Mooring Design & Dynamics Files
A Matlab® Package for Designing and Analyzing Oceanographic Moorings

Richard K. Dewey
Centre for Earth and Ocean Research
University of Victoria, BC, Canada

Mooring Design and Dynamics is a set of Matlab® routines that can be used to assist in the design and configuration of single point oceanographic moorings, the evaluation of mooring tension and shape under the influence of wind and currents, and the simulation of mooring component positions when forced by time dependant currents. Version 2.0 (June 9, 2000) also includes the capability of predicting the shape (depth, wire length,...) associated with towed bodies. Version 2.1 included "clamp-on" components that attached to the mooring wire/line. The static model will predict the tension and tilt at each mooring component, including the anchor, for which the safe mass will be evaluated in terms of the vertical and horizontal tensions. Predictions can be saved to facilitate mooring motion correction. Time dependant currents can be entered to predict the dynamic response of the mooring. For a towed body, the user can specify a fixed wire length and predict the depth given a current profile and ship velocity, or request a desired depth, and have MD&D predict the required wire length. The package includes a preliminary database of standard mooring components which can be selected from pull down menus. Databases can be edited and expanded to include user specific components, frequently used fasteners/wires etc., or unique oceanographic instruments. Once designed and tested, a draft of the mooring components can be plotted and a list of components, including fasteners can be printed.

Version 2.2 includes a completely re-done formulation of the form and lift drag calculations. The older versions are nearly correct, but were not invariant to a rotation of the currents. Ugh! The re-formulated code (v2.2) is cleaner and more accurately represents the lift force terms described in section 3-11 of Hoerner (1965), and is invariant to the direction of the currents! The new formulation was updated in both moordyn.m and towdyn.m for both moorings and towed bodies. Solutions/values are very slightly different than the older (published) values. Version 2.3 (November 2016) fixed a small but critical bug for towed cylinders, fixing the angle of the bottom (towed) device, and version 2.4 (November 2021) fixed a tiny bug in the plot mooring routine. Version (2.1.2) included a user contributed improved convergence algorithm to help sheared current simulations.

Many people have worked on this code since I released it in 1998. Some have found bugs, others made improvements/enhancements, and many have added their own mooring devices to their private moornig database. I would like to hear from all users who find bugs, or the value of this program and/or any improvements you can think of/contribute. However, I have long sinced moved on to other research projects, such as running an ocean observatory (i.e. Ocean Networks Canada), and I have had little time to implement the many suggestions made with respect to MD&D. Although I will try to respond to emails, help get the code working (corrected), even test certain mooring configurations, this software is provided "as is" (free), without any formal support. Most issues are covered in the Uses Guide. The most common issue is people do not put essential "connectors" (i.e. a shackle) between mooring components. Not only are connectors needed in a real mooring, they are essential as my code uses them to (naturally) segment the mooring.

The FTP Files: Version 2.4, November 10, 2016

  • Mooring24.ZIP The complete zipped program file directory including example mooring movies (V2.4) 1.8MB.
  • Mooring24.EXE The PC self extracting zipped program file (V2.4). 1.9MB
  • MDDdoc.ZIP The zipped Users Guide file (V2.2). 5MB
  • MDD.pdf The PDF (printable) version of the Users Guide (V1.1). 2.6MB

  • Installation

    There are two (identical) archive files associated with MD&D: a ZIP file and a PC-based self-extracting EXE file. The program files are entirely archived in the latest version (which includes the document files, in /mdd/). The Users Guide (documentation) is also archived seperately in These archives should be expanded into subdirectories under Matlab, where you might store your private tool boxes. The program files should be expracted and renamed into something like:
    Then this path needs to be added and saved to your Matlab path using the add/path functions from the menus available from the top of the Matlab command window.
    MD&D can be started by typing "moordesign" at the MATLAB command prompt.

    The Users Guide files ( should be extracted into:
    The Users Guide will then be accessible from within Matlab by typing "mdd".

    To start MD&D, type "moordesign" at the Matlab command prompt. To view the Users Guide, load the "mdd.html" file into your web browser (Internet Explorer works better than Netscape (keep re-loading until it looks right)), or type "mdd" at the Matlab command prompt.

    Return to Mooring Design and Dynamics Home Page.
    Or go to the online Users Guide Page.

    You are visitor 30152 since 1/12/98.

    Last modified Nov 10, 2021.
    Questions and comments are welcome, Richard Dewey