Reef:
the maoster:
Seriously CF, if you tried your method with today’s vehicles you’d be ripping mudguards off quicker than you could refit them.
Not to mention the sickening crunch and instant dead stop followed by the realisation that apparently not all truck manufactures fit run up rails/ramps anymore.
As I’ve said yes no ramps is obviously an issue.Having said that I think it is possible,to go under a trailer,that’s sitting at a height,that’s low enough to catch the forks on the fifth wheel,without hitting the mudguards or anything else.
While your statement concerning ramps might help to at least partly explain why drivers are at unnecessary increased risk of trailers moving or even falling off.When they’d be expected to stay where they are because they should be safely coupled with the pin securely located where it should be in the jaws of the fifth wheel as opposed to sitting on top of it.
You seem fixed on the idea that it’s all about not spreading grease on the rubbing plate CF. That is no more than a useful unintended consequence of using air suspension correctly.
If I’m dropping my “own” trailer and have the lift facility on my air suspension that is sadly not on my current trucks, this is the procedure is follow and the reason why I do what I do.
First I dump the air from the trailer, this ensures that in case of an air leak or windy night that the trailer doesn’t rock forwards putting unnecessary force on the landing legs. I then release all the brakes, again to remove any tension caused by the lowering of the suspension. I then raise the rear suspension on the unit using one of the presets (which I’ve already set) to a position approx an inch lower than maximum height and apply the parking brake. I then apply the trailer parking brake, if split coupling, wind legs down until they contact the ground, pull the pin, pull forward a few inches to get the kingpin free of the jaws, lower the air suspension, pull forward a little more to give enough room to get my fat arse up on the catwalk to remove the suzies, get back in, pull out from under the trailer, set air suspension to the travelling position and off I go. If I didn’t need to split couple then I would remove the suzies before pulling forward to clear the kingpin and then drop the suspension, pull out, raise it back up and go on my way.
Coupling would be the same in reverse. Drop suspension, back under, if split coupling I’d check the trailer parking brake was on, connect airlines, back under until I was a few inches away from the kingpin, lift the suspension to maximum and back it up until the jaws engage, do a tug test, apply safety catch, wind up legs, release trailer parking brake, set trailer suspension to the travelling position, do my walk around checks and away I would go.
bald bloke:
Radar19:
What happened to putting the trailer brake in the cab like the Yanks have? I remember driving an FM once and it confused the hell out of me. I thought I was stuck on the bay, brought the air up to max and I still couldn’t move. Took me a while to work out what was going on, I don’t ever remember activating the brake though.
And how do you operate the trailer brake from the cab if you’re not connected up ■■
They’re the same in Australia. The trailer. Brake is in the cab… the brakes lock on. And if the red line isn’t on the trailer won’t move even if coupled it drags. As soon as the red line is on it releases the brakes. Still, doesn’t mean you shouldn’t check the pin is in and tug test etc. also still getting out and doing a visual check.
I have no sympathy for drivers who don’t check it’s just the basics of the job… never cut corners … it costs lives.
newmercman:
You seem fixed on the idea that it’s all about not spreading grease on the rubbing plate CF. That is no more than a useful unintended consequence of using air suspension correctly.
If I’m dropping my “own” trailer and have the lift facility on my air suspension that is sadly not on my current trucks, this is the procedure is follow and the reason why I do what I do.
First I dump the air from the trailer, this ensures that in case of an air leak or windy night that the trailer doesn’t rock forwards putting unnecessary force on the landing legs. I then release all the brakes, again to remove any tension caused by the lowering of the suspension. I then raise the rear suspension on the unit using one of the presets (which I’ve already set) to a position approx an inch lower than maximum height and apply the parking brake. I then apply the trailer parking brake, if split coupling, wind legs down until they contact the ground, pull the pin, pull forward a few inches to get the kingpin free of the jaws, lower the air suspension, pull forward a little more to give enough room to get my fat arse up on the catwalk to remove the suzies, get back in, pull out from under the trailer, set air suspension to the travelling position and off I go. If I didn’t need to split couple then I would remove the suzies before pulling forward to clear the kingpin and then drop the suspension, pull out, raise it back up and go on my way.
Coupling would be the same in reverse. Drop suspension, back under, if split coupling I’d check the trailer parking brake was on, connect airlines, back under until I was a few inches away from the kingpin, lift the suspension to maximum and back it up until the jaws engage, do a tug test, apply safety catch, wind up legs, release trailer parking brake, set trailer suspension to the travelling position, do my walk around checks and away I would go.
