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

[jeepster]

When I first bought my Hemming and Morris Marina 16 GT boat, Jeepster, on ebay, it came on a huge American-made, single axle, A-frame type trailer, 7' 2" inch wide, about 18 foot long, with 15" galvanised 5-stud wheels fitted with American truck tyres (the thread section being considerably narrower than the tyre itself).
I had to travel on the M4 from London to Reading to pick it up and tow it back, at the time oblivious to any weight limits that I may or may not have been exceeding.
The trailer had been modified for UK roads by the addition of a 2000kg braked Bradley Axle and heavy duty braked Bradley Hitch.
As you can imagine because it had a 2 tonne + payload it was made of very heavy Galvanised Steel channel and probably weighed 750kg on its own, but as my tow vehicle (A Mazda 2 1.4 TDS (2003 DY model)) can legally only tow a 750kg braked trailer, and the boat itself weighs about 450kg, this Yank behemoth simply had to go. Its only good points were that being so wide, it was very stable to tow, it had a heavy-duty electric winch fitted which took all the effort out of retrieving the boat from the water and that it had about 8 pairs of 5" sky blue "wobble rollers", with the roller arm pivot brackets welded to the crossbeams. This supported the hull of the boat quite nicely but being a totally rigid trailer and quite high off the ground meant it was very difficult to winch the boat back onto it in shallow water and you had to submerge the axle every time. Eventually I managed to sell it for £900, on ebay and bought a much lighter T-frame type trailer made from 2 1/2" x 2 1/2" x 1/8" (63.5mm x 63.5mm x 3.2mm)Galvanised Steel SBS, for £150, again on ebay.
It has olde-worlde Avon "hollow rubber spring" suspension and independant transverse swing arms, with Steel angle tie bars. It only has 8 inch wheels but it has very heavy duty tyres with a capacity of 1265 lbs (575kg) each at 120PSI!
Anyway, the first time I used it I discovered it has severe design shorcomings that make it extremely "difficult" to use when attempting to retrieve the boat from the water back onto the trailer. Because it only has a single keel roller at the rear end for the boats bow to roll up onto, any sideways movement of the boat caused by the boats stern being dragged about by the tidal current say, means the bow easily rolls off the roller and the steel bracket gouges deep scratches in the hull as it falls!
I resolved not to use the boat again until a better trailer can be found…Its been about a year now since I have used my boat and it has been parked in my front garden on this awfully designed trailer ever since.
I have been unemployed for over a year now and therefore obviously my budget is extremely tight, basically making buying another trailer totally out of the question.
So, I decided to make one myself!
After doing lots of web research on modern boat trailer designs I decided to only use the best design elements I could find from the various different trailer designs I found.
My design would be unique, easy to build, cheap to build, with excellent launch and recovery dynamics and with lots of wobble rollers for plenty of support for the hull of my boat....28 to be excact!
This would mean being able to dispense with prehistoric keel rollers altogether (well almost, as I will still use one, under the bow) and using dual swing beams, as all the newest and best boat trailer designs employ.
First I needed a braked axle and hitch, so I found an old caravan chassis going on on ebay for £60…I won the auction and drove up to Buckingham to collect it.
It still had the 40mm thick plywood and foam sandwich base of the caravan left on top of the chassis, along with the original black plastic mudguards.
The only relevant parts I needed from it were the axle and hitch so everything else had to go and after towing it home it took a couple of days to literally smash the base up with sledge hammers, saws and other heavy tools, leaving just a bare Galvanised chassis which I could dismantle at my leasure.
(Note: The braked axle and Hitch from this caravan chassis were made in Germany by Knott. The axle has a capacity of 1100kg and the hitch has a max nose weight of 100kg.)
Next I needed to devise a way to hold the axle onto the side rails of the trailer in such a way that made it fully adjustable (so I could adjust its fore/aft position later to get the hitch nose-weight correct).
Knott caravan axles are not designed to be adjustable fore/aft so I achieved this by fabricating some custom brackets with 50x50x6 Steel angle.
The top of these brackets is a T-section made from two back to back lengths of the Steel angle and the bottom end of each bracket bolts onto the trapezoidal shaped mounting-plates on the axle, via 4x M12 bolts and 4x 16mm x 4mm tubular bushes on each plate.
The 80x40x3 Steel RHS side rails run over the top of this 100mm wide flange and are then clamped firmly in place with 3x M10 square u-bolts from over the top of the rails and down through the flange. It took a fair bit of research to find the cheapest possible U-bolts and eventually I obtained the ones I needed from Becktons Trailers in Staines.
Next I fabricated the swing-beam to side-rail brackets from 60x6 Steel flat, 25mm solid Steel bar and a little more of the Steel angle.
They are loosely based on Indespensions “Hallmark” Swing Beam bracket design).
The swing beams themselves were fabricated from 60x40x3 Steel RHS, 50x50x6 Steel angle and some 8mm Steel flat to provide a wider bearing surface. (They are loosely based on a DeGraff trailer swing-beam design).
A2 Stainless M24 washers were used to space out the beams from the brackets correctly (Although they are supposed to be for use with M24 bolts they conveniently have a bore of 25.3mm, so they fit perfectly over 25mm solid bar!).
I “cut, bent and shut” the side rails to get the required 20 degree angle in each and welded some Steel reinforcing plates over the inside face of the bends, made from some folded 75x3 strip (Loosely based on a DeGraff trailer design.)
