Fifth wheel problems

“I have a very unusual case. At the beginning of December, I had an accident at work. The trailer detached, coming to a stop on the right side of the truck’s wheel arch. I’ve been trying to sort out this matter with the company I worked for, for quite some time now. Currently, I’m at the stage of appealing their decision. I was supposed to have a meeting last week regarding this issue, but I postponed it because I want to present more evidence confirming that I followed all the procedures as I was trained and that the trailer was properly attached to the truck. My company is accusing me of two things, but they haven’t provided any solid evidence to support that I did anything wrong. However, I have evidence showing that the trailer was attached. Cables and hoses were also in place, and the clip was fastened on the fifth wheel’s arm.”

I followed all the procedures by the book as I was trained to when attaching the trailer for the first time. However, the trailer did not attach properly on the first attempt. After that, I made a second attempt and heard that the trailer was attached. I maneuvered forward twice, feeling that everything was secured as it should be. I checked all the points one by one, and after confirming everything, I decided to set off on the journey. However, while taking a turn after about 20-30 meters, the trailer detached and fell off, damaging the right fender of the truck and the left corner of the trailer. If I could ask for your assistance based on your experience, it would greatly help me. I sincerely thank you in advance for any information provided.

I would like to ask you to provide me with all possible information about why trailers detach from trucks, what could be cause, any examples, including any relevant website links. Any assistance you can provide would be greatly appreciated. Thank you in advance. Regards."

Did you give the trailer a good hard tug when hitching up?

If there was a failed attempt at first, why was that? There must be a reason for it.

I don’t know what happened, but it possible that a trailer, a bit too high, will push the knife in, but the pin not be behind the knife.
One contributor here advices actually getting unde4rnaeth and shing a torch up the “V” of the 5th wheel to see that all is well. (before legs are wound up!)

I don’t know what went wrong, but it probably was driver error…Sorry, not what you want to hear.

If you followed them, then maybe the company instructions aren`t good enough.

Always give a good tug (I always give two) before anything else.

I did all By The Book.

yes I did twice , on the first attempt the trailer was to high thats why I couldent attached the trailer.

On the second attempt I lift air uspension attached the trailer I herad big bang , shunt twice, hand breake on, engine off, clip on king pin , leggs up, trailer brake off, dirve forward on the corner trailer was dropped.

After lifting the suspension on the unit, are you sure it was high enough?
Was the 5th wheel firmly rubbing against the trailer when shoving it under?
Did you actually see that it was making good contact?

And the forward manoeuvres were good firm tugs?

Putting the dog clip in you could see that the trailer rubbing plate was flat against the 5th wheel?

(If I`m asking awkward questions wait til later!)

I’ve done all. propper.

i cannot wait :slight_smile: for other questions.

I know when the trailer is attached. and yes , it was attached.

Was the safety clip still intact and preventing the bar from disconnecting, after the accident?
A couple of points about my own experience.
I never trust lifting the trailer by raising the unit suspension, always have the jaws just too low to slide easily under the trailer, and listen for a clear click.
I always crouch under the trailer to make sure I can see the bar, but not the kingpin.

If the fifth wheel has been inspected and there was nothing wrong with it, then driver error absolutely. There isn’t really an angle you can use in defence. Did you take a picture from behind the fifth wheel? If not, what evidence can you provide that will prove it was connected? The answer is not very much.

When I connect up, as a rule of thumb, I make sure the legs are off the ground. This makes sure that I am not going under the pin but also that the trailer can move without damaging the legs due to any slight misalignment I may have made.

If the trailer is far too high, I will wind down the trailer in low gear to a suitable height. Yes, a pain and a hassle, but I always do it. Another option is to call on a shunter to lift the trailer a bit while you wind the legs.