A very concise description of how to (un)couple a trailer without putting undue stress on any of the components. A job wel done sir. Now we’ll just wait for cf to come back and tell you in 10000 words that you’re wrong. 
the nodding donkey:
newmercman:
You seem fixed on the idea that it’s all about not spreading grease on the rubbing plate CF. That is no more than a useful unintended consequence of using air suspension correctly.
If I’m dropping my “own” trailer and have the lift facility on my air suspension that is sadly not on my current trucks, this is the procedure is follow and the reason why I do what I do.
First I dump the air from the trailer, this ensures that in case of an air leak or windy night that the trailer doesn’t rock forwards putting unnecessary force on the landing legs. I then release all the brakes, again to remove any tension caused by the lowering of the suspension. I then raise the rear suspension on the unit using one of the presets (which I’ve already set) to a position approx an inch lower than maximum height and apply the parking brake. I then apply the trailer parking brake, if split coupling, wind legs down until they contact the ground, pull the pin, pull forward a few inches to get the kingpin free of the jaws, lower the air suspension, pull forward a little more to give enough room to get my fat arse up on the catwalk to remove the suzies, get back in, pull out from under the trailer, set air suspension to the travelling position and off I go. If I didn’t need to split couple then I would remove the suzies before pulling forward to clear the kingpin and then drop the suspension, pull out, raise it back up and go on my way.
Coupling would be the same in reverse. Drop suspension, back under, if split coupling I’d check the trailer parking brake was on, connect airlines, back under until I was a few inches away from the kingpin, lift the suspension to maximum and back it up until the jaws engage, do a tug test, apply safety catch, wind up legs, release trailer parking brake, set trailer suspension to the travelling position, do my walk around checks and away I would go.
A very concise description of how to (un)couple a trailer without putting undue stress on any of the components. A job wel done sir. Now we’ll just wait for cf to come back and tell you in 10000 words that you’re wrong.
The question was why are so many drivers seeming to be getting themselves into dangerous aggro while coupling.Specifically in the form of the pin not being in the jaws of the fifth wheel.The only logical explanation being that it’s over ridden them.
In which case it’s not difficult to understand,how the idea of dropping the unit lower than the trailer when it’s put under it,then hoping to lift it after without fouling the pin,could create that situation.
While assuming the thing is fitted with a decent set of ramps how does coupling up possibly put any strain on the legs when their action is to lift the legs off the ground from the first point of contact.
Carryfast:
The question was why are so many drivers seeming to be getting themselves into dangerous aggro while coupling.Specifically in the form of the pin not being in the jaws of the fifth wheel.The only logical explanation being that it’s over ridden them.
In which case it’s not difficult to understand,how the idea of dropping the unit lower than the trailer when it’s put under it,then hoping to lift it after without fouling the pin,could create that situation.
While assuming the thing is fitted with a decent set of ramps how does coupling up possibly put any strain on the legs when their action is to lift the legs off the ground from the first point of contact.
What would you know about dropping or picking up a trailer, aren’t you an alcoholic who drives an Austin Aleggro?
The fact you can’t understand how to couple up using air shows you’re a complete halfwit or living in the dark ages. If those who squash themselves took the time to couple up properly they would still be here, simple.
Maybe they were as thick as you and couldn’t work out how to couple properly.
A.
Think about what you’ve just said CF. Can you imagine the shock loadings you put on both lorry and trailer by hooking up or dropping a trailer as you describe?
You’re suggesting that the legs are wound down so that they’re clear of the ground by an inch or so, to allow the trailer to drop to the ground by sliding down the ramps as you pull out.
That’s a lot of weight and force being put on the legs as they hit the ground (approx 15ton) and that’s a big difference to suddenly come off the unit suspension which will fully extend in a split second while under maximum pressure.
Hooking up will be the opposite, a sudden massive weight applied to every component on the rear air suspension on the unit and if there’s any lateral force from being slightly askew as the jaws engage the pin, it will all be transferred to the landing legs.
It’s like using a sledgehammer to crack a nut.
newmercman:
Think about what you’ve just said CF. Can you imagine the shock loadings you put on both lorry and trailer by hooking up or dropping a trailer as you describe?
You’re suggesting that the legs are wound down so that they’re clear of the ground by an inch or so, to allow the trailer to drop to the ground by sliding down the ramps as you pull out.
That’s a lot of weight and force being put on the legs as they hit the ground (approx 15ton) and that’s a big difference to suddenly come off the unit suspension which will fully extend in a split second while under maximum pressure.
