Trailer for fin keel with extending hitch

[jhughes]

I plan on welding up a trailer for my fin keel yacht and was pondering having an extending/sliding shaft with the hitch on the end to faciltate getting the trailer into the sea without getting the vehicle wet.
I was thinking along the lines of a 7M long trailer (the length of the boat) with say a 4M extending shaft running up the centre of the trailer with the hitch on the end and a series of locking holes/pins to adjust the length between hitch and axle.
For road use the shaft could be shortened to its minimum length and for launching and recovery it could be extended giving around 3 or 4M clearance between the rear of the car and the bow of the boat.
Possibilty of using the winch to wind the shaft in and out.
Before I start the AutoCad up and try and reinvent the wheel has this been done before? Seems safer than a strop between the trailer and hitch.
One problem which would need to be resolved would be the brake cable length changing.

 

[Lakesailor]

Don't fancy towing with a drawbar that's adjustable.
Why not make an extender?
A bar with a simple ball hitch at one end (unbraked as it's just for slip use) and a ball at the other end. The bar extends beyond the ball and locates in a loop below the drawbar to prevent a steering effect at that point.
Tricky to explain but I've made a couple for people.
When not in use it fits alongside the trailer backbone.

 

[pampas]

I think you will find that under the C&U regulations that this method is not allowed to be used on the roads. Remember years ago that a simular scheme was contemplated for commercial use and that the regulations forbade it

 

[oldsaltoz]

We used a simple chain that was fixed to the cradle and had a ring that fitted over the tow hitch, towed to top of ramp chocked and hooked onto normal tow frame.

We had no brakes but did have two large chocks chained to the cradle.

Avagoodweekend......

 

[VicS]

[ QUOTE ]
We used a simple chain

[/ QUOTE ] Similar to the way the boat yard launches and recovers. The yard tractor manoeuvres the trolley or trailer to the top of the ramp, the wheels are chocked, the tractor unhitched, moved back away from the slipway then reconnected with a wire rope. The chocks are removed and the boat and trolley slowly allowed to run down the ramp still under the control of the tractor. Once the boat is off the trolley is hauled back up with the wire. The tractor never goes near the water.

 

[andy_wilson]

C & U

C & U regs. are generally rather lacking in how to achieve anything, the only criteria is that it is a good engineering solution.

On the basis that all trailer drawbars are adjustable and removable, the question boils down to how many nuts, bolts or other fastenings are required to acheive what you want.

I have never thought an extension arm with ball and hitch on each end is entirely satisfactory as it relies purely on gravity to get things going down the slip and trailers attached with these (or rope) can become a little wayward if for instance one wheel goes in the mud or hits a brick on the slipway.

If overcoming the brake coupling issue is two problematic, wht not just double up the drawbar with a parallel extension c/w towing hitch - a bit like a retractible bowsprit - that can be extended or retracted and locked off securely as required?

Also see:

http://www.degraafftrailers.co.uk/Multi-Roller-Boat-Trailer-PA1000-2ADJ.htm


"AND INCORPORATES THE ADJUSTABLE DRAWBAR WHICH ALLOWS THE LENGTH OF THE TRAILER TO BE ALTERED TO SUIT THE SIZE OF BOAT. THE DRAWBAR CAN BE REMOVED WHEN STORING"

 

[Lakesailor]

Re: C & U

[ QUOTE ]
I have never thought an extension arm with ball and hitch on each end is entirely satisfactory as it relies purely on gravity to get things going down the slip

[/ QUOTE ]
If you read my suggestion again you'll see that I make them with a longer tail going beyond the ball fitting and locating into a hoop I fit beneath the trailer's drawbar. This makes the extension rigid and steerable. You can push or pull with it.

 

[jhughes]

Re: C & U

I like the idea, only problem I can see is you are stuck with a fixed length.

 

[jhughes]

Re: C & U

Thats solved that problem then, thanks.

 

[pheonix]

I tend to aggree with lake sailor however as being used on a considerable incline no need to pass beyond the hitch as the steering effect does not come into it as the extension is allways in tension unless you intend to reverse on level ground which i would not personally recomend.
on the other hand just use a suitable lenght of rope remembering to chock the trailer wheels and not rely on the trailer brakes as my mate did when launching my pandora

/forums/images/graemlins/laugh.gif

 

[davidbfox]

I have just bought a trailer with extendable drawbar as you describe. It is american, made by Performance Trailers. The extension piece is prevented from extending under way by having a strong pin through it.

Brakes are hydraulic, which is presenting a new maintenance problem as the trailer is 15 years old and spares are going to be hard to get.

The extension is allowed by having a loop of flexible brake hose to allow for the draw bar being extended or not.

 

[oldsaltoz]

[ QUOTE ]
on the other hand just use a suitable lenght of rope remembering to chock the trailer wheels and not rely on the trailer brakes as my mate did when launching my pandora

[/ QUOTE ]

I would avoid rope as it will spring if it parts, a chain will just drop.

Avagoddweekend......

 

[Lakesailor]

Check it out carefully re: legality, as many US trailers are illegal here.

 

[Avocet]

I made a separate extension bar when we used to trail and sail. It had a tow ball on one end and a hitch on the other, as described above. It got round the problem of allowing the brake cables to extend but wasn't particularly satisfactory in other respects. When launching, I was surprised at the number of times I had to "push" the trailer a little as a result of one of its wheels getting stuck. In this situation, there was no real way of telling which way it would move! Obviously, as the extension rod is "pin jointed" at both ends, the trailer is resting on its road wheels and the jockey wheel. There isn't much weight on the jockey wheel with the boat on a sloping slipway and there is a danger of the whole lot tipping over if one (or both) of the back wheels get stuck and the tow vehicle pushes a little. We were just about OK as it was a 4 wheel trailer but I wouldn't like to try it on a single axle trailer!

When recovering, it was much more satisfactory but the jockey wheel got a really hard time - especially at the top of the slipway when the vehicle went from the slope to the horizontal and the trailer was still on the slope. This put a big downward load on the jockey wheel. I ended up putting an oversized one on.

The extending tow bar is a MUCh better idea but I would be wary of underestimating the loads on it when in compression!

 

[Lakesailor]

If you had connected it to the trailer as per my diagram, these problems would have been overcome.

 

[Avocet]

Indeed!

But I didn't, so they weren't!

I was trying to discourage the OP from making the same mistakes as I did and having a coupling at each end. If I was doing it again, I'd probably do something either like your sketch or, if the shape of the trailer lent itself to it, something telescopic with a second (cheap) tow hitch on it - thereby just getting round the problem of what to do with the brake cables. The other minor disadvantage of the completely separate extension is stowing it and lugging it round!

 

[Lakesailor]

Cunningly we put a second loop on the trailer and a second ball hitch so the extension could be slid into the loop at one end and the hitch attached to the ball at the other. This was alongside the boat keel on the trailer chassis.

Did I explain that very well?

 

[Avocet]

The sketch did!

 

[johnpye]

This has to be an optimal solution but I can't visualise the storage bit.
Where does the second hitch go? Another sketch please?

 

[Lakesailor]

OK. 2nd ball alongside trailer backbone. You ould bolt a standard hitch on sideways but better to avoid drilling the drawbar and weld a plate on for a bolt-on ball.