Rigging question

[RT MAN]

I want to lift my boat off the trailer, boat ways 5000lbs. I want to lift it using a rope block and tackle.

Does anyone have experience lifting with rope and pulley with this much weight?

I need to know what type of pulley block to use, I assume a minimum of two tripples but maybe two tackle setups one at the bow and one at the stern.


My best reason for doing this so far is the I found close to 1200 hundred feet of really good rope last weeked frozen in the snow, some must be dissapointed about that because it was in pretty good condition.

Rope ranged from 1/2" to 1"

Nice tripple braid 11/4 nylon (I think nylon)
Anyone care to chime in.

Rufus

[Hwyl]

I'd be wary of lifting 5000 lbs with some random rope. Test some of it first at least.

[rbgarr]

Where would the lifting point (in a building?) be?

[dm_scott]

http://www.woodenboatstore.com/prodinfo.asp?number=325-134

[ClassicBoatWorks]

Why do you want to lift it off the trailer?

[redbopeep]

Why do you want to lift it off the trailer?

Do you ever notice that there's always someone who says "why?" ;)

If you don't have far to go with it, you might just jack it off your trailer with a couple inexpensive 8T bottle jacks and some blocking. Don't know what kind of trailer you have or if you're just trying to get at painting it. If so, blocking and some jacks would work well for you. Cheaper, easier, safer than block/tackle/rope etc.

[Bill R]

A big part of my job is lifting heavy stuff really high in the air (rigging towers and hanging antennas).

You have scared the hell out of me.

5000lbs is a lot of weight to lift with block and tackle the way you have described. make sure your blocks and rope are ALL rated for this kind of weight.

QUOTE: "I found close to 1200 hundred feet of really good rope last weeked frozen in the snow" DO NOT use this rope for an overhead lift like you are describing. You don't know the history of the rope, and being frozen in the snow may have damaged the rope, especially the unseen inner core.

If you need to get the boat off the trailer, you will be much better served by jacking and blocking from underneath. If you have to pick from overhead, hire a properly equipped pro with a boom truck or crane. Overhead lifts of this kind of weight are not something to be messed around with by an inexperienced amateur. The risk of personal injury or at the very least damage to the boat is too great.

[Wooden Boat Fittings]

Do you ever notice that there's always someone who says "why?" ;) ... Don't know what kind of trailer you have or if you're just trying to get at painting it.

Ah. You see? There's always a reason for asking this question because it helps you better understand the problem being faced. And the more you know the better advice you can give.

The one and only time I wanted to lift Aleen Louisa was because she was on her trailer which had had it and was about to dump her on the ground. I wanted to lift her up, remove the old trailer, and wheel a new one in under her. So no jack-and block system would have worked.

I did what Bill suggested and hired a mobile crane. It worked perfectly.

Points to note --

A. The boat was in the open and I didn't have any sky-hooks to suspend tackles from.

B. While I had sufficient line of sufficient quality, I didn't at that time have the right blocks.

C. And in any case I'd rather use webbing than rope for this purpose anyway, as having less tendency to bruise the woodwork.

Even if you're in the happy position of having a sufficiently strong and high overhead structure to suspend tackles from, I agree with those who've said don't use your salvaged line for anything important until it's been tested (all of it.)

Having said that, if you're going to lift her that way you'd certainly want at least two slings (three would be better) place in such a way that they wouldn't slip forward or aft under load. And for that amount of deadweight you'd want tackles on tackles for each sling , which would be awfully cumbersome. I wouldn't for a minute consider doing it myself.

Bill's answer is the right one.

Mike

[Don Z.]

There is this method:
http://www.warboats.org/images/jpg/HeloLift/071212-N-4772B-080.jpg

[RT MAN]

The ropes I found look fine they are relatively new. My question was more about block rating wrather than the quality of the rope. I'm lifting the boat which weighs about 2500 lbs at the present time so I can install the new lead keel. Once that is installed it will weigh 5000 lbs. I plan to devide that weight between two pully rigs one at the stern and one at the bow. So it should equall out to 2500 lbs each rig. I'm pretty sure the rope I have is rated much higher than 2500 lbs. Lifting something heavy with a damaged rope isn't my intention. I will thoroughly inspect the rope before the deed is started.
This will be done out side.

[banjoman]

Have you considered having a crane come out and lift it on to some stands?

[RT MAN]

Have you considered having a crane come out and lift it on to some stands?

It is an option although I thought it would be much interesting to hoist it up using a rope set up.

[banjoman]

Interesting is a good word.
My vote would be to hire the crane and be done with it. May cost a bit but at least it is safe.

[BBSebens]

There is this method:
http://www.warboats.org/images/jpg/HeloLift/071212-N-4772B-080.jpg

I'd be happy to lend you my spare blackhawk if you like....:D



It is an option although I thought it would be much interesting to hoist it up using a rope set up.

