The three-axle or 6×2 tractor unit has become the de-facto standard in the UK due to legislation that demands the third axle for the largest 44-tonne gross train weight configurations. Tractor units themselves have been the mainstay of heavy transport for some years now. This was always going to be the case after the introduction of standard shipping containers, which transformed global freight. Designed to be transferred quickly and easily from sea to road without being opened up, the containers required tractor units to make the system work. Now they dominate our roads, moving loads from all over the world.
The 6×2 tractor units are the more flexible of the two versions as the 4×2 is now limited to lighter loads. In addition to its compatibility with container freight, the main advantage of the tractor unit is its ability to quickly swap loads. This is hugely important in the competitive world of trucking, where time is always money. These trucks are a major investment for any operator and as a rule they only make money when they are moving. Having such assets waiting around to be loaded is inefficient and the tractor unit maximises its productive time by not having to sit idle while being loaded or unloaded.
Instead, they can simply unhook one trailer and hook up another and be back on the road in a matter of minutes. Another advantage over rigid-bodied trucks is flexibility. The tractor unit is not restricted to one type of load and can be swapped to different types of trailer. Tilt trailers, tippers or tankers can all be added when required. The load is also spread across several axles, which makes the combined unit more manoeuvrable than the equivalent rigid-bodied truck. The third axle on a 6×2 tractor unit is raised when not towing a trailer to decrease tyre wear and improve fuel efficiency.
The flexibility of the 6×2’s haulage capabilities is reflected in the type of cabs on offer. Day cabs, for example, are perfect for daily domestic work. These cabs can be pretty spacious and comfortable for full-time daily use but lack any sleeping quarters. If you are involved in overnight runs or longer trips, you are either going to have to arrange overnight accommodation, which will obviously add to your costs, or consider a sleeper cab.
For anything other than standard daily work, a sleeper cab is a must. These cabs will save you lots of money on accommodation and save you time too. A sleeper cab becomes your home from home on long-distance jobs and can come with lots of mod cons. Some versions have microwaves, refrigerators and other appliances built in. If you do a lot of work as a team, the sleeper cabs also come in double-sleeper configuration to accommodate your co-driver or mate.
Finally, make sure you check the operation of the lift axle when buying a second-hand 6×2 tractor unit, in addition to all of the normal checks you will run through.