Because I wanted the trailer to be completely dismantlable, in case I wanted to have it Galvanised later say, there are no cross beams welded directly onto the side rails.
I really admire some of the great Engineering features used by Brenderup trailers and one of these features is a beam design which has clamp brackets at the end of the cross beams allowing them to be quickly and easily removed, or refitted, to the side rails and the coach bolts used to clamp them in place mean there are no rough edges on the outside face of the brackets to cut yourself on…A very neat solution.
For ease of assembly I inverted their design (theirs come up from underneath the side rails, mine come down on top) and rather than have folded steel brackets (which would have cost me over £80 to have made up at a local Engineering firm) I fabricated mine myself on the cheap from 12x 105x100x6 steel flat and 6x 41.5x100x6 steel flat, fillet welded along the top corners.
Before I welded them I drilled 2x M10 holes through each plate 12x12 from each bottom corner to take the 65mm long M10 Carriage bolts used to actually clamp the brackets in place.
The holes in the outer side face of the brackets were filed square with a square file to take the square shank on the inside of the carriage bolt head. On the other end I used M10 BZP penny washers and M10 A2 stainless Nylocs.
Because the trailer is being built outdoors in my front garden, each part of the trailer has had at least two coats of Tractol 927 before assembly.
It is a special paint that contains 90% pure zinc but which can be obtained relatively cheaply (Only £25 for 2.5 litres), from a company called Smith and Allan. It dries very quickly and to a nice matt battleship-grey colour, which looks a bit like a weathered galvansed finish.
The larger parts (the siderails, I-frame and swingbeams were painted with a Wickes mini roller handle and gloss rollers. The smaller parts and awkward parts like the axle, were painted with no-bristle-loss paintbrushes from Tescos.
I fabricated some mudguard brackets from 40x4 steel flat and fitted Brenderup reinforced plastic mudguards. At £25 each these are certainly not cheap but they are the best available in blue plastic.
I replaced the old Knott brake cables with brand new stainless Steel Bowden cables, with nice blue outer sheaths, obtained relatively cheaply from Knott/Avonride.
The only parts I could not fabricate myself easily were the 14x U-shaped roller arm pivot brackets and the 8x “L brackets”, so I got a local engineering firm to fold up the former brackets on their big hydraulic press from 25x5 steel flat...Cost me £20.
These were welded onto the "Equaliser arms". The front E-arms are 24" long with three brackets welded to the top of each and the rear ones are 36" long with four brackets welded to the top of each.
The E-arms are drilled through and bolted onto the L brackets. The 8x Galvanised L-brackets were obtained by mail direct from the Indespension trailer factory in Southampton...They proved to be quite expensive…£6.50 each, inc VAT, plus delivery! I simply had to have them to complete the project as planned though so I had no choice but to go ahead and splash out for them.
The L-brackets are held onto the swing beams with 8x M10 square U-bolts, again obtained as cheap as possible from Becktons Trailers in Staines.
The 14x roller arms are fabricated from 1" x 12swg (2.5mm wall thickness) Steel tube and 3" lengths of 1" x 1" x 2.5mm cold-formed Steel channel. The channel was drilled through and welded to the tube, which prevented weakening each tube by drilling an 8mm hole through the middle of them.
Each completed roller arm needed 4x4mm holes accurately drilled through the ends so to make sure they were all drilled exactly the same, I fabricated a special drill jig from Steel angle and 10mm Steel plate.
I sourced some 1" A2 stainless washers and 5/32" (4mm) x 1 1/2" stainless split pins to hold the wobble rollers onto the roller arms and after spraying each arm with two coats of ZG90 “cold galvanising spray” I could finally assemble them and get them onto the trailer.
The pretty blue & white, 5” diameter, Bramber BR1 wobble rollers have been sitting on a shelf in my room for months now so it was great to finally get them onto the trailer as planned. They have white Nylon “rims” and ribbed blue PU “tyres”.
I really like Brenderups winch post designs so I based mine loosely on theirs, but I made mine fully adjustable fore/aft, for height and for post angle, where theirs is only fore/aft and height adjustable.
After some protracted telephone negotiations with the manufacturer of the BR1 wobble rollers, I managed to source the last two medium blue V-snubber blocks he had, one at cost price, and the other for free!
He said he isn’t going to make any more in blue as they don’t sell very well and besides that, it takes him at least 4 hours to set up the tooling.
The trailer is nearing completion now, and I have tried the boat on it and made adjustments. There are just the brakes, adjustable height bow roller bracket and lighting bar holder arms to sort out.
Going by the weight per metre of the various Steel sections used, I calculate the un-laden weight will be between 135kg-150kg and it will have a capacity of at least 1100kg.
The early stages of the build were welded with a cheapo Sureweld 140 arc-welder but then I decided to use my old Oxford dual-voltage, oil-cooled, arc-welder so I could get consistent welds when fabricating the front I-frame brackets. It made the job relatively easy. The rods were good quality Lincoln 6013's.
I estimate I have saved at least £1200 by building it myself, probably more.
Note, I didn’t make any proper design drawings for my trailer, basically just working on the fly, using the occasional rough sketch where required else just making it to look like I dreamt it should look.
Here are some pics of the project showing the various stages of construction.











