Caravan MOTs......... maybe?

Just to add a bit of insight into brake testing. In my younger working days, when I had to take HGV's for testing, flatbed, curtain side, box body and tippers were subject to being artificially loaded with a crane like device that was locked to a rail in the ground and pushed down  on the load area of the vehicle. This made any load sensing valves increase the rear brake effort of the vehicle relative the load applied.  Tankers were required to be presented for test loaded. 

I would be interested to understand how a caravans overrun  system is tested "over there" and what is actually tested. Such as checking for imbalance and ovality / run out as well as general performance measured against the the vehicles weight.

Correct, that's how it is done, just like checking the braking performance of a motor vehicle. Head, side or tail wind is irrelevant if the measurement is carried out within the test centre. Each axle is tested separately and left and right hand wheel, too. In the case of a trailer/caravan, it remains hitched to the towing vehicle, which of course is not on the rolling road and the driver is asked to apply the car's brakes. The overrun will automatically deploy.

So if the car is stationary but the caravans wheels are being rotated by the rollers, what causes the caravan brakes to apply.

Unless there is force applied to the towing coupling the caravan wheels will just rotate unless they are just being tested with the hand lever being  operated . 

Agreed. In normal operation, the caravan will catch up to the car & push against the back of the car to compress the hitch which will apply the caravan brakes. Applying the car's brakes while stationary will do the square root of zero to the caravan's brakes/wheels.

Agreed, MM, and Lutz doesn’t say that the car's brakes are applied to operate the trailer brakes so the only reason I can think of for being told to apply the car's brakes is to stop the trailer/caravan being pushed off the rollers when the trailer's handbrake is applied. Obviously, the trailer will move forwards slightly when its handbrake is applied which will put pressure on the coupling creating the impression that the over-run system is operating. This would prove the brakes are set up correctly but not the operation of the over-run system. A properly set up over-run system cannot fail to work.

The question of over-run brake testing was being asked in the trade in the 1970s when the current type of HGV testing system was introduced. No answer was forthcoming from any source.

Agreed, Milo, I had forgotten the load sensing.

We are in accord regarding the method described by Lutz. 👍🏻

Perzackly!👍🏻

We just need Lutz to get back to us to describe how German caravan's brakes are tested 👍

Hi everyone,

I've spoken to my colleague in the technical team who has advised that the Club has always sought to balance the sometimes conflicting demands of ensuring caravanning is as safe as possible with a wish to minimise the costs and inconveniences which are imposed on caravanners.

It’s correct that a few years ago, we successfully argued against EU proposals for the introduction of MOTs for caravans. At that time, the details of the proposed scheme were poorly-targeted, and would not have addressed the relevant risk factors with caravans, but would have been extremely costly to introduce and apply. As it was not a beneficial scheme, we objected to it.

Last year, Parliament tasked the Department for Transport with looking into the safety of O2-category trailers - i.e. above 750kg but no more than 3500kg, which includes almost all caravans and also a great many other commercial and leisure-use trailers. While we know that examples of unroadworthy caravans are around, most owners look after their ‘vans, with extended warranties and relatively high residual values providing incentives to do so. This is not the case for many other types of trailer. The Club has therefore submitted evidence on the specific issues affecting caravan safety, along with details of where improvements are already occurring, and where further improvements could still be made. DfT are due to publish a report on this topic in July 2019, after which the Government will decide whether any changes to the regulatory regime are required or not. If they decide changes are needed, it’s likely that specific proposals will be put out for further consultation, which we would again expect to comment on.

The introduction of MOTs for caravans is always a possibility, but the Club would only support such a move if there was evidence that the targeting of inspections to address relevant concerns could be done in a cost-effective and practical manner. At present, as far as caravans are concerned, there’s probably rather more benefit in improving the enforcement of existing usage requirements, including those for loading, speed, breakaway cable attachment and extension mirror fitment etc. None of those issues would be influenced by the introduction of an MOT.

Such things as axle failure would be apparent during an MOT but the same thing would be the case during a service hopefully. 

Indeed. Our Yaris is serviced every 3 years whether it needs it or not 

An engineer I know often quips that servicing is taking something apart to see why it works. 😄

Dave - whatever happened to him?