Custom Trailer Build - Any IVA Help?

Hi guys,

I'm in way out my depth here and hope someone has some more knowledge on the process of IVA testing and could shout up if anything is clearly going to make it fail. But initially i'll tell you about the trailer itself. Very long story short I am a rower and own fine (racing) rowing boats, one is a single person boat and is 7.94m in length, which is fine to be carried on the roof of a vehicle for transportation. However recently I purchased a 2 person boat which is 10m in length and so requires a trailer to be legally transported. I use this boat with my training partner and he also has his one one person boat which is 8m.

One option that was open to us was to buy a ready manufactured trailer, however like most things to do with rowing they are horrendously overpriced and because of the overhang at the front can't be towed behind my defender due to the drawbar not being long enough. Having spent so much on the boats we were reluctant to be spending stupid amounts of money on a trailer that we'd have to hack and bodge to make work for our needs and so decided to build our own that ticked every box and for a very small fraction of the cost of a manufactured one.

Our main priority was to ensure that the trailer was over engineered for the load (single boats are 12kg each and two person boats 30kg, so not hard to contract a carrying frame easily capable of carrying that) and accommodated the length of the boats (rowing boats when out of water can only have certain areas of them used to support their own weight due to the thin carbon fibre construction). I also wanted to make the trailer so when fully loaded it still sat below the level of the defender in order to reduce drag for long distance towing, combined with making it lightweight. Most of the weight is also very low because rowing boat trailers are prone to tipping in strong crosswinds.

Purchased an ALKO single axle caravan chassis as a starting point: (temporary mudguards for journey home)


Then built a simple steel construction to get the shelving into the correct position for accommodating the boats, and to strengthen the whole construction:

As you can see also added lighting which almost in it's entirety is routed internally through the box section and then through mounted conduit. The steel is all galvanised after the initial build and almost all of it is held together using multiple 8.8 high tensile bolts.

We then added flooring and racks for the oars and an adapted all weather lock box for straps, wheel changing equipment and other general stuff.


The front end was extended with a custom draw bar, the design of which is like this:

(Brake line also extended, the plate which attaches to the existing chassis is of the same size and gauge to the original.)


The next step is getting the trailer through the IVA testing which is the part we're struggling with currently. Finding the form and the requirements as clear as mud and conflicting info online.

Trailer Category: O1
Unladen Weight: (Yet to be confirmed but around 300kg)
Laden Weight: (Again to be confirmed but not more than 450kg)
Length Inc. Drawbar: 7.6m (Max length for an O1 trailer is quoted at being 7,000mm. Is this including the draw bar and hitch?? Or is there exemptions when the load exceeds the max length?)
Length Exc. Draw Bar and hitch: 6.15m
Width at extreme: 2.08m
Braking: The trailer is equipped with the ALKO standard caravan type inertia braking system however due to the lightweight of the trailer will not be functional (or so we think??) so is it then a non braked trailer?
Lighting: The light board is from Trailertek however as for confirming it's legitimacy on the unit itself I'm unsure
Tyres: Brand new and are 175 13C's and 95/97Q

Has anyone put a trailer they have built from scratch through the IVA testing, and has any pointers on what I've done that may be an issue when the test comes around or anything I'm blatantly missing off the build, or should I just fill it out the best i can and hope for the best and just pay to get retests done to get it through.

Or if you have failed IVA testing would you mind sharing exactly on what?

Cheers,
Tom

Only one i can think of who may have done an IVA inspection is @listerdiesel .

Cheers

I'm interested in this as am considering making an expedition trailer from scratch

OK, I'm building another drawbar turntable trailer myself, so I had to investigate the IVA process for my own needs.

If you modify an existing trailer with a manufacturing date prior to 29th October 2012, then no additional testing is required. I have that confirmed by VOSA.

If you manufacture a new trailer after that date then it will have to go through IVA inspection, documentation on the Gov website:

https://www.gov.uk/government/publications/individual-vehicle-approval-iva-it

Modifying a post-29th October 2012 manufactured trailer would also require IVA inspection/Test.

Watch out for overall trailer length, there are limits on how long it can be.

Hope this helps.

Peter

VOSA response:

1) If we home build a new trailer now, it will require Basic IVA, yes or no?
Yes. It would need a statutory IVA as an O1, O2, O3 or O4 (depending on weight) and you would apply on form IVA 1T.

2) If we modify/rebuild an existing trailer that was built prior to June 2012,
we would not need to seek Basic IVA, yes or no?
If the manufacture date remained as prior to June 2012 approval would not be needed, if the date of manufacture was after 29th October 2012 (or 29th October 2014 for a special purpose trailer) it would need an IVA.

3) We understand from a trailer parts manufacturer that drawbar turntable
trailers with front steering axles may be being permitted very small runs or
individidual trailer manufacture with overrun brakes, is this the case or not?
Under IVA there is no restriction to trailers with front steering axles and over-run brakes. All of the trailers wheels must have operational brakes.

"If you modify an existing trailer with a manufacturing date prior to 29th October 2012, then no additional testing is required. I have that confirmed by VOSA."


This is great mate thank you, the chassis is from a caravan built prior to that date, would i be able to get away with saying it's a modified version of that or is that stretching it a bit considering the level of change it's been through?

I suppose I'll have to get in contact regarding the length because unfortunately there is no alternative because the boat being 10m long thats the only way it'll fit! I know there is exemptions for special loads on some trailers such as O2 glider carriers, I am not aware of anyone who has modified/built their own rowing boat trailer so this may be a new area to go under that heading.

Thanks again,

Tom

Do you need to get it tested? You're not building a new trailer but are surely "modifying" the caravan.

private penguin said:

Do you need to get it tested? You're not building a new trailer but are surely "modifying" the caravan.

