Part Maker Tutorial      

1. Part Maker Introduction    2. Geometry Files    3. Getting Started With Part Maker    4. Making Models in Part Maker   

Maintained by Creative Systems, Inc.,Creators of GHS.    Click here for information about GHS and other fine marine software.

Introduction

This tutorial will help you get started using the Part Maker program. We will begin with a general discussion about the structure of vessel models, and then move into a guided 'hands-on' tutorial. If you have never used Part Maker, this is a good place to start. If it has been awhile, it can also serve as a refresher course.

Part Maker is an essential module of the GHS System. PM makes it practical to build a detailed model of your vessel in the hydrostatic sense -- one which accurately represents all of the significant buoyant parts (called 'displacers' or 'displacer parts') as well as the internal parts such as tanks and compartments (called 'containers' or 'containment parts').

The term 'displacers' covers not only hulls, skegs, rudders, etc. but tunnels, wells and notches of all sorts that you find in some hulls. These are most conveniently handled as 'negative displacers', since being open to the sea they simply deduct from the gross displacement of the hull envelope. It is usually much easier to make them 'negative appendages' than it would be to force the hull envelope itself into such convolutions.

Containers, on the other hand, are normally not open to the sea, but rather they hold some kind of liquid. If they are compartments, they are normally considered dry when intact. Although you could put some bilge water in a compartment and so treat it as a tank if you wanted to.

There is no difference between the actual effect of a flooded container and a negative displacer; both are open to the sea. But a container has the option of being made intact or flooded, whereas a negative displacer is always 'flooded', so to speak. In fact, we usually don't care about dealing with the negative displacers once the model is built. They are there to make the hull model more accurate and realistic, but we don't need to be concerned about filling, emptying or flooding them as we do with tanks and compartments. Therefore, it would be best to group all of your displacers and the hull (or hulls if it is a multi-hull vessel), with all its additive and deductive appendages, under one heading and call it simply the HULL.

Part Maker allows you to do this. You can create a complex structure from as many pieces an you like, but have them grouped under an overall part name, like HULL. This reduces the complexity so it does not produce unnecessary detail when you work with the completed model. Of course, the computer continues to handle the detail under the surface. But that is as it should be, for computers thrive on detail that would completely overwhelm us humans.

Tanks are a little different. Because you will probably want to get at each tank to specify its contents, load level, and even to flood it from time to time, it is necessary to make each tank its own part with a unique name by which you can refer to it after the model is built. But this doesn't mean that a tank can't be built up out of pieces.

In fact, since some tanks are often more complicated than hulls when you take into account their wings, wells, tunnels, overlaps, etc., it is just as essential to be able to build your tanks from various components, including negative or deducting components. Part Maker allows you to make tanks out of as many of these component pieces as you wish.

Geometry Files