Hi,
The fleet of vehicles where I work are 38 tonne 4x2 Scania tractor units which pull tri axle trailers. We also have a couple of 44 tonne 6x2 tractor units.
A couple of weeks ago my boss asked me to take another company’s trailer back to their depot. It was a tandem axle trailer, and my boss told me I would need to swap my 4x2 unit to a 6x2 in order to pull the trailer. As he’s the boss, I did as I was asked without any questions.
Can anyone tell me the reason for this? The only thing I can think of is that the train weight would have exceeded 38 tonnes, but in that case would it still be legal for a tandem trailer to have such a heavy load on it?
Also, why do trailers need to have different amounts of axles / wheels?
Cheers,
Neil.
TruckerNeil:
Hi,
The fleet of vehicles where I work are 38 tonne 4x2 Scania tractor units which pull tri axle trailers. We also have a couple of 44 tonne 6x2 tractor units.
A couple of weeks ago my boss asked me to take another company’s trailer back to their depot. It was a tandem axle trailer, and my boss told me I would need to swap my 4x2 unit to a 6x2 in order to pull the trailer. As he’s the boss, I did as I was asked without any questions.
Can anyone tell me the reason for this? The only thing I can think of is that the train weight would have exceeded 38 tonnes, but in that case would it still be legal for a tandem trailer to have such a heavy load on it?
Also, why do trailers need to have different amounts of axles / wheels?
Cheers,
Neil.
Yes because the gross weight for 5 axle artics applies to both 3+2 outfits and 2+3 ones but you need 3 trailer axles if you’re using a 4x2 unit at 40 t or a 6x2 unit at 44 t.It’s just that in the case of a 3+2 configuration it will need to be loaded heavier on the front than if it’s a 2+3.
I believe the tax used to be based on amount of axles, so if your unit was taxed as a 2+3, you couldn’t legally run as a 2+2 with a tandem. I don’t know if this is still the case?
TruckerNeil:
A couple of weeks ago my boss asked me to take another company’s trailer back to their depot. It was a tandem axle trailer, and my boss told me I would need to swap my 4x2 unit to a 6x2 in order to pull the trailer.
Your 4x2, 38 tonne unit will be taxed in either band E or F and if in band E you can pull a tandem trailer while grossing up to 34,000 kg and if in Band F you can pull a tandem trailer while grossing up to 38,000 kg. So, maximum 34t you could have pulled it anyway with your unit but if it was between 34 and 38t your unit would need to be taxed in Band F. If the trailer was empty when you were returning it then you could pull it with your unit.
TruckerNeil:
The only thing I can think of is that the train weight would have exceeded 38 tonnes, but in that case would it still be legal for a tandem trailer to have such a heavy load on it?
A 44t thee axle unit will be taxed in either Band E or G and if in Band E it can pull a two axle trailer up to 38t and in Band G up to 40t.
TruckerNeil:
As he’s the boss, I did as I was asked without any questions.
Big mistake. 
Roger Breaker:
I believe the tax used to be based on amount of axles, so if your unit was taxed as a 2+3, you couldn’t legally run as a 2+2 with a tandem. I don’t know if this is still the case?
It changed quite a lot of years ago and units are no longer taxed as 2+3, 3+3 and so on. It is now a more flexible arrangement whereby there are different bands which allow you to pull 1, 2 or 3 axle trailers, subject to certain weight limits, without having to re-tax the vehicle.
It also the reason why that popular driver’s tale about having to run with a lift axle down as soon as you put 1 little box in the back is just a myth these days.
Sounds about right for me, always one foot in the past! Thanks Neil.