Questions about trailers, trailers, trailers

UK PROFESSIONAL DRIVERS FORUMS THE UK PROFESSIONAL DRIVERS FORUM (INTERACTIVE)
1

Some trailers (DDs?) have 2 brake buttons: red and black; red is engaged when pulled out, black - when pushed in (according to the pictures next to them). What’s the black button for?

DDs have 2 sets of clips and levers, top one for coupling but what’s the other one for?

Trailer height: is it always based on 1.25m 5th wheel height? How do you get your own 5th wheel height? Is 1.25 standard for all trucks (with suspension leveled)?

WHen de-coupling, do you lower suspension BEFORE driving away from the trailer (disengaging the kingpin) or do you drive out a bit first, then lower, then drive out fully? What’s the difference/reasons as I (think) have been shown both

When coupling trailer, lower truck first then drive in/engage, then raise then tug test or am I wrong?

Internal straps - one per pallet or 2 (one for each ‘end’)?

Thanks to anyone who feels like answering one or two :=)

2

Black knob is the shunt button , push that and brake one in when no Air lines attached allows you to move trailer
WARNING ! Don’t use on a fully loaded trailer as you have no trailer brakes

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3

ETS:
When coupling trailer, lower truck first then drive in/engage, then raise then tug test or am I wrong?

Congratulations. You just missed the pin and snapped your (bosses) wind deflectors off. On a side note I see more and more Stobfart trucks these days with missing deflectors. Oddly enough it seemed to coincide with them getting rid of all their decent drivers and replacing them with foreign agency drivers. But I digress.

Lower your suspension, reverse partly under the trailer, raise up your suspension so the legs are off the floor (if possible) then reverse back and engage the pin. Now you can do your tug test. This doesn’t need to be done in first so you’re wheels are spinning for 5-6 seconds. Seen that a few times recently.

4

Long winded answer

When coupling trailer, lower truck first then drive in/engage, then raise then tug test or am I wrong?

Line yourself up to the trailer but don’t make contact with it.
Apply parking brake on tractor unit and switch off the engine and remove keys if reqd.
Get out and check if the parking brake on the trailer of on (red knob out)
Also check the area around the trailer is safe and anyone nearby knows what your doing.
Get back in cab start engine
Drop tag axil (if fitted).
lower suspension.
Turn on side lights and hazard lights.
partially reverse under to get the 5th wheel under the plate, but don’t reverse all the way, fully lift suspension so the landing legs are clear of the floor, this prevents damaging then when connecting to the truck, and minimises scraping the grease off the plate and possibly ending up on you and your clothes.
Wind your window down and then slowly continue to reverse under the trailer till you hear it click in (don’t ram it in), then engage forward or 1st gear and gently squeeze the throttle and you will feel resistance from the trailer, do this twice. This will prove the connection between the tractor and trailer.
Now apply the parking brake on the tractor unit and switch off the engine, and get out and look under the trailer and fit the dog clip. If you have a torch look under the trailer from the gap between the tractor unit and landing legs at the jaws of the 5th wheel and you will see that the locking mechanism of the 5th wheel has engaged.

Now this is where everyone’s routine may differ.
When I get out the cab to fit the dog clip, I put the trailer number plate on the cab step. Then go fit the clip, this prevents me from forgetting to put in in place as I’d have to step over it to get back in the cab. then as I move around the vehicle to complete the various stages I carry the plate with me, placing it next on the platform while I connect the suzies, then on the mudguard while I wind up the landing legs.
After connecting the suzies look up and around the front of the trailer and check it the white marker lights are on, wind up the trailer legs, release the trailer parking brake and move on towards the rear of the trailer checking the wheels and tyres. Once at the back fit the number plate and check the lights at the rear are working, also look down either side and check the orange marker lights and on. Then continue to check the wheels and tyres of the other side as you walk back to the cab.

Don’t try to do the above and strap down or fasten curtain buckled at the same time as you go around the truck. Do them as separate operations otherwise you will make mistakes

5

ETS:
WHen de-coupling, do you lower suspension BEFORE driving away from the trailer (disengaging the kingpin) or do you drive out a bit first, then lower, then drive out fully? What’s the difference/reasons as I (think) have been shown both

Me personally I drive forward a bit, then lower the suspension before driving away. You can lower first but I’ve had issues doing that in the past and the pin has ended up re-engaging meaning I had to get out and pull the arm again. In some situations, like when you cannot pull the arm for whatever reason dropping the weight off the 5th wheel can help release the arm. But like I said, if I can I’ll drive forward first.

