Question regarding Welding Aluminum baot upper deck

the layout of our boat link : https://youtu.be/myQcQaoQsLw

Our aluminum fishing boat pricipal dimensions
LOA 10.4M
LBP 8.66M
B(MLD) 2.7M
DEPTH(MLD) 0.85M
DRAFT(DLWL) 0.25M

aluminum : 5083alloy H321 made in Alcoa
all thickness of aluminum plates of our boat are 5mm.

A boat which have above dimensions is being built in our company and first ship.

We are very dificient..T_T

Today, we are getting into very large problem.

Originally we intended to single welding upperdeck to side shell plate.
But, Korea ship safety and technology Authority's inspector want us to double sides welding of upper deck.

but, we can't weld beneath upperdeck. as you see our dimensions, the depth is very low. so worker can't get into under deck. besides, In the single weldingng, the depth of penetration is enough for a strength aspect.
so we think that The double welding isn't needed and also we can't carry out double welding.

But, the inspector want us to double welding.



cf) There aren't any Law of welding less than 24meter in Korea.
and also, there are no shipbuilding with aluminum company for Fishing boat(less than 24meter.)
so, We can't find any case of aluminum boats in korea. help me..

How shall i do?

If u guyz have any information or photos that carry out single welding of upperdeck in aluminum boat, please send me as soon as possible.
email:wonmin@sdn-i.com



our all product lines stop now...

 

If I understand you correctly...since you have not posted any pictures or diagrams/dwgs...

You have 3 choices:

1) Edge prep the plate then fully weld one side.
or
2) You need to full weld both side a small flat bat to the side shell, then you can fully weld, single side, the deck plate to the FB you have just welded...like a laptop joint.
or
3) Have rider bars acting as doublers, on your transverse frames. Cut slots into the plate and fully weld, by plug welding, the plate to the rider bars of the fully welded transverse frame below.

 

https://youtu.be/myQcQaoQsLw
the design link.

 

yes, u understood corectly.
1)=> this way isn't exsistent in korea standard and If we bend the aluminum, the crack would occur in the bending point.
=X

2)double side welding using FB => is denied by KST inspector.
=X

3)one side welding +plug welding=> I told this way to inspector and
he said to me,
"Give the other ship's photo using plug welding in the other company's case to me."




so, If u have photos, Please email to me...
I will compensate for your attachments of email.

 

KST is a signatory of IACS. This is taken from IACS Shipbuilding repairs standards no.47:



Thus, they must accept this, otherwise they are contravening their own rules of acceptance standards via by IACS.

 

Isnt it regarding doubler plates?
Are there relation between Doubler plate and Upper Deck?

 

Makes no difference. Doubler/plug welding....call it what you like.
It is very clear...you have a Flat Bar on the frame acting as a backing bar - or doubler - on the frame web..and then you cut slots into the main deck plate..and plug weld to the backing bar - doubler - on the frame. As shown and approved by IACS above.

You can also tell him, all the South Boats in the UK have their main deck plug welded like this too.

 

Thanks a lot.
Now i am in the car to go to the KST authority.
I will say to him as u said to me.
If this way is approved, i ll compensate for u.
Thanks!!♥