thecoder0:
I had a quick look at one of the trailers the other day when parked next to one…and the ones they use are not new and have another air connector for stretching and shrinking (I Guess )
You can’t judge age by appearance, sadly - and when I say new, I mean less than about 5 years old. The one of ours it happened on was about that age. Basically, if it has a 20ft position, use it.
looking down the side of the trailer i noticed two pin holes one marked 3 and the other marked 4 (not a clue what they mean )
There’s usually another sticker somewhere with a guide telling you which is which. If it had positions labelled 3 and 4, and 2 sets of twistlocks at the front (making it a “14 pinner”) it will have a 20ft position, and I would guess that 4 is for 40ft or 2x 20ft…3 is for 45ft (using the front-most pins) and loaded 20ft…2 will be for 30ft and 1 will be for tipping 20fts ONLY.
If only one set of front locks (so a “12 pinner”) then 4 will be for 40/45/2x20ft…3 will be for 30ft…2 for running loaded 20ft…1 for tipping 20ft.
That said, we recently had on hire an SDC which looked like the first type above, but actually wanted you to put 20fts in the position normally used for 30fts - position 2, in the above case.
It sounds really complicated, but the quick way to tell if there’s no sticker is to get underneath and see where the chassis has been re-inforced. You’ll see large pieces of metal welded or bolted vertically to the rails. With a loaded 20ft, you need a reinforced position which will allow the weight to be distributed sensibly, basically. You have enough brains and experience to be able to work the rest out, I reckon.
Another trap not to fall into is using the shunt button to go the last few feet onto the bay with a ready to tip 20ft rather than faffing about with lines and locking the pins in to release the brakes. That bends the chassis too - the locked pins are an integral part of the strength of the trailer. These things are built to take 32 tonne boxes, so need to save weight at every turn to stay legal. Ditto running with your empty 20ft still fixed in tip position back to the docks. Not stable, and won’t do the trailer any good at all, never mind your underpants!
Simple rule is that if a position is available, it is available for a reason. Use it or damage it.
Ps. Just to complicate the issue further, the one exception to this is the instruction which tell you to not to use the front pins on a 14-pinner for 40ft boxes. We always run like this, have been pulled like this, etc etc and have never had any problem. Ditto not putting 45s on the second pins. No idea why it is not recommended - does anyone else know?
I know that a 13.6m swapbody will be overlength on the second pin, so that makes sense, but since we are only talking a couple of inches, it’s fine with a 45 AFAIK?
Toward the back of the trailer it looked like there was an arm at either side that could be moved over in two directions not sure what they were either.
Those are your rear bolsters for 40 and 45ft boxes. They will swing up into that position when needed - various methods of fastening, all obvious.
When you need to slide a 30ft or 20ft right to the back for tipping, they would be in the way and prevent you from doing this (as well as causing yet more damage should you try as the top half of the chassis slams into them…), so you swing them down into stowed position (it’s all about position in this game ).
You don’t HAVE to do this before you get to your tip, but they don’t half clank around if you don’t, and the more obsessive types (like me ) will tell you that it looks crap and lazy running that way too, so best to stow after you get lifted on. Sliders clank like nothing else at the best of times, never mind having something more back there flapping about - the first time you do a blindside reverse and hear a BANG you’ll be out like a shot to see what you’ve hit, only to find out that it was just the weight making the two halves of the chassis shift about…
HTH.