6

Pull forwards by a couple of inches until you hear the pin disconnect from the jaws, stop, dump the air, pull out. Fifth wheel grease then stays where it should be instead of being deposited in a big gooey clump on the front edge of the trailer.

Many companies have disconnected the shunt button by putting a spring clip behind the plastic button. If you know what you’re doing you can pull the button off and take them out :smiley: . Take heed of the warnings about moving heavy trailers on the shunt button. Your foot brake effectivity is reduced by at least 50% and it’s very easily to get complacent with your speed around the yard.

7

I learnt (scania) taking into account all the variables, ground status, and 5th heights a bit higher than other makes apparently…

So for me uncoupling it’s, axle down, raise it to say plus 30 to aim her away from cab… (again weight/gradient depending!!)…
Then its legs down to contact, do all ya shizzle, release the hound
Slide out till pins free, lower the air just enough to be sure it on ground an clear of Jaws, then lower it gently leaving the plate horizontal to chassis that way if anything failed hopefully unit will save the trailer and the weight would spread across the chassis thus less damage to unit, plus it may then slide back into Jaws…
Or if you needed to save it hopefully adjusting the air will give you the chance to do so without it heading into the cab or over the plate onto owt else.

Then Its lower her clear an pull out, rather than dragging all the grease along for the next bloke, or risking pulling on trailer an legs!!

If coupling, regardless of weight its mid lift down, lower her a bit, slide under without rubbing the faces till pins just before
Jaws, then lift it just enough to make contact with plate face, an take weight off the legs say half inch off ground max… (again incase it started to roll back or some shizzle lol…)… then it’s slide her back nice an gentle till you hear that sweet sweet double clunk.

Then I check she’s in, clips on, an with legs clear of the ground by a touch its couple tugs with trailer brake on, do all my gubbins with it still raised slanting trailer away from cab, then level it off once happy, adjust axle/airs to suit an off I popski.
As an added ■■■■ trait before setting of I like to do a little hot foot to be sure it won’t be left behind at first jump out into oncomings…(unless it’s a lycra jokey [emoji8]…) rather in the yard for me[emoji16]

I tried to avoid split coupling unless it was quiet as hey you never know, but if I were to do so it’d be jacked up as high as possible and avoided 99% of time if the gradients towards cab, or tbh if I just wernt happy.

I shall now await BIGTRUCK3s opinion on the above.
It could be a while I fear as he’s probably fury frapping to a picture of his favourite Stobart truck that he failed to get a job driving, which I’m sure explains why he’s so fond of targeting them or owt to do with em so much on here…[emoji8][emoji38]

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8

blue estate:
Black knob is the shunt button , push that and brake one in when no Air lines attached allows you to move trailer
WARNING ! Don’t use on a fully loaded trailer as you have no trailer brakes

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And hope you have enough air in the trailer to complete your movement!!!

9

Benjie83:
If coupling, regardless of weight its mid lift down, lower her a bit, slide under without rubbing the faces till pins just before
Jaws, then lift it just enough to make contact with plate face, an take weight off the legs say half inch off ground max… (again incase it started to roll back or some shizzle lol…)… then it’s slide her back nice an gentle till you hear that sweet sweet double clunk.

On heavy trailers leave the legs on the ground but aim for a sweet spot of taking some of weight off them but not to the point where you have to plant your foot to the floor to force the unit onto the pin with a big slam. It’s better to line yourself up properly so that the pin goes straight in the jaws without touching the sides, that way you won’t have to worry about lateral forces on the legs potentially bending them. Always lift the weight off the legs before doing the tug test. If you hear creaking noises you’re doing it wrong.

10

R420:

Benjie83:
If coupling, regardless of weight its mid lift down, lower her a bit, slide under without rubbing the faces till pins just before
Jaws, then lift it just enough to make contact with plate face, an take weight off the legs say half inch off ground max… (again incase it started to roll back or some shizzle lol…)… then it’s slide her back nice an gentle till you hear that sweet sweet double clunk.

On heavy trailers leave the legs on the ground but aim for a sweet spot of taking some of weight off them but not to the point where you have to plant your foot to the floor to force the unit onto the pin with a big slam. It’s better to line yourself up properly so that the pin goes straight in the jaws without touching the sides, that way you won’t have to worry about lateral forces on the legs potentially bending them. Always lift the weight off the legs before doing the tug test. If you hear creaking noises you’re doing it wrong.

