Trailer for Caledonia Yawl

[biglad]

As many will know, my CY is nearly finished so I'm starting to think about a trailer. In the UK, for now at least we can still build trailers, though we do have an EU rule about to commence which means I'd need to get any trailer I build approved. It doesn't cost much and there's a centre not to far from me I can take it to, so I'm not discouraged by this.

I have ordered an axle complete with suspension and hubs which will be here in two weeks. I also have 2 no 7.6m lengths of galvanised box steel (50mm x 50mm x 2.5mm wall).

I've put my thoughts down - hopefully the photo below works. The drawing is not to scale but hopefully gives an idea of my thoughts.

In words, I'll have a central spine the length of the boat (6metres). The winch will be set back from the tow hitch say around 800mm or so. As the boat is around 6m long, this means I'll have around an 800mm overhang at the rear. The fabricators who are making me the axle are welding plates on before it goes for galvanising so I can u-bolt the spine to the axle with some 6mm plates underneath. I'l have two longitudinals either side of the spine - the fabricators are welding plates for these too. These longitudinals will be c 1.6m long and around 500 - 600mm apart. I've fitted bilge runners to the hull of the boat so these will be placed in the position that enables the bilge runners to rest on the carpeted bunks. There will be two cross members -one at each end of these longitudinals and again they will be u-bolted together. I've set the axle roughly in the middle of where the boatwill sit but this can be adjusted so for optimum noseweight. I'll fit 4 keel rollers to the spine to take the weight and have the carpeted bunks for the bilge runners to stop the boat falling over.

I'm able to weld (though welding galvanised box steel is likely to breach the internal surface and cause corrosion from the inside out) but I like the adjustability of building a trailer this way. Also, the galvanisers are miles away and my breached surfaces where I cut the steel can be treated with Galvafroid or similar.

I won't be towing far - the boatyard is 4 miles from my house.

What do you think? Any and all suggestions most welcome. Has anyone a breakback trailer? Does it make launching & recovery any easier? Is it worth making? Can you share some photo's??

[Reynard38]

Looks like a sound design, not at all unlike the trailex I'm about to order for the Coquina.

[kenjamin]

Here's my trailer that I made from a 16' boat trailer that I extended with pressure treated pine. I've trailer my CY from Florida to Mystic Seaport, Connecticut twice, a total distance of 8000 km. Make sure your spring set is not to stiff because the CY is quite light for a 19' 6" boat. Good luck with your trailer build. Hope this picture helps somehow.
Just ignore the curved mast. The humidity here in Florida is terrible!

[Wayne Jeffers]

I suggest that you move the box section further aft so that the tongue is longer and the wheels further back. For the sake of stability while going down the road, you want the trailer wheels well aft of the balance point of the trailer/boat/cargo combination. The last thing you want is to be inducing sway as a result of a too-light tongue weight.

The weight of the tongue at the hitch should be about 12 to 15% of the total weight. If in doubt, for a trailer and boat this light you can use a bathroom scale sitting on a chair to check the tongue weight. Actually, for a boat and trailer this light, a little more than 15% tongue weight probably wouldn’t hurt. Note the photo of kenjamin’s trailer, which I believe has the setup just about perfect.

Note also in the photo that he has extended the bunks for supporting the stern of the boat, and that the central spine/tongue does not extend beyond the box section. This is the normal practice. If you had in mind a roller or other support for the keel at the stern, I think you will find in practice that this will be very difficult to line up under the keel when retrieving and that the bunks extending well aft are a far better choice.

Wayne

[biglad]

That sounds like a good plan. If I move the axle back 500mm that will also mov the bunks back. I have enough steel to make the longitudinals longer which will in turn let me have longer bunks. I can extend them a fair way back.

I'm up for anything I can do to help make launching and recovery easier. Where I will keep my boat is quite windy and can be choppy so everything that makes my life easier is welcome. That was my thinking behind making the trailer break back.

[Wayne Jeffers]

Longer tongue is a good thing, within reason. It makes it easier to back up (trailer does not react as quickly to turning input from the tow vehicle.) It makes it easier to keep the rear wheels of the tow vehicle on somewhat dryer pavement at the launch ramp.

Padded, near-vertical guides for the trailer on each side at the stern- quarters of the boat will help keep the boat in place as you're pulling the trailer out of the water in windy conditions. Especially useful when working alone. They need to be padded/carpeted on the inside.

The utility of the business end of the trailer breaking back will depend upon how long and steep the ramps are. If it is easy to back the trailer into adequately deep water, the breaking feature is less useful as you can simply float the boat mostly onto the trailer, and finish the last foot or two with the winch prior to driving up the ramp and lashing her down.

