MacGregorSailors.com

In another thread we recently worked out that duel axels is not legally required to beef the trailer up past having a 2000kg limit. There is also a pretty strong argument that duel axel trailers are not better than single axel ones and some pretty cluey guys argue duel axel trailers are actually more dangerous.

Does anyone know if its possible to beef the trailer up and reregiser it for say a 2500kg limit (without going duel axels)? If it is possible, what needs to be replaced? is the difference in registration much? Has anyone done it??

The 1920kg limit on the standard trailer is simply not enough for these boats, and I reckon sooner or later someone will end up in hot water (or worse!) over this issue

Everything is possible, contact the RTA Technical Department, see what they will be looking for when the trailer is engineered, sometimes it pays to get info straight from the horses mouth.

Fair Winds
Glenn
VK2FUN

Hi Paul,
I think this is the best place to start
http://www.infrastructure.gov.au/roads/ ... index.aspx
Basically from what I understand you need to comply with both state and federal law - but often easier said that done - as in 'we've got it, you come and find it' type stuff. The above Qld bulletin covers trailers up to 4.5tonnes. It tends to 'simplify' the issues down a bit and gives reference to the relevant sections of the ADRs (Australian Design Rules) that seem to be connected to this link under the Dept of Infrastructure & Transport - well today anyway.
http://www.infrastructure.gov.au/roads/ ... index.aspx
Probably not that difficult to get your head around given enough time. I guess you need to compare that with the time that would be spent getting a trailer manufacturer to do the job and looking over their shoulder to check everything is correct. I am not at all convinced that some of the trailer manufacturers have their facts right all of the time - particularly when it comes to boat trailers and particularly when it come to more 'unusual' breeds like Macs.

The next layer of issues is the fact that what complies in one state may not comply in another - the same issues we have with boat set-up such as nav lights. My understanding is that in Qld your port and starboard can be contained side by side in the one light, whereas in NSW I think the two need a metre seperation - don't hold me to that but I picked that up in my mind about 12 months ago. Boat overhang I think is one of those boat/trailer issues that varies between states I think.

Trust the above ramble is of some assistance. I know you are probably looking for someone who has already been there rather than re-inventing the wheel. As Glenn said, if you can find a tech person on the State side of things they may be able to help guide you through the Federal legislation.

Thanks guys, I will look into it and post here what I find next week...

Oh, and thanks for your comment on the other forum Cruiser, which a) gave me a close weighbridge to use and b) put the nail in the coffin of the duel axel trailer idea - I too, have a very tight driveway to get my boat in the backyard and I hadn't really considered the problems that would cause........

What was the weight ???? or did I miss it somewhere.

Wasnt actually going to post the weight but since you asked...

I took everything out of the boat except sails and rigging, mast raiser; an EPIRB, flares and 4 x life jackets. Then there is my 47L Evacool fridge (perhaps 15kgs) a 120 watt solar panel, 4 speaker stereo system, an electic toilet and three batteries rather than one. I weighed it with NO fuel and No water in it.
Total weight was 1960kgs!!! These trailers are only rated to 1920kgs. And so,even if I take every single thing out of the boat including the fridge which is bolted in, I will probably still be illegal. The Ms seem to weigh considerably more than what they are advertised at.....

The amount of other stuff I had in there was pretty amazing!(Its still sitting in the corner of the shed for me to pile back in the boat ....)

It dont really matter too much now, because I only launch from the ramp out the front here, but I'm Not sure where all this stuff will go when I do the whitsundays etc road trips later on.... which is why I'm looking into making the trailer legally capable of handling more than 1920kgs... ........

I weighed ours three times and between 2200 kg and 2300 with a fair bit out, I have suggested many times that others weigh their boats just so they know, could have knocked me down with a feather each time.
When travelling only the absolute bare essentials for living are carried in the boat but reckon the trailer should be able to carry 2500kg min.

Yes, I guesstimate that all the junk I keep in the boat is another hundred kilos or so, then if we are going away for a week or so, there would be another 50 kgs in food and cloths, and then say 70 kgs of fuel and 150 kg of water. It all adds up pretty quick.... Considering I am overweight with next to nothing extra in the boat, I get the feeling most of us would be towing in a state where our insurance aint going to be worth too much if something happens...

