Chassis Cab Extensions

[Zedstack]

Hello all

I wonder if any of you gents or ladies could point me in the right direction? I want to know if a Certification is required for the extension of chassis cabs. I'm doing a project about it at Uni, but have struggled to find the Certification needed to undertake such work

Oh and Welshpug is there any forum which you arent on

 

[English Steve]

Certification as such is not required (yet), but the chassis manufacturer will have set parameters which you must remain within. Shortening or extending the rear overhang is done all the time by bodybuilders - we probably modify 80% of the chassis cabs we use in this way - but modifications to the wheelbase are a different story.
There are a number of specialist companies who are approved by various vehicle manufacturers to carry out this type of work. One which springs to mind is Wheelbase Engineering, but there are several others.

Remember, you MUST comply with Construction and Use regs, and if it is an HGV you should also inform VOSA of the modifications.

When Whole Vehicle Type Approval (Directive 2007/46/EC) comes into force for the vehicle type you are considering, you will have to gain approval for your modifications before putting the vehicle on the road or offering it for sale.

 

[john224]

ext cab

What type of motor are you talking about?
Me and my mates have shortened several landrovers over the last 2 years from 110" to 80" and all road leagle ,Most of them are for compertition work so have to be extra safe as well as complying with (mot) they must be complyant with the (RAC MSA) motorsports ass?? AS you dont want it falling in half at 80mph across ploughed fields,,,,

 

[Zedstack]

Thanks Steve

I'm talking about extending the wheelbase, ie chopping the chassis in half and adding a piece in to make the chassis longer. Perhaps for Tipper systems or Tankers?

The reason I ask is because a friend of mine was approved to lengthen chassis by Dodge Trucks back in the 1980's, and I thought it would be a good subject to write up about.

 

[English Steve]

Zedstack - no problem, and good luck with the college work.

Johnwestmids - what you are doing is a known conversion carried out by many triallers, but it isn't strictly 'legal'. The 110 is a type-approved vehicle and by modifying it to that extent you have invalidated that approval. 80" is a known Landrover wheelbase and parts are readily available for the conversion, but in effect you are creating a kit car and should have it SVA'd to remain fully road legal (I know no-one bothers).

 

[SC_BK]

A lot of the 3.5t recovery trucks (beavertail) have extended chassis, you basically cut it in half and add a few foot in the middle

 

[john224]

Zedstack - no problem, and good luck with the college work.

Johnwestmids - what you are doing is a known conversion carried out by many triallers, but it isn't strictly 'legal'. The 110 is a type-approved vehicle and by modifying it to that extent you have invalidated that approval. 80" is a known Landrover wheelbase and parts are readily available for the conversion, but in effect you are creating a kit car and should have it SVA'd to remain fully road legal (I know no-one bothers).

Hi All the vehicals that we shorton or lengthon are checked by a (VORSA) technition , We finnished a 88" lengthened to 130" and covverted to a 6 wheeler and 6 wheel drive ,.
when we finnish a motor we fill in the log book and send it of so when it comes back all is correct with swansea and the motors are Re mot~d with all the mods done?

 

[snowcat]

Isn't this just oversight by VOSA tho? , I have little interest in cars but do get fairly involved with Regs and VOSA in a different world..

I cannot see how a standard MOT inspector wouldn't have a scooby about if the design is approved, safe, etc... or even if a weld is structurally sound....

Maybe I'm wrong, If chassis can be cut without an SVA it seams like an accident waiting to happen.....

 

[john224]

ext cab

when they are put on the road they are listed as hybrids ,,,
When the chassis is sleved/puddle welded/ butt jointed and diamond plated it is actually stronger than when it was orriginal , We would not do this sort of thing if it was not safe as every motor we build it treated the same as if it was our own, We wont put our family in a motor that we have built if its not safe , So why should we let anybody else drive one of these motors if we wont drive it our selves,,,

We have 2 lads that are qualified welders one welds big machinery and the other welds aro space parts for a living both over 15 years each,,

2 lads are qualifide machanics one 15+ years the other 25 years
and ime machinest for 30 years,,

So between us i think we are qualified to do this work,,,john

 

[snowcat]

John its not a question on the procedure, Its more on the legality, If you can chop and lengthen a chassis then surely it makes a mockery of testing and the SVA?

I'm not doubting it can be done structurally I'm just bemused that this sort of practice can fall under the radar of VOSA, changing from the original design must change braking steering and all manner of other things..

qualified welders they may be, but without a WPS, approved design, and a qual/code to match the job, It means little within the eyes of the law or HSE...

I'm not starting, just trying to understand at what point the line is drawn......

 

[English Steve]

This is exactly why the new regs are coming in. The type of modification mentioned above can be done perfectly safely by a competent person, but can also be bodged up by a cowboy and be dangerous.
These regs have a designated 'type' for special purpose vehicles - camper conversions, wheelchair enabled conversions - they are all covered, even bolting on a hiab will require a stage of type approval.
JohnWM, if this is your full-time business I would strongly recommend that you read the Type Approval regs to find out WHEN (not IF) they will apply to you. A free download is available from the Department of Transport here, but be warned - it's heavy going.

 

[Zedstack]

I've taken a look at the Wheelbase link that you posted up Steve, but I'm struggling to interpret the C & U regs

I'll delve a little into the project I'm doing so that you have a little background knowledge. Its all fictional but needs some real world facts/certs/regs to make it believable and most of all worth reading and marking

My Company, Artic Services is looking to expand its current premises to accommodate facilities to modify HGV chassis cabs, for Tipper usage mainly.

The project involves me designing a purpose built structure or perhaps (to keep costs down) find a suitable ready built premises. This has then to fitted out with all the equipment needed. All this then needs to costed for feasability. (this bit doesnt matter so much)

I'll then need to draw some diagrams to illustrate exactly what I'm doing to the HGV. Why I'm cutting the chassis in a certain place, how the chassis is to be lengthened and braced and how it will be joined together.

Obviously there is going to be a weight issue, how many axles,tyres are needed to carry a certain payload etc

Would it be best to give VOSA a ring and let them specify what is required? Or maybe visit some local HGV dealers?

 

[john224]

chassis

Hi no its not my or my mates full time job but just a hobbie at the moment its down to how you interpritate the rules??Dont matter how good the rules are theres always a loop hole to work with you just have to find it??/
It does help when you know 2 mot inspectors and a couple of inspectors from(vorsa),,,john
Ps will have a look and study the link...

 

[English Steve]

Zedstack, have a look on some of the truck manufacturers websites. All of the manufacturers issue Bodybuilders Instructions telling us how where and what we can do. Some of them will require you to register, but some will give you instant access. I don't have time to look for the links at the moment (supposed to be working ) but if I get the chance I will have a look later.