Good morning all, first post so please bear with me, I am fairly new to the world of HGV.
I run a forestry and tree surgery contractracting company and we are looking to get our first proper hgv.
Ideally I would like a 6x4 day cab tractor unit that we can remove the 5th wheel and fit a tipping chip box with a hiab at the rear.
I would then like a drawbar to tow a plant/timber trailer.
Is this legal and feasable? I know it varies between models of hgv but what sort of capacity would we be able to put onto the tractor unit alone. And with a drawbar trailer what sort of trailer weight would I be allowed to tow?
Thanks David
Well the unit would probably be plated around 26 ton and weigh about 9 - so deduct this and the weight of the crap you are fitting (hiab & body) eg another 4 ton & that would give you a 13 ton payload.
Train weight probably 44 ton depending on number of axles on trailer - so could potentially pull another 18 ton.
There will also be axle weights to consider
Good Morning and welcome to the Forum. What follows is not meant to be an instant rebuff. I hope we can help you with this and other matters, but unfortunately there is an element of hostility towards the agricultural industry because of the concessions it is allowed regarding road going vehicles. What you propose can be done within the construction and use regulations relating to HGV, but you will probably find your services uncompetitive if you attempt to do so. The modifications to stay within C&U will quite probably become subject to a notifiable alteration examination by the DVSA because of alterations to body type and fixed equipment.
transportoffice.gov.uk/crt/r … e%2005.pdf
You are probably going to be able to license your ‘contraption’ (no insult intended) as an agricultural vehicle, so therefore more or less exempt from just about everything except lighting regs, tyre law and H&S. You need to enquire about that from within your industry. This is definitely the loophole which seems to be used. If you do go down this route and intend doing a significant road mileage do please remember that the Police and DVSA can still stop your vehicle for examination.
hse.gov.uk/aboutus/meetings/ … paper2.pdf
fwi.co.uk/machinery/tractor- … s-test.htm
The double drive unit will probably need a significant amount of ballast underneath the chip box to ensure traction even allowing for a rear mounted Hiab. Again no insult intended, but do get the trailer coupling engineered professionally with any welding carried out by a coded welder.
I will assume though that as an agricultural vehicle you will be limited to a gross combination weight of 31 tonnes. Looking at your proposal through my hostile haulage industry glasses I would certainly hope that your gross weight would be so limited.
Good luck with your project and do please return.
Edit: links added
Thanks for the advice so far and the links, ill have a read through them when I get home later on.
As far as the aricultural registration I am looking to move away from all of that. I want to operate a 100% legitamate service with no grey areas. I know many people use these loopholes to their advantage, however its me on the line if there is an accident etc. Wheb you say it may need addittional ballast for traction is that under usual driving conditions or or more strenuous areas? I assume from the above comments that a drawbar hitch is rated to the same weight as a 5th wheel coupling?
Dave177:
Thanks for the advice so far and the links, ill have a read through them when I get home later on.
As far as the aricultural registration I am looking to move away from all of that. I want to operate a 100% legitamate service with no grey areas. I know many people use these loopholes to their advantage, however its me on the line if there is an accident etc. Wheb you say it may need addittional ballast for traction is that under usual driving conditions or or more strenuous areas? I assume from the above comments that a drawbar hitch is rated to the same weight as a 5th wheel coupling?
Google “VBG couplings” for the drawbar hitch, for example i run tandem trailers on 50 mm coupling, its designed for 1 ton imposed load and towing 24 ton.
Dave177:
Good morning all, first post so please bear with me, I am fairly new to the world of HGV.
I run a forestry and tree surgery contractracting company and we are looking to get our first proper hgv.
Ideally I would like a 6x4 day cab tractor unit that we can remove the 5th wheel and fit a tipping chip box with a hiab at the rear.
I would then like a drawbar to tow a plant/timber trailer.
Is this legal and feasable? I know it varies between models of hgv but what sort of capacity would we be able to put onto the tractor unit alone. And with a drawbar trailer what sort of trailer weight would I be allowed to tow?
Thanks David
Are you meaning a side tip ? Just wondering how your going tip with a crane at the rear , my 6 wheeler single drive weighs 12500kg,that is a roll on/ off with cab mounted crane and draw bar hitch , the tipper body adds 2500kg or the flat 2000kg ,with a tandem drag at 40 tonne I carry 21500 give or take depending on which trailer or body iam using .
Yes it would be a side tip, I would want the crane over the rear to have the option of loading trailers etc. I have been back and forth on different configurations of unit and was very close to going for an 8w hookloader but was strugging with getting the best use of it.
I mentioned ballast because apart from traction you need to consider braking and handling, the very last thing you want is the tail wagging the dog, which might happen if the drive axle weights are insufficient in relation to the towed weight. Any ballast is going to depend upon the weight of the trailer both laden and unladen. It will obviously also depend upon the weight of the unit’s tipping chip body and the Hiab.
