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

(Requires GHS 14.52B or later)

Every GHS user is familiar with the ADD command, which is the usual means of introducing fixed weights. The simplest form of the command adds a point weight at a given center of gravity. For example, adding one ton of crew and effects,
ADD "CREW & EFFECTS" 1.0, 35.0f, 0.0, 12.0
Larger weight items might be distributed (for the purpose of strength calculations). The ADD command provides a convenient way of spreading a weight uniformly over a longitudinal distance:
ADD "NETS" 15.0, 20.0a, 0, 17.0 /LENGTH:20.0
If a more detailed distribution is desired, a weight curve can be specified:
ADD "ICE" 0.15 @ 55f, 0.3@23f, 0.2@22f, 0.1 @ 40a, 0, 10.0
(This one has four points. Many more weight-density points can be given.)

Or if a simple trapezoidal distribution will suffice where the center and ends are known, let the program find the densities:
ADD "RATS" 0.1, 0, 0, 3 /LENGTH:40f, 30a
The STATUS command provides a report of these "fixed" weight items, but only the center of gravity is mentioned -- nothing about the longitudinal distribution.

If you want to show the distribution, the ADD REPORT command does it. Below is a comparison: first the STATUS FIXED output then the ADD REPORT output.

Lately we discovered that ADD REPORT does not work if ADD PREFIX is in use. You can get an update to fix this by downloading ADDEXTENSION.LIB to your GHS program folder. Copy and paste these commands into GHS:

copy "" TEMP.LIB
erase TEMP.LIB

Questions, comments, or requests?
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Port Townsend, WA 98368 USA

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