# calculate the list and heel of a rectangular pontoon type vessel

Discussion in 'Boat Design' started by Peterfromholland, Oct 27, 2017.

1. Joined: Oct 2017
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Location: Netherlands

### PeterfromhollandNew Member

Hi Guenter,

I am not familiar with boat design, however recently wanted to calculate the list and heel of a rectangular pontoon type vessel. It has an a-frame on one side and some equipment on deck. Searching the internet on how to calculate list and heel, brought me to your site. I am curious how the calculation of list and heel is done, I can't however open the calculations on your site. Is this something I can do in excel or do I need special software to calculate this? Thansk in advance, Peter

2. Joined: Apr 2015
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Location: Berlin, Germany

### HeimfriedSenior Member

Hi Peter,

to execute this calculations an array of numbers is necessary which mathematically represent the hull of the vessel. "rectangular pontoon type vessel" sounds quite easy, could you describe it closer? Heel and list is very similar, no need for trim?

Does the website open and look similar to a screen I have posted in #23? Is the site showing a respond if you are clicking buttons? At what point the answer of the site is not what you expect?

Last edited: Oct 28, 2017
3. Joined: Oct 2017
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Location: Netherlands

### PeterfromhollandNew Member

Hi Guenter, thanks for your quick reply. You are right, its the list and the trim I am looking for.

The pontoon type is something that will be used to move anchors from one location to another. We are considering one pontoon of 6m long and 4m wide with an Aframe. A winch will lift the anchors (2000-3000kg), so that a smaller boat can relocate the pontoon after it can drop the anchor again, often used in the dredging industry. This same pontoon is also used to lift other heavy equipment.
I would like to understand what happens when you lift an anchor or pipe line and how many degrees the pontoon will tilt. Also i would like to know the maximum height an anchor can be lifted to avoid stability issues.
If I understand how this calculation works, it helps me to play with the figures (length, width, height Afram etc) to keep it safe! Also a catamaran type pontoon can be considered (two smaller rectangular pontoons connected by the aframe.
To drive the winch a powerpack will be installed, placed somewhere on the pontoon, i estimate the weight at approx 5000kg.
Peter

4. Joined: Oct 2017
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Location: Netherlands

### PeterfromhollandNew Member

Hi Guenter,
the website seems to be working, am trying to figure out how everything works but am sure i will manage to do so.
Peter

5. Joined: Apr 2015
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Location: Berlin, Germany

### HeimfriedSenior Member

Last edited: Oct 31, 2017
6. Joined: Mar 2018
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### DarkNew Member

Hi Guenter,

I need trim angle for rectangular pontoon 82,5 meters long and 6 meters wide with 0.6 meter draft bearing in mind installation of anchor piles three of them 10 tons each on one side. Piles are mounted on the pontoon side shell with mounting frames. Height of the piles is 18 meters. your help will be appreciated.

7. Joined: Apr 2015
Posts: 525
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Location: Berlin, Germany

### HeimfriedSenior Member

To calculate an answer there would be some more data needed, I think. Assuming the rectangular pontoon is yet without the anchor piles an swimms in even keel condition in calm water, the volume displaced is 297 m³, if it is fresh water, the DISPM is 297 t. What about the depth of the pontoon? Where is its VCG? Where will be the CoG of the anchor piles if added?

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