Trailer mod - What should i do?

[NTMID8]

When in the shed the motor is in the full down position then angled full lock to fit in the corner but it just wont fit (bastard lol), in the photo the section from about an inch infront of the jockey wheel is what hangs out.

My plan was to cut the whinch post down and make the angle steeper (with additional bracket at bottom) them mount the whinch on top. Remove the jockey wheel and fit to other side but as a non removal item (ie moves 90deg).
Have a bracket made on the side of the whinch post to hold a spare tyre (i blew a tyre 20km out of Pt Augusta last week NOT HAPPY JAN!) then have the hinge fitted just behind the post allowing the front foot (maybe foot and a bit) to fold back and allow perfect storage.

I have searched the net and i cannot find anywhere that states the trailer would need to be engineered, i rang a compliance shop today who told me that as long as i dont exceed any of the factory peramiters (ie length/width/height/weight) then i can modify as i see fi (within reason)

[cormorant]

I think the engineering bit is concerning making sure someone who is an engineer and qualified welder does the work and is insured. In truth any structural trailer modification that involves change to a standard production trailer possibly needs aengineeer to sign off on otherwise you may be left in insurance hell uncovered if something went wrong.

Sleeving just moves the stress point / flex point , spreads load sometimes and doesn't change the thickness of original metal and welds. That original drawbar may not be up to it longer term.

I've not seen ones with the hinged drawbar have cable brakes May be hard to keep adjusted and still have the hitch hinge?

Are you on cable steering? If you disconnected teh steering rod at teh motor would teh motor pivot sideways enough to get you in. Quite easy to use a pin and r clip instead of current set up and would take only seconds to do each time? Same if the motor have a permatrim - how much do you need teh permatrim?

I'm not a fan of cutting Gal trailers but at least if you have it done it won't be the end in the salt water.

From the photo it doesn't look like you can move the winch post forward and then more boat forward as it would also meand moving rear roller brackets and also axel forward. OK if it was all bolt on but I think Makay weld on suspension etc now?

I'd forget the hinge and simply put a small "v" block on the winch post and slide it back,, cut drawbar to a length that it would fit in shed, internal sleeve the existing drawbar and double horizontal through bolt it somewhere back under the winch post with high tensile bolts and locknuts.. Then do a outer sleeve with your hitch attached which could be held on by normal hayman reece style towbar pins. For a quick release of the brake cable you can buy rated stainless locking, quick release shackles that are used on yachts The inner sleeve it to ensure the hayman reece style pins pull on solid thick walled metal as your existing drawbar won't be real thick. An engineer would probably sign off on that as stressed components are off the shelf and no new welding of thin walled drawbar, and except for the one cut end of existing drawbar couple of holes and everything can be hot dipped..

Must love that shed more than ya trailer.

[NTMID8]

I dont like the shed at all, it is my in laws place and ive been told taking half his shed is already pushing my luck, if i mention the word "modification" and "shed" in the same sentance he will tare my head of lol.

Im intregued by your suggestion but im not totally sure i follow (forgive my stupidity) i assume your talking about the entire front section of the hitch being removable from the trailer? Then it slides back in and held with 2 horizontal bolts (similar to removable tow bar balss on cars?) Is that correct?

[Giffo65]

A mate has the same setup as you are looking at,he has a 17 to 18 foot glass boat that did not fit in the garage,works well for him.

Cheers
Giffo

[NTMID8]

A mate has the same setup as you are looking at,he has a 17 to 18 foot glass boat that did not fit in the garage,works well for him.

Cheers
Giffo

As in the hinge design or the sleeve and removable hitch?

If it was the hinge design has he got any pics? What brand did he use? Any towing issues?

[cormorant]

I dont like the shed at all, it is my in laws place and ive been told taking half his shed is already pushing my luck, if i mention the word "modification" and "shed" in the same sentance he will tare my head of lol.

