safety stop on chassis for roll-on containers.

Roll-on Tipping Trailer

Light weight waste disposal trailer which has a roller system and a scissor-like lifting system which allows the tipping body to be raised and emptied into high sided containers.

Roll-up system

System used to easily open side curtains.

Roller backstop

Roll container trailers have a depression at the rear where the rollers rest and are locked.

Roller shutters

Widely used instead of rear doors because they are quicker to use, save space and easier to open at loading bays.

Roller stop

Roll container vehicles have an adjustable front stop that correctly positions containers of different lengths.

Rolling curtain

Curtain system commonly used on sides and rear of beverage delivery vehicles. The curtain is quickly and easily rolled up. Rolling curtain systems are also used to cover tipper bodies and other open topped vehicles. In this case the curtain material is rolled horizontal across the top of the vehicle.

Rolling floor

Floor system comprising a number of longitudinal tracks containing rollers that are lifted during loading and lowered when travelling. Goods are quickly and easily rolled in and out of the body. Widely used for airfreight vehicles as similar systems are widely used in the air transport industry.

Rolling test station

Equipment used to test vehicle brakes. Wheels are turned on rollers and braking is electronically tested.

Roof cross-member

Profile running laterally between cantrails supporting a fixed aluminium/grp or tilt cover roof skin.

Roof crossmember

The lateral roof members that run across the body between side walls and carry the roof skin.

Roof hatch

Roof openings are usually required for ventilation.

ROP Roll-Over-Protection

Equipment from the Company Knorr which prevents vehicles tipping over in critical situations.

ROR axles

Leading British manufacturer of axles.

Rotos Bogie

Bogie from the manufacturer Schmitz including components from manufacturers SAF, Knorr, SKF & Wabco. Schmitz guarantee the bogie for 1 million kilometers maintenance free.


Manufacturer of silenced compressors for silo vehicles.

Rubber sleeve

Rubber sleeve protecting the mechanism of a braking device e.g. on an over-running brake.

Rubber torsion axles

Primarily axles for car trailers where suspension is achieved by rubber extrusions in a steel hollow box section.