Hooking up will be the opposite, a sudden massive weight applied to every component on the rear air suspension on the unit and if there’s any lateral force from being slightly askew as the jaws engage the pin, it will all be transferred to the landing legs.
It’s like using a sledgehammer to crack a nut.
Firstly all the forces you’ve referred to are obviously catered for at the design stage.Bearing in mind that we’re not talking about coupling up a trailer by running flat out at it in high range reverse or dropping it at a similar speed.
Which leaves the obvious question how was it that we didn’t have unit rear suspensions and landing legs falling to bits,having been smashed by the coupling un coupling process and why were we always taught to make sure that we dropped trailers at a lower height than the fifth wheel height and why did we have ramps and how did we ever manage before air suspension.
Thereby also answering your question,why didn’t we have potential examples of drivers being caught on the catwalk between the unit and a runaway trailer because it’s been mis coupled.Which if I’ve read it right was your question.Which I think I’ve in large part answered. 
Carryfast:
…While assuming the thing is fitted with a decent set of ramps how does coupling up possibly put any strain on the legs when their action is to lift the legs off the ground from the first point of contact.
There is going to be some horizontal force as the unit suspension is compressed. Have you never watched a trailer move when coupling in the manner you advocate?
Using the air WILL allow the competent driver to lift vertically from the first point of contact.
It’s all Scargill’s fault. If we still had coal powered trucks, we could just ram 'em under those cast iron heavy duty trailers that were made out of the Titanic’s hull. ( It never really sank-insurance job ).
In my next life I want to be CF’s keyboard. Getting fingered just for the sake of it
Wiretwister:
Carryfast:
…While assuming the thing is fitted with a decent set of ramps how does coupling up possibly put any strain on the legs when their action is to lift the legs off the ground from the first point of contact.
There is going to be some horizontal force as the unit suspension is compressed. Have you never watched a trailer move when coupling in the manner you advocate?
Using the air WILL allow the competent driver to lift vertically from the first point of contact.
It’s obvious that when the unit suspension has compressed much of the load has already been transferred from the legs to the unit at that point.With that transfer only increasing to the point where the legs are clear of the ground with the majority of any horizontal loads during that process taken by the trailer axles not the legs.Having said that if anyone really thinks that longitudinal loadings are an issue then bracing the legs in the horizontal directions are the usual widely available solution.
While using the air is just a solution to a non existent problem.But ironically which does introduce the dangerous problem of its own in creating the perfect condition for mis coupling trailers by mis judging the lowering and lifting points and thereby fouling the pin.Which is why we were always taught to drop trailers lower than the fifth wheel height and to make sure that we picked them up preferably using the ramps,or if not fitted,the tapered fifth wheel forks both of which being designed for that purpose of lifting the trailer onto the fifth wheel and thereby ensuring that the pin is at the correct height to enter the jaws properly.
Which in large part answers nmm’s question as to why the obvious problems of unsafe coupling procedures now as opposed to previously.
Carryfast:
Wiretwister:
Carryfast:
…While assuming the thing is fitted with a decent set of ramps how does coupling up possibly put any strain on the legs when their action is to lift the legs off the ground from the first point of contact.
There is going to be some horizontal force as the unit suspension is compressed. Have you never watched a trailer move when coupling in the manner you advocate?
Using the air WILL allow the competent driver to lift vertically from the first point of contact.
It’s obvious that when the unit suspension has compressed much of the load has already been transferred from the legs to the unit at that point.With that transfer only increasing to the point where the legs are clear of the ground with the majority of any horizontal loads during that process taken by the trailer axles not the legs.Having said that if anyone really thinks that longitudinal loadings are an issue then bracing the legs in the horizontal directions are the usual widely available solution.
While using the air is just a solution to a non existent problem.But ironically which does introduce the dangerous problem of its own in creating the perfect condition for mis coupling trailers by mis judging the lowering and lifting points and thereby fouling the pin.Which is why we were always taught to drop trailers lower than the fifth wheel height and to make sure that we picked them up preferably using the ramps,or if not fitted,the tapered fifth wheel forks both of which being designed for that purpose of lifting the trailer onto the fifth wheel and thereby ensuring that the pin is at the correct height to enter the jaws properly.
Which in large part answers nmm’s question as to why the obvious problems of unsafe coupling procedures now as opposed to previously.
That’s the way it was taught in the 70s you turps nudging old codger, times change.
