I’ll try and take you a pic at work next week at some point. There is one on here already though, from the last time we “did” this subject, if you can be arsed to search for it. (I can’t. 
)
Just my tuppence…(taken from the side of my old trailer, a couple of weeks ago)
shuttlespanker:
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 commona 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
Cheers mate I’ve always wanted to do a bit of container work some day.
But the ‘sliding’ bit the 20’ box is on, is raised from the actuall trailer isnt it? How does this go flush with the trailer chassis if u wanted to load a 40’ box on? Cheers mate, probably sound like stupid questions to you box boys 
the rear set of twistlocks are on bolsters that hinge and fold down when you need to shorten the trailer
as can be seen here
and the same trailer with a 40 foot box
shuttlespanker:
the rear set of twistlocks are on bolsters that hinge and fold down when you need to shorten the traileras can be seen here
1
and the same trailer with a 40 foot box
0
That’s a bloody clean trailer, 1 just like that with a similar cab too, maybe same, passed me before, you been down southampton today? Late-ish on?
Cheers Shuttlespanker great info mate
waynedl:
shuttlespanker:
the rear set of twistlocks are on bolsters that hinge and fold down when you need to shorten the traileras can be seen here
1
and the same trailer with a 40 foot box
0
That’s a bloody clean trailer, 1 just like that with a similar cab too, maybe same, passed me before, you been down southampton today? Late-ish on?
the first pic was taken when i collected it brand new from the factory, the second pic was after approx 2 weeks and just been washed, and i have not been to Southampton for a few weeks
Some very good answers and explainations but none that cover my question. On the dennison trailer i can carry a 45’ in the 20’ position but not a 40’ although they fit. I don’t understand how a 40 is different the stress must be the same.
I have tried looking on the dennison site but it’s not much help.
it all goes down to wheel base and overall length regarding the 45’ boxes
knight:
Some very good answers and explainations but none that cover my question. On the dennison trailer i can carry a 45’ in the 20’ position but not a 40’ although they fit. I don’t understand how a 40 is different the stress must be the same.
I have tried looking on the dennison site but it’s not much help.
it’s all to do with weight distribution on each axle. if you put a 45ft box in the 40ft pins vosa will nab you with £200
a 45ft box is used in the 20ft pins, but you use the far front twistlocks on a dennison trailer.
thats what dennison told me.
i hope it answers your question.
knight:
Some very good answers and explainations but none that cover my question. On the dennison trailer i can carry a 45’ in the 20’ position but not a 40’ although they fit. I don’t understand how a 40 is different the stress must be the same.
I have tried looking on the dennison site but it’s not much help.
I understand the question you’re asking. I can only fathom that it would be down to weight distribution over the axles. Who says you can carry a 45’ in the 20’ position ?
Thanks mike, It’s on the trailer that that is the correct position using the front twistlocks. According to dennison the front twistlocks should only be used for a 45 footer.
knight:
Thanks mike, It’s on the trailer that that is the correct position using the front twistlocks. According to dennison the front twistlocks should only be used for a 45 footer.
You’ve got me scratching my head here. I’d of sworn that the only way a 45’ would go on is in the fully stretched (40’position). Just to clarify. when a 45’ goes on there is an equal overhang to the front and rear? It may be possible to put them on otherwise but i don’t think its a correct or acceptable way? You’re not putting the front twistlocks on the foremost locators on the 45’ box are you?
You are all bloody wusses anyway, sliding skellies, who needs them?
youtube.com/watch?v=AovYxaNSc-o
Someone mentioned that Carryfast could be living in Nigeria 
Can’t believe they didn’t loose that box going up that hill.
the 45ft frount pins are the same distance fom the 40ft pins as the positions on the slider if that makes sense??
a 45ft box is a 40ft box with 2.5ft welded on either end and yep thet do use the same locking holes as on a 40ft box.
it fits cause the 45ft frount pins are say 6inches forward of the 40ft frount pins anf the chasis is shortened by 6inches in to the 20ft loaded running position thus putting rear and frount pins in to the right position to take the 45ft box.
if i end up with a 20ft box at some point tomorrow i will try and sort some pics.
Spot on caveman a 45’ box is a 40’ box with two and a half foot on each end so why can’t I carry them in the same position on the skelly. Yet my instructions say the front twistlocks should only be used for a 45’?
Wheel Nut:
You are all bloody wusses anyway, sliding skellies, who needs them?youtube.com/watch?v=AovYxaNSc-o
Someone mentioned that Carryfast could be living in Nigeria
That is insane!!
No way did that bloke walk underneath it at 3:05 . Braver man than me.
Did anyone notice the angle of the wheels on the JCB as it was going up those hills? The wheels were pointing at right angles to the direction it was being pulled in. I don’t think it did any driving at all - the tractor unit just pulled it along up the hills!
I can’t believe it stayed on either! The benefits of a 6x4 I suppose.
I noticed that on the JCB but if I remember correctley you can steer them with the brakes on the rear wheels. It’s nearly 40 years since I had a go on a JCB so they may have changed a tad. 
knight:
Some very good answers and explainations but none that cover my question. On the dennison trailer i can carry a 45’ in the 20’ position but not a 40’ although they fit. I don’t understand how a 40 is different the stress must be the same.
I have tried looking on the dennison site but it’s not much help.
Its to keep the skelly and the container within the C&U dimesion regs. The maximum length of a trailer from the kingpin to the rear most part is 12.2 metres, so that why running on the very front twistlocks with a 45 (13.6 metre) box is essential to keep things sweet with the pen pushers .