Any approved Naval Architecture software?

[Barry Deakin]

Hello,

I have only just joined this group but noticed this discussion, and the fact that no software developers have engaged in it.

I work at the Wolfson Unit MTIA, where we have developed naval architectural software over the last 40 years. Our software once was approved by the Norwegian Maritime Directorate which, as far as I know, is the only regulatory authority to have offered such an approval process. This was some years ago, and was a very prolonged business because all software suites differ in their approach, particularly in the most complex damage cases, and we had to spend a lot of time matching the complex arrangements exactly, and interpreting our data and theirs to ensure that the results matched precisely. It is understandable that authorities do not wish to spend time with it.

Our feeling is that all reputable programs should give correct results, provided they have no serious bugs, but a thorough understanding of the way the program conductes the calculations is required when very complex arrangements are to be modelled. It should be no problem to compare intact stability calculations on a simple monohull for example, but to match the results for an asymmetric flooding case on a chemical tanker with many irregular tanks will usually prove difficult. I have much personal experience of this problem through working as an expert witness on legal cases, where any differences between the various calculations by different experts, and existing stability data for the vessel, must be resolved or explained to the court. In almost all cases we find that differences are due to the operators rather than the algorithms. It may be simple errors in data input, or a misunderstanding of the way the program's algorithms work, but usually differences can be resolved. This is not to say that there are no programs out there that get the wrong answers, but I have no experience of them.

Our software is used throughout the Maritime and Coastguard Agency's marine offices, both in the ports and at their headquarters, for checking stability submissions. We feel this is as good as having it officially approved.

I don't think these fora should be the place for marketing, but I feel justified here because Guillermo has expressed disappointment with the lack of response from suppliers.

Details of our software are available on our website: www.wolfsonunit.com

[Guillermo]

Thanks a lot for your post, Barry. Your feedback is most important to me.

So, it seems only the Norwegian Maritime Directorate has been involved in the approval of stability software. I can understand the difficulties involved in an approval process, as well as I know most of the times the problem is related to users, not the softwares themselves. I also know difficulties get bigger when assessing complex damage stability.

But what I'm talking about is getting different results for simple intact stability analysis for the same vessel and load conditions. We run the thing with three different softwares: the well stablished one we daily use at our office, a second one we had recently bought to try how it worked (had some promising aspects we were interested in) and then a DOS based (which we also have but no longer use) well stablished old one a senior colleague still uses since many, many years ago. I asked him to check our results because of the differences we had found.

And, to my surprise, the third software (my colleague's) also produced a significantly differing set of results away from the other two.

I know my daily used software is also used by the maritime authorities in Spain, and hundreds of vessels' stabilities have been approved using it. Such approvals also happen for the 'old' one, which has been widely accepted, not only in Spain but in the UK and the USA, as far as I know. I learned the new software had a lot of bugs, because we, very, very painfully, suffered the process of discovering them.

So I submited all three results to our maritime authorities, asking them to analyze them and give their comments and, if necessary, to initiate a validation process, so pros around here know which programs to trust. Specially when a new software comes into the market. We unfruitfully spent thousand of euros with this problem and we still do not know who and how to claim.

My submission was previously analyzed by our local maritime authority (several NAs work there), who supported it in written and sent it to the central authorities. This was 9 months ago and we are still waiting for a response, although we already know (unofficially) they are not going to impulse a validation process.

Thanks again for your input. You may freely market your product in this thread.
All the best.

[Chris Ostlind]

It would be wise to listen to the learned advice of our Spaniard friend, Guillermo. He has gone through so many trying experiences in the course of his education, as well as cultural upbringing in Galicia, that it makes for a really powerful sense of truth in his words.

Chris