Tractor units / Prime movers

Used tractor units for sale

Tractor units (also known as prime movers) are heavy-duty vehicles designed to haul semi-trailers. They are equipped with a powerful engine, a strong frame, and a cab designed to accommodate the driver. The tractor unit is connected to the trailer via a fifth wheel and a kingpin, which allows the trailer to pivot and turn while the tractor remains straight. The engine provides power to the drivetrain, which in turn powers the rear wheels to pull the trailer. Common types of tractor units include day-cab and sleeper-cab variants, as well as conventional and cab-over configurations.

The most seen and used tractor units in Europe are called cab over engine (COE) or sheer face tractors. In the USA you will see more "torpedo front " tractor units / or tractor units with a nose where the engine is in front of the cab.

• Standard tractors
  The most common type of tractor in the transport world.
• Heavy load tractors
  These tractors are equipped with a heavier chassis and several (driven) axles to realise a higher loading capacity. In addition, the heaviest tractors are often equipped with a torque converter so that they can move any heavy load. 
• Volume tractors
  These are tractors that have a maximum height of 105 cm from the ground at the top of the fifth wheel. These tractors can be used to transport high trailers (Volumetrailers, Megatrailers) without exceeding the maximum legal height. These tractors are also often used to transport high, indivisible loads on open trailers. Other names for Volume tractors are: Mega tractors, Jumbo tractors and Lowdeck tractors. 
• Dangerous goods tractors (ADR)
  These are tractors that are specially equipped to transport dangerous loads. Examples are a main switch/kill switch, fire extinguishers, hazard signs or an emergency power supply that can continue to cool or heat liquids when the engine breaks down. 

Tractors with crane

A truck mounted crane is a common piece of equipment. These powerful telescopic cranes can load and unload on the spot regardless of the type of trailer attached. 

PTO (power take off)

A truck mounted crane is driven by a power take-off PTO. This can be switched on separately. It is an extra system on the gearbox or reduction gearbox of a truck. However, the engine of the tractor is used.  A truck mounted crane is, as said before, an attached implement which works with PTO (power take off). The tractor does not have to drive to use the implement. PTO is not only used for truck mounted cranes but also for driving water pumps on a fire truck.  

In terms of wear/ consumption, you can use the following rule: 1 hour operating the crane is equal to 50 km driving.
Tractors with PTO 

Intarder, retarder and engine brake are additional braking systems

Intarders and retarders are transmission brakes. Truck manufacturers are increasingly using the name intarder because this retarder system is fully integrated into the driveline, whereas a retarder used to be retrofitted to a driveline. An intarder or retarder is especially recommended for routes through mountainous areas. It increases safety and reduces wear on drum or disc brakes. A 
An engine brake generates extra braking power by completely closing off the exhaust system and thus providing the engine with a great deal of counter-pressure. 

Cabs

International transport is driven with tractors with a sleeper cab. These are luxury cabins with a sleeping place for the driver who is sometimes on the road for days/weeks. National transport tractors often have a day cabin. Many brands use their own names for the different types of cab. Volvo, for instance, has the Globetrotter cab, especially for long distances, while DAF calls it a Space Cab.  

Known brands

• DAF tractors
• Scania tractors
• MAN tractor units
• Volvo tractor units
• Mercedes-Benz tractor units
• Renault tractors
• Iveco tractor units

The look

Tractors vary greatly internationally. The term "standard tractor" means something different in the EU than in the US. Standard tractors in the EU have a flat front with the engine located under the cabin. In the USA they call it a Cab over Engine. When an American talks about a standard or conventional tractor, they mean the European term torpedo tractor. Here the engine is in the nose of the tractor unit.