Wheel Nut,it seems like a handy book you refer to…Would we all be able to get a 30% discount and if so can you tell us where from?
Thanks.
Santa:
Just remember that if you stop suddenly, that 20 tonne coil will want to keep going. The only things holding it back from wiping out the cab on its way to the road in front, are the chains you used to tie it down.
we have these in our trailers, very sturdy metal posts that stand in corresponding holes in the floor. just set them up and load the coil/paperroll/whatever against it. you still have to fasten it but its a big help against stuff shooting forwards
ShropsBri:
Wheel Nut,it seems like a handy book you refer to…Would we all be able to get a 30% discount and if so can you tell us where from?
Thanks.
I am not sure how much they will discount it normally. I have bought from them for about the last 12 years. normally around £55 each.
Wheel Nut:
stevieboy308:
I just need to sleep on the rear axle thing now!! I would’ve thought that you went off the centre of the middle axle? (On a tri axle with equal spacing) But I’ve been wrong before!!The rear axle makes sense to me. You are trying to carry weight on the whole bogie but you still need some over the pin. I reckon if you take your measurement from the centre, that will put you over on the pin.
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o…o…o o..Generally I have measured the load by pacing it out, then pace it from behind the rear axle forward to give me a clue as to where the load sits comfortably
now i’ve not slept yet, but…
you’ve got a single axle trailer, that is loaded at the front putting the drive axle bang on its limit, but you’re nowhere near the gross. you put a 3t block with it’s center of gravity, which is in the middle of the block, over the middle of the trailer axle, therefore the 3t all goes on the axle and nothing is transferred to the pin.
you then put 2 identical blocks, one to the front and one to the rear of the original block with no gaps in between. the load now weighs 9t and the center of gravity is still in the same place above the middle of the axle with no weight being transferred to the pin.
you now add 2 axles, 1 to the front and 1 to the rear of the original axle with equal spacing, i don’t understand why we need to move the 3 blocks back until the the middle of the middle one is over the middle of the rear axle to stop us from transferring any weight to the pin?
stevieboy308:
Wheel Nut:
stevieboy308:
I just need to sleep on the rear axle thing now!! I would’ve thought that you went off the centre of the middle axle? (On a tri axle with equal spacing) But I’ve been wrong before!!The rear axle makes sense to me. You are trying to carry weight on the whole bogie but you still need some over the pin. I reckon if you take your measurement from the centre, that will put you over on the pin.
(—!
!..!..:::::::::::::::::
o…o!o…o o o..
(—!
!..!..:::::::::::::::::
o…o…o o o..
(—!
!..!..:::::::::::::::
o…o…o o..Generally I have measured the load by pacing it out, then pace it from behind the rear axle forward to give me a clue as to where the load sits comfortably
now i’ve not slept yet, but…
you’ve got a single axle trailer, that is loaded at the front putting the drive axle bang on its limit, but you’re nowhere near the gross. you put a 3t block with it’s center of gravity, which is in the middle of the block, over the middle of the trailer axle, therefore the 3t all goes on the axle and nothing is transferred to the pin.
you then put 2 identical blocks, one to the front and one to the rear of the original block with no gaps in between. the load now weighs 9t and the center of gravity is still in the same place above the middle of the axle with no weight being transferred to the pin.
you now add 2 axles, 1 to the front and 1 to the rear of the original axle with equal spacing, i don’t understand why we need to move the 3 blocks back until the the middle of the middle one is over the middle of the rear axle to stop us from transferring any weight to the pin?
The centre of the rear axle is where you measure from, to the fifth wheel pin to give you a figure which you then multiply by 5500. That would give you your maximum gross weight.
This formula gives you a figure which may be higher or lower than your gross weight for that class of vehicle.
44000 - less tare of 15170 = 28830 available payload
Different 3x3 Wheelbases
Centre of rear axle to pin is 7.3m = 40150kg
Centre of rear axle to pin is 8m = 44000kg
Centre of rear axle to pin is 6.4m = 35200kg
You can see only the red trailer can carry 28830kg the two blue ones would be overweight by 3850kg and 8800kg respectively.
Same unit, same load, different trailer or axle spacing.
I have stolen this picture to explain how the position of the load makes your job easy or difficult 
Imagine the little man is your fifth wheel pin and consider what figure three would do in winter.
Which figure is closest to the centre of gravity?
Not got around to digging my formula out yet, nor have I read the whole thread in detail, but when calculating loads on tractor unit and trailer you calculate on the wheelbase of the trailer, that is for a tri axle trailer between the centre axle and the kingpin. Loads behind the centre axle (ie over rear axle) remove weight from the kingpin.
For a tandem trailer the wheelbase is from the kingpin to halfway between the 2 trailer axles.
Wheel Nut:
ShropsBri:
Wheel Nut,it seems like a handy book you refer to…Would we all be able to get a 30% discount and if so can you tell us where from?