Lol... interesting is fun, but at this point i'm gonna say crane too. btw, you said you would be doing this outside?? so... what are you picking from? a big tree? an A-frame of sorts?

how about a crane? Built in block and tackle!:D:D

[Bill R]

Hire the crane. Won't be that expensive, and it will be one hell of a lot safer.

[ssor]

With what do you plan to pull the rope? Even with a six part tackle and lifting at two points it will take more than 200 pounds pull on the ropes.

[mmd]

Firstly, let me say that I fully agree with Bill R – this is a dangerous thing you are contemplating, and shouldn’t be attempted by the inexperienced with questionable materials.

But to let you know what to plan for, assume that the boat will weigh 5000 lbs when mated with its ballast keel. Assume a 5% error in weight estimation, so the boat now weighs 5250 lbs. Add the weight of the blocks & rigging and the boat weight becomes about 5400 lbs. Assume a factor of safety of 1.5 (and this is conservative) to protect your butt and those of any helpers you may have around; therefore, assume the boat weighs 8100 lbs. Now, assume that the loads will, at some time, be unequal in the slings; assume a 33% / 66% split, so one falls will be loaded to 5400 lbs. So, you will nee blocks rated for at least 6000 lbs! Preferably 7500 lbs or more. The loads on each fall of line are not too scary, but the aggregate load on the block straps, eyes, hooks, shackles, etc. is getting up to 3 tons. These are big numbers and the results of a failure of any of the components will be catastrophic, if not deadly.

Be very, very careful. Better yet, hire a crane.

[Todd D]

For a significant lift like that I would buy a couple of chain hoists rated at about 4 tons each and a couple of 6" wide nylon lifting straps. Chain hoists have a huge advantage over a block and tackle setup in that they don't reverse under load unless you want them to. Once you get the boat lifted, do block it some way so you don't have to leave it hanging.

If you decide to go the way of hiring the lift done, you might want to consider hiring a boat hauler with a hydraulic trailer. They can lift your boat up quite high for a very reasonable cost and you don't need the overhead clearance you would need for a boom truck.

[Canoeyawl]

I have an aversion to throwing away money and cranes are really expensive.
If you really want to rig it (and not just jack it and block it, - by far the best method for the boat) You can rent a big (roadable) forklift for less than 1/4 the cost of a crane.
rig slings around the boat from each fork, you won't even need a spreader.
Rigging is fun, but it is also dangerous
The industry standard for lifting is - the rigging should exceed the load by 3 times.
If it is overhead of a man it is ten times.
(of the breaking strength of the weakest link)

[Wooden Boat Fittings]

.
From another thread (http://www.woodenboat.com/forum/showthread.php?t=88425) --

http://www.skarp.no/Bildene/sagittaII/sjosetting/bilder/loftpaabil1.jpg

Don't muck around....
.

[peter radclyffe]

With what do you plan to pull the rope? Even with a six part tackle and lifting at two points it will take more than 200 pounds pull on the ropes.
you can use your truck to pull the ropes

[floatingkiwi]

It can be a time consuming operation filled with the usual unforseen things here and there, putting a keel on. I would think you need to sit it somewhere solid, so it won't move, to do it?
Have a look how I took my ballast off and reinstalled it, for free, on my own. It is in my thread,"a folkboat found me".
Kerry

[floatingkiwi]

http://images.masterpull.com/super/super-44861-1426.jpg

20,000 lbs plus. I have some. It is amazing stuff.

[RT MAN]

With 2 tripple b&t one at the bow and one at the stern and a 2500 lbs fudge factor, 4250lbs bow and 4250lbs stern on the loose end of the rope the pull would be around 70lbs not including rope friction. (If weight were equally ditributed which is not likely, but)

The risk is on the lifting side of the b&t that will bare the weight. Crane cost at the lake will be around $1700ea. big $'s, plus I'll need two minimum.
Will a fairly decent 1.25'" rope do the trick, I always thought a big rope like that was for lifting and should have high load capability at least 5-6 time the 4250 but I must do some research.
Rufus

[Brian Palmer]

Still need to explain why you cannot jack and block it from underneath. I've jacked and blocked my boat (a lot lighter, only 1200 lbs) to run the trailer out for painting a couple times now. I am sure others on this forum have done the same.

Or, hire the crane.

Brian

[Canoeyawl]

5000 lbs,
one 7 ton bottle jack
a bunch of blocks-
one hour off the trailer
(Bottom paint)
http://www.gunkholing.org/Images/11-7-05%20020rs.jpg

[htom]

If you do this, have someone standing well back, running a video camera; you may have a YouTube hit in the making.

Seriously, this is not a good plan. Rope frozen in the snow was probably discarded because it was bad, not because it just "fell off the truck". The freezing didn't help it. Ice crystals form, break some of the fibers. You can't just test a five foot length from the end; you're going to have to strain the entire length (and pray it doesn't let go!) By the time you've done all of the work of testing, buying blocks, mountings, ... you'd be money ahead to hire the crane.