Im intregued by your suggestion but im not totally sure i follow (forgive my stupidity) i assume your talking about the entire front section of the hitch being removable from the trailer? Then it slides back in and held with 2 horizontal bolts (similar to removable tow bar balss on cars?) Is that correct?

Yeah that's the idea like a square hayman reciever hitch. Just using the sleeve to stregthen it internally. The box section outer fitting with your hitch on it slides over the outside of your existing drawbar.

Ahhh just take round a couple of case of beer and after the first case it will all be your inlaws idea and do it then!!!

[NTMID8]

Yeah that's the idea like a square hayman reciever hitch. Just using the sleeve to stregthen it internally. The box section outer fitting with your hitch on it slides over the outside of your existing drawbar.

Ahhh just take round a couple of case of beer and after the first case it will all be your inlaws idea and do it then!!!

I offered him two bottles of Bundy, he thought about it then said " you took my daughter, you took half my shed now you want to cut it?" I didnt bother pushing my luck any further.....

[NTMID8]

For anyone interested there is no requirement for a trailer under a GVM of 4.5T to be engineered after a modification aslong as it stays within the guidlines here:

http://www.infrastructure.gov.au/roa.../vsb_01_b.aspx

I also rang club marine who told me that they have no dramas with any modifications provided they are withini the regs supplied.

Just some info for anyone thats interested.

[oldboot]

to a certain extent that is true.

But if you are thinking about chopping into your drawbar, you would at least have to have a few thinks about what you are doing even if you don't get out the slide rule.


Remember too.....that whoever does the modifications is responsible for them for the life of the trailer....and...the insurance company may be all happy over the phone..... but if the job is shoddy and fails $$$$ badly......the insurance company may change its tune.

also if said modifications either change the load rating or dimensions of the trailer it will have to be recomplianced a new VIN plate attached and main roads dealt with.

on the surface this whole trailer thing looks pretty easy going...untill the manure hits the impeller...then one would be wise to be able to justify your engineering decisions and be able to point to the suppliers of the components that broke and say ........."its their fault".

cheers

[NTMID8]

What is a slide rule?

The modification wont change the dimensions or load rating of the trailer at all, as far as the structual strength is concerned the mod im planning would increase the strength as instead of the drawbar being hollow 2.5 x 2.5 it will have a second sleeve fitted to the internal section (doubling the thickness of the steel) and will be secured via two pins (same as what hold your towbars on)

Transport SA ensure me (although not in writing) that aslong as i stick within the specified requirements then there is no legal ramifications to the modifications.

[cormorant]

There is a few catch all phrases


23.3 Structural Requirements

There are no specific body structural requirements, but the trailer must be safe and fit for purpose.
Note
It is suggested as a minimum that the Manufacturer should be able to demonstrate that the structure is capable of supporting the designed payload with a safety factor of at least 3 for highway use and a safety factor of 5 for off road use.

----------------------------------------------
You modify it and you become the manufacturer regardless of what part fails. If it fails and insurers chase the manufacturer - ouch. If you can't document it or show that it is engineered , the bits you add, or can be shown a manufacturer did the modifications??

None of this matters jack Schitt unless the worst case happens in a accident but there is always that risk.

Over here they are gradually stopping new homemade non engineered trailers from being able to be registered ( RTA has manufacturer engineers "sheets" hence a lot of folk seem to move number plates to new cleanskin trailer chassis , stamp some numbers of the old pre 1990's trailer on it.

Legally over here you would if you change the manufacturers structural elements have to hand in old plates and treat it as a new trailer., re- weighbridge, blue slip ( possibly require enineer sign off) affix new builders plate as homemade or whoever and reregister. Would anyone do it that way - well not likely especially with fees and stamp duty let alone the time it takes.


Get a local trailer manufacturer or welder/engineer to do the final fit up and get a receipt to cover ya bum. Worth the small extra few bucks to not have it come back to you in 10 years time after you have onsold it.







