I was having a wee read on RT and found this bit of information. Have a look at the section highlighted in red. On every artic I’ve drove, the front axle (steering) had parabolic springs fitted. There’s been no sign of air bags. Does parabolic springs fall under the catagory of ‘RFS’?
Roadtransport.com:
Weights
Maximum legal weights are determined by a number of factors, including the spacing between the axles, the outer axle and bogie spread, the number of tyres on each axle, and the type of suspension fitted. Vehicles with Road Friendly Suspension (RFS) and twin tyres on the drive axle are permitted higher weights than those without. The majority of vehicles with RFS operate on air suspension, but some rubber and hydraulic suspension may also count as road-friendly.
- 96/53/EC authorises trucks on international journeys at 40 tonnes GVW on five axles (a two-axle tractor towing a three-axle trailer) provided the drive axle weight does not exceed 11,500kg.
Did you know?
UK hauliers are allowed to operate at a higher weight limit than is generally the case in the rest of Europe. The government calculated that permitting 44 tonnes on six axles is less damaging to roads than the 40 tonnes on five axles authorised under EC96/53.
To operate at 44 tonnes both the tractor and trailer must have three axles, none of which should exceed 10,500kg and all of which must have RFS. The distance between the coupling centre and the centre of the rearmost axle of the semi-trailer must be at least 8m.
They must. You don’t even need air suspension on the unit, although most do. Volvo’s suspension was classed as road friendly at least, and probably loads more, when 44t came out.
It must be air suspension on the trailer though.
renaultman:
They must. You don’t even need air suspension on the unit, although most do. Volvo’s suspension was classed as road friendly at least, and probably loads more, when 44t came out.
It must be air suspension on the trailer though.
Was the Volvo suspension called B ride or S ride? I remember the idea was an S shaped spring that supposedly took the shock as well as air springs.
Wheel Nut:
renaultman:
They must. You don’t even need air suspension on the unit, although most do. Volvo’s suspension was classed as road friendly at least, and probably loads more, when 44t came out.
It must be air suspension on the trailer though.
Was the Volvo suspension called B ride or S ride? I remember the idea was an S shaped spring that supposedly took the shock as well as air springs.
I think it was S ride?
It was over 10 years ago mind.
ERF’s EC model with steel springs was also Road Friendly around the same time
Wheel Nut:
renaultman:
They must. You don’t even need air suspension on the unit, although most do. Volvo’s suspension was classed as road friendly at least, and probably loads more, when 44t came out.
It must be air suspension on the trailer though.
Was the Volvo suspension called B ride or S ride? I remember the idea was an S shaped spring that supposedly took the shock as well as air springs.
No, B ride is a twin tyred rear lift & S ride, the more common in the UK, single tyred rear lift, both are unfriendly steel suspension 
I know the springs you’re on about though, they were an S shape, but only on 4 wheelers so no good for 44tonnes anyway, although to run 40tonnes on five axles the same criteria applies.
Steve-o, don’t believe all you read on RT, some of these journalists talk a load of old tripe 
EDIT
Getting my A & B ride mixed up 
B ride is a light duty 4 spring 6x4 set up, A ride is/was the twin tyred rear lift
I would have thought that parabolic springs come under RFS as they are more pliable than the conventional multi leaf springs,as I know well,having converted my Land Rover to parabolics,the ride is now more like a coil sprung than cart sprung model.
Hiya … you can run a 8 legger at 40 tons and 165 road tax… If you talk to the guy,s who operate the mobile concrete
mixers that mix at your house ( just the required amount)you,ll find they operate at 40 tons because they come under Plant
i think they also run on red fuel…silly is,nt it.
John
