One of the skellies on our fleet got damaged by some drivers carrying 20’ boxes in the 40’ position so we have been issued with a sheet showing the correct positions etc,etc. But what I don’t understand is that I can carry a 45’ in the 20’ position but I can’t carry a 40’ in the same position. I queried it and was told it was to do with weight distribution, but I can’t see any difference. The sheet states that the forward twistlocks should only be used for a 45’. The trailers are dennisons. Can anybody explain to me how the weight distribution is different.
it is not just the weight dsistribution, it is also the stresses placed on the locking pins that hold the two parts together, this is why the trailer has got damaged due to having it set in the wrong pin positions.
they have been designed to work in a particular way or set up, this is all to do with load distribution, stresses on the pins and also the brake set up
oh, and FFS, do not run with a loaded 20 foot container in the fully closed position!!!
shuttlespanker:
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oh, and FFS, do not run with a loaded 20 foot container in the fully closed position!!!
mind if i ask why …? i’m just interested thats all … 
bowser:
shuttlespanker:
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oh, and FFS, do not run with a loaded 20 foot container in the fully closed position!!!mind if i ask why …? i’m just interested thats all …
because all of the weight will be over the trailer axles, thus lifting the front of the trailer and taking the weight off the kingpin and drive axle and leave you with a negative kingpin weight, even with an empty box in the fully closed position, you can see the front of the trailer bouncing up and down on the fifth wheel plate, and this can cause loss of traction, even in dry conditions
lets all get trained up on boxes
piccies please
shuttlespanker:
bowser:
shuttlespanker:
.
oh, and FFS, do not run with a loaded 20 foot container in the fully closed position!!!mind if i ask why …? i’m just interested thats all …
because all of the weight will be over the trailer axles, thus lifting the front of the trailer and taking the weight off the kingpin and drive axle and leave you with a negative kingpin weight, even with an empty box in the fully closed position, you can see the front of the trailer bouncing up and down on the fifth wheel plate, and this can cause loss of traction, even in dry conditions
i did’nt know that … cheers fella.
hitch:
lets all get trained up on boxes
piccies please
nowt wrong with that idea . away you go lads leasons please…
luckily i get to keep the same trailer all the time.
pull a mix of 20’s and 40’s on it. i always make sure the box is in the right position, empty or loaded, 20 as a 20, and 40, as a 40. its hardly hard work to set them up right, and takes a matter of moments really. i still don’t get why people run with an empty 20, in the fully closed position, daft really■■? traction is a mare, and wonder how you’d stand with insurance if you had a bump? also, is that set up illegal? i know vosa will show a keen interest, if they see you on the road, with a loaded 20, in the 40 slot.
Spanky, you can run an empty 20’ in the closed position, but only if you have a lifting front axle on the trailer, that makes a big difference to the handling, although I don’t know how you’d stand on this issue with VOSA, there were some Freuhauf flat trailers which were basically sliding skellies with flat bodies, they were designed to run in the closed position, but they all had a lift axle up front 
I don’t know how long ago that was, NMM, but you have to remember that skellie construction has got MUCH flimsier and lighter over the last few years, the result being that it is far easier to twist the chassis if they’re not used properly. Instead of being fully reinforced all the way along, most of them now only have bracing around the 20ft running position (with a 40ft the box itself creates the rigidity), and running around with the thing shut WILL cause damage at the neck end, regardless of how many axles you lift - although lift axles are also largely a thing of the past on skeletals, again because of weight.
On the plus side, you can still pull a 30 tonne box quite comfortably, despite large-cabbed tractor units being heavier, and you can load a 45ft to just over 26 tonnes. 
Lucy, the trailer I had was one of the Freuhauf models with a c coupling (basically 5th wheel jaws) for the closed and extended positions rather than locking pins, IIRC it was a late 90s model, I never ran it in the closed up position much, maybe a couple of times doing a removal in Central London or similar, I sold to a friend who still has it, he’s never had any issues with the sliding part of things, maybe, as you say, the older ones are a bit tougher, I haven’t had a sliding skelly behind me sice that one, between then and coming over here I had straight 4pin 40’s for the short sea 45’s, for the same reasons the new ones are lighter, I was struggling with ULW with sliders
Those old Freuhauf’s didn’t creak and groan like some of the sliders, maybe the 5th wheel couplings were a better method than the locking pins?
I was following an empty sliding skelly the other day, the locking pin type and to say it was flimsy was an understatement.
There must have been nearly 2" of side play in the 2 halves (accompanied with a loud crack !) and it looked almost articulated halfway down the trailer, I don’t know if this is normal but it looked wrong to me and this skelly looked like it was less than 12months old.
Forgive my ignorance here fellas but I know nothing about containers and have a couple of questions.
Firstly, the sliding skellies with a 20’ box on a 40’ trailer, are those trailers universal or just made specifically for 20’ boxes? Just seems a bit of a waste using a 40’ trailer that can only carry 20’ boxes.
Also how the hell do they slide? Obviously u set it in the middle during transit for weight distribution but then u want it on the arse end backing onto a bay.
