he 6×2 tractor unit is the workhorse of Europe and the wagon of choice in the UK. It is these prime movers that shift the container traffic around the country and are responsible for the backbone of our distribution networks. With a 44 tonne gross train weight, they have the capacity to get the largest jobs done. The advantage over a rigid truck is simple. The tractor unit can be hooked up to a wide variety of trailers without waiting for them to be loaded. The loading of the trailers can take place at any time, without the presence of the 6×2 tractor. The tractor needs only to hook up with the already-full trailer and get on its way. Clearly, this is a far more efficient option that waiting around to be loaded.
The 6×2 tractor also has another trick up its sleeve. Because it can be attached to all manner of trailers, it greatly extends the flexibility of operators. Instead of buying fleets of tankers, fridge trucks or tippers, the operator need only focus on the 6×2 tractor. The tractor is also more manoeuvrable than a rigid truck of similar size and shares its load across several axles. When not required during lighter loads and when running without a trailer, one of the axles can be raised to avoid tyre wear.
In the US, tractor units are almost always of a bonneted design, with the engine in front of the cab and over the front axle. This set-up was originally favoured for easy access to the engine for servicing and maintenance. Some drivers also report a better ride quality and an increased feeling of security that comes from being protected from frontal impacts by a long bonnet. In Europe, however, this design has been almost totally superseded by the cab-over-engine set-up. This makes most efficient use of maximum allowable truck and trailer combination lengths. The reliability of modern trucks makes the bonnet access argument redundant and suspension systems are now such that a comfortable ride is easily achieved.
The 6×2 naming system refers to the number of axles. This set-up has three axles, of which one is driven. A 6×4 tractor has three axles with two being driven. This latter arrangement is more common in long-distance haulage environments. The 6×2 tractor unit allows for a wide range of cabs to suit different operating circumstances. Day cabs are common place, but larger sleeper cabs with either one or two bunks are available for long-distance work. Many manufacturers also offer specialist low roof and short cab versions.
Some 6×2 tractor units have special modifications to suit specific industries. These can include a crane mechanism mounted behind the cab. Such units can still pull trailers, although payload will be reduced due to the weight of the crane. Other modifications include specialist 6×2 tractor units for use with tankers and flammable liquids. These have to be modified in a number of ways to reduce fire risk.
When buying a 6×2 tractor unit you should check for smooth operation of the lift axle and also connecting mechanism. Modern 6×2 tractors are, however, extremely robust and capable of covering a million kilometres or more.