Makers of MOSES - The Final Answer in Marine Simulation
What Is New In Rev 5.07

General Changes:

For the moment, this has been a minor release. In addition to the things discussed here, we have:
  • Since WINDOWS has a problem with the suffix ".com", we have changed the suffix of the Command Input file from ".com" to ".cif" and the name of the Command Output File from ".oco" to ".cof". One can still use .com (or .comi), but all of the files we supply will have the new suffix.

  • Added new values TITLE, SUBTITLE, and FIG_NUM to the string function &D_SET and the option -FIG_NUM of &DEVICE has been extended. The first of these things allow you to get the title and subtitle and the last two get you the next figure number to be plotted, or to set it. Click Here for more details.

  • A new option -STATISTICS has been added to the SET_VAR command in the Disposition Menu. This gives you access to the statistics of a column of data. Click Here for more details.

  • We have added a some new macros which are useful for computing stability and finding allowable KGs. Click Here for more details.

What No Longer Works:

Some of the seriously out of date (not in the documentation for over three years) values for reports in &STATUS and &NAMES (both command and string function) have been removed. Also in the process, the names of things have been made consistent among the commands. In particular, load groups are now LOADG, load sets are LSET, and the names of the structural cases are now S_CASES for the load cases which were solved and R_CASES for the S_CASES and those you defined via combinations. Also, some of the out of date options for RARM have been removed.

Also the "interface commands": &X, &P, and &C have been changed to !, +P, -P, and !C. Click Here for more details.

The -LOAD option on the &CONVERT command has been changed. Now, instead of either YES or NO, one has more control over the way the loads are converted. Click Here for more details.

The values returned by the &COMPARTMENT string function have changed. Now, instead of two tokens for each tank selected, there are three. This makes it easier to use it directly in saving data for later use with the &COMPARTMENT command. Several new options have also been added here.

What Answers Will Change:

The changes made with respect to compartments (click here for more details) will, in some cases, result in answers changing. These stem from three sources:
  • The new way in which inertia is computed changes the total inertia of the system,
  • The new treatment of -FROZEN may result in the CG of frozen compartments changing, and
  • The new treatment of -SIMPLE will change: the inertia, the force, and the GM.
In most cases, the changes are minor, but with some -SIMPLE compartments, the changes can be quite large.

In the past, we considered the interaction of the current velocity with the velocity of the vessel in computing the convolution contribution to the force on the vessel. It was pointed out that for many problems, this produced two effect: a large starting transient and an additional mean force. Both of these are not really desirable, so we have made it the default to ignore this interaction. If you want to have this, you can include: 

    &device -special 25
which will include the interaction, but will remove the extra starting transient. If you want exactly what you had before, you need: 
    &device  -special 24
If you use either of the above, you may get an additional mean force due to the interaction.

Obtaining Assistance:

Several basic things have changed in the user interface. One of the most noticeable is the the &V_LOG menu is gone. The display area of the window is now always a view of part of the log! You can move up or down the log with some primitive commands: +P(the page down key on a PC) moves you a page down in the log, -P (page up on a PC) move you a page up, -F "STRING" find the first occurrence of "STRING" above the current location ( +F find after), +N and -N find the next occurrence of "STRING", ? gives you the "current" location in the log as a percentage of the length, @ "percent" moves the display to "percent" in the log.

This was implemented in such a way that the same system works when you are in the &MANUAL menu. Thus, even within MOSES you can search for strings, etc. Click Here for more details.

In the past, there were three commands &X, &P, and &C which gave you control over executing, viewing, and changing previous commands. These have been changed to begin with a !. Click Here for more details.

Compartments:

With REV 5.02 we began adding sophistication to the way in which MOSES can deal with compartments. Some of these changes had unintended consequences. What we did with this release was to add changes which remedy most of the hardships we induced and also added a bit more sophistication.

The -SIMPLE method for filling compartments has been radically altered. What we had before was directly take from the PRINCIPLES OF NAVAL ARCHITECTURE. Some of our users did not like this and also, it really was not a good way of approximating the situation. In essence, what we used to do was "add something" to the CG. This resulted in several bad things. First, it puts the mass of the tank at an unreasonable position. Second, there is only one correction, so that either the longitudinal or transverse GM will automatically be wrong. Finally, when applied blindly, it does not give good results for the force on the body. Now, we have a new system: We compute a "GM reduction" for both the longitudinal and transverse GMs and reduce the GMs accordingly. We also use the GM reductions to find an approximation to the CG location as the body moves and apply the force at the new location. Here, we are not moving the CG vertically, but horizontally. This new scheme yields essentially the same results as the "exact ones" (computed via -SLOSH) not only for CG, but for force and CG location.

The -FROZEN method of filling tanks has also been changed. In the past, it used the same method of computing the CG as -SIMPLE, but it was not corrected. Now, it simply uses the CG in existence when it is frozen. If you change the percentage full in a -FROZEN tank, the correct one will be computed and used with no correction later.

We have added three new &STATUS values for compartments: CG_COMPARTMENT reports the name, method filled, weight, percentage full, sounding, CG, and GM corrections for a tank. S_COMPARTMENT reports the name and the ends of the sounding tube. V_COMPARTMENT reports the name, fill type, valve location, valve normal, friction factor, and valve area. The &STATUS B_W report has also been changed. The CGs are no longer corrected, the percentage full and sounding have been added for compartments, and if the weight does not equal the buoyancy, the GMs are not reported. This last change was made because GM, as traditionally defined, is only useful when the weight equals the buoyancy. Click Here to see the examples of these new reports, or Here to see the new &STATUS documentation.

Now, the flow of water into and out of a tank is considered in the frequency domain. To properly account for all of these extra features, one can now specify the direction of the valve discharge. In the past, we neglected the contribution of the flow in computing the force. We now consider it. Click Here to see the new documentation.

Mooring Lines:

The MOVE command in the Connector Design Menu has been changed. The old syntax still works, but now one can move a body around in a circle as well as along a line. The report has been changed so that in addition to the information about the most heavily loaded line, information about the least loaded line is also reported. Click Here to see the new documentation.

A new status applicable to ALINE connectors, LINES has been added. It type produces a report about the ALINE connectors which include: the horizontal distance between the fairlead and anchor, the length of the first segment, the line on bottom, the tension and ratio at the top, and the horizontal and vertical pull on the anchor. Click Here to see an example of this new report.