DVSA safe towing campaign

[monkeybusiness]

I've seen towbar bolts snap on vans several times. Fortunately I've only ever had one bolt fail myself, discovered when next stopped (the other held miraculously). I know of a big 3.5 tonne exhibition box trailer destroying a garden when it left the tow vehicle as a result of broken towbar bolts - what could-have-been doesn't bear thinking about. All of the instances I know/have been involved with have happened to well maintained vehicles with legally weighted trailers. The breakaway cables are essential potential life savers, and should always be attached to something fixed to the vehicle (not attached to anything held in place by the towball bolts).

[Matthew Storrs]

I've seen towbar bolts snap on vans several times. Fortunately I've only ever had one bolt fail myself, discovered when next stopped (the other held miraculously). I know of a big 3.5 tonne exhibition box trailer destroying a garden when it left the tow vehicle as a result of broken towbar bolts - what could-have-been doesn't bear thinking about. All of the instances I know/have been involved with have happened to well maintained vehicles with legally weighted trailers. The breakaway cables are essential potential life savers, and should always be attached to something fixed to the vehicle (not attached to anything held in place by the towball bolts).

 

I was under the impression though that the trailer handbrake is not entirely effective if the trailer is going backwards? In which a brakeaway cable isn't really a fail safe. I'd have though a suitably rated chain between the trailer and vehicle chassis would be a safer bet, even if it's not in the 'rulebook'!

[josharb87]

Is it legal to loop a cable/chain from the trailer to towball...is case the trailer hitch failed? Used to do this with an old trailer but someone thought it illegal.

 

Not sure on legalities but certainly not a good idea too, this would mean the break-away cable can't activate the trailers brakes if the hitch failed, you'd have a run-away trailer dangerously coupled to you with no positive pressure on the rear end of the tow vehicle (trailer possibly weighing far more than the tow vehicle and no brakes!)

[treequip]

I was under the impression though that the trailer handbrake is not entirely effective if the trailer is going backwards?!

 

Only if the trailer is getting pushed backwards by the towing head, I.E a vehicle. Its what auto reverse is all about

[richy_B]

Tragic to hear of a kiddie dying like that. I have always been cautious but decided a year ago (after an incident) that I needed to take our trailer use very seriously. Traded in my old trailers for new ones, Include them in our weekly vehicle checks and have an annual check up with our local trailer dealer.

 

Maybe excessive but I know of a lot of people using 3.5t trailers that are unknown age, unknown history, unknown brake or hub conditions. Its risky in my opinion. I know nothing of the case in question but as a commercial user I would expect there to be serious, if not manslaughter charges for someone not using a brake away cable or using a trailer with defective brakes that ended up like this.

 

I expect in the coming years an MOT like test will be introduced for trailers over 750kg. An expense but worthwhile in my opinion.

Edited December 6, 2016 by richy_B

[richy_B]

I was under the impression though that the trailer handbrake is not entirely effective if the trailer is going backwards? In which a brakeaway cable isn't really a fail safe. I'd have though a suitably rated chain between the trailer and vehicle chassis would be a safer bet, even if it's not in the 'rulebook'!

The trailer handbrake should be effective both forward and backwards. The handbrake is attached to a spring that pulls the brake cables so provided the whole unit is in good order you should have no issues. The brake away cable activates the handbrake so again, if it's in good order it is a fail safe.

 

The issue of brakes not being effective on trailers in reverse relates to over run brakes. It is the same braking system but controlled by a different mechanism -brakes cables are pulled when the tow head compresses, active by the tow vehicle slowing and the trailer pushing towards the tow bar. In reverse there is no tow coupling compression so no brake activation.

 

I have previously been in a crash (i wasn't the driver) where a heavy duty chain has been used on a trailer. This did indeed keep the trailer attached (despite the tow bar being ripped off) and prevented it going into another lane, hitting any other vehicles. Once the tow bar came off though the trailer brakes would no longer have been active so making the situation worse.

 

If you are going to use a chain make sure it is long than the break away cable so that if the trailer disconnects the handbrake is firmly applied. Perhaps a heavy steel braided cable might work. Perhaps could result in shock loading and damage to the tow vehicle though.

Edited December 6, 2016 by richy_B

[openspaceman]

 

If you are going to use a chain make sure it is long than the break away cable so that if the trailer disconnects the handbrake is firmly applied. Perhaps a heavy steel braided cable might work. Perhaps could result in shock loading and damage to the tow vehicle though.

 

That makes sense but I thought the legal requirement was no chain with overrun brakes, just the break away cable. A chain must be used with unbraked trailer under 750kg and must be short enough to prevent the drawbar hitting the ground if the trailer detaches.

[richy_B]

I hae no idea about the legal aspect, was just thinking safe.

[richy_B]

The aforementioned trailer held by a chain. Quite dramatic as you can imagine but afterwards I felt glad the chain was there as it meant the trailer stayed with us and didn't injury anyone.

 

[Daniël Bos]

Above statement re how trailer brakes work isn't accurate.

On most trailers the reverse deactivation mechanism of the brakes is in the drums. The shoes pivot away from the drums in reverse, disengaging them.

The handbrake pulls on the selfsame cable as the overrun mech, so in reverse most trailer brakes don't work, neither overrun or hand.

 

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