Over the past couple of weeks, Lyn & Sally traffic have mentioned accidents, where trucks have lost their trailers 
Does anybody know anything of these accidents?
Is it a failure of the king pin/5th wheel?
Or driver error?
Has anybody experienced this?
When on agency for TNT I was given loads of paperwork to read and one was a safety information about the clip. Their fifth wheel have a clip which drops down instead of the old clip and chain, but it seems in some cases it doesnāt sounds like it needs oiling regulary, so they say it must be checked it is in th down position when hooking up to a trailer.
The other Iāve noticed is not all drivers do a tug test when they hook upto the trailer.
Just ideas donāt really know the cause,
I lost the wife once
She found her way home for pay day 
this happened to one of our nightshift as he was returning from risley nr manchester.he was coming through motherwell just at the top of merry street at the roundabout,as he came off the r/about the unit pulled away as if your foot had slipped of the clutch he thought wtf was that as he looked in his mirror he saw the trailer fall to the ground.weāre still waiting to find out the cause. 
muckles:
The other Iāve noticed is not all drivers do a tug test when they hook upto the trailer.
Just ideas donāt really know the cause,
Muckles i used to always do a ātug testā but i was tought by an old boy once to always go under and make sure the jaws of the fifth wheel had gone round the pin to this day when i drive trucks i always do it, the legs are still down so its a safe method of checking.
I dont know if there is anty truth at all behind this but i was told by someone somewhere once that the new M.A.N. fifth wheels are more likely to disengage or have problems than any othwer truck, true or not i don`t know.
I drive MANās , they have the same clip and TNT (taylor Barnard trucks have)and the other day a driver lost a trailer in the yard, however its unsure the exact reason as one driver backed under the trailer and another then came along and connected the airlines and lifted the legs drove off and when he braked to leave the yard off comes the trailer.
There can be many causes, king pins failing by not locking or just breaking but unfortunatly human error is the most common cause. As far as I am concerned the habit of tug testing is a good one.
We use a lot of 10m Rear Steer Trailers so we can do London a bit easier.
The shunters in our Depot had a few problems a while back. These Trailers are (Rear) Steered by the 5th Wheel. The King Pin is in the usual place and there is a āwedgeā that sits just behind it that fits snugly into the āopenā wedge of the 5th.
Sometimes, if the Trailer has not been dropped absolutely square, this trailer wedge is offset slightly and can give a false impression of being ālockedā in place when you back on. Shunters being shunters, they dont normally check other than with a quick ātugā. Obviously they dont hang around and as they have turned the corner the Trailer has gone straight on with the tug going where it should be, loaded trailersā¦ legs downā¦ you can imagine the damageā¦
Every time āheavy lifting equipmentā has had to be brought in, at great expense of course. This was the explanation given to us, we were also told (with these trailers) to make sure we backed on with a little bit extra āooomphā, just to make sure and (obviously) check the release handle and clip are always in place before moving off.
Terry
Beware the ātug testā when coupling up, recently doing a trailer change at a customers premises, went to pick up trailer on bay. Did quick tug to check fifth wheel had connected and shot forward as the last driver had not applied the park brake, but had pushed the shunt button in luckily I had only given it a gentle tug as there was only about 10ft from the cab to a fence.
the man has two safety clips, one is the dog chain clip,the other is a metal L -shaped which is attached to a piece of wire which you have to lift to remove the 5th wheel, so i think its down to driver error.
kitkat:
so i think its down to driver error.
That is a sweeping statment,
If you have read the whole thread, it seems that they could be a fault and its being investegated. Lets wait till the expert decides if it is driver error or not!
drive MANās , they have the same clip and TNT (taylor Barnard trucks have)and the other day a driver lost a trailer in the yard, however its unsure the exact reason as one driver backed under the trailer and another then came along and connected the airlines and lifted the legs drove off and when he braked to leave the yard off comes the trailer.
if the 1st driver had connected the unit to the trl properly then thereās no way it would have come off at roughly 10mph as he was leaving depot.the king pin would have to be hanging off for that to happen.and also if another driver takes over from another driver aināt it his duty to check that unit and trl are connected properly 
I agree kitkat 100 %
but i alse remember another drive who is very experienced driver and it happend to them I dont think it was a MAN but it happend all the same!
in fact if I remember it was Pat from the PDA maybe she has some ideas why it happens I could be wrong but I am sure it was Pat
the only time i saw this happen critic was when my friend pulled a trl of a bay and the unit went one way trl another,we found out what happened .one of the warehouse staff thought heād play a trick on my friend and pulled the lever so as he pulled away the unit would seperate from the trl. lucky for my friend he noticed this b4 it dopped to the floor after this the warehouse guy got what he deserved sacked on the spot.his warehouse guys grassed him up,other wise my friend would have been disiplined.
