General HydroStatics
Ship Stability Software
Command of the Week
(New or interesting aspects of GHS that you may not know about)

(Requires GHS version 16.16 or later with SK Module)

Lately we've received a lot of inquiries about SEAKEEPING. What can it do? The answer is that it can do quite a lot, and SEAKEEPING invokes a truly massive computation that happens behind relatively few parameters. However, with a massive computation comes a very large amount of data, and a multitude of ways to process that data. And when flexibility and customization are important, ease of use can suffer.

In an effort to make SEAKEEPING more user friendly, and to allow for more complex analyses, we are proud to offer the SEAKEEPING Wizard.

The SEAKEEPING Wizard is a graphical interface, controller, and post-processor based on the SEAKEEPING command. When it really comes down to it, the wizard is carefully preparing a large matrix of parameters for SEAKEEPING and calling the command one or many times to get the desired results. These results are then automatically post-processed, if needed, and the final output is generated.

The interface is decidedly adaptive: it adjusts to offer users the right options for their intended goals. It also attempts to help new or inexperienced users set up an analysis, because let's face it, the subject of seakeeping is not entirely intuitive if one is unfamiliar with the process.

A step-by-step approach is used, where the user first specifies the Geometry, sets a Loading Condition, and selects an Analysis Type. The Wave Environment is then established before selecting any Post-Processing options and running the analysis.

The Wave Environment is highly customizeable. This means users can set up any combination of speeds, headings, and wave types, and send these runs to SEAKEEPING with the click of a button. All three seakeeping wave types (single waves, wave ranges, and wave spectra) are supported. Above is a screenshot of the wizard while setting up a Long-Crested anaysis. Notice that many different types of runs are possible within the same configuration.

The release version offers two general analysis types: Long-Crested and Short-Crested. The Short-Crested feature is something we are rather proud of because it harnesses the SEAKEEPING and WAVE commands in a careful way to compute expected responses in a "3D seaway" modeled using a spreading-function.

The "Load" and "Save" buttons at the top of the wizard let users save the wizard configuration at any time during the set-up, up to right before running an analysis. If a previous configuration file is in the current directory, pressing "Load" will restore the configuration.

The wizard also has a unique parameter checking system built in. This means the validity or existence of all required parameters is verified upon user acceptance. If issues are found, the specific issues will be listed for the user, and the issue will be highlighted in the wizard to help the user find the problem. For example, here we forgot to specify the Mean Wave Direction for our Short-Crested analysis, and the wizard alerted us to this problem.

We think you will appreciate the expanded capabilities and ease-of-use that the SEAKEEPING Wizard provides. Be sure to send us your comments and suggestions, as we hope to see the SEAKEEPING Wizard added to your GHS toolbox.

Questions, comments, or requests?
Contact Creative Systems, Inc.

USA phone: 360-385-6212 Fax: 360-385-6213
Office hours: 7:00 am - 4:00 pm Pacific Time, Monday - Friday

Mailing address:
PO Box 1910
Port Townsend, WA 98368 USA

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