All was done so perfect, That was my dailt routine like mornig coffee. yes I Have pic from behide, pics with clip on after trailer dropped, pics with all hoses attached. The Comapny dont have any hard proof that could be my fault ( But IM sure it was not my fault ) for sure something mechanical could cause that accident. Was inspected but by this company garage, so thatr even if mechanical was something wrong ,they could fixed… :((((( its tough staff tbh. thank you

As aid if the 5th wheel was inspected and no physical damage or broken parts then it is most likely driver error. It happens sometimes to the best and worst of drivers, it’s unlikely you will be able to fight it even if you did do everything right as the trailer still became detached. Which only happens due to either mechanical failure or driver error. It’s always one or the other.

I’m gonna be fighting and I will proff them that wasn’t my faul. They just assumed that was my fault ( no hard proofs ) . I want to win to warn other drivers that the trucks are not in the greatest condition as they know that.

I just need to show them some examples.

why the trailers detached witn no drivers fault.

If you need proof ask to see any CCTV footage or any footage from the cameras on the other trucks

the thing is why they not use as their evidence ■■? Only assumed my negligence that might be my fault. It wasn’t I’m sure for sure.

I need some www links , videos links, articles etc. , anything what could help me to proof mechanical truck fault.

Once you have had a few days to mull it over, consider that it may be better just to put it down to experience and look elsewhere.

Say the company is running badly maintained kit and then having dodgy inspections done after incidents, is this the type of company you want to work for anyway?

No it wasn’t.
We know it wasn’t perfect because you told told us so already.

You have already told us that you had an attempt without checking for correct height the first time.
How do we know you got the height correct the 2nd time?

Trailers do not fall off by themselves.

hesitant to ask this here but is it possible if the pin goes over the fifth wheel and drops in front of it the impact of that would trigger the mechanism and allow the dog clip to go in?

I cant see any other way that one could be able to move forward but the second you make a turn the pin slides out. or is it a case of enough friction to hold onto the pin when going straight but the force required to turn the trailer over comes the friction?

Yep…more or less…

The bottom of pin could touch the top of the knife/bar and so trigger it to shoot across.
The pin will then be inside the “V” of the 5th wheel but the wider base of the pin will be sitting on the knife, not trapped under it.
The dog clip can be inserted because the knife is across all the way, but it isn’t holding the pin in.

It should be visible that the 5th wheel isn`t touching the rubbing plate of the trailer evenly, but in the dark, and unless you really are looking for it, you won’t notice.

When doing the tug test, I always give it some wellie. A gentle one isn’t enough.
Then I give a reverse push and a second tug.

Most trucks are close couples so if the pin goes in front of the 5th wheel it should be obvious the cab/trailer clearance is all wrong.

And another habit I got myself into is after all checks are done, is to stand beside the door and mentally check all of my physical checks again.

As you said there used to be a regular contributor that advised sticking ya head under the trailer and looking up the v which i took on board and always do it but didn’t know/ think about the fifth wheel on the rubbing plate i will add that to my list.

may i ask why you do a reverse tug for want of a better phrase inbetween your two forward tugs

I don`t think it makes much difference, but it does make me feel better! A bit of a habitual twitch rather than something thought out.

Fair enough. At the moment i am extra paranoid about it as the new place i am working at wont allow split coupling under any circumstances so I have had to go back to the black system. Although some of the practices and procedures they do have make me inwardly cringe.

For clarification here is my procedure

reverse up to trailer with suspension lowered and stop about a foot away from trailer and eyeball fifth wheel is low enough to go under trailer

check park brake is on and do trailer checks

reverse back so fifth wheel is under the trailer but fwd of the pin

raise suspension so the legs are 2 - 3 inches off the ground

reverse back gently and listen for the 2 clicks do 2 good tugs fwd.

put dog clip in and shine torch up the v and make sure pin and knife are correctly located check fifth wheel is flat against rub plate (just added)

connect air lines and wind up legs

push park brake in and hold for count of 10

check airlines and legs have been done then double check clip

pull off bay check load close doors and put plate on.

anything else you would add?