# Please help me with the BV Classification Society

Discussion in 'Class Societies' started by thinhuk, Sep 24, 2018.

Tags:
1. Joined: Jul 2018
Posts: 10
Likes: 0, Points: 1
Location: Vietnam

### thinhukJunior Member

I use BV classification society for scantling structural of an aluminium high-speed vessel, and I got a problem with checking the criteria of the resistant weld section Aw (connecting the ordinary stiffeners to the web of primary members. Aw is easy to calculate by a formulate in the Rule, however, I don't know how to check it for stiffener items 50x3_35x3 with a thickness of a plate attached is 10mm. Anybody knows about that and help to understand it? Thanks in advance!

2. Joined: Sep 2011
Posts: 7,378
Likes: 706, Points: 123, Legacy Rep: 300
Location: Spain

### TANSLSenior Member

I believe that the formula to calculate Aw is always the same but in it there are some variables that depend on the type of element to be welded or the type of welding, continuous, chain, staggered. etc.
Could you show here the pages of the Rules, or paragraphs, that you do not understand?

3. Joined: Oct 2008
Posts: 7,788
Likes: 1,688, Points: 113, Legacy Rep: 2488
Location: Japan

### Ad HocNaval Architect

Well, if you know how to calculate it, you should know how to apply it?! If you don't, you're just plugging in numbers without understanding. Go ask a naval architect...!!

What does the rule say?..it says: "....connecting the ordinary stiffeners to the web of primary members,...."

So, how are you going to connect your "...50x3_35x3.." to the main frame?

How you connect it, is the Aw. So looking at this angle bar to main trans. frame web below:

The region highlighted in red, is the weld connection. The Aw.

#### Attached Files:

• ###### upload_2018-9-25_11-1-3.png
File size:
13.9 KB
Views:
378
4. Joined: Sep 2011
Posts: 7,378
Likes: 706, Points: 123, Legacy Rep: 300
Location: Spain

### TANSLSenior Member

@thinhuk, after reading the previous post I think I already understand the doubt you had. This is what I found in the Regulation of the BV for yachts of March 2012

#### Attached Files:

• ###### Snap11.jpg
File size:
61.7 KB
Views:
446
5. Joined: Jul 2018
Posts: 10
Likes: 0, Points: 1
Location: Vietnam

### thinhukJunior Member

@TANSL Yes, the formulate is the same with BV for high-speed craft 2012. And I don;t understand for checking the Aw also. In this case, the ordinary stiffener is 50x3_35x3, how we calculate the resistance welding of this stiffener?
Anyway, thanks a lot for your response.

6. Joined: Oct 2008
Posts: 7,788
Likes: 1,688, Points: 113, Legacy Rep: 2488
Location: Japan

### Ad HocNaval Architect

Agreed. BV rules are clear as mud.

The text makes it very clear what it means...yet the formula proposed for Aw appears to suggest otherwise. Yet weld length, which is not Aw, is dealt with elsewhere...go figure?!

BV rules are terrible...with poor nomenclature.

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.