about towing couplings and safety chains.

[oldboot]

I note that there have been some towing related posts of late & a very recent incident braught this issue to mind.

Have a good look at your coupling, the ball and your safety chains.

A good and carefull mate was towing his fully loaded, employer provided mowing trailer thu and intersection recently and the coupling came off.
By the time he managed to get the whole thing to a stop the safety chain had ground thru on the road and drawbar had run under the vehicle and the tray had smacked the tow bar. of course the electricals all pulled out too.

He was surprised because the coupling had a pad lock thru the tang and was still in place.

any way we got it back on the ball and patched up the wiring & chain so it could be moved.

upon inspection it was clear that the coupling was worn...the tounge that comes down from the handle no longer had a good cup in it.
So a good solid bump and off it came.........

So first and most important check your coupling....... by feel and by sight...... while you are at it make sure the ball is OK too.

now the second problem was the safety chain.........the regs require that the drawbar should not strike the ground if the coupling lets go......HMMMMM

Check this one out......... almost without exception......most hook ups dont comply
Also most safety chains are welded on the bottom of the draw bar........so when the draw bar does strike the ground the safety chain can grind thru on the road.
exactly what happened in this case.

Now I looked at the installtion sheet that came with my hayman reese bar and they strongly recomend two chains and to cross them over in front of the ball on top of the tounge.............now I know exactly why.
It gives you a much better controll of the draw bar should the coupling pop off and just about the only reel way to prevent the drawbar striking the ground on most vehicles.

a couple of other points about chains...... the regs make certain minimum requiremants for chains.... but after this I think they are bare minimum.
points of concern

Most chain attachments to the draw bar put both the chain link and the welds in a very bad shearing position should they have to do their job.
Chain is strongest in an unrestricted straight line pull..... outsiide of this strength is greatly reduced.

Very large forces can come into play and having looked at the minimum requirements........... mild steel chain and the sizes required.
I am not confident that those sizes are enough particularly in a single chain.
I would be happier with rated aloy chain.... at least load binding chain if not overhead lifting rated.

Un Rated, domestic shackles....... the vast majority of trailers are hooked up with hardware store shackles that have very poor and definitly not guaranteed shrength . and they are usulay too small
My view is that the shackles should be "rated" lifting shackles.

Poor attchment faculities on the tow bar.
I'm very happy with my hayman reese........ not 1 regret with the extra price.
But I have looked at a number of tow bars, patricularly those from local tow bar shops..... and the safety chain attachment facilities leave a lot to be desired.
either you cant get a decent shacle in the holes or the holes present the shackle in a shearing attitude or there is only 1 available attachment.
I mean seriously there is no way I could make an attchment that would stand up to a proper overload test on some bars I have seen

Then there is the sum of the problems
If you want to use rated chain, you cant just weld it on because you cant get the required welding coverage on the links that are shorter on real chain besides that welding would weaken the chain.
so you have to attach a loop or something else........ yep fine happy with that.

because it is real chain & has short links..... you can only attach to the end..... so it has to be the right length.

then you have to get a decent fix to the car...... mine has two big loops on the bar... great........ but others don't..... so you have to use two shackles per chain.

Oh the fiddle.........but what price peace of mind.

So after fixing the offending trailer........I am about to revise the arrangements on my own.

I am constantly disapointed at the respect that is shown toward trailers and never surprised when I see some sort of failed trailer beside the road.

cheers

[PinHead]

now have you also checked that the bolts holding the tow bar to the vehicle are tight...have you also checked that the towball is also tight...right up on the spring washer.

I doubt the safety chains would ever be put in a shear stress condition in any circumstances I could think of on a trailer set up..more important is the tensile strength of the chain and at what point plastic deformation becomes evident.

These can usually be provided by the supplier..a simple graph can show these.

In your friend's situation I would also check the set up of the trailer...the weight on the tow ball should keep the hitch connected.

[oldboot]

If the first link is welded to the side of the draw bar pointing down, that link and its welds will be anything but in a straight line pull, ( a straight line pull would be down) the first link will then bind on the draw bar and futher compromise the situation.

I definitely agree that the tensile strength of the chain is a very important factor.

an even bigger factor is the srrength of the shackle.....if you are using rated shackles and any of the "T" graded aloy chains....... the biggest shackle that has a pin fits thru the chain will be rated less than the chain its self.

strength of standard aloy chains can easily be optained from the manufacturer or off standard tables.......aloy grades are pretty much standardised.

there was pelnty of drawbar weight.

if a trailer crosses uneven section of road no amount of static drawbar weight will keep the hitch connected if it is faulty.

comparing the failed hitch with a new one it was plain and obvious where the problem lies.

cheers

[Dr_Dan]

Had a similar thing happen when i was a young bloke with my first tinny. Got dropped off at the ramp, was only about the second time that had it out, gave the bow a bit of a lift as we were shoving it off the trailer, and the coupling came off the ball. So off goes the trailer down the ramp. Thankfully chain was attached. Would have been damn scary tho if it had happend on the road. The coupling was an old OLD screw up type. Obviously had been worn right down, didn't fit at all. Needless to say, replaced it that weekend, drove very carefully on the way home that day!

[finga]

I think the vast majority of incidents with trailer are a direct result of poor maintenance, poor understanding of what is required and poor setting up and/or loading of the trailer.
Oldboots example is a prime example. A lack of maintenance.
If only one person goes out after reading Oldboots thread and finds something wrong with their trailer then Old mate Oldboot has done a great service.
Other then the usual things that go wrong they're pretty fail safe if used correctly and maintained right.

A thought though...are the pins used to hold the Hyman Reese rhs tongue in place load rated??
What about the aftermarket lockable pins??
What about the way some towbars are put onto cars etc. Are all the bolts rated and tensioned to specs.??
Where do you stop??