Iād like to comment on this one ā¦but I canāt provide an answer only some evidence 
I backed under a trailer, fairly gently, as I always do, in the dark and felt, and heard it connect, I tugged it as I always do fairly hard and everything was OK.
My Scania had the L shaped lever and no dog clip. I did a visual check on the L shaped lever and as far as I could see in the dark, all was normal.
I pulled out of the parking bay but couldnāt clear the top of the row of trailers facing me So I reversed back down (now thatās where it should have gone adrift )
I pulled forward and turned a very sharp right drove along the yard and at the next sharp right the trailer came off. 
I was mortified, after 23 years of hooking up trailers and doing the same thing, how could that happenā ā ?
We picked it up and restacked the load and I finally got back to our yard to find my Boss in full support of meā¦another experienced driver had done the same thing with that type of fifth wheel in our yard a couple of months earlier
He had all those types of fifth wheels changed straight away, although JOST denied that anytrhing could be wrong
However, the replacement ones they sent out HAD THE DOG CLIP ON THEMā ā ?
Stobarts, apparently are having the same trouble with their Scanias with this L bar fitted, and have had a technition ( spelling, my minds gone blank!!) from Jost down, due to the amount they have lost, but he denies there is anything wrong
That is all I can add, but I KNOW I did exactly the same as Iāve always done and if the pin wasnāt in, then why didnāt it come adrift when I reversed down the row of trailersā ā ?
Pat
Just going off on a slight tangent, I donāt know if anyone else has the problem but my N-reg FH12 wonāt auto-engage the 5th wheel pin and once as tight under the trailer as I can go I have to get out and engage the pin myself which is tedious. I think Iām the only one who bothers to get back in the cab and give it a tug (after lifting drive axle suspension so that it lifts trailer legs off the ground) to make sure. One time it hadnāt engaged and Iāll always remember that time
Also, I see some drivers - generally big fleet drivers - tug the trailer so hard that the trailer is pulled a good few inches across the yard I donāt think thatās at all necessary myself.
FWIW.
Pat, Our MANās only have the L shaped clip and no dog clip, also the TNT trucks were Scaniaās and have the same clip. Their safety bulletin just said make sure the clip is down covering the lever, which makes me think they cease into the up position.
Kit Kat, I think the incident is probally driver error, the second driver admits he just assumed that the truck had been connected and didnāt check, Although the first driver said he had hooked up correctly, but it really is the driver who is taking down the roads job to check regardless. However you canāt discount the a fifth wheel problem.
Rob, I think you have a problem with the fifth wheel adjustment, Iāve had trucks that do the same and have been adjusted when they go into the workshop. I seem to remember at one point it would hook up to old trailers, but not to the new oneās we were taking out of the factory.
Finally Iāve been told that the tug test isnāt foolproof and the clip is only there as a last resort and a properly working fifth wheel shouldnāt disengage even if the clip is not on.
I agree with all your saying Muckles 
But I still canāt understand why it didnāt come adrift when I reversed back at least 300 yardsā ā ? Surely thatās when it would have gone?
And why did Jost supply replacements WITH a dog clip?
I think thereās definately a design fault there that no-one is prepared to admit to.
Pat
Pat:
I agree with all your saying MucklesBut I still canāt understand why it didnāt come adrift when I reversed back at least 300 yardsā ā ? Surely thatās when it would have gone?
And why did Jost supply replacements WITH a dog clip?
I think thereās definately a design fault there that no-one is prepared to admit to.
Pat
Were you pushing the trailer of was it downhill?
Nobody will admit to it, but somebody might get killed and the easy option will be to blame the driver and quietly fix the design.
agreed muckles we donāt have these type of 5th wheels you are reffering to.
rob kā¦i had an fh12 up until 5month ago when i pulled from under a trl and went under another one every now and then it would not engage. so i had to jump out of the cab and just slightly knock the 5th wheel lever back. once i done this it would engage no problems.this would happen every now and then rob.