Now people are taught to drop and pick up trailers properly and safely, using the air suspension. Anyone who misses the pin doing it the proper way hasn’t done it properly.
A.
Carryfast:
It’s obvious that when the unit suspension has compressed much of the load has already been transferred from the legs to the unit at that point.With that transfer only increasing to the point where the legs are clear of the ground with the majority of any horizontal loads during that process taken by the trailer axles not the legs.Having said that if anyone really thinks that longitudinal loadings are an issue then bracing the legs in the horizontal directions are the usual widely available solution.
And while the unit suspension is compressing? I’ll repeat my question, in big so you can see it.
Have you never seen a trailer move when coupling using the method you advocate?
carryfast:
While using the air is just a solution to a non existent problem.But ironically which does introduce the dangerous problem of its own in creating the perfect condition for mis coupling trailers by mis judging the lowering and lifting points and thereby fouling the pin.Which is why we were always taught to drop trailers lower than the fifth wheel height and to make sure that we picked them up preferably using the ramps,or if not fitted,the tapered fifth wheel forks both of which being designed for that purpose of lifting the trailer onto the fifth wheel and thereby ensuring that the pin is at the correct height to enter the jaws properly.
Which in large part answers nmm’s question as to why the obvious problems of unsafe coupling procedures now as opposed to previously.
You are, IMO, confusing procedure with application. Processes have revised as the capability of the kit has changed. Are you seriously suggesting that no trailer pin was ever missed before the introduction of air suspension because I doubt human ability to take shortcuts and ■■■■ up has, it is the human application that is the greatest variable and more often than not the reason behind these avoidable accidents.
Franglais:
Radar19:
What happened to putting the trailer brake in the cab like the Yanks have? I remember driving an FM once and it confused the hell out of me. I thought I was stuck on the bay, brought the air up to max and I still couldn’t move. Took me a while to work out what was going on, I don’t ever remember activating the brake though.
Was that really the trailer brake? On some Volvos a small black button beside the handbrake will pop out if the air drops, and must then be pushed back in manually.
Oh aye, the ‘Broms Brake’ I remember those on the Volvo FL10 I had years ago! I seen it catch a lot of drivers out
who wondered why the hell they couldn’t get their motor moving! Lol 
What a debate over something so very simple 
Four very easy things to do when coupling up a trailer, five if you want to check the lights work and some on here have made it so unnecessarily complicated
It makes me glad to be able to say that I’ve never had air suspension on a semi, only steel. I drove a rigid with air which could come in handy if you were on a sloping dock.
I can only comment that I’d be making sure the trailer brake was on. As Discoman says, ours are in the cab like they used to be when I was driving in the UK.
RIP to those that die doing it, but there’s only one person to blame is the harsh truth of it.
CF you have a rather different view of why we used to do things the way we did. Even back in the mists of time, the correct procedure was to have the 5th wheel ever so slightly lower than the rubbing plate of the trailer, you backed under the trailer, the jaws engaged the pin and then you had to use the low gear setting on the legs to lower the trailer onto the unit and let the unit springs settle under the weight imposed by the trailer, then whack the legs into high gear once they were free of any imposed load. The whole process was done in reverse to uncouple from a trailer.
That was the correct “on paper” method of doing it, in practice however we did it the easy way, if dropping an empty trailer we would leave the legs a few inches off the ground so that when we hooked up to it once it had been loaded we never had to stand there winding the legs in the low gear as the springs on the unit settled under the weight, dropping a loaded trailer we would stop winding as soon as the legs hit the ground and then pull out from under it. It wasn’t done this way to ensure we hit the pin properly, it was purely to avoid standing there twirling the winding handle for ages or having to put your back into it.
A short cut, a way to make life a bit easier and nothing more, it wasn’t a practice advised by the manufacturers of landing gear, 5th wheels or tractor units and rightly so as it was a heavy handed approach and before spring brakes it could be a very dangerous practice as the trailer could and often would, go for a little trip around the yard as you rammed your unit into it.
Wiretwister:
Carryfast:
It’s obvious that when the unit suspension has compressed much of the load has already been transferred from the legs to the unit at that point.With that transfer only increasing to the point where the legs are clear of the ground with the majority of any horizontal loads during that process taken by the trailer axles not the legs.Having said that if anyone really thinks that longitudinal loadings are an issue then bracing the legs in the horizontal directions are the usual widely available solution.
And while the unit suspension is compressing? I’ll repeat my question, in big so you can see it.