Can u put a 40’ box on a 45’ trailer or do you have to have the exact same trailer for whatever box your picking up? Sorry if I sound a bit thick 
its got too complicated by the looks of things , i drove skellies years ago and my trailer was a 40 foot fixed length thing with full set of twist locks … horrible if you had to carry 20 footers i would imagine but luckily i did’nt . aint techynorlergy wonderful ■■.. 
bring on the good old days were my rose coloured glasses work perfectly…
FarnboroughBoy11:
Forgive my ignorance here fellas but I know nothing about containers and have a couple of questions.
Firstly, the sliding skellies with a 20’ box on a 40’ trailer, are those trailers universal or just made specifically for 20’ boxes? Just seems a bit of a waste using a 40’ trailer that can only carry 20’ boxes.
Also how the hell do they slide? Obviously u set it in the middle during transit for weight distribution but then u want it on the arse end backing onto a bay.Can u put a 40’ box on a 45’ trailer or do you have to have the exact same trailer for whatever box your picking up? Sorry if I sound a bit thick
I dropped a 40’ at Alcombury quite some time back and had a 45’ put on, without me knowing it was going to be 5’ longer. It fit on the same pins that the 40’ came of so I was non the wiser…until I did a U turn on the Airfield and knocked off the Fire extinguisher that was fitted on the back of the cab. I had to move the 5th Wheel to stop the extra 2 1/2’ causing anymore damage. I also had to pull out the crash bar thingy at the back. Phew, what a day that was. I didn’t get charged for the damage cos apparently that trailer shouldn’t have had a 45’ on it.
FarnboroughBoy11:
Forgive my ignorance here fellas but I know nothing about containers and have a couple of questions.
Firstly, the sliding skellies with a 20’ box on a 40’ trailer, are those trailers universal or just made specifically for 20’ boxes? Just seems a bit of a waste using a 40’ trailer that can only carry 20’ boxes.
Also how the hell do they slide? Obviously u set it in the middle during transit for weight distribution but then u want it on the arse end backing onto a bay.Can u put a 40’ box on a 45’ trailer or do you have to have the exact same trailer for whatever box your picking up? Sorry if I sound a bit thick
generally, a sliding skelly can take 1x20, 2x20, 1x30, 1x40 or 1x45 foot box
if 1 heavy 20 foot box is to be loaded, it is placed in the centre of the trailer, when it comes to tipping the container, the front part of the skelly ‘slides’ over the rear bogie adn places the doors at the rearmost part of the trailer, the trailer now has become 30 foot
there are some skellies that are tri axle sliding skellies that can only carry 1x20 foot box, but they are not very common
a fixed skelly is just that, it is a fixed chassis, they can carry a heavy 20 foot box in the centre, but it will not be able to be tipped from that trailer, they are generally only used for carrying 40 or 45 foot boxes, a 45 foot box has the same twistlock positions as a 40 foot box, and there is a 2 1/2 foot overhang at each end, there is a pull out extendable bumper at the rear, and also a pull out suzie bar at the front
Lucy:
I don’t know how long ago that was, NMM, but you have to remember that skellie construction has got MUCH flimsier and lighter over the last few years, the result being that it is far easier to twist the chassis if they’re not used properly. Instead of being fully reinforced all the way along, most of them now only have bracing around the 20ft running position (with a 40ft the box itself creates the rigidity), and running around with the thing shut WILL cause damage at the neck end, regardless of how many axles you lift - although lift axles are also largely a thing of the past on skeletals, again because of weight.On the plus side, you can still pull a 30 tonne box quite comfortably, despite large-cabbed tractor units being heavier, and you can load a 45ft to just over 26 tonnes.
Sorry Lucy but I fear you are talking BS 
and this is one of the biggest urban myths going. This same discussion came up some years ago and if you remember I emailed Dennison? (or was it the other outfit? (not Fruehauf)) about running an empty 20’ in the closed position and they stated that there was no problem with it at all so long as axle 1 was raised. It was also mentioned that there would naturally be a slight reduction in stability vs running it fully open but there was no mention of it being “dangerous” like some on here claim.
I always ran my empty 20s in the closed position if I’d just tipped one and never once had any traction, stability or chassis bending issues.
some years ago
^ That’s the important bit. Sliders manufactured in the last 3 or so years are specifically marked up forbidding their use for running in the 20 tipping holes. The necks bend. VOSA are aware (the local STE around here hangs around our yard on a regular basis, he’s an old friend of our FM from back when the company worked with VOSA to resolve the issue of cracking disc brakes when they first came in) and WILL prosecute.
Sorry, Rob, but you’re out of date on this one.
Ps. Remember - as stated further up - that lift axles on sliders are also a rarity now. It’s all down to weight saving.
Lucy:
some years ago
^ That’s the important bit. Sliders manufactured in the last 3 or so years are specifically marked up forbidding their use for running in the 20 tipping holes. The necks bend. VOSA are aware (the local STE around here hangs around our yard on a regular basis, he’s an old friend of our FM from back when the company worked with VOSA to resolve the issue of cracking disc brakes when they first came in) and WILL prosecute.
Sorry, Rob, but you’re out of date on this one.
Pics?
ETA: If there’s no lift axle then there’s no point actually (common sense alert 
).
ETA2: Just chuckling to myself remembering watching a guy trying to reverse a fully loaded 20’ box round a corner in the closed position with all 3 axles on the deck. Not laughed so much in a long time. 
(and yes I did “rescue” him when my sides could take no more ).