Frequently Asked Questions

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1.  Can I change the specific gravity value that is used in the FastShip hydrostatics calculations?

Yes, the specific gravity can be changed in the Units tab of the Preferences dialog (in the File menu). You may enter either a specific gravity or a mass density.

Note that this value is saved with the surface file (in the aux file), and is also saved as a system value.


2.  When I export polylines in DXF format from AutoCAD 14, the FastShip DXF translator doesn't translate the polylines. Why not?

As of AutoCad Release 14 a new entity called the "lightweight" polyline (lwpolyline) has been introduced, which is a smaller more efficient form for the 2D polyline. The FastShip dxf2idf conversion routine only recognizes the standard polyline entity used in earlier versions of AutoCad and still supported in Release 14. Any lwpolyline entities encountered in a DXF file will be ignored by the FastShip converter. Therefore, if a user wishes to export a DXF file from AutoCad in a form which can be translated by FastShip, he/she must ensure that all polyline information is stored as standard polyline entities. If the AutoCad 14 user wishes to ensure that the AutoCad PLINE command creates standard polylines (and that when opening older drawing files, standard polylines are not converted to lwpolylines) set the PLINETYPE flag to 0. If the AutoCad 14 user has a drawing file which already has lwpolylines in it, choose the ACAD R13 export option when exporting to DXF to have lwpolylines converted to standard polylines in the DXF file. Please see the AutoCad R14 documentation for further details.

3.  When using the file conversion tool to convert a DXF file to an IDF file I encounter one of the following messages, "Maximum number of points exceeded", "Maximum number of curves exceeded", or "Maximum number of layers exceeded". What should I do?

Beginning with FastShip 5.030, the user can control the maximum limits on points, curves, and layers when converting a DXF file through settings in the FastShip initialization file, 'fs5win.ini'. A new section was added to the initialization file called "Import Parameters", and this section contains three keys called "DxfLayers", "DxfCurves", and "DxfPoints". The default values used for these three parameters (and the values used if these keys are not found in the .ini file) are 150 layers, 150 curves, and 150 points per curve. You can change these values to increase/decrease these limits. However, the you should be warned that increasing these values will require more RAM memory to be allocated by the program during the DXF file conversion process. Hence, you should consider reinstating the default values after converting a given DXF file if system RAM is limited.

4.  The file conversion tool successfully converts my DXF file to an IDF file. However, when I import the resulting IDF file into FastShip, the offset data seems to be oriented incorrectly. How do I correct this?

The CAD model from which the DXF file was generated had some inherent coordinate system which was different from that used in FastShip. FastShip assumes x is the longitudinal coordinate, y is the transverse coordinate, and z is the vertical coordinate. It will be necessary to transform the CAD model coordinate system to the FastShip coordinate system. The file conversion dialog box allows you to specify the coordinate transformation to apply when converting a DXF file. There are six possible coordinate transformations. The transformation defines which axes in the CAD model correspond to the FastShip longitudinal, transverse and vertical coordinates. So for example, the transformation 'yzx' means that the CAD model y coordinate corresponds to the FastShip longitudinal coordinate, the CAD model z coordinate corresponds to the FastShip transverse coordinate, and the CAD model x coordinate corresponds to the FastShip vertical coordinate.

5.  Upon importing an IDF file generated by the DXF to IDF conversion tool it seems that portions of the offsets are in the wrong coordinate system while others are ok. What is happening here?

At least some of the information in the DXF file is 2D polyline data. The DXF translator built into FastShip is a fairly simple one. Strictly speaking it only imports 3D polylines or 3D polygon meshes. However, it can also import 2D polylines with the following caveat. The DXF file specification requires that vertex locations of the entities in DXF files are saved in each entity's own Object Coordinate System (OCS) to conserve space. For 3D polylines and 3D meshes, the OCS corresponds to the World Coordinate System (WCS). However, for 2D polylines, the OCS is not necessarily the same as the WCS and therein lies the rub. The translator does not currently take into account differences between the OCS and WCS. Two things can be done in this regard. First, all of the lines in the original CAD model should be defined in the same User Coordinate System (UCS). If this does not solve the problem change the lines from 2D polylines to 3D polylines in the original CAD model before exporting them to a DXF file. Then they will be exported to DXF with WCS coordinates.

6.  When I try to print a hardcopy from FastShip of a solid shaded image the disk seems to grind away for minutes with nothing happening on the printer side. What can I do to get this to work?

Check to make sure you do NOT have software z-buffer on. Although this is a generally useful way to expedite rendering of a shaded model it should not be used when printing a hardcopy.

7.  Why is my volume of displacement reported from the hydrostatics calculations so different from what I expected?

It is likely that one or more of your surfaces have their positive normal directions pointing in the wrong direction. FastShip assumes that the positive normal is pointing into the buoyant fluid. This can be checked by turning the surface curvature calculation on (via Measure, Surface Curvature in the main menu) with the curvature type set to 'None'. For surfaces with an incorrect normal direction use the Flip Normal command under NURBS to correct it.