The trickiest part has been making the winch post as its a fairly complex design. I ruled out using U-bolts to hold it onto the trailer as these would have been very expensive to buy so I opted for carriage bolts, similar to the way Brenderup do it.

And here is the winch post with the boomerang bars complete with what are probably the last two medium bow snubbers of their kind in the world that are made in blue, obtained direct from their manufacturer in Wales via the post (All the other V snubber blocks you will find in blue are either small or large ones but medium ones will only come in Black):

I chose the medium ones because they are the best looking ones but mostly because they fit the bow of my boat like a glove!
And here is the nearly finished trailer, showing all 28 wobble rollers:

[Pikey Dave]

Bejeesus, that's a hell of a first post, I can't say I read it all, more like measured it..............with a calender
welcome to Ribnet

[jeepster]

Originally Posted by Pikey Dave

Bejeesus, that's a hell of a first post, I can't say I read it all, more like measured it..............with a calender
welcome to Ribnet

Thanks...But there is more!
As an update...I have now got the brakes working. Had to make a special bracket from 50x50x6 angle to drop the brake rod entry into the hitch by 45mm, so the brake rod reserve spring could clear the bottom of the I frame, and I used some Dexion unequal angle to make a bracket from which to hang an eyebolt from to support the brake rod.
Very conveniently two of the holes in the Dexion bracket lined up exactly with the two M10 carriage bolts on the rear centre bar bracket of the I frame, but the holes were only 8mm diameter, so I drilled them out with a 10mm drill and it fitted perfectly first time! Happy days!
Found that I had to add an M10 extender to drop the eye of the eyebolt by 30mm, to stop the brake rod from hitting the bottom of the front swingbeam.
Just had enough time to adjust the brakes before it got too dark.
Now I can easily roll the boat off the trailer onto some car tyres in my garden whenever I need too, and winch the boat back on again easily, all by myself...With the old trailer I needed at least two others with me to help push the boat off it!
I will add updates until the trailer is finally finished.

[actions]

Bloody hell. I think you deserve a medal for that post. if you've put as much effort into building the trailer as you have the post then Im sure its great.

Ill be honest too though. I didnt read it and just skipped to the pictures. Ha ha.

Sent from my phone so excuse the predictive spelling / lack of smilies and short reply.....

[jezza2011]

Are you going to fit anodes as it just looks painted and not galvanised.

[Leapy]

Originally Posted by jezza2011

Are you going to fit anodes as it just looks painted and not galvanised.

Be a shame not to galvanise. All that work potetially rusting away. The self build is cost driven though. Still ...