What someone who understands it needs to comply with
http://www.comlaw.gov.au/ComLaw/legislation/legislativeinstrumentcompilation1.nsf/0/0F361EA03C2D0BD0CA25731D000186CB/$file/ADR6201comp1FINAL.pdf



14. ‘DRAWBAR’ REQUIREMENTS
14.1. The ‘Drawbar’ must be securely attached to a substantial portion of the trailer.
14.2. The ‘Drawbar’ including the connections between ‘Drawbar’ and trailer must
withstand loads as per Clause 14.2.1 or 14.2.2 without incurring either any
residual deformation that would interfere or degrade the function of the
assembly or any breaks, cracks and separation of components. Alternatively
approval can be by calculation as per Clause 14.2.3.
14.2.1. ‘Drawbars’ to withstand a dynamic endurance test for 2 million cycles:
14.2.1.1. ‘Drawbars’ for ‘Pig trailers’ up to 3.5 tonnes ‘ATM’ and hinged ‘Drawbars’
for other trailers to withstand a horizontal oscillating force of ± 0.6 x
‘Coupling’ ‘D-value’ in the longitudinal direction concurrently for 2 million
cycles, applied at the intended ‘Coupling’ centreline. The frequency must not
exceed 35 Hz, and must be chosen not to coincide with any natural frequency
of the system;
14.2.1.2. Rigid ‘Drawbars’ for ‘Pig trailers’ over 3.5 tonnes ‘ATM’, to withstand a
minimum horizontal alternating force of (± 0.6 x ‘Coupling’ ‘D-value’) acting
in the longitudinal axis of the ‘Coupling’ and a minimum vertical alternating
force of (static vertical coupling load ± 0.6 x ‘Coupling’
‘V-value’) in the vertical axis of the ‘Coupling’ applied through the ‘Coupling’
centre asynchronously for 2 million cycles.
Static vertical coupling load in kN = g x S
where:
g = acceleration due to gravity (assumed to be 9.81 m/sec2)
S = vertical load in tonnes (‘ATM’ - ‘GTM’)
The frequency of the longitudinal and vertical forces must differ by between 1
% and 3 % and not exceed 35 Hz, but must be chosen not to coincide with any
natural frequency of the system.
14.2.2. ‘Drawbars’ to withstand a static test:

[Mr__Bean]

Oh my god, here we go again.......

For God's sake. don't anyone fart or you will upset the insurance company.

- Darren

[wetryin]

I would go against doing drawbar modifications as looking at the pic of the boat and your trailer that you posted the distance between the bow of the boat and the trailer ball looks to be by far well over a metre.
My current boat is a barcrusher and the bow sits like less than a foot from the tow ball. So rather than going to all the trouble like you are suggesting in the post I would try moving the whole boat forward.
The previous boat that I had to this one was longer than my current boat (only by 5cm) however as this winch post on this boat is way forward than the last boat so I have saved almost a metre to my storage space, which is also the kids rumpus room.
I would move the winch post to the other side of the jockey wheel. Or even replace the winch post altogether so that the boat be positioned closer to the winch post. Just my thoughts

[Charlie]

I'm reasonably sure that Skeeter boats sold in Australia have the Fulton swing away coupling on their trailer as a standard feature, anyway my forbie is fully engineered but I see no reason to currently engineer a trailer unless you changing the load rating or tyre size as noted on the vin plate.

[NTMID8]

I spoke with a trailer builder here in SA today, they have said that if i fit an external sleeve to the drawbar then i will not loose any structual integrity. They have suggested pretty much what Cormorant suggested and they have stated that it is quite a common modification (i personally havent seen to many) there is no engineering required as the load points have not been altered as the overall length of the drawbar remains the same.

In relation to wetryin, moving the winch post back wont fix my problem as the motor leg will foul on the back of the trailer (there is only about 1/4 foot gap between rear of trailer and leg when fully down) I plan on moving the which post closer to the boat to increase the drawbar space to be able to add a spare tyre.