The axel is only rated to 2 tonnes so I guess the trailer will need to be completely rebuilt to make it legal

Paul
If you are just over 2000kg you may be ok if you can get your existing trailer checked out by an engineer and certified correctly.
Mine and probably most come into Aust as the equiv of 1902kg and are usually specified as that for ATM
and GTM I believe the ATM should have the drawbar or the weight carried by the car included and also the GTM should be able to be certified at 2000KG giving you 2250KG or thereabouts with little if any modifications.
If you are going to do big mileages I would suggest longer heavier springs and a bit of beefing up, if I was going to keep our boat I would put an Aust axle under it with 6 stud Cruiser wheels and better tyres and have the trailer galvanised.
2200KG is not enough IMHO but it would be fairly expensive to go higher.
The quote below is from TSP by Zebedee, there are a couple of blokes on there who may be able to get you on track.
Don't be too sure the axle itself is only rated at 2 tonnes but better to replace it with aust brakes/rims etc.
Do not sell the standard trailer short ours has done a lot of k's and even with just the mods at present would happily drive to Perth and back the long way round.

This NSW document makes it plain that trailer brake requirements are determined by the trailer's GTM, and explains what GTM means:

"GTM (GROSS TRAILER MASS) IS THE MASS IMPOSED ON THE
GROUND BY THE TRAILER WHEELS WHEN THE TRAILER IS
CARRYING ITS MAXIMUM LOAD, IT DOES NOT INCLUDE ANY
WEIGHT IMPOSED BY THE TOW COUPLING ON THE TOWING
VEHICLE." (My emphasis)

According to this source, ATM is defined in the ADRs as:

"The ATM is defined in the Australian Design Rules as: The total mass of the laden trailer when carrying the maximum load recommended by the 'Manufacturer'. This will include any mass imposed onto the drawing vehicle when the 'Combination Vehicle' is resting on a horizontal supporting plane."

If you're just over 2000kg ATM, you may be able to manipulate your drawbar weight within acceptable limits (see the tow vehicle's towbar ADR plate) to keep your GTM below 2000kg.

Hey Bob,

I'm not really up with all the trailer stuff. I thought the ATM was the total weight of the trailer and everything on it...
So I thought that that means my ATM of 1920kgs is the max the trailer and boat can weigh...?

What do you mean when you say a the GTM (dont think I have that one listed on my trailer) at 2000kgs would give you 2250kgs ???

HI Paul,
A few more bits of good info:
Good Articles on Boat Trailers
"Bow2Stern- the passion for boating in Qld" http://www.bow2stern.com.au - series of 6 articles on trailers from Issue 3 (Nov 2008) to Issue 8 (Feb 2010)
Issue 3 (Nov 2008) - Aust Desing Rules (ADR), Vehicle Standards Bulletin (VSB1), Lights/wiring, Brakes, Drawbars & Couplings, Wheels & Tyres
Issue 4 ((Feb 2009) - Different types of boat support systems on trailers
Issue 5 (May 2009) - Trailer safety/maintenance check issues
Issue 6 (Aug 2009) - Galvanising
Issue 7 (Nov 2009) - Suspensions
Issue 8 (Feb 2010) - Safety - sway, towball weight, windage, brake controller, driver experience

Plus
These are VIN plate definitions of the Caravaning Aust web site although I can't get the link to work:
http://www.caravanqld.com.au/media/9824 ... itions.pdf
A.T.M. (Aggregate Trailer Mass)
This is the weight on all the wheels, plus the ball weight, plus your personal load, including water, gas and
any accessories you fit. The total of all of these weights is the Aggregate Trailer Mass (A.T.M.)
G.T.M. (Gross Trailer Mass)
This is the weight on all the wheels, plus your personal load, plus water, gas and any accessories you fit.
The total of these weights is the Gross Trailer Mass (G.T.M.)
TARE (Tare Mass)
This is the weight on all the wheels, plus the ball weight. The total of these weights is the TARE. The TARE
does not include water and gas as these items form part of your personal payload.
PERSONAL LOAD
Personal load means the weight of all items added to your trailer or caravan such as - clothes, food,
hoses, crockery, cutlery, tools, water, gas and any accessories you fit (ie. TV set, radio, awning, push
bike, additional spare wheels etc.). The total weight of all items added to your caravan or trailer is the
Personal Load.