8.  Why does FastShip start up in demo mode?

There are several possible causes for this behavior, both hardware-related and software-related. First is there anything else on your LPT1: parallel port other than the FastShip lock? Although the FastShip lock is generally compatible with other locks from Rainbow Technologies, locks from other manufacturers may not be. Try removing any other locks to see if this corrects the problem. If a printer is connected to the parallel port behind the FastShip lock, it must be powered on or disconnected for the FastShip lock to function. As a final hardware issue, it is possible that the hardware lock or the parallel port is bad. Try printing something directly through the parallel port to rule out the latter. To check the former try running the utility program 'FastLock' which was installed with FastShip and which resides under the FastShip 5 Program Group. If FastLock reports that it cannot read the hardware lock it is likely a bad lock. Assuming none of the above items reveal the cause of the problem it is likely that you are trying to run a version of FastShip released after your maintenance contract expired. Use FastLock to determine the support expiration date programmed into the lock. If your support is up to date but is not reflected in the hardware lock or if you wish to renew your support, please contact us.

9.  After selecting the OpenGL display driver, FastShip displays a series of error messages on startup? How do I fix it?

In Release 5.101, the user was given the option of selecting the OpenGL display driver when using FastShip. According to the HOOPS documentation, "The Windows OpenGL driver supports OpenGL v1.1 under both Windows95 and Windows NT 4.0 ... The driver should run properly with any OpenGL 1.1 compliant graphics hardware." If the user attempts to use the OpenGL driver with a non-compliant graphics card, FastShip will display a series of error messages. To restore the default Microsoft Windows Driver for FastShip operation, use the Task Manager to end the FastShip task, open the Windows Explorer, navigate to your FastShip installation directory, and double-click on the file called 'RestoreMSW.reg'. This will make the appropriate entry in the system registry to reinstate the Windows driver. (download RestoreMSW.reg)

10. When I start up FastShip 6, I get an error message that says, "Could not load intact hydrostatics components. Please contact us ". If I click OK, the program continues and seems to run fine, but the error message reoccurs every time I try to start FastShip. What is the problem?

There are several possible causes for this. The most likely cause is an incomplete registration of dll's. To correct this, use a utility called regsvr32.exe which should be located in the "\Windows\System" or "\WinNT\System32" directory under Windows 9x and WindowsNT respectively. From an MS-Dos prompt in the FastShip 6 installation directory type "regsvr32 PEExcelLink.dll <Enter>" and "regsvr32 PEHydrostaticsHelper.dll<Enter>". You should get a popup window in each case confirming that the dll was registered.

If you are running under the original release of Windows 95, you may need to install a Microsoft DCOM patch called dcom95.exe. This patch is located in the FastShip installation directory. Locate the file with Explorer and double click on it to install. Follow the installation instructions provided by the install program. Without this patch you will not be able to execute the FastShip - Excel hydrostatics link but all other functionality should be accessible. CAUTION: Only install this patch on systems running Windows 95!

11. FastShip cannot find my network lock. What is wrong?

In order for FastShip to find the network hardware lock you must do the following:

  1. Choose a machine on the local area network to serve as the FastShip security server.
  2. Insert the FastShip network lock onto the parallel port of the selected FastShip security server.
  3. Install the Rainbow parallel port drivers on the selected FastShip security server so that the software can communicate with the lock. These drivers should be on the FastShip installation CD in a directory called Sentinel Parallel Port Driver. You can also obtain these drivers from our website at
  4. Install the NetSentinel security server program onto the selected FastShip security server machine. The version of the server program you install depends on the operating system of the machine but assuming a Win32 operating system (Win98/NT/2000/XP/Me) you should install either nsrvgx.exe or nssrvice.exe which can be found in the installation CD under the Netsentinel Network Security Server directory in the Win32 subdirectory. If the FastShip security server machine is running NT or W2000 you are probably better off using the service version of the program, nssrvice.exe which will start automatically each time the machine is booted, regardless of whether or not anyone is logged on (the program nsrvgx.exe requires a logged in user to start). The installation instructions for this program may be found in the document nssrvice.txt found in the same directory but consists mainly of opening a command prompt, navigating to your windows system32 directory and running nssrvice /i to install the service (a reboot may be required).

After installing the network lock and security server program, and of course installing the FastShip program itself on a machine somewhere in the LAN, the lock should be found.

12. When I try to install FastShip/FastYacht I get an error message which says, "Error 1935: An error occurred during the installation of assembly component .." The installation then terminates. What is causing this?

  The installation of FastShip/FastYacht requires administrative rights for things like COM component registration, Windows registry access, and others. Make sure you are logged on to the computer with an account that has administrative rights. Contact your IT administrator if you are uncertain how to do this.




  The user is strongly encouraged to read carefully the VisualSMP User's Manual or attend a training session before using this program. The user is also expected to be familar with linear hydrodynamics, frequency domain ship motion theory and statistics.

1.  What operating systems VisualSMP requires?

 We have tested our newest version (3.1) on Windows 7, Windows XP and Vista. VisualSMP will work properly on these systems. However, certain settings of the user's computer or network may prevent VisualSMP from running. Such cases are very rare.