Have you never seen a trailer move when coupling using the method you advocate?
carryfast:
While using the air is just a solution to a non existent problem.But ironically which does introduce the dangerous problem of its own in creating the perfect condition for mis coupling trailers by mis judging the lowering and lifting points and thereby fouling the pin.Which is why we were always taught to drop trailers lower than the fifth wheel height and to make sure that we picked them up preferably using the ramps,or if not fitted,the tapered fifth wheel forks both of which being designed for that purpose of lifting the trailer onto the fifth wheel and thereby ensuring that the pin is at the correct height to enter the jaws properly.
Which in large part answers nmm’s question as to why the obvious problems of unsafe coupling procedures now as opposed to previously.
You are, IMO, confusing procedure with application. Processes have revised as the capability of the kit has changed. Are you seriously suggesting that no trailer pin was ever missed before the introduction of air suspension because I doubt human ability to take shortcuts and ■■■■ up has, it is the human application that is the greatest variable and more often than not the reason behind these avoidable accidents.
As I said of course there’s some lateral loads when picking up a trailer doing it the ‘proper’ way.Most/all of which are transferred to the trailer axles while the legs are only going one way together with the front of the trailer and that’s up not back.Having said that it’s no problem to brace the legs fore and aft if anyone is that bothered.Which leaves the question this thing is obviously on air so what are those ramps for behind the fifth wheel if not to pick up trailers in the usual old school way. ■■.
trucklocator.co.uk/2007-daf- … ck-258116/
While yes the human application is the greatest variable.In which case it was/is far less likely that a trailer would be mis coupled by picking it up at a lower height than the fifth wheel to the point where we didn’t even need to think about the process other than making sure that the trailer was low enough.Than the variables you’ve created by going under a high trailer with a low unit then hoping to lift the unit in the right position without fouling the pin.While if there supposedly is no problem then nmm obviously wouldn’t have asked the question.
newmercman:
CF you have a rather different view of why we used to do things the way we did. Even back in the mists of time, the correct procedure was to have the 5th wheel ever so slightly lower than the rubbing plate of the trailer, you backed under the trailer, the jaws engaged the pin and then you had to use the low gear setting on the legs to lower the trailer onto the unit and let the unit springs settle under the weight imposed by the trailer, then whack the legs into high gear once they were free of any imposed load. The whole process was done in reverse to uncouple from a trailer.
That was the correct “on paper” method of doing it, in practice however we did it the easy way, if dropping an empty trailer we would leave the legs a few inches off the ground so that when we hooked up to it once it had been loaded we never had to stand there winding the legs in the low gear as the springs on the unit settled under the weight, dropping a loaded trailer we would stop winding as soon as the legs hit the ground and then pull out from under it. It wasn’t done this way to ensure we hit the pin properly, it was purely to avoid standing there twirling the winding handle for ages or having to put your back into it.
A short cut, a way to make life a bit easier and nothing more, it wasn’t a practice advised by the manufacturers of landing gear, 5th wheels or tractor units and rightly so as it was a heavy handed approach and before spring brakes it could be a very dangerous practice as the trailer could and often would, go for a little trip around the yard as you rammed your unit into it.
If we were only meant to put a lower unit under a higher trailer then drop the trailer onto the unit using the winder why did we have ramps and why were we taught to make sure that we always dropped trailers lower than fifth wheel height ?.
As opposed to what I was taught that the plate needs to be sitting with all its weight on the table from the start to ensure that the pin enters at the right height as it couples.
Which leaves the question what’s being described here ?.
poferrymasters.com/carrierin … upling.pdf
In that it obviously isn’t saying anything which you or others have described.But also seems to have lost its way between stopping with the fifth wheel ramps contacting the trailer plate and then fig 4 lower the suspension obviously matching the fifth wheel height to the level of the plate ( Why ? ).When all that’s needed from the point where the ramps have contacted the plate is to couple the thing making sure that all the weight of the trailer is sitting on the table when the pin goes in.Which is what the ramps/forks are for in lifting and then dumping the trailer onto the table before the pin goes in.
IE it’s actually closer to what I’m saying.Than what you and others are saying in dropping the fifth wheel height ‘below’ that of the trailer plate then putting the unit under then raising the height to pick up the trailer then coupling it,but no cigar.
newmercman:
CF you have a rather different view of why we used to do things the way we did.
youtube.com/watch?v=CfEdLsJtW_s 2.43 - 3.39.
Edit to add I think this is closer to everything I’ve said than you and others regarding how to couple up without ramps let alone with them.Watch and learn.