How Do I Move My Half Hulls Around??

Thanks, RX, but I don't want to put you through the trouble.

I've been through this problem from every angle:

*Building a custom Travelift from gantry lifts (too wide and will not work)
*Using gantry lifts in a normal way (not tall enough and if they are tall enough, they are $3000 each)
*Using engine hoists (have to grab very close to hull and will hit the side of the hull when arm is raised to near vertical)
*Setting up some kind of indoor crane (way too expensive and also I have a round building/roof)
*Using people to just lift and move (can't get under the hull because it has battens all along the mold - hull lip is at shoulder height)

None of these will work with either my building, mold or combination thereof.

SO... I think I've narrowed it down to a final solution: Just stick the boom of a big crane into the building to move the pieces around. I will use a long lifting bar (30ft?) and run many lifting straps around the hull. Very expensive, but no more expensive than a pair of gantry lifts.

 

I think the solution you had in post #2 had merit. But you could/should prepare your mold for the dismantling before you start laying foam. You probably have scrap pieces of plywood lying around to use as gussets. You cut the molds at a good spot and screw them back together with the gussets. Now when your hull half is glassed, you crawl under and unscrew the gussets, remove one side of the mold and pull the hull half out sideways (using your enginehoists). Putting the mold back together should be easy too.

Lifting the previous half on top of the other for joining has me scratching my head a bit though.

Just my 2 cents.
Lurvio

 

RX has things about right cat, before you spend the money on a picker do a little more thinking. Any means of lifting you chose you will have to prep your hull to keep it from flopping around. You will have to use a comalong in the center lift point to adjust and keep the hull from folding or flexing. The male frames along with stringers screwed into your temp lifting eyes, add some tabs on the bottem as well and the male form is tied to your hull . Lift it vertical , pull the female form to one side, lower your hull down untill the male frames that you cut the rocker in touch the ground , lean the top in the direction you want it to go and sit down with the stringers setting on the ground, now your on the male mold and ready to glass, your foam edges never touch the ground and the hull never flexes.Your 1/4 hull should,nt weigh more than 400 lbs + or -, think all this though , refine the process, you have the help on the forum to do it . Give me some weights and work area sq ft, I,ll ask our engineer to give me some ideas next week , he plans out all our heavy lifts. rick

 

Thanks, guys.

Rick, the weights are as follows (estimated extra heavy):

Half hull coming out of the mold: Approx 500lbs
Full hull joined together with bulkheads: Approx 1500lbs

Dimensions: it is a 45' long panel, 8' wide, with a "c" shape, since it's half a hull with attached deck.

One note: There is no male mold. Everything is done on the female mold and I can't move it around while building the first four hull halves. It's very fine tuned so they all come out the same.

There are some good pictures of this kind of build here:

http://cruising.stuffiminto.com/everything-else-boats/1487-moving-half-hulls-around-again-7.html

 

I was thinking 1/2 a hull, not 1/2 a deck too. Even with a spreader beam with short choakers for verts you will need a spreader at 45 to 60 degrees, what kind of head room do you have? You dont have much room to swing a crain, you may look at renting a lull with a boom for a month or more at a time, you may be able to get a deal on one. Depending on your head room you may want to have 4 pick points , a shorter spreader beam with two spreaders at the ends 45 to 60 degrees. rick

 

Still think that you are overestimating the difficulty.
Attached photo has a 15m hull in it, sorry for the poor quality as its a flash photo of a magazine. To build something like this from scrap timber is not going to cost you $3000.

You build two of these to straddle your building form and sufficiently high to clear it. Should only need to lift ~1.5m, what is your hull beam?

Wheel the half hull out, rotate either in the carrier or if unable hire a small crane for 1hr to do so.
Bring the hull back inside and prop up with additional supports, scrap 4 x 2 timber.
Next build the inboard half hull, simply lift above the building form and support insitue.

Dismantle and reverse the form.

Build next outboard half hull, lower the one suspended above it down and join.
Glass the top half (outer laminate).
Pick this up with your lifting straddle, take out rotate and bring back in.
Complete the other half of the outer laminate.

Build the last inboard half hull, pick up the very first half and place over the forms and join, etc etc.

 

I like it.

 

Transverse lifting gear

Or like this.

 

I like it too.

Andrew is like my error checker along the way. This is the second time he has kept me from wasting time and effort all along the way. Thanks, Andrew. I will measure everything up to see if this technique will work. I think it will.

My problem was not suspending one of the half hulls above the mold for part of the process. That made the building too crowded to use the gantry lifts. With one suspended up above the mold, I have far fewer moves to do and can use the gantry to move the others around without running out of space... I hope.

Thanks, again... you have saved my *ss from another mistake. I don't know where in Australia you are, but I owe you a VB next time I'm there!

 

Yes, those are good too. Those gantry lifts in the States go for $3000 each though. The chain falls are an extra cost. Bad for the budget when I only need to use them 5 times (and they don't help you lift a bridgedeck)

 

Expensive over there. We built it (two) for less than a thousand dollar including the chain block and lifting straps (China of course).

 

What is the area of your half hull? I know you have posted it somewhere but I could not find it.

 

Half hulls are 3 ft deep, 8 ft wide, 45 ft long.

A full hull, to clear the mold, has to have its topmost point 10 ft, 4 inches off the ground.

 

Half hulls are 3 ft deep, 8 ft wide, 45 ft long.

A full hull, to clear the mold, has to have its topmost point 10 ft, 4 inches off the ground.

 

Ok, here's the latest:

I had a professional marine crane rigging company come in. They specialize in moving hulls inside of buildings and supplying marine companies with hoists and stuff.

They came on site, analyzed the situation and requirements and came up with the following:

I rent this from them:



Also, they rig up a spreader bar and some nylon straps.

They confirmed that the angle was wrong to put a large crane boom in from outside the building. They confirmed gantrys won't fit in and out of the building in the case that the full hull is lifted to clear the mold. Actually, it's getting back in the building that's the hard part.

I do believe their solution is a motorized engine hoist, no?

************

And what about this? Could I just make up a "super hoist" that has a good height to it, almost like half a gantry?

What would the scantlings on something like this be if I want to lift up 1500lbs max?