Glossary of Terms

• ADR (This is the European Agreement concerning the international carriage of Dangerous goods by Road derived from the French "L'Accord européen relatif au transport international des marchandises Dangereuses par Route")
• Artic / Articulated vehicle (Vehicles that comprise of a tractor unit and trailer)
• BHP (An abbreviation for Brake Horse Power, a measurement of the power created by an engine)
• Bonneted Truck (The cab is behind the engine - like the American and Australian trucks. These have recently been launched in the UK by Scania and Volvo)
• Class 1 (The driving licence required to drive an articulated truck in the UK)
• Class 2 (The driving licence required to drive an rigid truck in the UK over 3.5 tonnes under the new photocvard licence)
• Class C (The driving licence required to drive an rigid truck in the UK over 3.5 tonnes under the new photocvard licence)
• Class C+E (The driving licence required to drive an articulated truck in the UK)
• CPC (Stands for Certificate of Professional Competence)
• Curtainsider (The loading area of the vehicle has curtains to the sides of the vehicle/trailer allowing wider access to load / unload the vehicle, usually by fork lift truck)
• Derv (Diesel fuel)
• Diff (stands for Differential. Each axle has its own differential which transmits the drive created by the engine and gear box to the road wheels. This means when the truck corners, each axle can move at it's own speed)
• Diff lock (stands for Differential Lock. Each axle has its own differential which transmits the drive created by the engine and gear box to the road wheels. Diff lock locks the axles so that they travel at the same speed. This is useful when you are caught in mud or loose road surfaces and cannot get moving due to no grip. Diff lock can only be used for short distances and should not be used for normal driving)
• Drawbar (Trucks that have a rigid front unit with a 'drawbar' trailer pulled behind. This should not be confused with Artic which consists of a cab unit hauling a semi-trailer.)
• Fifth Wheel (The equipment on the cab unit used to hold the kingpin on a semi-trailer)
• GCW (stands for Gross Combination Weight. This is the gross vehicle weight of tractor and trailer or complete drawbar)
• GTW (stands for Gross Train Weight. This is the maximum allowed total weight of a towing vehicle with its trailer when loaded)
• GVW (stands for Gross Vehicle Weight. This is the total allowed weight of the vehicle when loaded)
• HGV (stands for Heavy Goods Vehicle though LGV is now used more commonly)
• Jack Knife (This is a term given when an axle slides and the side of the semi-trailer turns to meet the back of the cab unit [i.e. at a 90 degree angle])
• Kingpin (This is the pin located on the semi trailer which sits in the fifth wheel when a semi-trailer is coupled to the cab unit)
• Kerb Weight (The full weight of a vehicle without driver or load)
• LGV (Stands for Large Goods Vehicle)
• Payload (The maximum weight of a load that can be carried on the vehicle to stay with the GVW)
• Plate (A plate on the vehicle displaying GVW and individual axle weights)
• PTO (Stands for Power Take Off. This is where auxiliary equipment uses the vehicle's engine or gearbox - for example where a milk tanker uses the vehcile's engine to create a vacuum in the tank)
• Rigid Truck (Quite simply a non-articulated truck)
• Semi-trailer (The type of trailer used with a tractor unit)
• Susies (These are the pipes and cables that are used when connecting a tractor unit to a trailer. They typically include an emergency red line, an auxiliary blue line and a service yellow line. There may also be a black ABS line) 
• Tachograph (An instrument used to record speed, activity type and the time. There is a legal requirement to use these on vehicles over 3.5 tonnes and can either be an analogue tachograph [uses tachograph charts] or a digital tachograph [uses smart card technology to record activity])
• Telematics (On board computer systems for collecting and transmitting data about the truck, its movements and mechanical condition. It can record such data as number of gear changes or harsh braking incidents)
• TIR (Stands for Transport Internationale Routiers. This is the European Carnet System to facilitate international movement of goods)
• Torque (is measured in Newton metres or pounds-feet and is the measurement of the force of an engine at the crankshaft output flange)