In the preliminary stages, significant portions of port development work can be carried out using the Kongsberg simulation software and, where possible, using what Kongsberg refers to as “carrier vessels”, which are fully interactive and completely influenced by external forces such as large vessel speed, wind and sea conditions.
From a purely simulation and mathematical point of view, Fast Time Simulation offers the same reliability and accuracy as real-time simulations, with the main difference being the control systems of the ships being represented and the degree of human involvement in the environment.
With the table station, all aspects of the simulation and ship control devices are controlled by a single computer with a single user interface for the instructor, unlike the full mission simulator ship and tug, fully immersive, where a tug master steers each tug using real controls and a real pilot, using real controls and radio devices, controls the large ship and coordinates the towing operation.
In addition, with accelerated simulation, the analysis is based entirely on the evaluation of digital outputs and plotted data, while real-time simulation adds the fully immersive environment that involves human factors, the human-machine interface and the (sometimes subjective) assessment of operational feasibility and risk analysis as if the operation was being performed live.
With this distinction made, it is important to understand that accelerated simulation can be used to evaluate manoeuvres that are not overly complex, such as emergency braking manoeuvres, turning with one or two escort tugs, or the ability of two or more assistance tugs to hold a vessel against the wind or to overcome leeway or the effects of the current.
This type of simulation can also be used to conduct preliminary assessments of the ship’s movement, the adverse effects of sea state and variations in towline load under different conditions. The limiting factor with these simulations is the simulator operator’s ability to manoeuvre the tugs in a manner and timeline that is consistent with real-life manoeuvres (using the rudimentary keyboard and mouse control system), and thus maintain the simulation’s integrity. In addition, any ship or tug manoeuvre must be performed at actual speed, while manoeuvres or manoeuvring segments that do not involve rudder action or change in engine speed may be performed at an accelerated rate.
Highly specialized manoeuvres and operations such as the final stages of docking, or manoeuvres requiring a great deal of tug movement, should only be carried out in real time, unless a certain inaccuracy is deemed tolerable.