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ContinuousWave: The Whaler GAM or General Area
Lifting a 17' Whaler
|Author||Topic: Lifting a 17' Whaler|
posted 07-03-2002 05:10 PM ET (US)
Mine is a 1980 model. When I went with the mechanic to check out the boat we drove up and lifted the boat off of the trailer with a hoist and two hooks on the transom tow eyes and one hook on the ring up on the bow deck. Launched and loaded the same way. No problem. I liked this process because the trailer didn't get wet and it seemed like an easy way to get the boat in the water. On previous threads, people have talked about a harness, but it did not seem necessary. When I asked another mechanic about it his only suggestion was to get some short nylon straps to put through the eyes on the boat, beacuse sometimes the hooks are too big and if they are in a bind, they can cause some damage. Is it okay to launch this way? What is anybody else's experience? Kelly
posted 07-03-2002 06:07 PM ET (US)
Kelly - I suspect that the transom and bow eyes/mounts were designed for a vertical load - rather than much of a horizontal or somewhat axial load. That is the reason that the many lift hoists will use a strongback which permits having the lift cables quite vertical. In the event a strongback cannot be use, then having each of the three lift cables at least as long as the boat, will give reasonably small horizontal loads - but that requires a high crane/hoist. ----- Jerry/Idaho
posted 07-03-2002 06:12 PM ET (US)
Ok, I'll ask - what is a "strongback". Certainly you are noy referring to me!
posted 07-04-2002 09:57 AM ET (US)
Living on the GA coast with it's 6/8 foot tides we often launch with a sling, I think all Marina's and some public ramps in this area have a sling. Most are 10'000 lb cargo slings with a spreader bar,strong back,. I don't know why you would want to make one, unless you have an overhead hoist?
posted 07-04-2002 10:49 AM ET (US)
Kelly - the strongback is simply a structuraly rigid beam (such as a heavy I or wide-flange beam or other similarly strong beam) which is hung from the crane/hoist at about the center of the beam and which provides support cables to the load (the boat in your case) from the ends of the beam. The support cables are therefore essentially vertical. As Jim points out, a strongback (and long support cables) require a high crane/hoist.
A spreader bar is a bar (pipe, smaller I beam or similar device) which spreads the lift cables (at about the mid-length of the cables) so that the lift cables below the spreader bar are essentially vertical. The spreader bar is taking all of the horizontal load. The spreader bar arrangement also requires a high crane/hoist.
But, your 17' is not going to weigh all that much and you should be alright using lift cables about the length of the boat and not leaving the boat hung on those cables for a long period of time (weeks or months).
I suggest using cable and not rope because rope will stretch under load and can break. One-quarter inch diameter cable will work well. Double clamp each end. ------ Jerry/Idaho
posted 07-04-2002 05:24 PM ET (US)
This did happen to be on the Ga Coast near Shellman's Bluff. The pieces of nylon that I was talking about were a foot or less just to provide something to hook onto the boat rather than the hooks on the lift. The lift we used is capable of adjusting the three hooks so that they are over the three points on the boat(two at the stern and one at the bow) thus lifting vertically. It sounds like this is a suitable way to lift the boat. It sure makes launching easy. Thanks. Kelly
|Tom W Clark||
posted 07-04-2002 09:48 PM ET (US)
Yes, lifting your Whaler like this is just fine. That is what the lifting eyes are for.
I think the idea of loops of nylon is a good way to protect the chrome on the eyes too.
A harness made of three cables swaged to a central lifting ring is the usual set up.
As Jerry points out, the more horizontal the cables, the greater the strain on the eyes in the hull (and the cables themselves), but the Whaler hull can easily withstand a cable angle of 45 degrees or less. Many, many Whalers on the decks of yachts use harnesses with a pretty low angle in order to lift clear with on board cranes.
