keel welding problem(Urgent)

By Jfei Date 04-14-2008 04:13

i m new in this field.i m having this kind of problem, for the joint between 2 keel of a vessel(horizontal and Long.), is it necessary to penetration weld?if not, what will be the porosity inside the joint?because keel is the very important of a vessel. At the same time, where can i get those general knowledge of vessel construction before i go further details.Please help me solve this problem because some of the contractors told me that it is not necessary to penetration weld the joint, some say need.this really make me blur and confuse....

By makeithot (***)

Date 04-14-2008 04:59

I do not really follow your question but I'll take a shot.When you are weldng the keel you do infact need a full penetration weld. How you achieve that is dependent on weather you are assembling the keel with a keel bar or not. What type of boat are you building? How big? Aluminum or steel?

By Jfei Date 04-15-2008 01:01

It is steel typed. 46m Landing craft. The problem is the keel is already welded with the keel plate without penetration weld.According to the supervisors, other shipyard is all doing the same way, join the keel and keel plate without penetration weld.As been told by them, inner part of vessel is not necessary for penetration weld.Is it true?but they didn't even make the bevel at the edge of the joint.I had referred to some class surveyors, some say it is acceptable,some say cannot.Any better suggestion?

By 803056

Date 04-15-2008 22:40

I would defer to the design and detailed drawings and study the welding symbols. The approved drawing should be the "accepted" way to weld the keel.

If this is for the U.S. Navy, the design should have been approved by the Navy, including the welding details. For more detailed welding information you can review the information included in MIL-STD-22D. That document provides additional information such as fit-up tolerances for standard joint details. NAVSEA S9074-AR-GIB-010/278 lists joint details approved for various applications. Nonstandard joint details would require specific approval from the Navy.

Best regards - Al

By Jfei Date 04-16-2008 01:57

Thank u guys so much.Thanks for the input and the information.it really helps. Any way, i m new guy in this field. where can i improve my knowledge, i mean like some of the special term of the hull block part and general knowledge of hull construction. i m really willing to learn. is there any website that i can gain extra information from there?and is there any short course suitable for me after my working hours.

By valoman (*)

Date 05-02-2008 18:05

Dear Jfei,

you can get some general knowledge on ship design eg from the "Practical Ship Design, Elsevier Ocean Engineering Book Series, Volume 1, by D.G.M. Watson", ISBN 0-08-043921-7.
Also looking at the rules of various registries is very helpful.
For example ABS Rule Requirements for Materials and Welding both for Steel and Aluminum Vessels are very detailed.
Those you could download for free from the ABS website http://www.eagle.org/
Good Luck,

Valoman