[Pikey Dave]

Originally Posted by jeepster

Thanks...But there is more!
As an update...I have now got the brakes working. Had to make a special bracket from 50x50x6 angle to drop the brake rod entry into the hitch by 45mm, so the brake rod reserve spring could clear the bottom of the I frame, and I used some Dexion unequal angle to make a bracket from which to hang an eyebolt from to support the brake rod.
Very conveniently two of the holes in the Dexion bracket lined up exactly with the two M10 carriage bolts on the rear centre bar bracket of the I frame, but the holes were only 8mm diameter, so I drilled them out with a 10mm drill and it fitted perfectly first time! Happy days!
Found that I had to add an M10 extender to drop the eye of the eyebolt by 30mm, to stop the brake rod from hitting the bottom of the front swingbeam.
Just had enough time to adjust the brakes before it got too dark.
Now I can easily roll the boat off the trailer onto some car tyres in my garden whenever I need too, and winch the boat back on again easily, all by myself...With the old trailer I needed at least two others with me to help push the boat off it!
I will add updates until the trailer is finally finished.

All you need now is a RIB to go on it

[Maximus]

Just what I was thiking!

[jeepster]

Thanks guys. I would love to get it Galvanised but I only have about £50 left in the world right now so that wont be happening anytime soon.
Dont know about getting a RIB...I mean when you have a boat as pretty, comfortable and as seaworthy as Jeepster, a RIB seems a pretty poor choice in comparison.
Anyway, the trailer is pretty much finished now, with just a few minor tweaks needed to the brakes...Here it is on its maiden journey, carrying Jeepster:

[kerny]

Originally Posted by jeepster

Dont know about getting a RIB...I mean when you have a boat as pretty, comfortable and as seaworthy as Jeepster, a RIB seems a pretty poor choice in comparison.

[Pikey Dave]

Wilifish!!! SR4's back, your country needs you

[jambo]

Dont know about getting a RIB...I mean when you have a boat as pretty, comfortable and as seaworthy as Jeepster, a RIB seems a pretty poor choice in comparison.

what the hell are you doing on here them. Get yourself to boatmad or another power boat forum

Sent from my iPhone using Rib.net

[willk]

Lads - Be nice to the Newbie (he's a Newbie for another 6 days )

Jeepster - The members tend to take jokes about RIBs overly to heart. While this is primarily a Forum for RIBs and SIBs, we have room for others to paddle in the shallows. Enjoy yourself but expect to have your boat pointed at

[jeepster]

Originally Posted by kerny

Waiting for the fireworks to begin?

[jeepster]

Originally Posted by jambo

what the hell are you doing on here them. Get yourself to boatmad or another power boat forum

Sent from my iPhone using Rib.net

Thanks for the headsup...Wasn't aware of Boatmad before.

[Anchorhandler]

Originally Posted by jeepster

Waiting for the fireworks to begin?

I knew we'd manage to convert him....joined a day ago and already he's thinking about setting fire to his hardboat...

Simon

[kerny]

Originally Posted by Anchorhandler

I knew we'd manage to convert him....joined a day ago and already he's thinking about setting fire to his hardboat...

Simon

[wavelength]

ah well beauty is in the eye of the beholder...
What does the total rig weigh in at?
The trailer board is illegal!

[Leapy]

Think I'd worry about your strapping method Last time I saw something like that it was around a suitcase destined for a weekend package tour to Majorca.

[Anchorhandler]

Originally Posted by Leapy

Think I'd worry about your strapping method Last time I saw something like that it was around a suitcase destined for a weekend package tour to Majorca.

Not a bad job though with respect to the build of the trailer...
My only worry would be the thickness of the main longitudinals rails...are they 3mm thick? As they are not doubled or built using a 'ladder' design they have to be pretty strong. At the moment, the weight of Jeepster and the wobble rollers is being transfered down to the rails at a nearly equidistant point either side of the axle meaning that the rail is resisting being 'bent' over the axle.

You say the boat weighs approx 450kgs meaning that with the weight of the rollers/bars +fuel+gear on board, (not counting an engine) etc... you can easily be in the region of 600kgs (or 150kgs acting down either side of the axle on both sides).

Its just my opinion but i would consider Either reinforcing the side rails or adding a keel roller or two as close as possible to the axle to alleviate the weight on the sides.

Maybe an optical illusion but in the pictures it looks like the side rails are already slightly bent as they are loaded?...might just be my poor eyesight though


Simon