1. ShipWeight logo
High resolution logos can be downloaded here:
2. ShipWeight vs competitors
Head of Customer Relations, Runar Aasen, gives us his view about ShipWeight and potential competitors:
“To our knowledge, there are no other vendor today that offer a complete weight control suite like ShipWeight. This does not mean that we do not have competitors. Here is what we compete against:
Excel spreadsheet is today our biggest competitor. Excel has the advantage of being a low-cost flexible system that in principle can be used for any calculation task. However, Excel has the following disadvantages compared to ShipWeight:
– Excel is a single user system, not a multiuser system
– Excel gets related to the inventor and difficult to implement across the organization. When the inventor leaves the company, often the knowledge of the spreadsheet leaves with him.
– Excel has a lack of security and permission control.
– The biggest disadvantage to Excel is that it is not a database application. When storing data and calculation in the same place, Excel gets prone to errors, especially as the size of the spreadsheet grows. It is much more secure to have data stored in tables in a database and let the calculations be taken care of by an application on top. You may compare it with a accounting system: in theory you could use Excel for accounting, however when data size increases, most companies will buy a database application for their accounting. Same goes for weight control. It is not without reason that the ISO standard for offshore weight control requires a database application for class A weight control.
Many large yards have in-house developed weight control systems. However, more and more of them realize that they should be in the business of shipbuilding and not in the business of software as they realize that it takes a lot of efforts to keep up with the development of operating systems, database systems and documentation. Almost without exception the in-house systems ends up as an outdated software with too little budget for the needed development to take place.
INITIAL DESIGN SYSTEMS
Some initial design systems offer weight and centre of gravity estimation. Compared to ShipWeight we have yet to see any that can utilize historical data in the same way as ShipWeight by doing regression on a selected number of historical vessels. However, and maybe more important, these systems do not look beyond the initial phase. They are not suited to do tracking and monitoring, and we have not seen these kind of systems that can cope with the amount of data that will evolve during tracking, nor capabilities to do revisions, compare revisions and report project development on the required details and grouping.
CAD systems are not really a competitor for us, but these tools can also report weight and center of gravity of modeled items. However, these systems lack capabilities to do early design estimations and, of course, you can get weight only from the modeled items. Most often, equipment and machinery is not modeled to a level where you can calculate weight and even steel will often not be modeled to a degree to give an accurate weight estimate. Further and more important, same as the initial design systems, these tools has no capability for tracking, monitoring and weight control reporting. But CAD systems work well together with ShipWeight as a source of input to ShipWeight.
A few weight systems made for offshore constructions do exist, but only with a very small user base. In reality, these are not a true competitor for us within the shipbuilding market as they seem to be very focused on offshore specific issues, like estimation and tracking of the topside, and in reality they are not suited for a ship structure. In general they seems to be much less flexible than ShipWeight and very tailored to offshore. Further, from what we’ve seen of these systems they tend to be less “matured” as far as the software solutions, often relying on Access databases instead of SQL “heavy duty” databases. That being said, due to the flexibility of ShipWeight, we are steadily increasing our presence in the offshore market, as ShipWeight actually has no problems handling the tasks of offshore weight control.
3. ShipWeight in 1 2 3
Step one: Define the necessary custom codes in ShipWeight, to at least cover information needed in reports and database transmittal.
The needed codes should be defined into ShipWeight custom codes C01, C02, etc… The codes would preferable in ShipWeight be defined as listbox type (will give a selection droplist in ShipWeight containing the options for each code when filling in data) or of type combobox (will give a droplist, but also the possibility to enter in free text), or a combination of listbox and combobox.
To define custom codes, please see or user guide or our knowledgebase article
Tip: Whenever you define something in ShipWeight it is a good habit to always go to the line below to “enter” or “confirm” the information in the line you have input data to.
Step two: Get your weight data into ShipWeight
Once the custom codes are defined, the task is to get the weight items into ShipWeight and this is usually through:
Manual input, typically weight take off from drawing
Import from generic files such as Excel, Access or text files
If you do manual input, you need to know how to navigate through the SWBS, this can be done in three ways:
Selecting the appropriate SWBS group in the main window and open up items dialog
Selecting/Changing the SWBS group directly in the item dialog by opening up the navigation three and select SWBS group
Use the “quick change” by selecting the SWBS (type it in) in the weight group field in the toolbar in to item dialog. In this field you can also use the wildcard % to select multiple (or all) weight groups in the item dialog. This way you can load many weight groups into the item dialog at the same time and also get several weight groups to select from in weight group droplist when entering in new items.
