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pbmaise · 21-11-2015, 03:39

I am considering building a lift for my trimaran and want to make it versatile for other multihulls. About how wide is the ama on a typical Lagoon 450 and Lagoon 520 or other cats in these size ranges?

colemj · 21-11-2015, 03:47

These boats can be supported by their keels, so if you want to make it general enough, just provide a platform for the keels to set on.

Mark

pbmaise · 21-11-2015, 04:00

I am thinking of building two lifts that will be 8 or 10 feet wide and 40 feet long. Marine plywood here is 4 by 8 sheets. Anyone have the weight of a loaded Lagoon 520 with fuel, food, and spares etc.

**GordMay** · 21-11-2015, 07:21

Lagoon 52:
Length over all 15,84 m / 52'
Beam 8,74 m / 28'8''
Draft 1,55 m / 5'1''
Mast clearance 27,97 m / 91'9''
Light displacement (EEC) 26,03 t / 57 403 Lbs
Fuel capacity 2 x 496 l / 2 x 131 US gal (x 7.49 Lbs = 1,962 Lbs)
Fresh water capacity 4 x 240l / 4 x 63 US gal (x 8.35 = 2,104 Lbs)

Hence: 57,403 + 1,962 + 2,104 + 1,531 misc = ± 63,000 Lbs (approx)

SailFastTri · 21-11-2015, 08:08

With your 40 foot beam I can certainly understand why you may find it difficult to find haul out facilities, but why design something? There are commercial boatyards that could accommodate your beam, cranes and heavy jacks that can be rented, or marine railways that can be built in-place. Once the boat is lifted and positioned there are countless ways to improvise stands from relatively common materials at hand. So I'm curious about the situation that's motivating this project.

**David M** · 21-11-2015, 08:33

Wouldn't a haulout cost less and be less detrimental to the environment?

As a rule of thumb for cats, the beam is roughly half the boats length.

jdazey · 21-11-2015, 11:08

As I read it, the OPs question was about hull beam.The hull length/beam ratio on cats ranges from 7 or 8:1 to14:1 or more on the more performance oriented boats.

pbmaise · 22-11-2015, 06:06

Thanks for the weight on the Lagoon 5200. I can make it the target weight.

I am considering building two floats to lift my own boat out of the water for several reasons. Yes one of the biggest is only the big yards here in Philippines can handle my vessel. I have seen the conditions of these yards and dont want to go near them again.

Costs are high to do what I want to do. I am far too anal retentive to do a slap on paint job. I know some can beach a boat and toss a quick coat of paint in between tides. I need to do some epoxy touchups after a tree in the South China Sea. Then sanding and refairing, two coats of Interseal, then two coats of bottom paint. I also want to move the waterline lower and repaint. Further all the wooden boats have made a mess of my stern doing pick ups and drop offs.

SailFastTri · 22-11-2015, 06:22

Makes sense. Will you use air bags or hydraulics? Will you lift from the crossbeams, so that you can access the very bottoms of hulls?

pbmaise · 23-11-2015, 05:34

Quote:

Originally Posted by SailFastTri

Makes sense. Will you use air bags or hydraulics? Will you lift from the crossbeams, so that you can access the very bottoms of hulls?

Lifting this very large trimaran is a challenge. To get my main hull (wa'a) fully clear of the water and provide dry working space below, means she must be lifted 8 feet.

My trimaran is designed to be held aloft by 4 of the 6 cross beams (aka).

The floats I am thinking of building are solid and essentially inverted hulls with many air compartments. On top of each solid float there will be four pillars for a total of 8 support points.

You are correct if you are thinking this is expensive. That is why I am thinking of making it so I can easily lift other big multihulls.

Initialy I was thinking two floats about 40 feet long by 10 feet wide. However, waves may cause problems .

Therefore a single submersible platform 25 ft long and 30 ft wide may be better.

I am also thinking I will need a section of floating dock that can be moved around as each section of the boat is worked on.

SailFastTri · 23-11-2015, 07:14

Quote:

Originally Posted by pbmaise

Lifting this very large trimaran is a challenge. To get my main hull (wa'a) fully clear of the water and provide dry working space below, means she must be lifted 8 feet.

My trimaran is designed to be held aloft by 4 of the 6 cross beams (aka).

The floats I am thinking of building are solid and essentially inverted hulls with many air compartments. On top of each solid float there will be four pillars for a total of 8 support points.

You are correct if you are thinking this is expensive. That is why I am thinking of making it so I can easily lift other big multihulls.

Initialy I was thinking two floats about 40 feet long by 10 feet wide. However, waves may cause problems .

Therefore a single submersible platform 25 ft long and 30 ft wide may be better.

I am also thinking I will need a section of floating dock that can be moved around as each section of the boat is worked on.

It seems to me that you're building a "boat" to service a boat, and it's going to bring yet another set of maintenance issues with it.

What is your land access to water there? What is the tidal range there? I think a marine railway would be a better solution, if you own (or lease long term). However, for a marine railway to work the tide range must exceed your draft + at least 18 inches (the height of the rail car plus tracks). I have some experience using a marine railway at a boat club that's member-run.