# Freeboard Calculation for ship under 24m of length

Discussion in 'Stability' started by santoo, May 11, 2011.

1. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

Hallo all member,

Can anyone help me for information about rules to calculate freeboard height for ship under 24m length. I have reference to calculate freeboard, INTERNATIONAL CONVENTION ON LOAD LINES - 1966, but that for ship under 24m length.

I'm so waiting for your answer, this afternoon I have to send it to my boss.

Thanks,

===================
Santoo

2. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

Sorry, I mean,

I have reference to calculate freeboard, INTERNATIONAL CONVENTION ON LOAD LINES - 1966, but that for ship above 24m length.

3. Joined: Aug 2002
Posts: 15,513
Likes: 1,047, Points: 123, Legacy Rep: 2031
Location: Milwaukee, WI

### gonzoSenior Member

4. Joined: Mar 2005
Posts: 3,644
Likes: 188, Points: 63, Legacy Rep: 2247
Location: Pontevedra, Spain

### GuillermoIngeniero Naval

Yes. Under 24 m rules are flag state's ones.
And they may vary depending on type of vessel and size.
What kind of vessel and size are you talking about?

5. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

@ Gonzo : Hm... Ok, I'll learn it... Thanks Gonzo...

@ Guilermo : This is for Tug Boat with 23 m Length (96% LWL at 85% Height of ship), can you give me more specific rules for it? Thanks

Thanks all

6. Joined: Mar 2005
Posts: 3,644
Likes: 188, Points: 63, Legacy Rep: 2247
Location: Pontevedra, Spain

### GuillermoIngeniero Naval

You may use the INTERNATIONAL CONVENTION ON LOAD LINES - 1966
But most probably what will tell what the freeboard needs to be is the complying with the stability criteriae.
You'll have to check both.

1 person likes this.
7. Joined: Sep 2005
Posts: 109
Likes: 11, Points: 28, Legacy Rep: 77
Location: UK

### gwboatsNaval Architect

Under 24m Freeboard

Santoo,

Try MGN 280(M) Small Vessels in Commercial Use - Section 12 Freeboard and Freeboard Marking.
Hope this helps.

8. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

Dear All,

@ Guillermo : Like I posting before, that for INTERNATIONAL CONVENTION ON LOAD LINES - 1966 , I have, just for vessel above 24m length... This is from my reference. Or, maybe you have any ICLL-1966 which comply for vessel under 24m length. I'm very grateful for your help....

@ gwboat : I'm still trying to find it...

9. Joined: Sep 2005
Posts: 109
Likes: 11, Points: 28, Legacy Rep: 77
Location: UK

### gwboatsNaval Architect

10. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

Ok, gwboats....

Thanks to all too...

11. Joined: May 2004
Posts: 56
Likes: 3, Points: 0, Legacy Rep: 31
Location: Vietnam

### Luc VernetSenior N.A.

Excuse me, gwboats, but MGN 280 is for yachts (under 24m. LLL), and although taken as a reference for yachts in many countries, and also containing essentially IMO regulations, it is "only" a publication by the Maritime Coastguard Agency regulation, a UK body, as only applicable for UK registered yachts.
This do not apply to a tug in Indonesia.

Santoo: for such boat, only State regulations apply. Consult your State authorities, as said in other posts.

1 person likes this.
12. Joined: Mar 2005
Posts: 3,644
Likes: 188, Points: 63, Legacy Rep: 2247
Location: Pontevedra, Spain

### GuillermoIngeniero Naval

Yes. And I'd bet they will most probably be a mix of the International Convention on Load Lines and the stability requirements, whatever these are in the particular country, as is quite usual for tugs the world around.

13. Joined: May 2011
Posts: 1
Likes: 0, Points: 0, Legacy Rep: 10
Location: sunbury

### domn8New Member

hi im doing some major work on a 21ft fiberglass hull and i was wondering if i could get some advise on center o gravity n how much wieght is to much to put above the water line ? basicly we have built the original walls of the deck higher an added a cabin all using 12mm ply witch will be eventully sealed.i wont to know if this will though the senter of gavity of and make the boat easely tip .plus the original out inboard has benn removed an in proses of getting an alloy pod built. il get some photos on as soon as i figur out how
can any 1 advise me plz
cheers Dom

14. Joined: Sep 2005
Posts: 109
Likes: 11, Points: 28, Legacy Rep: 77
Location: UK

### gwboatsNaval Architect

To Luc Vernet,

You said:

Sorry to disagree but MGN 280(M) applies to all vessels under 24 metre in commercial use. The full title of MGN 280(M) is 'Small vessels in commercial use for sport or pleasure, workboats and pilot boats'.
For yachts the publication relates to vessels that are only used commercially i.e. charter yachts and so not to all yachts.
Applying this standard to a tug under 24 metres is perfectly acceptable. I understand your point about UK registration but as santoo was not getting any other specific sources I felt this may help him. It was not obvious from his original posting that the vessel was specifically for Indonesia but I agree with other posts that local certification takes precedance.
It is my experience that as most certifying authorities relate to IMO regulations, so using MGN 280(M) as a design guide without having any other information was a valid point.

Cheers,
Graham Westbrook

2 people like this.

15. Joined: Apr 2010
Posts: 39
Likes: 0, Points: 6, Legacy Rep: 10
Location: Indonesia

### santooJunior Member

Now I waiting for comments from my State authorities, I will inform to you all if I have a result.

Thanks gwboats, thanks Guillermo and thanks Luc VERNET. You all so helpful for me...

I confuse enough for this project, because usually I work for vessel above 26m length. This forum so good, because contain of many people from many country and back ground...

Applause for this forum... for BoatDesign.net/forums...

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.