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

Probabilistic Damage (DAMSTAB2 wizard)
(Requires GHS with Advanced Features and Condition Graphics)

The GHS DAMSTAB2 wizard addresses the various probabilistic damage stability criteria.

Wizards in GHS are like "applications," not the classical wizard that leads you through a series of steps to achieve one simple thing. However, GHS wizards have this in common with classical wizards: they embody a procedure, and they explain themselves.

In the DAMSTAB2 wizard the yellow button is always a good choice if you're wondering what to do. If more input is needed, it will take you to the appropriate dialog. Or you can poke around and explore the tools and options.

Here is the main DAMSTAB2 dialog.

The DAMSTAB2 wizard will arrange subdivisions automatically. Or you can specify them manually.

An efficient approach starts with the automatic subdivision arrangement and then makes refinements and adjustments to get a better overall subdivision index and higher allowable VCG. The first cut can go very quickly as GHS analyzes compartments and picks bulkhead locations.

A typical result of the automatic assignment is shown below. Tools are provided for changing subdivision boundaries.

The wizard provides tools to examine and modify every aspect of the subdivision arrangement.

There is not enough space here to describe or even mention everything that the DAMSTAB2 wizard provides for modeling the complexities of tanks and compartments, including progressive and cross flooding.

Someone wanted to see pressures, so we made those available too:

A visual check of a subdivision is helpful and reassuring, which pops up when you press the Div button. You can get it upright as shown or solved for the actual heel, trim and draft.

At any time during or after the subdivision setup, a trial calculation of the attained index can be made.

The launch dialog presents all of the particulars that apply to various kinds of vessels.

Below is a snapshot of the screen while GHS is calculating the survival probabilities for each increment of damage penetration.

The output is a report that looks like this.

If you want to know more about how the calculations were performed, a text file of notes is generated as seen in the sample below. If you want to drill down further, a trace file can be generated where every step is recorded (not shown here).

The DAMSTAB2 wizard was developed over a number of years and is regularly updated as new requirements emerge.
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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