Wayne

[kenjamin]

Here's another shot of Xena on the trailer this time with my little Tacoma (the other truck was a friend of mine's). I was wrong before, I've actually taken Xena to Mystic three times so it's more like 12000 km that I've towed her with this trailer. With the Tacoma's 2.7 liter four cylinder engine I get 18.5 miles per gallon which is pretty darn good. In this photo you can see that there is a central 2" x 10" board laid flat that reaches all the way back and has a roller on it and there are two angled rollers to help contain the bow when I'm winching the boat on in the yard when I'm by myself. Most of the time at the ramp all those aft rollers are underwater so don't really come into play. They do help me, like I said, when I'm home in the yard and have to get Xena on the trailer and I'm by myself. The wheel location on my trailer must be pretty good because it tracks very well with hardly any tendency to fish tale. After trailering a while, I almost forget Xena's back there. For what it's worth, the 2.7 liter Toyota motor has good reserve power for passing too.

[biglad]

Another good suggestion! I had a look at some commercially available trailers and one I remember looking at had a set of ' wobbly' rollers at the back of the trailer to line the boat up as it comes onto the trailer. I'll fit either a set of the wobbly ones or fixed side rollers to help recovery- especially as I will be on my own a lot of the time too.

Kenjamin, how did you fix your eyebolt? I have read some folks have drilled a hole right the way through the stem. I can't really do this as I won't be able to reach into the buoyancy tank far enough to get the nut on the back. Would an eye fixing threaded into the stem be able to cope with the pressure of being winched onto the trailer? I have left fitting the eye bolt until I know what height the winch will be at to avoid excessive pulling up or down on the stem.

Ben

[Wayne Jeffers]

In my experience, winch height can be adjusted to match your needs, at least on commercially-built boat trailers. On one trailer, I even extended the post on which the winch was mounted (using a piece of stout wood) in order to get the proper alignment.

Wayne

[David Cockey]

.....

The weight of the tongue at the hitch should be about 12 to 15% of the total weight. If in doubt, for a trailer and boat this light you can use a bathroom scale sitting on a chair to check the tongue weight. Actually, for a boat and trailer this light, a little more than 15% tongue weight probably wouldn’t hurt. Note the photo of kenjamin’s trailer, which I believe has the setup just about perfect.

....

The standard in Europe for weight on the hitch is around 6% of trailer with payload weight. My recollection from four decades ago is in the US the recommendation used to be 5% to 10%. Recently folks are recommending more. My guess is that if the loaded trailer is light compared to the tow vehicle a heavy weight on the hitch won't cause problems (as long as within the hitch and tow vehicle limits). Positive weight on the hitch is critical.

[Wayne Jeffers]

Most references I have seen recommend 10% to 15%. A Google search will confirm this, I believe.

My own preference is to favor the higher end of the scale. When in doubt, I err on the heavy-tongue-weight side, assuming it is all within the capacity of the tow vehicle, etc.

Wayne

[Thorne]

I've never had problems towing boats with up to 20% of total/tongue weight, as above this weight is **critical** to stability when towing at high speeds. And remember that you may end up towing far further in the future, possibly with the boat loaded with gear, so I wouldn't rely too much on the current weight and towing distance.

The wobbly rollers and standing rollers for guide-on can be critical, as getting the boat back on the trailer by yourself or even with another person in crosswinds and currents can be tricky. So think of the rollers and bunks as having two functions -- guiding the boat on and off the trailer, and supporting the boat when on the trailer. Keel rollers are nice for taking most of the weight, but bunks are good for holding it in place and additional support. If you've gotten an axle rated for a much heavier boat (quite common), you should plan on the trailer doing quite a bit of dancing about and leaping under tow when you hit rough spots or a big lorry passes you.

Speaking of getting the boat on and off, keep the whole rig as low to the ground as possible. With the UK's tidal changes, you may find that you launched in plenty of wet stuff, but have to get it back on in a fraction of that amount and depth. Build it solid and steady, but resist the temptation to raise it any higher than necessary. Ditto for the length -- handy when you carry the mast on the boat rather than the roof of the car, but it can be limiting when manuevering to launch or turning around in a narrow lane.

Here's a few photos of the trailer I modified. It was foolish of me to use a non-marine trailer and axle, and I've paid the price to replace it since, but overall it worked reasonably well structurally.

[biglad]

The trailer I'm proposing would look similar to the one in the picture above though the central spine will sit on top of the axle. I'll have c.1.5m of box left so will attach this at the aft end of the spine. It will give somewhere for the lightboard to be attached to an also the wobbly or side rollers. The axle comes back from the galvanisers today so should have it soon.

The axle is set for 750kg and the trailer will weigh around 150- 200kg (guessing a bit) so I agree that it could be slightly stiffer than necessary.

[stromborg]

I would recommend moving the axle back pretty significantly. Taking a look at where it is on Xena's trailer I'd say it was just about right. The longer your overhang is, the shallower the angle of departure gets. Every time your tow vehicle goes over something (speed bump, curb etc) that lifts the hitch the tail end of your trailer is going to move down a corresponding amount. Same thing happens when the tow vehicle starts up a ramp and the trailer is still on the flat. I've been commuting on our local ferry system for years and seen a number of vehicles struggle with the ramp when we've docked at low tide.

It helps that the CY is double ended, but it would be a shame to drag it's tail.
Steve