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Sunday, April 8, 2007

M/V Iyanough Problems?

The very first day the SSA's M/V, Iyanough arrived here, I noticed large areas on her hull and superstructure that looks to be dimpled. I'm not sure if dimpled is the proper word or not. I took the picture below this afternoon. I circled the dimpled areas in red-
Click on any picture to enlarge.

Here's a closer shot-

I'm not a shipbuilder and I have never aspired to be one but something doesn't look right. I have never seen a ship dimpled like the Iyanough. Is this common practice in today's shipbuilding? I'm surprised they let her out of the yard looking like this. Is there anyone here that is familiar with shipbuilding that could provide some insight on this? If so, please leave a comment in the comment section. Thanks.

I added a new feature on the left. Click on the picture for a weather radar of the east coast.


Anonymous said...

The dimmpling is normal when welding aluminum.


Martie said...

Yeah, but them are huge dimples, no?

Anonymous said...

Control of Distortion
The problem of distortion is as inherent with aluminum as it is with other common metals when they undergo welding. While it is impossible to prevent distortion occurring on a weldment, there are ways of controlling it by adopting a carefully planned procedure.
It is not possible to specify in detail such a procedure, but the following factors make significant contributions towards controlling distortion on aluminum fabrications:

Always try to allow individual plates and sections some degree of freedom of movement and weld from a fixed to a free end to prevent possible build up of locked-in stresses.
Plan all welding sequences so that they are balanced symmetrically about the neutral axis of a joint.
Avoid wide included angle preparations and excessive root gaps on butt joints, keeping the excess weld metal to a minimum. Weld sizes on fillet joints should be kept to a controllable size, i.e., as small as the design requirements will allow.
Once a weld run has been commenced it should be completed without unnecessary interruptions.
Use the highest welding speeds possible compatible with the material thickness and welding position consistent with proper fusion of the joints; thus keeping the heat input from spreading throughout the components. To achieve this, the MIG process is to be preferred to AC TIG; DC TIG can be acceptable when mechanized.
Finally, the effective use of chills, jigs, and fixtures is recommended wherever possible.

Anonymous said...

Looks the same as the Grey Lady--same yard too.