If you have the vertical room, then by all means feel free to lengthen the cables and minimize the strain on the hull. But rest assured, the Whaler hull can take it either way.
posted 07-05-2002 10:05 AM ET (US)
Somewhere back in the archives, I posted the
lengths of the cables on the sling for my
|Tom W Clark||
posted 07-05-2002 01:34 PM ET (US)
Here you go: http://continuouswave.com/ubb/Forum3/HTML/000645.html
posted 07-05-2002 05:09 PM ET (US)
Tom and Chuck have some good points and references. Regarding 3 point sling lengths - here is a little guidance based or referenced to the vertical load on each cable. For an angle of 60 degrees from the horizontal to the cable, the horizontal load will be about 0.6 times the vertical load, for an angle of 45 degrees, the horizontal load will be 1.0 times the vertical load, for an angle of 30 degrees, the horizontal load will be about 1.7 times the vertical load, for an angle of 20 degrees, the horizontal load will be 2.8 times the vertical load and for an angle of 10 degrees, the horizontal load will be about 5.7 times the vertical load.
The vertical load is the proportional load on each cable. That is for a 1000 pound boat, there might be 500 pounds on the bow cable and 250 pounds on each of the two stern cables.
Using cables that are the same length as the boat, gives an 3-point sling cable angle of about 60 degrees. Cables that are about 0.7 times the boat length will give a 3-point cable angle of about 45 degrees. ---- Jerry/Idaho
posted 07-05-2002 06:17 PM ET (US)
Your comments are reassuring. It sure is an easy way to launch a boat.
posted 07-06-2002 10:18 AM ET (US)
The set up you spoke of is quite common, I have used them at most marina's on the GA coast, I usually launch at 2 Way Fish camp,neat place, or Blythe Island park near Brunswick.
posted 07-10-2002 10:19 AM ET (US)
Kelly - I use a similar rig to launch my Newport 17 and it works fine. The hoist I use doesn't have the clearance to manage very long hoist lines, so I'm heartened to hear Tom's comment that the hull can take the strain of using short ones. I take the forward lifting line to the outside bow ring anyway, to keep the load in shear instead of in tension, just to be safe.
I have to respectfully disagree with Jerry's comment about using wire rather than rope to lift the boat for less stretch and more reliability. That was certainly true once, but nowadays there are several hi-tech fibers used in some rope that make using those lines perfectly safe (the breaking strength is astonishingly high and there's virtually no stretch). If you'd like to do this, look for lines made with Kevlar or Spectra. They cost a lot more than regular rope, but the difference in assembly cost saves some of the material cost, and if you leave the lifting rig in the boat while you use it, as I do (I'm lazy), it's much easier to live with rope than with wire.
posted 07-14-2002 01:10 AM ET (US)
If you use cables or ropes that are the length of the boat, you're going to have trouble finding a hoist high enough. The rope lengths used are so short that dynamic rope (stretchy rope designed to cushion a fall) can be safely used--the elongation in that short a length is trivial. Carabiners from the same climbing shop you buy 10 mm diameter Perlon rope from are plenty strong enough. Rob Schmidt (see his article here on fuel tanks) has a cable harness that works perfectly on his Montauk--maybe he could measure the lengths for you. They're nowhere near the hull length of the boat. His Montauk harness worked perfectly on my 15 as well.
|Tom W Clark||
posted 07-17-2002 12:21 AM ET (US)
I was just perusing the Boston Whaler Owner's Manual from the 1970's and it says with respect to the three part bridle:
"The apex of this bridle must be at least three or four feet above the boat's gunwale."
It goes on to say that if there is not enough height for this then use a stongback or spreader.
posted 07-17-2002 12:47 PM ET (US)
Tom - interesting information, the first such information I have seen from B/W and therefore, a 'solid' reference point. That specification also says that the length of each cable should be at least 55% of the boat length. Thanks Tom ---- Jerry/Idaho
posted 07-18-2002 09:23 AM ET (US)
The information and quality of the responses on this forum never cease to amaze me.
posted 07-24-2002 06:17 PM ET (US)
The topic is lifting a 17' Whaler. How about an 18' OR with a 150 and 60 gallons of fuel?
Great information about lenght of rope/cable, angles etc. My question is, for a heavier 18' should I only consider cable or will larger diameter kevlar/spectra rope do the trick? If using rope will a bowline be sufficient for attaching or will it be imposible to untie?