Bless ya, yeah I forgot too add that I think, or I’ve worded it my way [emoji849]
Tbh I’d already bored everyone with the length so I just sent it… [emoji849][emoji16]

I had one once full of soft drink, first ever FULL trailer pull as a complete lone newbie.
Tug had left it 400ft in air but I needed to drop it about an inch on the legs to make it as no tug about so no choice ffs.

Added bonus wind speed on legs was shot too for good measure, my god was it creaking on the way Down, really wernt happy doing it to the trailer but again no choice.
I must admit I was creaking from the rear myself as it came down [emoji38]

Trouble is there never seems to be a universal rule for everyone to share with regards to heights/etiquette as Alot of motors are different from what I’ve been told let alone the drivers…[emoji38]

But yeah really appreciate the input fella, always good to have the brain jogged by those with the distance under em [emoji41][emoji41]

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11

Just to add that most New Gen Scanias are fitted with a 5th wheel height of 1350mm, thast a 100 mm difference or a shade under 4 inches in old money !
So your 4.0 metere trailer is now not!

12

Benjie83:
Trouble is there never seems to be a universal rule for everyone to share with regards to heights/etiquette as Alot of motors are different from what I’ve been told let alone the drivers.

Most drivers over about the age of 55 won’t ever use the air because they still think they’re in the 70s and 80s when everything was on springs. These are the sort of the drivers that will slam into a fully loaded trailer and deposit all the fifth wheel grease onto the catwalk so you end up with it in your car and on your floor at home. Also the same ones who get launched like a bullet when pulling out from under a loaded trailer, nearly taking off the rear light clusters because they still think you must leave the legs 2" off the ground after winding them down. They will happily tell you that they’ve “done more miles in reverse than you have forwards” but air suspension is too hard for them :smiley: .

Modern trailers are much more flimsy than older ones and will sag quite noticeably forward of the legs when there’s a lot of weight on them. This can make it difficult to couple up to for the next person as they can’t get the back end of the unit low enough for the ramps (if it has them). I consider it to be good practice on a heavy trailer to raise the suspension by a few inches and then wind the legs fully to the ground before uncoupling. After pulling out, the trailer front end settles to a normal height and the next person can couple up to it without issue.

13

R420:

Benjie83:
Trouble is there never seems to be a universal rule for everyone to share with regards to heights/etiquette as Alot of motors are different from what I’ve been told let alone the drivers.

Most drivers over about the age of 55 won’t ever use the air because they still think they’re in the 70s and 80s when everything was on springs. These are the sort of the drivers that will slam into a fully loaded trailer and deposit all the fifth wheel grease onto the catwalk so you end up with it in your car and on your floor at home. Also the same ones who get launched like a bullet when pulling out from under a loaded trailer, nearly taking off the rear light clusters because they still think you must leave the legs 2" off the ground after winding them down. They will happily tell you that they’ve “done more miles in reverse than you have forwards” but air suspension is too hard for them :smiley: .

Modern trailers are much more flimsy than older ones and will sag quite noticeably forward of the legs when there’s a lot of weight on them. This can make it difficult to couple up to for the next person as they can’t get the back end of the unit low enough for the ramps (if it has them). I consider it to be good practice on a heavy trailer to raise the suspension by a few inches and then wind the legs fully to the ground before uncoupling. After pulling out, the trailer front end settles to a normal height and the next person can couple up to it without issue.

I refuse the even acknowledge run up rails lol, sadly nowadays as you may know modern training/test doesn’t seem to teach, again, any real form of general etiquette on what’s best.

I was lucky me dad drove, learnt all I could, then since passing I’ve met some top blokes so have tried to learn all I could with regards to the ultra modern ways and as you say suspension configurations.

And yeah as for the sagging point, bloody definitely noticed that one even with my short stint, two pallets of rice over the pin and it’s sagged about 6inch, I just put it down to Stobarts saving money for the Christmas party…

Funnily enough even the sorta 5yr old trailers felt Alot more solid, utterly battered yes, but alot more solid than say the Yr old ones they had.
Although if I never saw one of their old xct trailers again I’d not loose sleep, ■■■■ old scrap, only piece that weren’t hanging were the light lenses [emoji38]

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14

ETS:
DDs have 2 sets of clips and levers, top one for coupling but what’s the other one for?

