C844 Stability Software

The following software was developed for the US Navy and has been used by USN, USCG, ship design agents, and some foreign governments.  The SHCP hull form geometry, appendages, decks, and compartments form the core geometry input for all 3 major software applications: SHCP, FCCS, and ASA (FLMASA & FLMNet).  The pre-processing software tools support the database development of these 3 major applications.  The post-processing tools mainly support the stability and reserve buoyancy analyses from SHCP results and the development of typical design products.

SHCP

The Ship Hull Characteristics Program (SHCP) is an industry standard for naval architecture software.  SHCP consists of a basic geometry interpreter, which is used to load various volumetric and centroid properties into a ship data table (SDT), and a set of naval architectural modules which interrogate the SDT for information required to perform basic naval architectural calculations.  The following core calculations are performed by SHCP:

  • Hydrostatics,
  • Trim Lines,
  • Longitudinal Strength,
  • Floodable Length,
  • Limiting Drafts,
  • Intact Stability,
  • Intact Statical Stability on Waves,
  • Damaged Stability Cross Curves,
  • Damaged Transverse Stability,
  • Damaged Longitudinal Stability,
  • Damageable Length, and;
  • Tank Capacities & Free Surface

SHCP can model and perform calculations for all types of hulls including mono-hulls, catamarans, trimarans, SWATHs, surface effect ships, and submarines.

SHCP Pre Processing Tools

  • EditSectW – An editor for SHCP offset data providing the user with a means of modify existing offset sections or create new parts by modification of existing offset parts.
  • GHS_Cvt – Converts GHS hull offset data to SHCP formatted data.
  • Picture – Wire frame viewer of SHCP offset, and appendage data.  Accommodates the SHCP, FCCS and ASA geometry origin and orientation systems.
  • PictSolid – Similar to Picture but provides a shaded model view instead of a wire frame.  Using OpenGL graphics the user may easily change the view point.  Provides a easy to view means of verifying proper offset and appendages fit.
  • MapIt (PostDXF) – Supports the development and verification of SHCP compartment data.  Development of compartment data is supported by the “Draw Compartments” function which uses a 2D deck view approach with graphic rubber-band input and a compartment parameter input  dialog.  Verification is supported by 2D plotting of sections, waterplanes/decks, and buttock cuts and 3D graphical displays of individual or groups of compartments.  2D plotting can be viewed on-screen or directed to an AutoCAD DXF file.  Damage groups can be automatically created for ‘box prism’ damage extents or for 3D damage extents for ships with layered protection systems.  Damage groups may be reviewed and modified on-screen.

SHCP Post Processing Tools

  • SHCPPlot – Views the various plots created by SHCP.
  • AreaWin -Static stability analysis tool for the evaluation of intact and damaged stability via user specified criteria and hazards.  Provides numerical and graphic evaluation, manual and automated analyses using either manual or SHCP generated inputs.
  • CoFGen – Creates a Curves of Form drawing (plus Bon Jeans and Cross Curves of Stability) from SHCP data.  The user controls the scale, location and extent of the various curve values and can add grids, labeled axes, ANSI standard boarders and text.  The drawing can be exported as an AutoCAD DXF format file for subsequent development.
  • KGA-View – Views the AreaWin summarized Allowable KG (KGa) limits for different stability criterion for each damage case.  Allows user to visually identify longitudinal areas that need stability improvement, the type of improvement needed, and areas that might accommodate reductions in stability in order to improve other areas.
  • Nomograf – Creates a draft diagram and functions of form nomograph used in Damage Control Book, Part II(a) from a SHCP hydrostatics output.  Output can be converted to AutoCAD DXF format via PostDXF.
  • Picture & PictSolid – Both programs provide a means of reading the SHCP DAMTS output data for a selected intact or damage case and correctly orient the hull and appendage model at the interpolated draft and trim for a chosen heel angle.  Also supports depth, heel, and trim input from FCCS and ASA models.  PictSolid includes a time-history player which allows time based draft, heel, trim data to change the model orientation over time – typically using ASA time-history saved in a .CSV file.
  • VLines – Calculates the Flooding Water Levels I and II (V-Lines) for a given combination of LBP, roll-back angle, damage extents, associated drafts & trims and bulkhead deck definition.  Several different combinations of drafts & trims may be entered for the same damage extent in order to determine the “worst case”.   Either parallel or trapezoidal V-lines can be calculated for FWL II (V-lines on decks).
  • Wind – Wind Heeling Forces program calculate wind heeling forces based on a given profile of the ship.  Uses USN calculation methods.

FCCS Tools

  • MapIt – Creates waterplane, buttock and section views in FCCS SPX format.
  • PanelCalc – Determines the area, centroid, and unit normal of a 3 or 4 sided panels.  It is intended that the corner points of the panel are to be co-planar. A check for co-planar points will be performed for 4 point panels. The results of the program output may be selected for one of 3 different formats – Picture Panel Primitives, ASA RECTPORTAL2 data, or FCCS Ice Load data.
  • PlotSPXw – Edits and augments FCCS “point to damage” SPX files created by MapIt.

ASA Tools

  • MapIt (PostDXF) – Provides extensive verification of ASA artifact (portals, holes, sources, sinks, equipment) placement via 2D and 3D plotting and compartment adjacency checks and compartment ‘stranding’ checks.  Portals may be placed via the “Define Portal Location” function which allows the user to select the type, size, and orientation of the portal and place it into or between automatically identified compartments.  Portals may be fit to user selected surfaces for non-orthogonal orientation cases.
  • PictSolid – Displays ASA models via a time-history player which allows time based draft, heel, trim data to change the model orientation over time – typically using ASA time-history saved in a .CSV file.