Click to expand...

On a different note, I vaguely recall something about vehicles over a certain length requiring side positioning lights. Not sure whether that would apply to your trailer, but it might be worth fitting them anyway to reduce the risk of someone T-boning it at night.

My only real comment on the trailer you've made is that the coupling arrangement may look a little strange, but having said that we've been out with our big 6-wheeler in the UK and never had any comment or been stopped, here or in Europe.

Might be worth getting the chassis serial number dated by Alko, then you can't be touched on the mod's.

Maximum length is 7m excluding the coupling and drawbar, I don't see any exclusions for specials, but there may be something.

Peter

private penguin said:

On a different note, I vaguely recall something about vehicles over a certain length requiring side positioning lights. Not sure whether that would apply to your trailer, but it might be worth fitting them anyway to reduce the risk of someone T-boning it at night.

Click to expand...

Definitely a good idea, I will look into it. My intention was not to get it tested due to the fact it was modifying the caravan. Just i heard of the insurance issues that could arise if indeed i should have got it tested in the case of some incident

listerdiesel said:

My only real comment on the trailer you've made is that the coupling arrangement may look a little strange, but having said that we've been out with our big 6-wheeler in the UK and never had any comment or been stopped, here or in Europe.

Might be worth getting the chassis serial number dated by Alko, then you can't be touched on the mod's.

Maximum length is 7m excluding the coupling and drawbar, I don't see any exclusions for specials, but there may be something.

Peter

Click to expand...

Yeah the coupling was a bit of a ball ache in all honesty, wanted to reuse the existing coupling and just add in the draw bar and just extend the brake rod, but was easier said than done as it turned out. It was originally slotted holes for U Bolts to clamp the draw bar to the chassis but we found it wasn't as good a hold as we'd like so ended up welding it on instead and it's much better. Looks funky but functional.

Tom

I'd think about a wire and turnbuckle between the front and rear uprights to stiffen the chassis longitudinally, and maybe something extra at that front original hitch mount point to underneath, giving it more strength, but you'll need to load it and try it out to see if you have any weaknesses.

Ours was a complete one-off, designed and built by me, but I have drawings for everything I did and it's been to Europe 6 times at 3500kg max weight with no issues.

The new one is slightly smaller but the same principle.



Peter

listerdiesel said:

I'd think about a wire and turnbuckle between the front and rear uprights to stiffen the chassis longitudinally, and maybe something extra at that front original hitch mount point to underneath, giving it more strength, but you'll need to load it and try it out to see if you have any weaknesses.

Click to expand...

Will be something I will look into, it's thankfully after adding the ply it stiffened up hugely, I have ran some tests so far essentially overloading the front end to see how it coped and so far no signs of weakness/cracking in the welds. Thankfully the maximum weight of the load this will take is only about 100kg.

But have to say your's is beauty, what kind of time frame does it take you to construct one? Makes me wish I had the budget and the time to see a project like that through! Mine was built in such a short time because its needed in the coming weeks.

Tom

Actual build time was about 3 months, there's a link in my signature for the whole build blog with drawings etc.

The chassis was custom built:



Shotblasted, Zinc sprayed and powder coated:



We built it outside the front of the house:







and so on.

Hopefully the new one will avoid some of the traps we fell into with that one, although we didn't do too badly with it.

Peter

Outstanding, good luck with the new one.

Tom

Hi Mate this is my first comment on a post just happens to be in my field, i work for a company called Motiv Trailers we make all kinds of bespoke trailers and my job among other things is currently getting said trailers through IVA's,

all rules are depending on the tester its very much a bull**** test, they have no interest in trailer frame, rigidity or build just light positions and paperwork,

in regards to length you will have an issue there and although you may think your drawbar extension is safe, they probably won't,

your trailer will have a test for a braked caravan as it is very much not the same i would recommend a test, you will have to strip the axle of all braking so remove cables, auto reverse, brake shoes and so on,

all cables must be fixed at least every 300mm and if going through the frame just dab some silicone around it, or they will pull it up for potential of wires chafing.

two issues with lighting i can see is that the rear retro triangle reflectors and all lights must be a minimum of 400mm from the extreme edge of the trailer so you may want to measure up and consider a combination lamp with triangles built in

also you need amber side reflectors on a trailer your length you will only need 2 per side, one within a meter from the back and one in the middle third of the trailer but not more than 3 meters from the other

i hope that's of some help, anything else you need to know let me know

mikeepen said:

Hi Mate this is my first comment on a post just happens to be in my field, i work for a company called Motiv Trailers we make all kinds of bespoke trailers and my job among other things is currently getting said trailers through IVA's,

all rules are depending on the tester its very much a bull**** test, they have no interest in trailer frame, rigidity or build just light positions and paperwork,

in regards to length you will have an issue there and although you may think your drawbar extension is safe, they probably won't,

your trailer will have a test for a braked caravan as it is very much not the same i would recommend a test, you will have to strip the axle of all braking so remove cables, auto reverse, brake shoes and so on,

all cables must be fixed at least every 300mm and if going through the frame just dab some silicone around it, or they will pull it up for potential of wires chafing.

two issues with lighting i can see is that the rear retro triangle reflectors and all lights must be a minimum of 400mm from the extreme edge of the trailer so you may want to measure up and consider a combination lamp with triangles built in

also you need amber side reflectors on a trailer your length you will only need 2 per side, one within a meter from the back and one in the middle third of the trailer but not more than 3 meters from the other

i hope that's of some help, anything else you need to know let me know

Click to expand...

Champion mate thanks for that, I will look into all of the above cheers! I was hoping someone on here was a particular expert in the field, I will see how i go and I'll get back to you if theres any issue!

Tom