Tractor Units are the workhorse of the UK transport industry. They have been the biggest sellers in the UK for decades. Unlike Continental Europe where there is a penchant for drawbar outfits, the UK has a love of the ‘big rig’.
To the uninitiated, a tractor unit is the front part of an articulated vehicle and semi-trailer combination. In the UK these trucks can carry a maximum train weight of 44 tonnes if they have three axles (more on this below…). Most truck manufacturers have a range of tractor units – we list them all for sale here at Truckpages. The exception to this is Isuzu that does not sell a tractor unit in its current UK line up.
For Auction at the Euro Auctions sale Leeds - 27th, 28th, 29th & 30th January 2021. This item will go under the hammer on 2021-01-27. 2010 DAF CF85-410 6x2 Midlift, Manual Transmission, Slider, 2 Way Camera (Reg. Docs. &...
For Auction at the Euro Auctions sale Leeds - 27th, 28th, 29th & 30th January 2021. This item will go under the hammer on 2021-01-27. 2005 Renault 420DCI 6x2 Midlift, Slider, A/C - EU05 NWN - VF622JVA000105236
For Auction at the Euro Auctions sale Leeds - 27th, 28th, 29th & 30th January 2021. This item will go under the hammer on 2021-01-27. 2008 Volvo FM440 6x2 Midlift, A/C - 08 MN 6666 - YV2SJS02C58A670760
Carr Hill Industrial Estate, Doncaster, South Yorkshire, DN4 8DE
For Auction at CVA Carr Hill Industrial Estate, Doncaster, South Yorkshire, DN4 8DE on 2021-01-26 *DONCASTER* BIG SPACE CAB, MID-;IFT, A/C, SLIDING 5TH WHEEL MoT: 2021-10-31* Price is Plus VAT * * No. of former keepers: 1 Weekly...
For Auction at the Euro Auctions sale Leeds - 27th, 28th, 29th & 30th January 2021. This item will go under the hammer on 2021-01-27. 2008 Renault Premium 320DXI 6x2 Rear Lift, Beavertail Plant Lorry, Hyrdraulic Winch, Ramp -...
Whilst nearly every truck manufacturer has a tractor unit range, it is historically the Scania R-Series that has topped the shopping list for UK tractor unit operators – especially the Scania V8. More recently, Scania has introduced the S-Series which will no doubt take over at the top of the list.
The Volvo FH – especially the Globetrotter/Globetrotter XL is a desirable truck which has started to see some competition with the improved Mercedes Actros in recent years since the launch of the Euro 6 versions.
Sitting centre stage are the DAF XF trucks – excellent value but are some put off by the ageing cab design, despite DAF’s efforts at modernising the 1990’s cab?
Joining DAF is MAN with their TGX and TGS range of tractor units with the less favourable brands in the UK of Iveco’s Stralis and Renault Truck’s Range T bringing up the rear. These days this is less about the actual trucks themselves – nobody makes a bad truck these days – it is more about the reputation of the brand earned over the years.
The transport industry has a very long memory!
Tractor Units by Body Type
All tractor units are not the same. Firstly, there is the size of the cab. From a small day cabbed tractor unit for local distribution to a small sleeper cab for occasional nights out, to a double sleeper, medium roof to a flat floor, high roof sleeper for long distance and international work that has up to 2.25 metres standing room – as much as a house!
You can also get tractor units designed for heavy haulage. These giants can tow up to 150 tonnes gross train weight under s special license.
A specially equipped tractor unit is required to tow a tanker with flammables on bard. These must meet ADR regulations – more commonly in the UK these are called ‘Pet Regs’ tractor units.
More popular on the continent, you can get ‘low rider’ tractor units that have extra small wheels and tyres which tow an overheight trailer. As the bridges in the UK are higher than in mainland Europe, we see these less often here.
In bygone days and if you travel widely on the Continent, then 4×2 tractor units is all you would see. These are basically trucks with just two axles. The lack of a third axle means that they can legally carry just 40 tonnes when using a three-axle trailer in the UK.
In the UK these trucks are used only when the vehicle always carries such light, but bulky materials that they are physically full before they get to anywhere near their 40-tonne limit. Picture a truck full of polystyrene blocks, for example.
In days gone by, many supermarkets specified these 4×2 tractor units – they are physically a little smaller and cost less in road tax than the tree-axled counterparts. They were known in the used truck industry as ‘Supermarket Trolleys’ and were not very popular.
The problem is that these 4×2 tractor units are typically less desirable in the UK’s second-hand truck market. For this reason, an operator may opt for a 6×2 tractor unit, (see below) as they are easier to sell on their second life.
Many canny truck dealers will take these 4×2 tractor units and stretch the chassis, removing the fifth wheel (the hitch on the back that allows the truck to connect to the semi-trailer) and will fit a rigid body – perhaps a beavertail or crane body. This means that the operator will have a powerful truck for their application.
The other destination for these tractor units is overseas. Many trucks are exported to African countries where they drive on the left side of the road – therefore needing well-maintained right-hand drive used tractor units from the UK.
With three axles to spread the load, a 6×2 – or three-axle – tractor unit is able to carry up to the legal limit of 44 tonnes gross trail weight in the UK. There is still only one axle that does the driving in this example (the ‘6’ meaning six points of contact to the ground and the ‘2’ meaning the number of these that are powered and drive the truck forward.
Sure, the trucks are slightly heavier with the extra axle – let’s say an extra 1 tonne to 1500kgs, but this is more than compensated for by the additional 4 tonnes payload allowance.
These trucks should be better for the UK’s roads, as more axles means a better spread of weight. With a three-axle semi-trailer in both examples, the weight across each axle of a 6×2 tractor unit is lower than that of a 4×2.
There are a number of options how to add the extra axle. Check out DAF’s graphic which explains these.
You can have the axle placed before the drive axle, in the middle of the truck (Mid-axle) or it can go afterwards (rear axle). When not required (in other words when operating empty or only part-loaded, many of these axles are designed to lift up. This means that they are not in contact with the road and not getting worn out unnecessarily. These are called, somewhat unsurprisingly, ‘lift axles’. In the adverts for used tractor units in Truckpages you will see written ‘Mid-Lift’ or ‘Rear-Lift’.
These are less common sights on the UK’s roads. They are similar to a 6×2 tractor unit, but the third axle is also driven. This makes the axle heavier, as it has an extra set of wheels and tyres plus a central differential and propshaft all adding to the weight.
The only reason to specify a 6×4 tractor unit is for added traction – in the case of building site operation – collecting excavators and loaders from construction sites. It would be very rare to see a 6×4 tractor unit with a lift axle – but not impossible.
The other use for the 6×4 tractor unit is in heavy haulage mode. These are trucks that have been designed specifically to be able to carry more than the 44 tonnes GTW. Some of these trucks can manage as much as 250 tonnes, but these would require more axles again!
These are specialist trucks, normally seen in heavy haulage operation or decked out in military guise. If you see these trucks for sale in the used market, they will be expensive, as they are very expensive to buy new.