Thanks.I am not sure how much they will discount it normally. I have bought from them for about the last 12 years. normally around £55 each.
Thanks fella.
Wheel Nut:
stevieboy308:
Wheel Nut:
stevieboy308:
I just need to sleep on the rear axle thing now!! I would’ve thought that you went off the centre of the middle axle? (On a tri axle with equal spacing) But I’ve been wrong before!!The rear axle makes sense to me. You are trying to carry weight on the whole bogie but you still need some over the pin. I reckon if you take your measurement from the centre, that will put you over on the pin.
(—!
!..!..:::::::::::::::::
o…o!o…o o o..
(—!
!..!..:::::::::::::::::
o…o…o o o..
(—!
!..!..:::::::::::::::
o…o…o o..Generally I have measured the load by pacing it out, then pace it from behind the rear axle forward to give me a clue as to where the load sits comfortably
now i’ve not slept yet, but…
you’ve got a single axle trailer, that is loaded at the front putting the drive axle bang on its limit, but you’re nowhere near the gross. you put a 3t block with it’s center of gravity, which is in the middle of the block, over the middle of the trailer axle, therefore the 3t all goes on the axle and nothing is transferred to the pin.
you then put 2 identical blocks, one to the front and one to the rear of the original block with no gaps in between. the load now weighs 9t and the center of gravity is still in the same place above the middle of the axle with no weight being transferred to the pin.
you now add 2 axles, 1 to the front and 1 to the rear of the original axle with equal spacing, i don’t understand why we need to move the 3 blocks back until the the middle of the middle one is over the middle of the rear axle to stop us from transferring any weight to the pin?
The centre of the rear axle is where you measure from, to the fifth wheel pin to give you a figure which you then multiply by 5500. That would give you your maximum gross weight.
This formula gives you a figure which may be higher or lower than your gross weight for that class of vehicle.
44000 - less tare of 15170 = 28830 available payload
Different 3x3 Wheelbases
Centre of rear axle to pin is 7.3m = 40150kg
Centre of rear axle to pin is 8m = 44000kg
Centre of rear axle to pin is 6.4m = 35200kg
You can see only the red trailer can carry 28830kg the two blue ones would be overweight by 3850kg and 8800kg respectively.
Same unit, same load, different trailer or axle spacing.
I have stolen this picture to explain how the position of the load makes your job easy or difficult
Imagine the little man is your fifth wheel pin and consider what figure three would do in winter.
Which figure is closest to the centre of gravity?
I’m not disputing that you need weight on the pin, I just don’t believe that using the middle of the rear axle will give you the correct result.
what about a setup like that of the new longer trailers with a set back rear steer, would you still use the middle of rhe rear axle? I’d say as a quick guess without working it out that, roughly the distance between axles 2 and 3 minus the distance between 1 and 2 then divide it by 3 = the distance behind the middle axle. Basically a third of the extra distance!
More simply you could use the mid point between the front and rear axles. If you were loading a maximum load of blocks which exactly filled the load platform then I assume that it would be road legal.
A 20 tonne coil leaves a margin for error anyway.
Those posts look the business - a bit better than the bent metal bars you often see on steel carriers.
Santa:
More simply you could use the mid point between the front and rear axles. If you were loading a maximum load of blocks which exactly filled the load platform then I assume that it would be road legal.
Not necessarily
Wheel Nut:
The centre of the rear axle is where you measure from, to the fifth wheel pin to give you a figure which you then multiply by 5500. That would give you your maximum gross weight.This formula gives you a figure which may be higher or lower than your gross weight for that class of vehicle.
44000 - less tare of 15170 = 28830 available payload
Different 3x3 Wheelbases
Centre of rear axle to pin is 7.3m = 40150kg
Centre of rear axle to pin is 8m = 44000kg
Centre of rear axle to pin is 6.4m = 35200kg
You can see only the red trailer can carry 28830kg the two blue ones would be overweight by 3850kg and 8800kg respectively.
Same unit, same load, different trailer or axle spacing.
you’ve lost me on this fella 
where does the 5500 come from?
stevieboy308:
Wheel Nut:
The centre of the rear axle is where you measure from, to the fifth wheel pin to give you a figure which you then multiply by 5500. That would give you your maximum gross weight.This formula gives you a figure which may be higher or lower than your gross weight for that class of vehicle.
44000 - less tare of 15170 = 28830 available payload
Different 3x3 Wheelbases
Centre of rear axle to pin is 7.3m = 40150kg
Centre of rear axle to pin is 8m = 44000kg
Centre of rear axle to pin is 6.4m = 35200kg
You can see only the red trailer can carry 28830kg the two blue ones would be overweight by 3850kg and 8800kg respectively.
Same unit, same load, different trailer or axle spacing.
you’ve lost me on this fella
where does the 5500 come from?
right found it, that’s a construction and use reg, but it isn’t anything to do calculating axle weights
these boys go for the middle of the middle axle and they give you a axle weight calculator
broshuis.nl/en/aslastprogramma.html
Santa:
More simply you could use the mid point between the front and rear axles.
But that wouldn’t work if there isn’t equal spacing between the axles Like on the new longer trailers or when unequal loads are taken like the drive axle and midlift on a unit
For me. I just do it using the experience of several years, looking around how others are loading and asking questions.
dvtani.gov.uk/uploads/compli … oading.pdf
It is from norn Iron.
Or you could try to follow this. It makes no sense to me 
stevieboy308:
you asked!tri axle flat trailer 13.6m loaded with a 13.6m steel beam weighing 30t. 30t/13.6m = 2.21t per meter
you need to break the load into 3 sections, front of the beam - pin (2m), pin - middle axle (8.6m), middle axle - end of the beam (3m). all rough lengths to get the idea, change to suit.
section 1 = 2m x 2.21t = 4.42t but because its a overhang it needs to be balanced. so we take the balance from the centre of section 2 (so it doesn’t effect anything else). the centre of section 2 is 4.3m from the pin, the centre of the 4.42t is 1m from the pin, so divide 4.3 by 1 = 4.3. take the 4.42 and divide by the 4.3 we’ve just got = 1.03t + the 4.42t = 5.45t on the pin plus half of the unknown at the moment section 2
(think seesaw with 4.42t with a metre to the pivot and balanced on the other side 1.03t 4.3m from the pivot)
same for section 3 = 3m x 2.21 = 6.63, 4.3 divide by 1.5 = 2.63, 6.63 divide 2.63 = 2.52t + 6.63t = 9.15t on the middle axle plus half of section 2.
section 2 = 8.6m x 2.21 = 19t. but its had 1.05t and 2.52t of balance weight taken out = 3.57t. 19t - 3.57 =15.45t divide this by 2 = 7.73t add each half to the pin and middle axle
pin = 13.18t (plus weight of trailer)
middle axle = 16.88t divide by 3 axles = 5.63 per axle (plus weight of trailer)add the weights together to check we still have 30t = 30.06t near enough! slightly out due to rounding decimal places.
on a 4x2 unit, 4m wheelbase, lets say the fifth wheel pivot is 3.5m from the front axle
so 13.18t divide 4 then times 3.5 = 11.53m on the drive. 13.18 - 11.53 = 1.65 on the front plus the weight of the truck
stevie
Wheel Nut:
For me. I just do it using the experience of several years, looking around how others are loading and asking questions.dvtani.gov.uk/uploads/compli … oading.pdf
It is from norn Iron.
Or you could try to follow this. It makes no sense to me
stevieboy308:
you asked!tri axle flat trailer 13.6m loaded with a 13.6m steel beam weighing 30t. 30t/13.6m = 2.21t per meter
you need to break the load into 3 sections, front of the beam - pin (2m), pin - middle axle (8.6m), middle axle - end of the beam (3m). all rough lengths to get the idea, change to suit.
section 1 = 2m x 2.21t = 4.42t but because its a overhang it needs to be balanced. so we take the balance from the centre of section 2 (so it doesn’t effect anything else). the centre of section 2 is 4.3m from the pin, the centre of the 4.42t is 1m from the pin, so divide 4.3 by 1 = 4.3. take the 4.42 and divide by the 4.3 we’ve just got = 1.03t + the 4.42t = 5.45t on the pin plus half of the unknown at the moment section 2
(think seesaw with 4.42t with a metre to the pivot and balanced on the other side 1.03t 4.3m from the pivot)
same for section 3 = 3m x 2.21 = 6.63, 4.3 divide by 1.5 = 2.63, 6.63 divide 2.63 = 2.52t + 6.63t = 9.15t on the middle axle plus half of section 2.
section 2 = 8.6m x 2.21 = 19t. but its had 1.05t and 2.52t of balance weight taken out = 3.57t. 19t - 3.57 =15.45t divide this by 2 = 7.73t add each half to the pin and middle axle
pin = 13.18t (plus weight of trailer)
middle axle = 16.88t divide by 3 axles = 5.63 per axle (plus weight of trailer)add the weights together to check we still have 30t = 30.06t near enough! slightly out due to rounding decimal places.
on a 4x2 unit, 4m wheelbase, lets say the fifth wheel pivot is 3.5m from the front axle
so 13.18t divide 4 then times 3.5 = 11.53m on the drive. 13.18 - 11.53 = 1.65 on the front plus the weight of the truck
stevie
yikes 
i said earlier that my way was unnecessarily complicated compared to the diagram, but the way i did this one that you’ve dug up is more complicated again 
but whilst i don’t get the same answer as the website calculator i linked, i’m pretty close 5.63t per axle, the website get it at 5.58t. it’s possible that it’s just down to rounding. either way, i doubt many drivers going by the skeg of the eye, no matter how experienced they are would get that close