[oldboot]

Where do you stop?........ when its done right.

The genuine hayman reece pins in the slide out couplings will be " part of an engineered design".....the lockable pins I dont know about........ but If I was selling them there is no way I would unless they too had been engineered.

as far as the fitting of the bar to the car........ most of the bars come with very specific instructions and specified hardware...... thats if you got it new.

As minimum all the bolts should be high tensile....... that goes for the bolts in the coupling too.

There are also well accepted methods and practices that are used when connecting " items" to the structure of the vehicle.
Those of us that have been exposed to this sort of work would have no problem doing the right thing with a second hand bar.............I would be concerned by the methods of some of the " lower skilled" people who might try to do their own work.

As a matter of interest some of hayman reece bars come with a shackle supplied......it isnt a reated lifting item but it looks and feels better than standard harware store rubish & it is stamped hayman reece...... so there is probly some sort of QC & specification involved there.

cheers

[Eagle]

I certainly understand the problem of the safety chains from the viewpoint of hi-tensile versus mild steel. Yes, the welding does destroy the strength of a hi-tensile chain and can render the welded link to be an outright danger. This is not the problem with mild steel chains.
From what I know about using safety chains, I think there is a difference in the regulations of the different States (I may stand corrected on this?). However, the best way to arrange the safety chain is to have two chains fastened to the trailer, one on each side. When connecting them to the tow vehicle, the chains should cross each other before being attached. This forms a "cradle" that the draw bar can drop into and if the chains are fitted correctly, the drawbar will not drop onto the roadway. If the attachment point is widely spaced at the towbar, the crossover point of the chain is moved towards the rear and helps greatly to restrain the draw bar of the trailer if it does drop. The chains can be made much shorter when they are crossed over without affecting the turning circle of the trailer. In most States (?) it is against the law to allow the fallen drawbar to hit the ground. Regardless of the weight / size of boat and trailer, the crossed over chains are the best way to go for maximum safety. Crossed chains may also be a valid point with your insurance company, might be wise to check them out.
Joe

[BILLY THE KID]

dont know about anyone else but i always lift the drawbar hard 3 or 4 times to make sure it on . i have had one come off onto the chains with $30.000 worth of dirtbikes on it . scary thought when a simple yank on the drawbar will show if its locked in

having owned dirtbikes its a natural reaction to do this .

with the boat the jockey wheel is raised with the hitch on the ball , this will lift the arse of the car on the suspension when on properly .

this is done with any trailer i tow empty / full .

[Scalem]

D shackles can be very under rated as you have pointed out, not to mention the one on the safety chain holding on to the boat, along with the winch. I had the eyelet or bow tow point wear completely through and snapped. The only thing holding the boat was the winch strap and tie down on the back.

I doubt every boatie thinks about what you have mentioned here every trip, I thank you for the reminder

Scalem

[Getout]

My new trailer (and boat) jumped off the towball on its second outing while braking into a corner. The hitch was correctly set but appeared to unlock itself. I always pin the safety now. Chains did their job, but i had to use a jack to lift the hitch back on to the ball.
Bowsprit missed the rear windscreen by 100mm. Phew!

[Luc]

Fitting of the good coupling lock is also an extra insurance against the coupling coming off the ball.

A few years ago, the deckie attached the trailer and trailer lock for a trip to Boodooma.

At our first stop in Gympie, I did my usual walk round before continuing and found the coupling tounge had not been engaged and the only thing holding the coupling on the ball was the trailer lock.

Luc

[finga]

Does anybody check the shackle bolts in the springs??
These suckers cop a flogging

[oldboot]

A lot of people think that the cupling sits on the ball quite happily with the draw bar down force, but fail to understand that very significant lifting forces can act on the ball as the rig goes across undulating ground.
the three biggest culprets are crossing intersections that have a profile, railway crossings and speed bumps.

I think we all need to consider our trailers more...... think that " a blokes box trailer" will problay be towed by a sucession of vehicles a bloke owns....by the time a bloke gets to retire the faithfull box trailer he baught when in his twenties is over 40 years old. Many of the wear & tear issues just would not occur in the towing vehicle because it would be replaced at least every 10 years.

I;m very much feeling a trailer maintence working bee comming on.

You are right about shackle bolts.
I can certainly remember seeing at least two trailers with the wheels up under the guards beside the road....had to be either shackle or u bolt failure.

cheers

[big moose]

good point old boot I have the solution for you it just needs a small investment. 4t gtm trailers require rated chains with straight line pull fittings these are available from any reputable trailer shop last time I bought some they were about 400 buckaroos for a pait of brackets and chains and attach links then a simple matter of welding the brackets to the trailer. Cheap insurance I reckon
cheers and happy silly season

[oldboot]

Hmmm... if I had a 4T or near trailer.....a "manufactured item" would be a very atractive proposition....... with a view to keeping insureres happy and so forth.

But for a small trailer....$400:o :o ........I think there are a number of cheaper ways fo achieveing a satisfactory result..........I might be one of those prepared to pay the cost of doing something right........ but I'm not rich:( ;D


cheers

[big moose]

g'day old boot,
the brackets are nothing special a trip for a look at them in the shop and you could knock them up at hom for b'all the chain and links are also quite reasonable from your local ag co-op could probably diy for under 100regds

[big moose]

gday old boot,
you could knock up a set of brackets for almost nothing if you can weld, the chains and links are pretty cheap at ag co-ops maybe just a trip to the trailer shop for a reccy to check dimensions. from memory the brackets were 10mm plate with a 10mm pin welded in. sorry for the double post some finger trouble happening here
regds Gary