Tips: Using the TAB-key is a convenient way to move around in the items dialog, both in weight items area and toolbar
If you do file import through excel or text files you can define import definition files (*.swi) to accommodate to the files you need to import.
You can set up one SWI file for each “source” you need to import. It is a good idea to take a look at the step-by-step import example that is described in ShipWeight user manual, or you can check our knowledge base:
Tips: If you are missing some SWBS groups or want to rename them, see the user manual on how to change the SWBS structure. NB: You need version 8.0 or newer for this function.
Step three: Adding additional information to the weight items
Once the data is in ShipWeight you might want to edit some information that was not originally in the data source. In example, you might want to set a station letter (A-Z) to weights that has been imported from a source where this information was not present. Of course, you can manually select the weight items and set the station number one by one, but here an example of a way to do a multiple editing on items:
Open the items dialog and select all weight groups by applying only the wildcard (%) in the weight group box in the toolbar in the items dialog.
Open the filter dialog (Filter->Apply… on “Tools” menu – or “Apply filter” button on toolbar) in the items dialog and use this to set a filter for all items you want to assign a special value (in example: [LCG]>0 and [LCG]<20). Click “Test” button to verify filter and the click “Ok” to apply filter.
Go to Edit->Select All (or Ctrl+A) to select all weight items fitting the filter.
Go to menu “Items->Set field values…” and follow the pop dialog instructions to select the correct custom code for the field you want to set the value for and to specify the value you want to set.
Now, all selected weight items will get the station value assigned and you’re done.
Although ShipWeight is a database tool, you can use “Save as” from the Project menu just as you do with a file based software (such as Excel).
This means that once you’ve submitted a report and want to go on with the next revision, you can “freeze” the current version by doing a ” Save As..” to make a copy and work on from that copy.
4. The auto estimation dialog
The Auto estimation… dialog box is a three step quick estimate providing automatic results based upon the shipdatabase. The dialog box is found under the Estimate menu by selecting Auto estimation
5. Comparing projects
Projects can be compared on weight group level basis. The dialog is opened from the View menu by selecting Compare… . The different propertysheet tabs in the dialog are used to select which of the user defined codes structures the projects will be compared according to.
Several options in the dialog let the user do different comparisons:
– Listing: can be done for all weight groups or only for the ones containing values
– Sort: sort the listing either by hierarchy order or by deviation
– Show: the user can specify if VCG, LCG or TCG should be included
– Deviation: can be shown in absolute values or in percentage
– Predict: linear prediction will predict the total weight if the deviation in the project continues with the same percentage deviation for future weight registering as currently achieved. Constant prediction will predict total weight if the rest of the project has no deviation.
The following formulas are used for calculation of Roll gyradius:
7. Weight distribution calculations
In general, ShipWeight approximates the distribution for each individual weight item to either a uniform, triangular or trapezoid distribution.
These individual items are then added together making up the total “accurate” distribution. The accurate distribution can be converted to a distribution of stations or bars.
8. Weight distribution curve
When you are estimating or registering weight items, the extension of the item can be given:
Together with the Center of Gravity of the weight item, this will make a trapezoid approximation to the weight distribution for that single item.
9. ShipWeight visualizer
With the ShipWeight Visualizer Rhino plug-in you can do visual sanity checks during estimation and monitoring.
The plug-in displays center of gravity and extension in 3D for all parts of a vessel in a ShipWeight database. There are two modes of display: Line-display and box-display. Line-display shows center of gravity and extension of all items in each direction, box-display shows center of gravity and a ‘bounding-box’ defined by min and max values of LCG, TCG and VCG (if available).
When displayed as lines, extensions can be displayed even if values for one or two dimensions are undefined. You can also simulate min and max values for undefined dimensions, and then you can also visualize items as boxes.
You can select a particular item by clicking on it or by selecting it from a tree-view. The item is then highlighted and information about it is displayed in a window. By filtering on weight classes or individual items you can choose which items to display when rendering.
To use the Rhino Plugin you just need Rhinoceros 3D installed. Download an evaluation version here – just add your email and country.
Download Installation document
Download Description of Rhino Plugin