As someone who designs trailers for a living www.stevevick.com and supplies to the utility industry, where nothing remotely dodgy is allowed in the front door (although we all know what happens in reality!), I have to work with the regs quite a bit.
Since the law change requiring type approval, IVA, etc. things became a minefield but it basically works like this.
For existing old designs of trailers, nothing is retrospective, so you can use as was built and provided it complies with roadworthiness ie not rotten, brakes and lights work and tyres are legal then for private use off you go.
You can maintain that trailer using parts from anywhere and if it stays to the same basic design then you again will be fine legally, the problem would come if you changed that basic design, which a brake system change would do, and then got involved in an incident involving the authorities.
Any new design, even a 1 off for private use needs to pass IVA type approval, and then earn a ‘Confirmation of Compliance’ notification. Now you could argue that as its an existing older design it didn't need it, but in this case its a commercially produced, dateable design, that would be easily proven to have untested modern modifications made to arguably the most important part.
Modern over run brake systems are just that, a system. The wheel size, brake type, axles and hitch are all matched together to provide the performance that the GTW requires, and the IVA testing covers not only the forward braking performance, but also auto reverse, handbrake, breakaway and handbrake rollback, where the trailers handbrake has been applied and the vehicle is then rolled towards the rear and the brake must still hold.
The main reason that auto reverse brakes are so prevalent here in the UK is tow vehicle size and the law, max tow on over runs is 3.5t, just happens to match most sub 7.5t tow vehicle weights, over run brakes for that size are the least maintenance, most reliable, most economic systems.
Just how seriously the IVA is applied for commercial designs is this, I have to notify them if we change manufacturers of tyres fitted as standard, god forbid size, which require re-submission!
Of course, as a private citizen, just going about your own business you could do exactly as you want, weld anything to anything, and its all fine, until the day that its not, then you have to be able to stand up and justify what you have done and why your engineering was safe, design calculations proved due diligence had been taken and the vehicle was roadworthy and would not be contributory.
It doesn't need to be an accident that gets you pulled either, flat tyre on the M5 or just a suspected overweight by the motorway wombles and hares are set running if they are having a quiet day or got out of bed the wrong side!
Since the law change requiring type approval, IVA, etc. things became a minefield but it basically works like this.
For existing old designs of trailers, nothing is retrospective, so you can use as was built and provided it complies with roadworthiness ie not rotten, brakes and lights work and tyres are legal then for private use off you go.
You can maintain that trailer using parts from anywhere and if it stays to the same basic design then you again will be fine legally, the problem would come if you changed that basic design, which a brake system change would do, and then got involved in an incident involving the authorities.
Any new design, even a 1 off for private use needs to pass IVA type approval, and then earn a ‘Confirmation of Compliance’ notification. Now you could argue that as its an existing older design it didn't need it, but in this case its a commercially produced, dateable design, that would be easily proven to have untested modern modifications made to arguably the most important part.
Modern over run brake systems are just that, a system. The wheel size, brake type, axles and hitch are all matched together to provide the performance that the GTW requires, and the IVA testing covers not only the forward braking performance, but also auto reverse, handbrake, breakaway and handbrake rollback, where the trailers handbrake has been applied and the vehicle is then rolled towards the rear and the brake must still hold.
The main reason that auto reverse brakes are so prevalent here in the UK is tow vehicle size and the law, max tow on over runs is 3.5t, just happens to match most sub 7.5t tow vehicle weights, over run brakes for that size are the least maintenance, most reliable, most economic systems.
Just how seriously the IVA is applied for commercial designs is this, I have to notify them if we change manufacturers of tyres fitted as standard, god forbid size, which require re-submission!
Of course, as a private citizen, just going about your own business you could do exactly as you want, weld anything to anything, and its all fine, until the day that its not, then you have to be able to stand up and justify what you have done and why your engineering was safe, design calculations proved due diligence had been taken and the vehicle was roadworthy and would not be contributory.
It doesn't need to be an accident that gets you pulled either, flat tyre on the M5 or just a suspected overweight by the motorway wombles and hares are set running if they are having a quiet day or got out of bed the wrong side!