2. Does VisualSMP run on a 64-bit machine?

Yes. We don't have a special 64-bit version. VisualSMP 3.1 does work on a 64-bit machine.

3. I installed VisualSMP but it cannot find/read the USB lock?

 There are two possibilities. You may forgot to installed the license driver or you need to install the new one. Once VisualSMP is installed, there will be a "SupProDriver" icon on your desktop. Please double click it and install the driver. Without it, the lock cannot be read. VisualSMP 3.0 comes with a new license driver. Existing cutomers also need to install it in order for the program to work on Vista and 64-bit machines. It could also be that your M&S is not up-to-date. For example, VisualSMP 3.1 requires that your  "support due date" be 4/8/2011 or later. If your "support due date" is earlier than that, VisualSMP 3.1 will encounter an error and stops.

4. How to check my "support due date"?

With license driver  properly installed and a valid USB key plugged-in, go to start -> Visual SMP -> FastLock. If your lock is not up-to-date, please contact:  Russ Krull  (703) 933 6812,, telling him your lock number and licensed modules.

5. How to update my lock to a new "support due date"?

You need to contact  Russ Krull ( 703 933 6812, ) to get quote, pay the dues and you will get two passwords. To program your USB lock for the new "support due date". goto:  start -> Visual SMP -> FastLock -> Edit and set password and enter the two passwords.

6. What VisualSMP modules do I need?

VisualSMP has 4 sets of separately licensed modules: the regular and irregular wave modules, the time history module (STH), the SWATH module and the SEP module. The regular and irregular wave modules are the basic modules and licensed together. The basic modules and the STH modules are for monohull only. Normally, one needs to have these two modules in order for the other modules to work or work properly. All VisualSMP's pre-processing and post-processing functions are licensed together with the basic modules. However, we may be able to package the SWATH module and our post-processing together without the monohull modules on a case-by-case basis. The functionalities of each module are described in details in the VisualSMP User's Manual.

7. What is the learning curve like? 

The program itself is very easy to use, very user friendly. However, a basic understanding of the ship motion theory, mathematics and statistics behind it are assumed. The user is expected to read and be familiar with Principle of Naval Architecture, 3rd volume. Basic ship motion, statistics and seakeeping knowledge is required. 

8. Is there an automatic and easy way to import the hull geometry? Do I need any meshing or any other tool?

There many ways a user can import a hull form. VisualSMP takes an .IDF file or a .GF file. If one uses Alion's FASTSHIP to develop the hull surface, FASTSHIP outputs an .IDF file that VisualSMP can readily accept. Equally convenient, one may use GHS to output a .GF file, which will automatically be imported into VisualSMP. Both .IDF and .GF are text files. Their specifications are in the VisualSMP User's Manual. The user may also use other means to prepare a .GF or .IDF file. Once the hull form is imported, VisualSMP provides many convenient geometry manipulating functions to refine the geometry and clip to the correct waterline once the hull form is imported. Alternatively, one may use VisualSMP's GUI to manually input the hull geometry. Geometry importing, editing or building is very easy in VisualSMP. There is no need for any meshing tool.

9. I changed some input and re-run VisualSMP but the results do not change, why?

In VisualSMP, for the input modification to take effect and be saved, the user need to manually click save. VisualSMP deos not automatically save, nor does it remind you before you run it. This is true for all modules.

10.  How viscous damping effects are accounted for in VisualSMP?

Potential hydrodynamics assumes that water is an ideal fluid with no viscousity. This assumption does not work well with roll motion. Unlike other modes of motions, roll damping is not dominated by wave making damping, which can be accurately predicted by potential theory. Viscous damping plays a significant, if not dominant, role in roll motion. 

Almost all the meaningful/practical ship motion programs are based on potential hydrodynamics. Viscous effect cannot be included in potential theory calculations. It has to be based on empirical, tank test and measurement data.   

To get a meaningful roll motion prediction, viscous (nonlinear) damping due to all sorts of appendages has to be included. Even though the potential theory is the same, SMP is the best program of its kind in estimating nonlinear viscous damping. VisualSMP has the most extensive roll damping models which cover the friction, eddy shedding and lift effects of the hull itself and all sorts of appendages (the bilge keels, passive fins, rudders, active fins, roll tanks, moving weights, shafts, shaft brackets, bulb bow, sonar dome, etc), which we believe no other practical ship motion programs can rival.  

Appendages have to be defined by the user in order to be included in the roll viscous damping calculation. The hull friction and eddy shedding damping are calculated based on the input hull geometry. There should be at least three points in the bilge radius area for the correct computation of the bilge damping terms. The roll damping semi-empirical relations do not allow predictions for bilge radii of less than 3 feet. The roll damping effects due to hard chines can only be approximately modeled by appendages.

Viscous damping is nonlinear, the large the roll motion, the larger the viscous damping. In frequency domain, the nonlinear roll damping is treated in an iterative and quasi-linear way. That is why RAO is wave height dependent .   


Copyright 2011 Alion
Last modified:   April 28, 2011