I know each boat is different, but shouldn't the aft lines be a little shorter than the bow eye line?
posted 07-24-2002 07:03 PM ET (US)
I purchased a custom Lifting Harness from Sailnet.com. The quality and service were outstanding! The price ($160.00 including shipping) was about half what a local rigger, and my whaler dealer, quoted. The workmanship and quality are OUTSTANDING! All thimbles, wire, clips, and ring are stainless steel. The crimps are covered with shrink tubing.
The Here is some more information:
The price for a lifting bridle that will carry the load specified (2,500lbs) will be
I don't have the measurements, but I think I may have posted them in the "repairs section a year ago, or else Phil may still have them. The only change I would make is to have a egg shaped central ring.
posted 07-24-2002 08:46 PM ET (US)
BJ - I would use cables (1/4 or 3/16) covered with plastic and double clamp (cable clamp) each end of the three cables. The cable doesn't stretch much under the loads we are talking about and a single cable will hold the boats we are talking about here. Your 150 (350 - 400 lbs) and 60 gal of fuel (380 lbs) doesn't present a problem with cable. You can make this rig up for probably less than $50 (US). ----- Jerry/Idaho
posted 07-24-2002 08:55 PM ET (US)
BJ - I apologize as you ask a question regarding the length of the aft and bow lines which I did not note earlier. I would make the lines all the same length. Strictly speaking, each boat could require a special harness - depending on the engine load, fuel load, location of the c/g - et.al - but with equal length cables, your boat will be level or quite close to it.
|Tom W Clark||
posted 07-24-2002 09:57 PM ET (US)
Your intuition is correct. The stern cables need to be a little shorter than the bow cable. If they are all the same length the boat will point skyward when lifted. Note the lengths of Chuck Triboletís harness above.
Regardless of what exact rigging you have have it is safe to assume there a substantially more weight in the stern of the boat than in the bow. The motor is clamped to the transom after all.
You could use a low stretch rope but cable will be superior. It depends on your use. Are you trying for a one time lift or something you can keep in your tow vehicle for use several times a year? If the latter, then have one made up with cable.
Personally I would have one swagged by a pro instead of using cable clamps. If you want snap hooks that can hold up like the Wichards then expect to spend well over a hundred if not hundreds. The price that ratherwhalering reports above sounds VERY good. You might look into that.
If you use Spectra you could use bowlines. They'll untie just fine. Its just a matter of how much time you want to spend tying and untying the knots at launch and retrieval.
Your Outrage should present no problems at all. It is, after all, about 50% more boat than a Montauk and the strength of your harness should reflect this. There are photos of Tom Byrumís Outrage being launched with a harness in the Cetacea section of this site: ( http://continuouswave.com/whaler/cetacea/cetaceaPage34.html )
posted 07-25-2002 10:57 AM ET (US)
Thank-you gentlemen. I'm going to look into all the options. I intend to use the harness a lot. My boat stays in the water all summer. My Yacht club has two, 2 ton cranes used for hoisting sailboats which are very high to allow for keel clearance. Therefore I can go with long cables. Beside the crane is a pressure washer which completes the ideal set-up for cleaning the bottom. Just need the harness. Thanks again
posted 07-25-2002 01:10 PM ET (US)
For a 17 Montauk, what size rope would you use? 1/2? Would you use the same lenghts(133 & 85") or less due to stretch?
|Tom W Clark||
posted 07-25-2002 02:24 PM ET (US)
Here's another thread that reiterates the lengths that Chuck uses as well as the lengths ratherwhalering uses: http://continuouswave.com/ubb/Forum2/HTML/001173.html
BS, 1/2" would be more than enough for a Montauk especially if you are using one of the low stretch high tech ropes. 1/2" V-100 Vectran double braid has a breaking strength of 18,000 lbs! It cost about $6/foot so a harness made of this stuff would cost over $150 in rope alone. Cable might just be cheaper and easier.
posted 07-25-2002 02:55 PM ET (US)
$6/ft? What the hell is it made of.....platinum?
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