Scour Protection Installation Methodology

For details of the code implementation, please see Scour Protection Installation API.

Overview

The ScourProtectionInstallation modules simulates the installation of scour protection around the base of a offshore substructure. In many offshore site conditions, scour protection is a necessary step to reduce the effects of hydrodynamic scour development around the substructure. ORBIT models the installation of a rock layer installed at a diameter surrounding the substructure base. This process is not typically a significant cost driver for the project, but the installation time and associated costs are significant enough that they should not be ignored when computing BOS costs.

Configuration

This module is simple to configure, as the main parameter considered is the tons_per_substructure to install. Currently ORBIT models the simplest installation method, involving “Side Stone Installation Vessels” that dump loads of rocks next to the substructure without much ability to ensure that their payload is distributed evenly. A future version of ORBIT may expand this module to include more modern installation approaches using a “Fall Pipe Vessel” that allow for an even distrubution of scour protection material.

Example

{
    'scour_protection_install_vessel': 'example_vessel'
    'site': {'distance': 20},

    ...

    'scour_protection': {
        'tons_per_substructure': 1200
        }
    }
}

Processes

The scour protection installation vessel loads rock at port, transits to site and installs the required amount at each substructure until empty. At this point, it will return to port to load additional rock and repeat the above steps until all substructures have had scour protection installed. The process times for this operation are outlined below.

Process	Inputs	Default
Load Rocks	load_rocks_time	4h
Transit to Site	site_distance, transit_speed	calculated
Drop Rocks	drop_rocks_time	10h