WARNING You must never exceed the GTM (Gross Trailer Mass).
To do so could overload the suspension, chassis or frame and thereby cause an accident by component
failure.
If in doubt about the weight of your caravan or trailer you should weigh it when fully loaded on the road
including full water tank(s) and gas cylinder(s). This can be done at a Public Weighbridge (check Yellow
Pages for locations).
HOW TO CALCULATE WHAT PERSONAL LOAD YOU CAN CARRY IN YOUR TRAILER OR CARAVAN
To calculate the maximum load you can safety carry in your trailer or caravan, take the TARE (as stamped
on the trailer plate), from the aggregate trailer mass. A.T.M. (as stamped on the trailer plate). The A.T.M.
minus the TARE equals the maximum load your trailer or caravan can carry.
Information from the Recreational Vehicle Manufacturers Association of Australia in the interests of
customer safety.

....and .... whilst I am at it these guys are fairly near to you and I gather they have a good supply of trailer parts. Might be worth having a yarn with them as they probably spend their whole day discussing this sort of stuff with every second customer:
Active Fabrications
63-65 Logan River Road
Beenleigh
Ph: 3807 6666
Web: http://www.activefabrications.com.au
Mon-Fri: 7.00am - 5.00pm
Sat: 8.00am - 12,00pm
Closed on Long Weekends
Note: Have very good catalogue of trailer parts and seem to have reasonable prices

Thanks Cruiser, all very confusing.....So the only difference between ATM and GTM is that GTM does not include the weight taken on the ball - is this right?? (and that should be about 10 percent or something of the ATM shouldnt it?? .....................

Anyway, it seems the plate should have an ATM and Tare weight stamped on it to work out how much load you can carry. Unfortunately, mine just has an ATM But then I dont need work anything out anyway because it says the ATM is the weight of everything (on the wheels and ball!) including my personal gear and so surely that 1920kgs is my limit And the boat and trailer weight more than that without my gear.........

Paul
As Cruiser said might pay to contact that mob near you or an engineer, your trailer is probably the same as ours when it was originally registered the 1920kg was just transferred from the mac plate, if you and maybe I can have it certified by an engineer instead of an RTA licenced mechanic we may be able to have the GTM closer to 2000kg and the tare and ATM allowing for the weight taken by the towbar otherwise it is an axle or two replacement to get above 2000 kg and I believe these trailers should be rated minimum 2300KG but better at 2500KG.
My ATM and GTM are the same 1920KG and from one quote on TSP that is actually illegal?
Thanks for that info Cruiser I am not totally up with trailer regs which is why I have been labouring under the false impression for years that you cant have a single axle rated over 2 tonne but do know whats needed which unfortunately sometimes doesn't gel with what can be done legally or more importantly economically .

Mac26Mpaul wrote:...So the only difference between ATM and GTM is that GTM does not include the weight taken on the ball - is this right?? (and that should be about 10 percent or something of the ATM shouldnt it?? . .

Yes Paul, that is my understanding - although I think the 10% bit can vary a bit depending on trailer / vehicle.

Mac26Mpaul wrote: Anyway, it seems the plate should have an ATM and Tare weight stamped on it to work out how much load you can carry. Unfortunately, mine just has an ATM But then I dont need work anything out anyway because it says the ATM is the weight of everything (on the wheels and ball!) including my personal gear and so surely that 1920kgs is my limit And the boat and trailer weight more than that without my gear.........

My box trailer plate reads:
TARE: 180kg
ATM: 750kg
LOAD CARRYING CAPACITY OF AXLE OR AXLE GROUP: 1,000kg
When I had it built 10 years ago, to be a bit more carrying capacity than the averge box trailer, my understanding was that it could carry a load of 750kg. Obviously now I have had a look at the plate the load or 'stuff' in it is limited to 570kg.' The axle capacity thing just seems to be confusing but obviously it is not likly to break at an all up weight of 1,000kg just that it would be illegal.
My 26S trailer plate reads:
TARE: 200kg
ATM: 1,450kg
LOAD CARRYING CAPACITY OF AXLE OR AXLE GROUP: 1,450kg
It weighed 1,260kg ATM on the weighbridge without motor, water, fuel, anchors, chain and rudder blade.(say 160kg) - also no food, cloths, etc. So pretty much on the limit and really need to carry about 100kg of 'stuff' in the vehicle when towing. I suspect the official MacGregor weights are just hull and liner, deck and liner, mast and rigging, staunchions and life lines, pushpit and pulpit and nothing else.