Without checking on the specification of double drive tractor units likely to be available, I will assume that you might find that what you acquire has a steel sprung rear bogie. This will make the position and weight of the Hiab more important since air suspension makes axle weight distribution and braking force compensation easier to achieve. The issue with a drawbar coupling is more to do with the crossmember to which it is attached. It is vital that this and its attachment to the chassis is up to the job. The best way to achieve this is by reference to the chassis manufacturer’s detailed instructions for bodybuilders. While not an everyday occurrence, in exceptional circumstances it has been known for a drawbar trailer to rip the unit rear crossmember completely out of the chassis with catastrophic results.
i am selling this 14t/m ,10.4 metre reach as I’ve bought a new 26 t/m if your interested .
Dave177:
Yes it would be a side tip, I would want the crane over the rear to have the option of loading trailers etc.
You know you can always drop a trailer and park next to it to load. From what you have been saying about your needs, a three axle muck-away tipper with a draw bar coupling could be a cheaper and off the shelf way to get started but the grab would be mounted behind the cab on any off the shelf wagon.
Thanks for the offer on the crane, however I would be looki g at a grab lorry/timber crane as opposed to a folding z crane.
I have thought about getting a standard muck lorry and dropping the trailer to load, it just reduces the versatility of the unit.
With regard to the ballast when towing with no load on the unit I hadnt given it much thought, what sort of weight is usually put through the 5th wheel?
Below is a spec sheet for a 6x4 Scania unit with an air suspended bogie. This shows all dimensions and the axle weights for a bare chassis. A semi trailer at full weight can impose up to 15 tonnes on the 5th wheel, although this is likely to be less in practice. Even though you will be using a drawbar trailer, the position of its axles, how much weight is on it and how that is distributed is going to affect handling. What is going to matter is the weight of your tipping body plus the Hiab installation and their mounting positions on the unit chassis, this will govern the drive axle weights of your unladen unit, which will be the worst case scenario for towing your trailer loaded with whatever you need to take out to the job.In practice the need for any ballast might be overcome by the volume of the oil tank for the Hiab and body. From the spec sheet you can see that there is not a lot of room without extending the chassis. If that becomes necessary you are going to need to contact one of the specialist chassis modification companies, because the extent of the paperwork which needs to be presented for the DVSA examination can become very involved. What will also matter is the proposed gross weight of the towing vehicle; what is the weight of a cubic metre of chippings? Will a load be making a significant difference to the unit’s gross weight?
scania.com/content/dam/scan … 00_440(6x4SpecSheet_SAU2016-8-P400_P440_6x4_WEB.pdf
link doesn’t want to work, but if Scania 6x4 specification is typed into Google and 440 6x4 is selected the details will come up.
Firstly A frame drawbar configuration is far more tolerant of weight mismatch between prime mover v trailer than close coupled regards handling.Although car transporters seem to manage with arguable success in the case of the latter but obviously with lower overall gross trailer weights.
On that note ballast in the case of the former is mostly about traction.In which case what you seem to be describing isn’t rocket science.In that you seem to just be calling for ballast tractor/prime mover and drawbar trailer type configuration.But in which you want to replace the ballast component of the prime mover with a Hiab and payload instead.In which case you just need to find a good specialist truck chassis modification outfit that can do artic tractor unit to drawbar prime mover conversions.Also don’t see any reason why that outfit can’t run at 44t gross.
A while back, I was inspecting a (ex-army) 4x4 MAN for forestry industry.
This had a drawbar coupling and pulled a Centre Axle Drawbar (3axle), tipper body on the rigid, and crane (fast load timber crane) mounted on the trailer, but hydraulic driven from the truck pto.
The problem they had that in their set up the timber crane couldn’t be shortened enough to be stored on their short wheelbase rigid.
The whole combination was extremely capable in the woods and on bad roads.
The 4x4 configuration with the different diflocks would get them out every situation.
If you for a full drawbar (A-frame) a short prime mover and a long trailer would make it extremely moveable.
But not every drive is capable to operate this set up.
It seems to me like its going to be expensive and a lot of aggro, there must be an off the shelf product that will do the job?
6x4 tractor traction when running light is just plain rubbish, even an empty 8x4 tipper can get tail happy.
We used to look after a couple of 6x4 tractors and if you didnt get a little run up they would cross axle on the slight abrupt incline just getting out of the yard and that was on concrete!
Is this the kind of thing your after, mine is on a 6x2 with a 23002 palfinger behind the cab will reach just over 12 meters and lift 1.5 tonnes, I have a 10’ body that fits over the 5th wheel as you can see I have my ballast weight on in the picture (weighs 3 tonnes) that I use when towing large timber shredders
This is the body I built for it the dumper weighs 5 tonnes
