GMOOR 32 

              

Manufacturer: Global Maritime

Website: http://www.globalmaritime.com/software/gmoor32.shtml

 

Data Input:

For the input use has been made of an GUI. The chains, wires and other mooring material can be introduced via the graphical interface. The used mooring materials, wave- and wind spectrum can be chosen from a database. The mooring lines, anchors and field layout can all be input for the program. This is done via simple click and drag input.

Summary:

 

GMOOR32 is a vessel simulation program that allows one to calculate the behaviour of catenary moored vessels. The purpose of a mooring system is to maintain a vessels’ position. GMOOR32 solves the basic problem in finding the responses of the anchor lines to the forces and movements induced by the vessels’ environment.

The objective is to establish whether the mooring system is fit for the purpose where it is used for. The program can also be used for tending. It has been used for tending for several projects such as Totals’ Dunbar field

 

Applications:

 

The program can be used for the following applications:

  • Analyse the likely station keeping behaviour of a moored vessel
  • Analyse the Survival and Operation conditions
  • Perform consequence analysis in case a mooring cable fails
  • GMOOR can also with an special riser addition analyse station keeping behaviour of an moored drilling vessel
  • Simulate vessel behaviour under winch operations
  • Give guidance tot the system in order to minimise line tensions

 

Users:
  • Several offshore engineering companies (contractors, oil companies)
Computer systems:
  • PC (IBM compatible)

Postprocessor output:
  • Catenary layout, graphically
  • Vessel position
  • Spread file, The Spread File contains all the data relating to the make up of the mooring lines and the position of the vessel and anchors.
  • Every component of the field analyzed can have a numerical datasheet output.
Solution:

 

GMOOR32 uses the quasi-static mooring analysis method which assumes that the vessel takes up a mean offset where the moorings exactly balance the mean environmental loads (force and torque) and oscillates about this mean position in response to wave forces. The analysis method assumes that wave-induced surge, sway and yaw motions of the vessel (at wave periods, typically from 4 to 20 seconds) are not affected by the mooring system. These assumptions are reasonable for all large vessels with typical chain or wire moorings and are accepted and widely used by both certification authorities and designers. Low frequency (second order) motions can also be calculated and included in the quasi-static analysis.

 

GMOOR32 calculates the mean and maximum line tensions, maximum anchor loads, maximum and minimum lengths of grounded line and vessel excursions for multi-leg catenary mooring systems including the effects of seabed friction, seabed slope and non-linear line elasticity. GMOOR32 has been used for both design and verification of a wide range of mooring systems. GMOOR32 can handle multi-component lines (with intermediate buoys or sinkers), the calculation of transient motion following sudden line failure, will graphically display field features at the mooring location, can simulate the action of thrusters and has the capability to calculate environmental loads and motions from input weather conditions. Used with RISERDYN, GMOOR32 can analyze moorings with a marine drilling riser present to calculate the profile of the riser and the interaction with the vessel.

 

Screen shot of GMOOR32 input screen

 

Modelling:
  • Quasi static behaviour
  • Changing line tensions by winch actions
  • Damaged situation
  • Minimises line tension
  • Can model riser behaviour
Loading:
  • The wave and wind input is done via a wind and wave spectrum
  • Constant current
  • Damaged situation can be simulated
  • Anchor line pull forces can be varied, in order to change the vessels’ position.

Multiple runs can be performed using a batch analysis facility. Results from batch runs are saved and filtered using a powerful database reporting utility