Heavy lift floating marine unite

[Hisham]

My graduation project is designing a heavy lift floating marine unite, witch will be used in lifting the sunken yachts and boats up to 250 tone, and bring it to a shallow water area so it can be floated again and towed using common methods

The lifting unit is about 40 m length, and has a very simple hull like barges
It will lift the sunken yachts using onboard winches, then bring the yachts up near to the sea surface and below the keel of the lifting unit then the lifting unit will move to the nearest shallow water area carrying the yachts, then the yachts will be dropped again in the shallow area to be floated afterwards.

I will design it using ABS rules, The Question is …. Witch rule of ABS?
There is a rule for steel vessels under 90 meters (tugs, oil recovery vessels, supply vessels, fire fighting vessels and offshore supply vessels)
My lifting unit will be subjected to a very large stress so it can’t be treated as these types of vessels.

so wich rule of ABS should be used?
Need help plz

[kach22i]

I was trying to picture what you are talking about and found this:

Thunder Horse semisubmersible platform

http://www.rigzone.com/data/projects...?project_id=20

http://www.imcbrokers.nl/index2.php?...&pid=44&nid=33


http://www.ocean-resources.com/news/...sp?NewsID=3387


http://www.aapg.org/explorer/2004/09sep/index.cfm

The 59,500 metric ton semisubmersible Thunder Horse platform in August began its 60-day journey from South Korea, around Africa en route to Corpus Christi, Texas. In 2005 it will be moved to the Thunder Horse Field about 190 kilometers south of New Orleans. Both the platform and the transport vessel are the largest of their kind ever built -- appropriate, because the Thunder Horse discovery is the big reason why the deep water play now dominates Gulf activity.

[SailDesign]

I had something more like this in mind...
It is the Tog Mor, used to lift the "Mary Rose" in 1984, before she was converted to a shallow-water pipe-layer.

[CGN]

If you go to ABS Website you will find this information, I think is still available as a free download

"Guide for Building and Classing Liftboats (2002)"

Cheers!

[Herbert lotz]

Keep it simple guys only 250 tons..

[Hisham]

thanks guys,
i found the rules
i think this image explain my idea

what do u think guys a bout my idea?
do u think it will be effective and can be built?

[Ari]

For your design idea:1. To lift in shallow water should be no problem. 2. Transporting to port will be very risky.
To overcome the problem of hanging 250 ton vessel full with water..what a ballast man..those rescued ship are put on board the rescuer.Nearly all winch are design to lift..not to continuosly keep the heavy weight susspended.The type used by the British navy is real good.During the war in Falkland / Islas Malvinas a few British boat got sunk in the sound- Enteloppe and Sir Tristram ? They are lifted up and ride on the rescue ship to England.

[Guillermo]

Originally Posted by Hisham

thanks guys,
i found the rules
i think this image explain my idea

what do u think guys a bout my idea?
do u think it will be effective and can be built?

Your idea has been tried before with success, using two specialized barges to lift sunken vessels and bring them to shallower waters. Attached find a photo of some old units.

[Hisham]

thanks gus but i still having a problem.... the rules i have found in ABS site was for (liftboat) a boats that acts like jackup (self elevation boat) not for a bout wich could lift another boat ... i need somthing form floating cranes or something like this
any idea?

[Guillermo]

Hisham,
I'm not used to work with ABS rules, so If I were to design such barges by myself I'd rather use DNV, Lloyd's or BV.

Using DNV, i.e., there is a Crane Vessel notation which can be given to vessels specially intended for lifting operations, Ref. DNVs "Rules for Ships" Pt. 5 Ch. 7 Sec. 8
Note that the notation stipulates requirements regarding stability and watertight integrity for heavy lifting operations.
Maybe ABS has something like that.

In a quick visit to ABS web pages I found the "Rules for Building and Classing Steel Vessels Under 90 Meters (295 Feet) in Length (2006)" you mention (Small Vessels Rules), but I did not find Crane vessels devoted rules.
Although you mention your lifting unit will be subjected to high stresses, most probably for a 250 tons lift vessel the Small Vessels Rules are good enough. Just contact ABS and ask them.

[Hisham]

Thanks Guillermo
ur a very helpful man, and thanks all of u guys, this forum is great

[Davor]

Contact ABS, and they will suggest you which rulles to use.

Davor