DaySailer.org Forum

Hello-

Have any of you ever used a crane to pickup your DSII? If so, where did you lift the boat from?

The sailing club we are thinking of joining in the Spring has an electric crane that members can use to launch their boats. I saw one Flying Scot get picked off its trailer and placed in the water. They had one attachment point forward on the CB trunk and another further back to center the weight.

The club also has a ramp (not very great). I thought the crane might be an interesting option to explore.

Thanks,
Bill

we used to use a double sling. you could probably use two ropes as the boat is so light (or 4 strong guys)

I've used rope slings before to get the DS off its trailer to work on it. Compared to its own weight, the DS hull's pretty strong, so as long as you separate the slings enough for the boat to be balanced, you should be fine.

I do it all the time. I replaced the pins in my side chainplates with a shackle. A previous owner installed two rings at the stern quarters. The rings are backed with a piece of wood. The shackle pin (with the shakle) does double duty of lifting the boat, and holding the side stays. Then I made a bridle out of low stretch 3/8 braided nylon line. I tied 4 carabeaners (sp?) in the ends of the line to attach to the shakles and rings. The line is in two pieces, tied so there is a loop, approximately above the forward 1/3 of the centerboard trunk.The hardest part of the whole operation was getting the placement of the loop in the bridle so the boat was balanced. I did it several years ago, so I can't remember how long the line was. I think both pieces were about 25 feet, put together. I'd send pictures, but the boat is all wrapped up for the winter. If you remind me in spring, I can send them.

but the boat is all wrapped up for the winter.

Mine too. How depressing!

There is a ring on my transom amidships, that the mainsheet runs through to avoid the tiller. The rings is bolted through the solid fiberglass, I was wondering if that would be a good pickup point?

What I was thinking is making a bridle between the chainplates, and then lifting from the stern on that ring. Though before reading jp's post I hadn't really considered the chainplates strong enough.

Thanks for the ideas!

On the DS II the standard chainplates are not well backed up under the lip and I suggest lengthening up the backing plate to spread the load along a longer part of the lip. I then used a longer clevis pin where the stay adjuster meets the chainplate and put a shackle there on each side. For the aft area, I simply put a knotted line through the upper drain hole and attached the third part of the bridle there. It is really a very simple process but you have to mess with the line lengths a few times to get the boat balanced. Good luck.

Yeah, I should probably have mentioned that I have a DS1. Although, there are some DS2s at our club that do it this way. It probably wouldn't hurt to reenforce those anyway. Another DS2 has installed rings with wooden backing plates just inside the chainplates, through the side decks. For the stern, several people use the aft docking cleats. Again, you may want to reenforce those with more backing.

I too am grappling the task of making a strong bridle for a crane at our club. What about using 2 car tow straps? and for your configuration, do you have a photo?

Breaking strength (or Safe Working Load) for the ropes is likely not the problem. Modern ropes are amazingly strong. Fully rigged a DS comes to about 600lbs. Add some gear, and assume 750lbs. For a four or three point bridle, assume that the load isn't fully balanced, so that perhaps only one pair lifts, while the other rope or ropes merely balance. Then factor in a 45 degree angle (reduction to 70% of effective strength).

Based on that, I would think that a safe working load of 425lbs ought to do it. If you use knots, add a factor of two, so any rope that has 850lbs SWL should work. For standard polyester double braid, you already get 3300lbs at 5/16". That would represent a safety factor of nearly four.

For webbing, the breaking strength depends not only on the width but also on the thickness, the latter is more difficult to measure and verify. Some of the thinner 1" straps, I've seen listed show 1100lbs for the breaking strength. That's a bit marginal, even if there are only sewn loops and no knots to weaken the strap. Car tow straps would of course have a higher rating.

At our Club, Sonars, Lightnings, Thistles, Vipers all go in on bridles at a couple of different hoists that we have on the bulkhead. The only boats that go down a ramp are the Lasers, kayaks, etc.
My bridle has a ring that the lines (3) connect to. One line goes back to the transom and connects to the same boweye that my hiking straps connect to.
I have another 2 lines that go from the ring and connect to small stainless steel shackles that I put on each shroudplate (drilled a hole in these for the shackles).
The boat comes up a little nose heavy but I've never had a problem getting it on or off the trailer.
I also have a 4th long line on the ring that I hold in my hand along with the bow line so I can pull the ring of the hook on the hoist. This saves me the trouble of
having to get on the boat to disconnect the hoist and I can just walk the boat from up on the bulkhead to the fingerdock.
Taking the boat out I do have to get on it to hook the hoist up, but I have been thinking about some sort of funnel that I could drop the hook into to grab the ring. That would save a trip down the (vertical) ladder on the bulkhead. Anybody have any ideas?
I should be out to the boat in the next few days. I'll post line lengths, diameters and pix.

Anyone have some pics available? I would love to get my boat into the water!

I am an engineer dealing with cranes, rigging, heavy lifts in oil refineries, construction, and maritime.

A word of warning about tow straps, ropes, etc. They are not designed or rated to be used for lifting. Generally, lifting gear is rated for a 5:1 safety factor. If it has a 1000 pound breaking strength, you can safely lift 200 pounds. This is to account for dynamic forces and the loss of the efficiency at the connections.

If you are doing a lot of lifting at a club, purchasing proper slings would be best and because they are pretty small, you can probably get them for a couple hundred dollars. I am used to ordering $5000 slings to only be used once. They also have adjustable ones! Many rigging lofts (industrial, not sailing) can even produce custom lengths.

All that being said, I have definitely lifted my boat with Costco ratchet straps...

Also, remember to account for the angle of the slings used. Assume the boat weighs 500 pounds, if 4 slings are used and are at a 45 degree angle, each slings will be lifting 177 pounds instead of the 125 pounds.

I would be happy to run quick numbers for anyone that is thinking about making gear. SAFETY FIRST.

Good point about the 5:1 safety factor.