Dunno, unless you’re talking about 5th wheel slider, but thats on the truck, not the trailer.

ETS:
How do you get your own 5th wheel height?

With a trailer on, stand in line with the 5th wheel and use a measuring tape to get the distance between the ground and the bottom of the side rail

ETS:
Internal straps - one per pallet or 2 (one for each ‘end’)?

You will be lucky if you have enough for 1 per pallet. 2 per pallet will see you run out of straps halfway down.

15

One problem you can find is with a trailer with an air leak, or one that has been parked up a long time. As the air in the rear suspension leaks out, the front of the trailer will go up, making it impossible to couple up. You can either wind the legs down or couple the airlines and reinflate the trailer suspension.

16

Santa:
One problem you can find is with a trailer with an air leak, or one that has been parked up a long time. As the air in the rear suspension leaks out, the front of the trailer will go up, making it impossible to couple up. You can either wind the legs down or couple the airlines and reinflate the trailer suspension.

Yes that is a good tip for newbies Santa. You can just reverse up to it, connect your red line and have your unit engine running. It will reinflate the bags on the trailer which will lower the front end so you can reach the pin. If the trailer is empty often it’s quicker and easier just to wind up the legs by a couple of turns in high gear to bring the nose down :smiley: .

17

Isn’t hooking a trailer up part of the hgv Test?.

Just asking for a friend. :confused:

18

biggriffin:
Isn’t hooking a trailer up part of the hgv Test?.

Just asking for a friend. :confused:

Yes, but is that real world?

Like in the real world do we all do little sideshift reverses into boxes? No but that’s in the test…

19

Much of this us probably above, but just trying to make it easier to read. All of course opinion from experience so don’t sue if its wrong. :slight_smile:

1) Most trailers have the 2 buttons. Ignore the shunt (black) one and leave that for lazy shunters as it can be quite dangerous. It releases the brakes using the air left in the system.

Best to use red airline for moving trailers around the years, and both airlines for loaded ones. Remember red only releases the trailer brakes, it doesn’t apply them.

2) By 2 levers I assume you mean the tractor unit 5th wheel leavers? Big one releases trailer as you know, small one allows you to move the 5th wheel position.

Never done this myself and suspect many are jammed, so personally I wouldn’t worry about it. If you don’t get it locked back in, that could be very bad.

3) Most trucks will be that height, but some do seem to get slightly higher if the midlift wheel is up. Scanias have the rep for this, but have also seen it on a DAF. I have also noticed some Renault’s seem higher.

Personally I would always assume the trailer is 3-4" higher than stated. Allows for loaded / unloaded height, bouncing etc when encountering bridges etc.

If you do measure, make sure its a empty trailer as a full one will push the suspension down even when levelled.

4) Dropping trailer, I would pull out until you get the click, then drop suspension all the way and pull out. If its a full DD, expect it to bend quite a bit and prob won’t fully clear the trailer, but saves the massive clonk.

Some will drop it all the way and pull out, but it doesn’t always want to disconnect. Tends to get stuck and launches you forward when it finally lets go.

5) Coupling - first thing is check trailer brake is on!

I drop all the way, slowly backup until front of trailer is between 2 sets of wheelarches, lift suspension until you see trailer raise then slowly backup.

  • If you don’t see it rise, get out and look.
  • Don’t ram backwards, you get the idea of how much.

If trailer isn’t on level ground including on a slope, get out and check 5th wheel is level. If its not, it can make life harder and requires more getting out and looking.

Then quick tug test, but as mentioned, don’t burn tyres out. Then put in the clip. If clip wont go in, start again.

To check connection, go under the trailer and shine a torch up its bum. You should see the kingpin fully sitting inside the 5th wheel and the bar right across in front. If not, disconnect and start again. Juddian taught me this and its saved me a few times esp on bumpy ground.

6) Internals go one per pallet usually but remember they only work for upto 400kg. If you have spares then more is better, esp for barrels and 25L tubs. Don’t be afraid to use ratchets even below 400kg.

Oh and all the people who’ve been doing this since the ark who’ll tell you they only ever use internals. Yeah well, they can get stopped and pay the fines. Your load, your responsibility.

20

biggriffin:
Isn’t hooking a trailer up part of the hgv Test?.

Just asking for a friend. :confused:

Not if you pass in a wagon and drag.

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