Hello, has anyone ever used a 4x4 40t unit or a 6x4 where the steer axle drives? Seem quite common on the continent but I’ve never knowingly seen one in the UK.
ScottishC:
Hello, has anyone ever used a 4x4 40t unit or a 6x4 where the steer axle drives? Seem quite common on the continent but I’ve never knowingly seen one in the UK.
Never used one, but a 6x4 would be a 6x6 if all wheels drive.
Dave…
There are quite a few at the local quarry, I think the newest being around 11 years old and right hand drive. There were 2 2003 registered lhd there but are gone now. I drove both the rhd and lhd versions, mainly the latter. Pics in the links
wicklowvoice.ie/concerted-effort … -rathdrum/
independent.ie/regionals/ne … 54289.html
ScottishC:
Hello, has anyone ever used a 4x4 40t unit or a 6x4 where the steer axle drives? Seem quite common on the continent but I’ve never knowingly seen one in the UK.
I 've never seen a unit or rigid with 6 wheels where the centre axle is both driven and steers, but the front steer axle is not driven. Except possibly specialist heavy-haul kit
So, I would argue that they aren’t common.
4x4, 6x6, and 6x4 with single steer and double drive, all the above, but never a 6x4 twin or tandem steer.
Dave D is, I think, talking about 6x4 with a single steer, and IrishTrucker has links to 4x4 units.
Fair few 6x4 units on round timber work in France. The rules allow for 57 tons on 6 axles.
Sent from my SM-G361F using Tapatalk
Huntapac bought a couple of 6x6,don’t know if they still have them.
I’ve got vague recollections of seeing an artic that was all wheel drive, even the trailer wheels were driven! I saw it in tomorrow’s world, and I think it was a prototype for the army. It showed it in a quarry of some sort, racing to get out ahead of a mining explosion. I remember very little else about it though.
Does this ring any bells with anyone else?
Scratching my memory here but wasn’t that the AWD Multidrive, had a Leyland T45 cab?
Did a bit of research and there’s a Dutch company called pk trucks that seem to have a good few units like this and Tatra do that kind of thing too. Whether it’s Rhd being the limiting factor I think.
dave docwra:
ScottishC:
Hello, has anyone ever used a 4x4 40t unit or a 6x4 where the steer axle drives? Seem quite common on the continent but I’ve never knowingly seen one in the UK.Never used one, but a 6x4 would be a 6x6 if all wheels drive.
Dave…
I meant if the 6x4 had driven front and middle axles and a non driven tag axle. So to carry 44t.
WhiteTruckMan:
I’ve got vague recollections of seeing an artic that was all wheel drive, even the trailer wheels were driven! I saw it in tomorrow’s world, and I think it was a prototype for the army. It showed it in a quarry of some sort, racing to get out ahead of a mining explosion. I remember very little else about it though.Does this ring any bells with anyone else?
ISTR (or dreamed it) a haulier up around Yorkshire maybe trialling the things, 80’s?, tractor drive linked to trailer drive axles via a complicated prop shaft, said shaft obviously seriously limiting how much angle could be managed between tractor and trailer on turns, which negates the main reason for artics, a complicated vehicle to gain an extra 5 ton (if that, i bet the thing was seriously heavy) payload over a light bodied standard 8 wheel tipper of the time.
They didn’t catch on, swapping trailers must have been a complicated event 
Irishtrucker66:
There are quite a few at the local quarry, I think the newest being around 11 years old and right hand drive. There were 2 2003 registered lhd there but are gone now. I drove both the rhd and lhd versions, mainly the latter. Pics in the linkswicklowvoice.ie/concerted-effort … -rathdrum/
independent.ie/regionals/ne … 54289.html
Thanks for the pics. Are they all MAN’s they have?
Juddian:
ISTR (or dreamed it) a haulier up around Yorkshire maybe trialling the things, 80’s?, tractor drive linked to trailer drive axles via a complicated prop shaft,
Not a dream at all, I do remember a company I was with in the early 80s were considering one for farm work, but the cost and the weight stopped them going that route, they also looked at a system which
was a very similiar to modern day caravan movers but was operated by hydraulic motors, control of the system was the down side, because if the unit was stuck we felt the trailer tyres would be damaged and as such
would lead to more problems on site.
Dave…
dave docwra:
Juddian:
ISTR (or dreamed it) a haulier up around Yorkshire maybe trialling the things, 80’s?, tractor drive linked to trailer drive axles via a complicated prop shaft,Not a dream at all, I do remember a company I was with in the early 80s were considering one for farm work, but the cost and the weight stopped them going that route, they also looked at a system which
was a very similiar to modern day caravan movers but was operated by hydraulic motors, control of the system was the down side, because if the unit was stuck we felt the trailer tyres would be damaged and as such
would lead to more problems on site.Dave…
Bedford Multidrive?
flickr.com/photos/67384646@N08/8321362402
Just done a quick search and it is still available , and you can also have it as a steering trailer.
ScottishC:
I meant if the 6x4 had driven front and middle axles and a non driven tag axle. So to carry 44t.
You’d lose much of the extra 4 t capacity in the weight of all the transmission components needed to drive the steer axle.Might as well just go for conventional double drive axles unless it absolutely has to be a 6 x 6 on the spec sheet like the Huntapac example.
Also never seen a 6 x 4 with a driven steer and un driven tag being ‘common’ on the continent if ever. 
While any driven steer type is unusual in the case of tractor units and is more often seen in rigids if at all.
I’m sure not that long ago some landfill operator, like Biffa or someone, paid a fortune to have a refurb and the chassis shortened on old army rigid eight wheelers and a fifth wheel put on. I think they explored all the options as didn’t really want such old trucks but there wasn’t much else out there.
Thanks for all the replies. It looks like due to weight and mpg these units are really rare. They’d be handy for jobs like quarries or farms where grip combined with manoeuvrability in difficult conditions outweighs the disadvantages but these are few and far between. I too have never seen a 6x4 unit with a driven steer axle and a non driven tag axle but it would be a good compromise between a 6x2 for grip and a normal 6x4 for turning circle.
Man do a part time all whee drive system for trucks,
Search man hydrodrive in YouTube, a fair bit of information appears.
ScottishC:
Irishtrucker66:
There are quite a few at the local quarry, I think the newest being around 11 years old and right hand drive. There were 2 2003 registered lhd there but are gone now. I drove both the rhd and lhd versions, mainly the latter. Pics in the linkswicklowvoice.ie/concerted-effort … -rathdrum/
independent.ie/regionals/ne … 54289.htmlThanks for the pics. Are they all MAN’s they have?
In 4X4 guise yes but there are normal 8 wheeler tippers, mixers and block trucks and 6X2 tractor units from Renault and MAN
A 6x4 where first and second axles are driven, third is a steerable tag: