Building a super new boat trailer, but on the cheap!

[bedajim]

Originally Posted by Anchorhandler

Ahh but at least i dont need to worry about going under bridges with it sat on my trailer....

Long time no speak Jim, trust your doing well?

Simon

Very thanks even had time to use the new boat with new crew member

Jim

[Pikey Dave]

Originally Posted by willk

Oh yeah, he's good. SR4 - eat yer heart out. Those planning a fishing expedition should check if they are the Fisher or the Fishee

I refer the honourable gentleman to the answer I gave earlier

[Leapy]

Originally Posted by jeepster

1100kg is the maximum point load the axle can take but dont forget that the weight of the boat is not a point load, it is distributed along the length of the trailer

Yes, as long as you take out the word "point". I'm sure you're not suggesting that the axle can accommodate an infinite number of 1100kg point loads?

Originally Posted by jeepster

the trailer can have a gross weight of more than the axles maximum capacity.

No.

There are three elements to the mechanics of this discussion ... the boat, the steel fabrication (the "trailer chassis" you made yourself) and the axle that you rescued from a caravan.

Think it through ... you're quite right to say that the boat is not a point load on the "trailer" - as long as by "trailer" you mean the "trailer chassis" - but, the "trailer chassis" is most definitely a point load on the axle (well, two points loads actually). Not that that matters anyhow ... 1100kg capacity means 1100kg capacity regardless of how it's distributed or how you phrase it.

[jeepster]

Originally Posted by Leapy

Yes, as long as you take out the word "point". I'm sure you're not suggesting that the axle can accommodate an infinite number of 1100kg point loads?



No.

There are three elements to the mechanics of this discussion ... the boat, the steel fabrication (the "trailer chassis" you made yourself) and the axle that you rescued from a caravan.

Think it through ... you're quite right to say that the boat is not a point load on the "trailer" - as long as by "trailer" you mean the "trailer chassis" - but, the "trailer chassis" is most definitely a point load on the axle (well, two points loads actually). Not that that matters anyhow ... 1100kg capacity means 1100kg capacity regardless of how it's distributed or how you phrase it.

Its all about load distribution...If you dont understand how it works, as an example take a 2 axle 18 tonne lorry (I have an HGV2 licence so this stuff is my bread and butter)...Its U/W is typically about 10 tonnes and its maximum gross weight is 18 tonnes, so it has a maximum payload of 8 tonnes.
Note that even when fully loaded, at no point is there ever an 18 tonne load on either axle, despite the lorry actually weighing 18 tonnes when fully loaded, because the load is distributed, not a point load.
Typically the 18 tonne deadweight is split into an axle point load of about 40% on the front axle and 60% on the rear axle. Note that neither axle is able is take an 18 tonne point load directly though.
On a single axle trailer with a distributed load the maximum gross weight can also exceed the capacity of the axle, because the load becomes split between the weight on the hitch (the nose or tongue weight) and the axle. If your driving a 4x4 your towhitch can probably accomodate a 100kg nose weight comfortably so lets assume your towing a fully loaded single axle trailer with a 100kg nose weight and an 1100kg capacity axle...100+1100 gives a trailer with a maximum gross weight of 1200kg, more than the capacity of the axle!
I admit its not a large amount of weight difference but it is a difference.

[Leapy]

Originally Posted by jeepster

Its all about load distribution...If you dont understand how it works...

1100kg axle, 100kg nose weight, 1300kg rating ... yep, I don't understand.

I understand mechanics and load distributions though - I too have a day job.

Good luck with the trailer

[Anchorhandler]

Originally Posted by Leapy

1100kg axle, 100kg nose weight, 1300kg rating ... yep, I don't understand.

I understand mechanics and load distributions though - I too have a day job.

Good luck with the trailer

What dont you understand Leapy?.....we should all base our trailer loading calculations on the fact that 200kg's worth of nose weight is acceptable..

Simon

[Downhilldai]

Originally Posted by jeepster

I have an HGV2 licence

Originally Posted by jeepster

I have been unemployed for over a year now

Did you overload your lorry?

[wavelength]

get out there and use the outfit lad before the weather becomes even more unpleasant, and then let us all know how ya got on. A boat is for using not for arguing about on here. Don't forget to lock the trailer though before someone takes a fancy to it whilst you're swilling about at sea.

[Mcd22]

Erm, so does that mean that my twin axle trailer which is fitted with a pair of 1500kg axles can have a total weight of more than 3000kg? I reckon it should be good for at least 5000kg if i put lots of rollers on to spread the load........ ;-)

Each axle has a maximum weight that it can carry. The total of these weights when added often gives a greater mass than what is allowed.

For example,
I drive an 02 plate defender, front axle is 1580 and rear axle is 2200 giving a total of 3780kg yet the maximum gvw (gross vehicle weight) is only 3500kg.
If I exceed 1580kg on the front axle or 2200kg on the rear axle I am overloaded even though I may weigh less than 3500kg in total.
Equally if I weigh more than 3500kg in total I am also overloaded.
The total gtw (gross train weight) for the vehicle is 7000kg. This allows a 3500kg trailer to be towed.

My trailer has two 1500kg axles giving a total of 3000kg gross.
If either axle exceeds 1500kg I am overloaded even if my total is under 3000kg. If I go over 3000kg total then I am also overloaded.

A single axle trailer that has an 1100kg axle can not have a gross weight more than 1100kg or you are overloaded.

Also the gross weight of the trailer cannot exceed the towing weight of the car which is on the plate under your bonnet. If your car can only tow 750kg and you tow a trailer more than that then you are overloaded.

No matter how you look at it or want to try and justify it, your trailer has a maximum total weight of 1100kgs.

My suggestion is find a local weigh bridge and check your total axle weights. Much easier and cheaper than having VOSA do it for you.

[willk]

Anyone considering getting into complex debates with our new member might find it helpful to do some supplementary reading first.

Linky

[mick]

[BogMonster]

Originally Posted by willk

Anyone considering getting into complex debates with our new member might find it helpful to do some supplementary reading first.

Linky

Linky no worky?

[Leapy]

Originally Posted by BogMonster

Linky no worky?

It did at first but then it dropped out. Must have been overloaded

[Anchorhandler]

Originally Posted by Leapy

It did at first but then it dropped out. Must have been overloaded

Yeah, thats a shame its no longer working, there were some great quotes in there.... Im sure we would have all benefited from His vast experience... :-)

Simon

Sent from my iPhone using Rib.net

[jeepster]

I went to my local council tip to use their weighbridge today.
I was shocked to find that the boat and trailer combo weighed 910kg!!!...AAAAAAAARRRRGH!!!!!
My car can only tow 750kg, which is currently what jeepster must weigh on its own!
So it means unless I can get jeepster to go on a crash diet and lose at least 150kg I can't legally tow her at all!
It might be possible because she is right lardy ass at the moment...Apparently the boat was orginally designed to take a 50hp max but the guy I bought it off said it used to have a 90hp on the back! To allow it to do this safely the transom is heavily reinforced with steel beams. The one in the splashwell is 100x100x10 steel angle over a metre long...That weighs 15kg per metre so I could get rid of that and save about 20kg straight away...There is even heavier looking stuff inside the transom under the splashwell. The U/W of the trailer is currently about 150kg but by drilling largish holes at regular intervals along the sides of the side rails and I frame members I could probably lose 50kg there whilst keeping it just as stiff as before. The only other option is to fit a towbar to my ex's Ford Focus 1.8 TD and borrow that when I want to use the boat because that can tow 1200kg.
And no, she wont swap cars with me permanently..Dont even go there!

[Downhilldai]

Have you considered getting a mooring?

[gasman]

Get drilling that trailer, sounds like a right idea!! NOT!!! Boats full of wind arn't a bad idea after all !!

[willk]

Could you not have kept the 150kg on the tow hitch where it doesn't count?

[Anchorhandler]

Even without drilling holes in the fecking side rails that rectangular section tube is probably just on its strength limits and you want to go and weaken it even more!... Think about it, at the moment you have nearly a quarter of a ton bouncing up and down a meter or so either side of the fulcrum ( the axle) ... !!!

Honestly, stand at the back of the trailer and look down the length of those side rails and tell me there not significantly bending under the weight.... When i say significantly i mean anything more than a10mm deflection down its length.

If you let me know exactly what the rails dimensions are and what distance from the axle mounts the swing beams connect to them, l will work out how much weight you put though it....better safe than sorry..

Simon

Sent from my iPhone using Rib.net

[Poly]

Originally Posted by jeepster

I was shocked to find that the boat and trailer combo weighed 910kg!!!.--- My car can only tow 750kg, ---- lose at least 150kg I can't legally tow her

maths still not your strong point?

The U/W of the trailer is currently about 150kg but by drilling largish holes at regular intervals along the sides of the side rails and I frame members I could probably lose 50kg there

have you actually worked out how big and close together the wholes would need to be to loose 50 kg? Common sense says that is 1/3rd of the weight, but your weight includes the axel, the hitch and the wheels; so probably more like half the mass of the rails/beams.

whilst keeping it just less as stiff as before. The only other option is to fit a towbar to my ex's Ford Focus 1.8 TD and borrow that when I want to use the boat because that can tow 1200kg.

which will need to be braked. What is your tow car that can only tow 750kg, but can tow this unbaked?

Originally Posted by Downhilldai

Have you considered getting a mooring?

Any suggestions what he could use as a home made sinker?