[floatingkiwi]

Well, did you look into that rope I showed you a pic of?
20,000 lbs, yes twenty thousand, for the 3/8" rope. That is, if you are going to go the rope way.

[floatingkiwi]

http://www.gunkholing.org/Images/11-7-05%20020rs.jpg

That is one seriously nice looking hull. Do you have more pics of this craft?
Kerry
It is finished wood and not glass, right?

[Rational Root]

If you want to lift something, your typically use a system rated for 3 to 5 times the load.

That's blocks rated to 20,000 lbs

I suspect that you will only get chain hoists with that kind of rating.

Try the local Plant Hire to see if they have 10 ton hoists.

Really though, professionals will have insurance, will understand how to distribute the weight so as not to damage the boat.

As to using the "found rope", how much is your boat worth again ?

[RT MAN]

Well, did you look into that rope I showed you a pic of?
20,000 lbs, yes twenty thousand, for the 3/8" rope. That is, if you are going to go the rope way.

That rope looks like a tow rope. 20,000lbs towing on wheels is different from lifting 20,000lbs. I don't know the lifting capacity of 3/8 rope but I would think 20,000 would exceed the limit. I did check some lifting capacities of 1.25" that was in 30,000-40,000 range.

Canoeyawl, nice boat!, that hull and Keel is a very similar shape to Alerion. Jacking could work nicely. How did you balance it while jacking.

Rufus

[rob]

RTman,

Did you end up casting that keel yourself or shopping it out?

I don't know why you would need two cranes. It is normally done with one lift point and some spreaderbars to allow for 2-3 STRAPS to bear the hulls wieght.
Given that you do not know what type of rope you have you also need to consider a few things like how much stretch it has under load and it's history of use...prolongred periods of tension, or even a few high load shocks dramatically alter a rope's safe working load....diameter only means so much even when apparently visually perfect.
Jacking and blocking is how this job is almost always done....alignment is tricky enough when everything is steady, start swinging the boat around over the keel and you will have a hell of a time getting it just right. Ever notice how hard it is to perfectly steady a plumb bob? now magnify everything.
The hazard to the hull is the least of your concerns, it is the people who are under it that should be considiered first.
Good luck with it

[Canoeyawl]

That rope looks like a tow rope. 20,000lbs towing on wheels is different from lifting 20,000lbs. I don't know the lifting capacity of 3/8 rope but I would think 20,000 would exceed the limit. I did check some lifting capacities of 1.25" that was in 30,000-40,000 range.

Canoeyawl, nice boat!, that hull and Keel is a very similar shape to Alerion. Jacking could work nicely. How did you balance it while jacking.

Rufus

Thanks, There are similarities. Alerion was my first choice but I had trouble with MIT over esoteric issues. I wanted to plank it lapstake, as carvel planking will not work on a trailer in my climate - The librarian came unglued...

Supports - (I had to dig for that photo, but it's worth a thousand words)
There are diagonal braces right aft clamped to the top of the sternpost; they are faintly visible in the photo. The braces are locked in place with two plywood gussets screwed to a 4x4 and to the floor (also visible) Very safe and sure method.

In that photo the entire weight of the boat is basically balanced on one jack with support blocking under the aft end of the keel.
My procedure was to block the boat forward, (a specific block with plywood sides was clamped to the keel forward, shown above the jack in the photo) then lift the stern until it was all clear of the trailer, block it, rig the diagonals, move the jack forward again, then simply raise the rest of the boat until the trailer is clear to roll out from under. Two jacks are ideal (short ones are more useful) so that when rolling the trailer you can shift each time you come to a cross-member.
Cost - negligible - I'm too parsimonious to hire a crane!
Slow and steady wins the race!
Best of luck

[Rational Root]

Will anyone have to be UNDER the boat to line up the keel ?

If so, then I suggest that your foundling rope is just a bad bad bad plan.

Don't do it.

Really, Don't

Dave

[floatingkiwi]

[quote=RT MAN;2171561]That rope looks like a tow rope. 20,000lbs towing on wheels is different from lifting 20,000lbs. I don't know the lifting capacity of 3/8 rope but I would think 20,000 would exceed the limit. I did check some lifting capacities of 1.25" that was in 30,000-40,000 range.

The amsteel blue was originally made for marine use but has been successfully made into winching ropes for all the worlds leading winch manufacturers. I feel like a rep here, but the stuff is incredible. It has near twice the B.S. of wire cable, doesn't carry heat or cold, is easy to pull off the drum and is soft and loose with no "memory", lacks the ability to pierce you with those nasty wire spikes and if any of the setup snaps it falls harmlessly to the ground instead of recoiling through the engine block and cutting the firewall and the front seat in half.